Abstract
Purpose of Review
To illustrate the value of using zebrafish to understand the role of the Fgf signaling pathway during craniofacial skeletal development under normal and pathological conditions.
Recent Findings
Recent data obtained from studies on zebrafish have demonstrated the genetic redundancy of Fgf signaling pathway and have identified new molecular partners of this signaling during the early stages of craniofacial skeletal development.
Summary
Studies on zebrafish models demonstrate the involvement of the Fgf signaling pathway at every stage of craniofacial development. They particularly emphasize the central role of Fgf signaling pathway during the early stages of the development, which significantly impacts the formation of the various structures making up the craniofacial skeleton. This partly explains the craniofacial abnormalities observed in disorders associated with FGF signaling. Future research efforts should focus on investigating zebrafish Fgf signaling during more advanced stages, notably by establishing zebrafish models expressing mutations responsible for diseases such as craniosynostoses.
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Introduction
The fibroblast growth factor (FGF) signaling pathway is crucial in various biological processes during organ development and homeostasis, as well as at the cellular level, where it influences proliferation, migration, differentiation, and cell death [1,2,3]. In humans, FGF signaling includes 22 FGF ligands, 7 FGF receptors (FGFRs) with tyrosine kinase activity (resulting from alternative splicing of 4 genes: FGFR1-4), and numerous co-factors such as heparan sulfate and Klotho. The diverse functions of FGF signaling rely on precise regulation of expression and timing of FGFs, FGFRs, and co-factors [3]. Despite this tight regulation, multiple FGF signaling-related genetic disorders result in craniofacial anomalies (Tables 1 and 2) [51]. Gain-of-function (GOF) mutations in FGFR1, 2, and 3 are involved in syndromic craniosynostoses, characterized by premature fusion of cranial sutures [52]. Common forms of syndromic craniosynostoses due to mutations on FGFR2 include Crouzon, Apert, and Pfeiffer syndromes [32, 37, 38] with the latter resulting also from FGFR1 GOF mutation [32]. FGFR3 GOF mutations cause Muenke syndrome and Crouzon with acanthosis nigricans syndrome [47, 53]. FGF9 mutations are also associated with craniosynostosis [16]. Additionally, cleft palate, skull base anomalies, and midface hypoplasia are observed in several of these syndromes [40, 54,55,56]. Craniofacial skeleton anomalies are also described in other FGFR3-related disorders such as achondroplasia (GOF mutation) where patients exhibit skull base, cranial vault, and mandibular defects in addition to rhizomelic dwarfism, and in CATSHL syndrome, (Loss-of-function mutation (LOF)) characterized by overgrowth associated with microcephaly and Wormian skull bones [48, 57,58,59]. All these disorders highlight the critical role of the FGF signaling pathway in craniofacial skeleton development.
Numerous mouse models have been developed to understand the role of the FGF signaling pathway during craniofacial development [3, 60, 61]. Nevertheless, over the past quarter-century, zebrafish has emerged as a relevant model to study cellular and molecular mechanisms regulating craniofacial skeletal development and for the analysis of genetic variants underlying craniofacial defects [60, 62,63,64]. Approximately 70% of human genes have at least one homolog in zebrafish [65]. The presence of several homolog skeletal elements and the substantial conservation of the developmental mechanisms between zebrafish and mammals, makes the former an excellent model to study craniofacial skeleton formation. For example, the zebrafish ethmoidal plate of the anterior neurocranium is often described as analogous to the mammalian palate, the mammalian middle ear is analogous to the fish jaw. Cranial vault development and anatomy are also well conserved [31, 66]. From a technical point of view, the zebrafish model allows for high-resolution in vivo imaging during skull development thanks to the accessibility of the embryos and the relatively low cell count [67]. Finally, a wide array of genetic tools developed for this model, such as morpholino, Tol2 system, and CRISPR-Cas9, has facilitated the creation of transgenic lines and mutants, aiding in the study of craniofacial development under both normal and pathological conditions [68•, 69]. In this review, we present the literature data on Fgf signaling during zebrafish craniofacial development, providing insights into understanding FGF signaling-related anomalies in the craniofacial skeleton observed in human diseases, and offering promising avenues for future research in this field.
The Fgf Pathway in Zebrafish
31 Fgfs, including 6 paralogs resulting from genome duplication during evolution after teleost radiation, are described in The Zebrafish Information Network database (Table 1) [70]. In mammals, FGFs are often classified based on their mode of action, which correlates with the coreceptors needed to stabilize the interaction between the ligand and the receptor. While most ligands are paracrine and associated with heparan sulfate coreceptors, exceptions include the endocrine FGF19 family linked to Klotho (α and βklotho) and the intracrine FGF11 family, which do not bind to a receptor [71]. To our knowledge, zebrafish fgfs have typically been categorized only by gene location and never by their modes of action [70]. However, some studies on zebrafish coreceptors offer insights into the conservation of Fgfs' mode of action. Expression of heparan sulphate proteoglycans is also described as regulating the majority of Fgf signalling [72,73,74]. Klotho and klothob are αKLOTHO and βKLOTHO orthologs, respectively [75]. In zebrafish, Fgf23 seems to interact with Klotho, and both fgf23 and klotho mutants exhibit the same phenotype, suggesting conservation of the Klotho/Fgf23 system [76,77,78]. At last, while no evidence of intracrine action in zebrafish has been published for the Fgf11 family, the absence of the signal peptide domain in the C-terminus of Fgf11-14, akin to the human FGF11 family, suggests a conserved mode of action.
The zebrafish fgfrs include five genes encoding receptors with tyrosine kinase activity. Specifically, fgfr1a and fgfr1b are orthologs of FGFR1, and fgfr2, fgfr3 and fgfr4 are the orthologs of FGFR2, FGFR3 and FGFR4, respectively (Table 2). In humans, FGFR1-3 receptors have isoforms resulting from alternative splicing of exon 8 or exon 9 corresponding respectively to the immunoglobulin domain IgIIIb or IgIIIc [79]. Similarly, Fgfr1a and Fgfr2 have isoforms due to an alternative splicing (exon 7 or exon 8). The IgIIIb and IgIIIc isoforms of Fgfr1a and Fgfr2 respectively align more closely with the corresponding human IgIIIb and c isoforms. Fgfr1b and Fgfr3 show greater homology with their corresponding human IgIIIc isoforms. Finally, similar to mammals, the Fgfr family in zebrafish includes a receptor lacking a tyrosine kinase domain; specifically, FGFR5 has two orthologs in zebrafish, fgfrl1a, and fgfrl1b[50].
The Zebrafish Craniofacial Skeleton
The adult zebrafish skull consists of 73 bones (more than in mammals). There is a correlation between skull development and zebrafish size, therefore post-embryonic stages (beyond 5 days post-fertilization) are mostly determined by standard length (SL) rather than age [31]. The craniofacial skeleton is made up of neurocranium and viscerocranium. The viscerocranium is the most ventral part of the zebrafish skeleton and it is the first portion that develops starting from 48 h post fertilization (hpf). It is the feeding and respiratory apparatus and is composed of bones forming the jaw and five branchial arches: basibranchia, hypobranchials, ceratobranchials, epibranchials, and pharyngobranchials. The first four branchial arches support the gills, while the fifth carries the teeth. The neurocranium, supporting the brain and sensory systems, is comprised of four capsules: ethmoid, orbit, optic, and occipital, along with cranial vault bones [67, 80,81,82]. Cranial vault formation begins during the larval stage, around 7SL, approximately 1 month post-fertilization [31]. Similar to mammals, the zebrafish craniofacial skeleton is formed either through endochondral ossification or intramembranous ossification [83]. Zebrafish skull bones can be classified into four types: acellular and compact bones (e.g., frontal, parietal, occipital), cellular compact bones with osteocytes entrapped in the matrix (e.g., opercle, pterotic, sphenotic), tubular bones filled with adipose tissue (e.g., hyomandibula, basibranchial, ethmoid), and spongy bones filled with a trabecular network (e.g., quadrate, ceratohyal) [84].
Fgf Signaling and Early Craniofacial Development in Zebrafish
Despite its complexity, zebrafish craniofacial skeletal development closely resembles that of mammals. This model was widely used to study early step of craniofacial development including cellular dynamics and the involvement of signaling pathways like FGF signaling. The zebrafish skull bones derive from both the cranial neural crest cells (CNCCs) and the paraxial mesoderm [85, 86]. CNCCs originate from the junction between the neural tube and the ectoderm [87]. Around 12 hpf, coinciding with hindbrain segmentation into rhombomeres (R1-R7), CNCCs undergo epithelial-mesenchymal transition, delaminate, and migrate in three streams (mandibular, hyoid, and five branchial), populating the seven pharyngeal arches (Fig. 1A) [88]. CNCCs that contribute to the formation of the mandibular arch delaminate adjacent to the posterior midbrain-R2 whereas CNCCs of the hyoid and branchial arches originate next to R4 and R6-R7, respectively. Each pharyngeal arch comprises of cylinders of CNCCs surrounding a core of mesoderm, bordered externally by ectoderm and separated from other arches by endodermal out pockets called pharyngeal pouches (Fig. 1A) [21, 24, 89, 90]. These arches serve as templates for craniofacial structure development in adulthood, with the first arch giving rise to the lower jaw and palate, the second arch to the ceratohyal and hyomandibular bones, and the third through seventh arches forming the ceratobranchials, epibranchials, and pharyngobranchials [63, 64, 67, 86, 91].
Involvement of the Fgf signaling pathway during craniofacial skeleton development in zebrafish. A Diagram of the first steps of craniofacial development from the formation of the rhombomeres to the formation of the pharyngeal arches and pharyngeal pouches m: midbrain, r: rhombomere, PA: pharyngeal arch. B Endochondral and intramembranous ossification. The most important genes expressed during these processes are in italic. PCC: precartilaginous condensations. C Diagram showing all bones affected in the different fgf and fgfr zebrafish models published, in the viscerocranium and chordal neurocranium at 5dpf and in the cranial vault at 9SL. abc: anterior basicranial commissure, ac: auditory capsule, bb: basibranchial, bh: basihyal, cb: ceratobranchial, e: ethmoid plate, hb: hypobranchial, hs: hyosymplectic, lc: lateral commissure, m: Meckel’s cartilage, n, notochord, ot: otic capsule, pc: parachordal, pq: palatoquadrate, pbc: posterior basicapsular commissure, postch: postchordal neurocranium, prech: prechordal neurocranium, t: trabeculae, fr: frontal bone, pa: parietal bone, oc: occipital bone
In zebrafish, early craniofacial development is characterized by redundant use of Fgf signaling components. This is evidenced by the absence of distinguishable phenotypes in single mutants of the receptors fgfr1a, fgfr1b, fgfr2, and fgfr3 [92, 93••]. This differs from mice, where ubiquitous knock-out of fgfr1 or fgfr2 receptors are embryonic lethal [94, 95]. Nevertheless, the zebrafish studies contributed widely to reveal that fgf3 and fgf8 are part of a regulatory network controlling pharyngeal pouches and CNCCs homeostasis (Fig. 1A). Fgf8 is initially expressed in the lateral mesoderm, in the midbrain-hindbrain boundary (MHB) and in R2 and R4 domains. Its expression overlaps fgf3’s in neural MHB and R4 domains [5, 96, 97]. Between 18 and 28hpf, fgf3 and fgf8a are expressed in pharyngeal pouches adjacent to dlx2a-expressing CNCCs. Their expression in the mesoderm close to the endoderm is crucial for proper endodermal cell migration, segmentation of the pharyngeal endoderm into pouches, and CNCCs proliferation [98]. A link was reported between Fgf signaling and Tbx1, which deletion in human is associated to DiGeorge syndrome and developmental defects of the pharyngeal arches and pouches [99]. Research conducted in zebrafish brought two significant findings: firstly, Tbx1 triggers directional pocket growth through Fgf8a [10]; secondly, in pharyngeal pouches regulated by Pax1a and Pax1b, Tbx1 along with Fgf3 influences the expression of dlx2a in nearby CNCCs located in pharyngeal arches 3 to 6. Dlx2a is essential in guiding the differentiation of CNCCs into ectomesenchymal cells and chondrocytes [100•]. To complete this network, Fgf signaling functions downstream of Twist1 to suppress sox10 expression in the CNCCs while simultaneously activating dlx2a expression [101]. Additionally, it was recently demonstrated that Fgf8 is also involved in CNCCs differentiation through the negative regulation of Nkx2.3 [102].
Further, Fgf20b interaction with Fgfr1 is required for the ectomesenchyme formation [25]. fgf24 is expressed in pharyngeal pouches, and fgf8b, fgf17, fgf16, fgf18a, fgf18b expression was observed in pharyngeal arches but no data have been reported about their role during first step of pharyngeal arches morphogenesis [21, 24, 89]. By 24hpf, fgfr1a and fgfr2 are expressed in the MHB, hindbrain rhombomeres (R1-4), and pharyngeal pouches, with fgfr1a showing earlier expression [28]. Research using morpholino injection or CRISPR Cas9 mutagenesis revealed that while fgfr1a, fgfr1b, and fgfr2 are unnecessary for CNCCs migration into the pharyngeal pouches, they are vital for CNCCs maintenance [28, 92]. fgfr3 is also expressed in pharyngeal pouches [49••]. The role of Fgf signaling during pharyngeal arches morphogenesis, and CNCCs homeostasis is critical as it influences the later patterning of the viscerocranium and the neurocranium either via endochondral or intramembranous ossification [93••, 98].
FGF Signaling and the Viscerocranium Development: Focus on Endochondral Ossification
Zebrafish viscerocranium is exclusively derived from CNCCs and consists of bones formed via both endochondral and intramembranous ossification [83, 86, 103•, 104••]. In this paragraph, we focus on endochondral ossification. As in mammals, it occurs principally during growth and is characterized by a cartilaginous intermediate matrix formed by chondrocytes and invaded by blood vessels and osteoblasts that eventually convert the cartilage template into bone at larval stages. Initially, CNCCs of the pharyngeal arches differentiate into ectomesenchymal cartilage precursors expressing dlx2a and aggregate from 48hpf into precartilaginous condensations (PCCs) expressing barx1 [105, 106]. These PCCs dictate the morphology of the facial cartilage [36••]. At 60 hpf, cartilage precursors start expressing sox9a (necessary for producing the cartilage-specific collagen Col2a) and initiate chondrocyte differentiation. Subsequently, between 72 and 84 hpf, chondrocytes stack to form the pharyngeal cartilage [107, 108]. Chondrocytes differentiation is then completed by their maturation into runx2b and col10a1-expressing enlarged hypertrophic cells (Fig. 1B). As in mammals, zebrafish chondrocytes contribute to osteoblasts, adipocytes, and mesenchymal cells within the adult bones [109]. However, hypertrophic cells in zebrafish minimally contribute to bone growth and appear to be transient, as they are no longer present in later stages of development [103•]. The spatial organization of epiphyseal growth zones in zebrafish resembles mammalian long bone growth plates. The ceratohyal exhibits a similar organization to the long bones of mammalian limbs, featuring two prominent growth zones at each end and a marrow cavity. However, it is important to note the absence of secondary ossification in zebrafish [104••]. Each growth zone consists of a resting zone (Col2a1a +) followed by the proliferative zone (Pcna +) and a hypertrophic zone (Col10a1 +). Pharyngeal bones are separated by synchondroses, as in mammals, that produces a bidirectional growth formed by a resting zone flanked by two proliferative and hypertrophic zones [103•, 104••].
The zebrafish studies highlighted that Fgf signaling plays a key role during the first steps of chondrogenesis, including the regulation of dlx2a expression and the differentiation of CNCCs into ectomesenchyme (see previous section). Recently, Paudel et al. demonstrated that Fgf signaling participates also to PCC formation as it regulates barx1 expression directly and indirectly by inhibiting jag1, whose expression is inversely proportional to barx1. [36••]. With these insights, it becomes evident that disruptions in the Fgf pathway during early chondrogenesis have significant repercussions on the formation of cartilage, particularly within the viscerocranium. This assertion finds support in several studies. Firstly, the inhibition of Fgf signaling in zebrafish embryos between 24 and 36hpf, a crucial period for CNCCs differentiation into chondrocytes, using the pan-FGFR kinase inhibitor BGJ-398, resulted in smaller viscerocranium bones and mineralization defects at later stages (5dpf) [93••]. Secondly, the absence of both Fgf8 and Fgf3 has been shown to hinder posterior viscerocranium formation and significantly impact the development of the anterior viscerocranium [14, 98, 110]. Thirdly, fgfr1a; fgfr1b double mutants or fgfr1a; fgfr1b; fgfr2 triple mutants exhibit significant defects in the viscerocranium, including anomalies in the ceratobranchials, hyosymplectic, palatoquadrate, and Meckel’s cartilage (Fig. 1B and C). The triple mutant shows even more severe viscerocranium defects, with the involvement of the ceratohyal as well [92]. Finally, it was discovered that Fgf signaling is regulated partially by the von Willebrand factor A domain (VWA1), during CNCCs aggregation and differentiation, and its absence leads to chondrocytes disarrangement and deformities of craniofacial cartilage in zebrafish and to Hemifacial microsomia in Human [111].
To date, limited data are available regarding the molecular partners and roles of Fgf3, Fgf8, Fgfr1a, Fgfr1b, and Fgfr2 in the zebrafish endochondral ossification. However, studies have shown that the absence of Fgf8 or inhibition of FGF signaling results in the impairment of key genes involved in bone formation, such as runx2a, sp7, col1a1 and col9 [14, 93••]. A recent elegant study, revealed that, the stabilization of fgf8 mRNA by the rRNA-processing protein Nucleolin is essential for the proper formation of the viscerocranium in osteochondroprogenitors [112••]. In contrast, Fgfr3 plays a distinct role. It is highly expressed during viscerocranium development: observed at 60 hpf in the mandibular and hyoid arches cartilage, followed by expression at 72hpf in chondrocytes of branchial arches 1–5. Although its expression diminishes by 4 dpf, Fgfr3 persists in the head cartilage until adulthood [42, 49••]. Similar to its function in mammals, Fgfr3 serves as a crucial regulator of the endochondral ossification process in zebrafish as it was demonstrated by the analysis of fgfr3 LOF zebrafish, established using CRISPR-Cas9 technology, mimicking CATSHL syndrome with cranial vault and hyoid anomalies, along with midface hypoplasia [4••, 49••] fgfr3 LOF zebrafish model, Sun et al. described that the function of Fgfr3 is conserved between tetrapod and teleost during endochondral ossification. Fgfr3 serves as a negative regulator of chondrocyte proliferation and is also involved in the differentiation of chondrocytes into hypertrophic cells (Fig. 1B) [49••, 113]. They demonstrated that this regulation occurs in part via the activation of the canonic Wnt/β-catenin and Ihh pathways. During the endochondral process, Fgfr3 regulates not only chondrogenesis but also osteogenesis. This is evidenced by the delayed ossification of pharyngeal bones and the reduced number of osteoblasts observed in fgfr3 LOF fish. Finally, Fgfrl1a and Fgfrl1b also appear to play a role in cartilage formation, especially in the development of the gills. This is intriguing considering that in mammals, FGFR5 interacts with other FGFRs to modulate Fgf signaling in cartilage [50, 114].
Fgf Signaling and the Zebrafish Cranial Vault Development: Focus on Intramembranous Ossification
The zebrafish cranial vault is composed mainly by pairs of frontal and parietal bones formed via intramembranous ossification and the supraoccipital bone formed via endochondral process. These bones originate from both CNCCs and mesoderm, but contrary to mammals, where the boundary between CNCCs and mesoderm-derived cells lies between the frontal and parietal bones, in zebrafish, this boundary is situated within the frontal bones, with the anterior and posterior parts respectively derived from CNCCs and mesoderm [86]. The cranial vault bones, are the largest ones formed via the intramembranous process, and offer an ideal opportunity to analyse the cellular mechanisms involved in this process due to their prominent location, and their late development [115].
Intramembranous ossification begins with the differentiation of CNCCs and mesodermal cells to mesenchymal cells, expressing paired related homeobox 1a (encoded by prrx1a), muscle segment homeobox msx1 and 3, which initially aggregate to form the ossification center. Subsequently, these cells differentiate into osteoblasts through highly conserved mechanisms. The growth of cranial vault bones occurs at the periphery of the newly formed bone through the continuous differentiation of mesenchymal cells into osteoprogenitors expressing twist1a, 2 and 3 and runx2a and b genes. Osteoblast differentiation progresses with the expression of osterix (sp7), followed by the sequential expression of genes encoding bone matrix proteins such as osteopontin (spp1), collagen type 1 (Col1), col10a1, and osteocalcin (bglap) (Fig. 1B) [4••, 31, 116]. The expression of col10a1 in osteoblasts is noteworthy, as it is typically restricted to hypertrophic chondrocytes in mammals [117]. Furthermore, zebrafish cranial vault bones are acellular, as the maturation of osteoblasts in these bones does not lead to their embedding into the bone matrix and their transformation into osteocyte [84].
At the end of the cranial vault development, the bones come together and overlap, with a thin layer of suture mesenchymal stem cells (SuSCs) and fibrous tissue forming the cranial suture. Specific sutures delineate the boundaries between bones: the metopic suture (frontal-frontal), two coronal sutures (frontal-parietal), sagittal suture (parietal-parietal), and lambdoid suture (parietal-supraoccipital). Interestingly, all cranial sutures in zebrafish exhibit overlapping bones similar to the coronal and lambdoid sutures in mammals, and none feature bones facing each other, as seen in the metopic and sagittal sutures of mammals [118, 119]. The sutures impart flexibility to the cranial vault, supporting its growth until brain development concluded. It is worth noting that, unlike in mammals, where cranial sutures fuse by adulthood, the zebrafish cranial sutures remain an area of slow intramembranous ossification throughout the animal’s lifespan due to continuous growth [31]. At the cellular level, mammals exhibit four main clusters of SuSCs: gli1 + , axin2 + , prrx1 + , and Ctsk + SuSCs. In zebrafish, however, only gli1 + , prrx1 + , and grem1a + SuSCs have been identified thus far, necessitating further investigation [120,121,122,123,124]. Despite these differences, the limited studies on cranial vault formation in zebrafish emphasize the highly conserved nature of this process, which relies on well-orchestrated cellular and molecular mechanisms [31, 125,126,127].
Single cell RNAseq performed during zebrafish cranial vault development highlighted that some fgfs are expressed in the osteoprogenitors fgf2, fgf10a, fgf16, fgf18b, fgf2, fgf7, fgf24 and finally fgf18a, which has the highest expression. fgfr2 is mainly expressed in osteoprogenitors, fgfr1a, and fgfr4 in osteoblasts and fgfr1b in chondrocytes. Interestingly and contrary to what has been described in mice, fgfr3 is the most strongly expressed during cranial vault development and can be detected in late osteoprogenitors and osteoblasts [4••]. At adult stages, fgfr1a, fgfr1b, fgfr2, fgfr3 are still expressed in the cranial suture. Expression of fgf8a was also detected [13, 31, 42, 49••]. Despite the important role of FGF signalling in cranial vault formation, as evidenced by how FGFR1, FGFR2 and FGFR3 are all involved in craniosynostosis, limited studies have investigated Fgf signaling and cranial vault development in zebrafish. The fgfr3 LOF zebrafish model mentioned earlier, presenting cranial bone growth delay, wormian bones and cranial sutures anomalies, has provided us with an invaluable tool to study the role of Fgfr3 during cranial vault development. This model is the only fgfr3 LOF animal model with cranial vault anomalies, and has enabled us for the first time to highlight that Fgfr3 is an activator of osteoblasts expansion and differentiation during cranial vault development (Fig. 1B) [4••]. Further studies on the involvement of Fgfr3 during cranial suture formation are ongoing. Fgf8a plays also a role in cranial formation and fgf8a haploinsufficiency leads to adult skeletal defects including irregular patterns of cranial suturing, and ectopic bone formation (Fig. 1C) [13].
Many questions persist regarding FGF signaling in cranial vault and suture development. Studying LOF mutants of other fgfs and fgfrs in later stages could elucidate their roles. Establishing models with GOF mutations is essential for understanding the pathophysiological mechanisms of craniosynostosis related to FGF signaling. The zebrafish model's relevance for these diseases has already been demonstrated as for example the Saethre-Chotzen syndrome and craniosynostoses linked to Cyp26b1 [60, 124, 128, 129].
Fgf Signaling and Pre and Post Chordal Neurocranium Development
Finally, FGF signaling is also associated with other craniofacial anomalies such as cleft palate (observed in multiple synostoses syndrome type 3 related to FGF9), in Kallman, Apert, Beare-Stevenson and Crouzon syndrome, and with skull base defects as in Achondroplasia, Apert and Crouzon syndromes [15, 40, 54,55,56,57, 130]. In zebrafish the palate and the skull base are interconnected, delineating the prechordal (anterior) and postchordal (posterior) regions of the neurocranium. The first is made up of CNCC-derived cells and the second mostly of mesoderm-derived cells [63, 67, 86, 110]. The zebrafish palate consists of the ethmoidal plate, trabeculae and parasphenoid bones. Clefts, truncations, hypoplasia, or absence of these structures indicate orofacial clefts. The postchordal neurocranium includes the parachordal cartilages, anterior and posterior basicapsular commissures around the developing ear, lateral commissures, and occipital arches. Few zebrafish studies have explored FGf signaling and its role in these structures' development (Fig. 1C). Notably, one study identified fgf10a expression in both CNCCs and oral ectoderm, suggesting its necessary in palatogenesis. Morpholino-induced fgf10a knockdown results in shortened trabeculae and parasphenoid bones. Fgf10a likely regulates shh expression, guiding CNCCs migration towards the midline, triggering chondrogenesis, and facilitating trabeculae formation. A deeper analysis of Fgf10a's role during this process would be relevant, as FGF10 has been associated with pathologies resulting in dental anomalies and cleft palate (homozygous or heterozygous knock-out mice are either non-viable or exhibit only a very slight phenotype) [131, 132]. Interestingly, fish carrying the fgf8ti282 LOF mutation display ethmoidal plate defects similar to the ones described in humans with Kallman syndrome (characterised by cleft lip and palate) and due to mutations in FGF8 [14]. Further, Fgf8 and Fgf3 appear to be key regulators in postchordal neurocranium development by stimulating specification of mesoderm-derived progenitors [110]. fgfr3 expression is observed in ethmoid plates. Further analysis of pre- and postchordal neurocranium development in fgfr3 LOF mutants would be intriguing given their severe craniofacial phenotype [4••, 49••]. Anomalies in the post-neurocranium were observed in the triple mutant (fgfr1a, fgfr1b, and fgfr2), supporting their involvement in cranial base formation. However, their redundant activity during early craniofacial development impedes the determination of their respective roles. Thus, the development of a zebrafish line expressing fgfr GOF mutations could provide insight into their specific roles.
Conclusions
In conclusion, we have underscored the strengths of the zebrafish model, highlighting its close resemblance to mammals in craniofacial skeleton formation. This model proves invaluable tool for elucidating the role of the Fgf signaling pathway in the cellular mechanisms driving developmentand complement mammalian models, as seen in cases like mutant mice showing early lethality while zebrafish models display milder phenotypes (e.g., fgfr1, fgfr2, and fgf10). Conversely, there are instances where mice show no phenotype, yet the zebrafish model exhibits one, such as craniofacial anomalies in CATSHL syndrome linked to FGFR3. Studies using zebrafish, consistently demonstrate Fgf signaling's involvement at every stage of craniofacial development, from CNCCs to the formation of numerous craniofacial bones. From early investigations to recent ones, conducted during the early stages of zebrafish cranial development, they all emphasize the pivotal role of the Fgf signaling pathway during this stage that profoundly influences the development of various structures constituting the craniofacial skeleton. These data partially account for craniofacial anomalies observed in FGF signaling-related disorders, including cleft palate, cranial base defect or midface hypoplasia. Future research efforts should aim to elucidate the precise roles of specific Fgf ligands and receptors at later stages of craniofacial skeletal formation. Notably, studies utilizing fgfr3 LOF zebrafish at later stages align with this direction and demonstrate the zebrafish's potential as a valuable tool in understanding FGF signaling-related craniosynostosis. Advancements in genome editing techniques in zebrafish, including base or prime editing, present opportunities to introduce point mutations associated with human pathologies. This will accelerate our comprehension of FGF-related craniofacial skeletal disorders and allow to establish zebrafish model for exploring new therapeutic strategies for these diseases.
References
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance
Ornitz DM, Itoh N. The Fibroblast Growth Factor signaling pathway. Wiley Interdiscip Rev Dev Biol. 2015;4:215–66.
Xie Y, Su N, Yang J, Tan Q, Huang S, Jin M, et al. FGF/FGFR signaling in health and disease. Sig Transduct Target Ther. 2020;5:181.
Ornitz DM, Itoh N. New developments in the biology of fibroblast growth factors. WIREs Mechanisms of Disease. 2022;14: e1549.
Dambroise E, Ktorza I, Brombin A, Abdessalem G, Edouard J, Luka M, et al. Fgfr3 is a positive regulator of osteoblast expansion and differentiation during zebrafish skull vault development. J Bone Miner Res. 2020. Role of Fgfr3 during cranial vault development
Maves L, Jackman W, Kimmel CB. FGF3 and FGF8 mediate a rhombomere 4 signaling activity in the zebrafish hindbrain. Development. 2002;129:3825–37.
Liu K, Lv Z, Huang H, Yu S, Xiao L, Li X, et al. FGF3 from the Hypothalamus Regulates the Guidance of Thalamocortical Axons. Dev Neurosci. 2020;42:208–16.
Grillo L, Greco D, Pettinato R, Avola E, Potenza N, Castiglia L, et al. Increased FGF3 and FGF4 gene dosage is a risk factor for craniosynostosis. Gene. 2014;534:435–9.
Zhang Y-B, Hu J, Zhang J, Zhou X, Li X, Gu C, et al. Genome-wide association study identifies multiple susceptibility loci for craniofacial microsomia. Nat Commun. 2016;7:10605.
Jackman WR, Draper BW, Stock DW. Fgf signaling is required for zebrafish tooth development. Dev Biol. 2004;274:139–57.
Choe CP, Crump JG. Tbx1 controls the morphogenesis of pharyngeal pouch epithelia through mesodermal Wnt11r and Fgf8a. Development. 2014;141:3583–93.
Kesavan G, Raible F, Gupta M, Machate A, Yilmaz D, Brand M. Isthmin1, a secreted signaling protein, acts downstream of diverse embryonic patterning centers in development. Cell Tissue Res. 2021;383:987–1002.
Walshe J, Mason I. Unique and combinatorial functions of Fgf3 and Fgf8 during zebrafish forebrain development. Development. 2003;130:4337–49.
Albertson RC, Yelick PC. Fgf8 haploinsufficiency results in distinct craniofacial defects in adult zebrafish. Dev Biol. 2007;306:505–15.
Gebuijs IGE, Raterman ST, Metz JR, Swanenberg L, Zethof J, Van Den Bos R, et al. Fgf8a mutation affects craniofacial development and skeletal gene expression in zebrafish larvae. Biology Open. 2019;bio.039834. https://doi.org/10.1242/bio.039834.
Xu H, Niu Y, Wang T, Liu S, Xu H, Wang S, et al. Novel FGFR1 and KISS1R Mutations in Chinese Kallmann Syndrome Males with Cleft Lip/Palate. Biomed Res Int. 2015;2015:1–9.
Rodriguez-Zabala M, Aza-Carmona M, Rivera-Pedroza CI, Belinchón A, Guerrero-Zapata I, Barraza-García J, et al. FGF9 mutation causes craniosynostosis along with multiple synostoses. Hum Mutat. 2017;38:1471–6.
He X, Yan Y-L, Eberhart JK, Herpin A, Wagner TU, Schartl M, et al. miR-196 regulates axial patterning and pectoral appendage initiation. Dev Biol. 2011;357:463–77.
Swartz ME, Sheehan-Rooney K, Dixon MJ, Eberhart JK. Examination of a palatogenic gene program in zebrafish. Dev Dyn. 2011;240:2204–20.
Jovelin R, Yan Y-L, He X, Catchen J, Amores A, Canestro C, et al. Evolution of developmental regulation in the vertebrate FgfD subfamily. J Exp Zool B Mol Dev Evol. 2010;314:33–56.
FGF17 - an overview | ScienceDirect Topics [Internet]. [cited 2024 Feb 15]. Available from: https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/fgf17.
Nomura R, Kamei E, Hotta Y, Konishi M, Miyake A, Itoh N. Fgf16 is essential for pectoral fin bud formation in zebrafish. Biochem Biophys Res Commun. 2006;347:340–6.
ZFIN Publication: Thisse et al., 2005 [Internet]. [cited 2024 Feb 15]. Available from: https://zfin.org/ZDB-PUB-051025-1.
Cooper WJ, Wirgau RM, Sweet EM, Albertson RC. Deficiency of zebrafish fgf20a results in aberrant skull remodeling that mimics both human cranial disease and evolutionarily important fish skull morphologies. Evol Dev. 2013;15:426–41.
Mitchell JM, Sucharov J, Pulvino AT, Brooks EP, Gillen AE, Nichols JT. The alx3 gene shapes the zebrafish neurocranium by regulating frontonasal neural crest cell differentiation timing. Development. 2021;148:dev197483.
Yamauchi H, Goto M, Katayama M, Miyake A, Itoh N. Fgf20b is required for the ectomesenchymal fate establishment of cranial neural crest cells in zebrafish. Biochem Biophys Res Commun. 2011;409:705–10.
Sugimoto K, Hui SP, Sheng DZ, Kikuchi K. Dissection of zebrafish shha function using site-specific targeting with a Cre-dependent genetic switch. Elife. 2017;6: e24635.
Rothenbuhler A, Fadel N, Debza Y, Bacchetta J, Diallo MT, Adamsbaum C, et al. High Incidence of Cranial Synostosis and Chiari I Malformation in Children With X-Linked Hypophosphatemic Rickets (XLHR). J Bone Miner Res. 2018
Larbuisson A, Dalcq J, Martial JA, Muller M. Fgf receptors Fgfr1a and Fgfr2 control the function of pharyngeal endoderm in late cranial cartilage development. Differentiation. 2013;86:192–206.
Koch P, Löhr HB, Driever W. A mutation in cnot8, component of the Ccr4-not complex regulating transcript stability, affects expression levels of developmental regulators and reveals a role of Fgf3 in development of caudal hypothalamic dopaminergic neurons. PLoS ONE. 2014;9: e113829.
Rohs P, Ebert AM, Zuba A, McFarlane S. Neuronal expression of fibroblast growth factor receptors in zebrafish. Gene Expr Patterns. 2013;13:354–61.
Topczewska JM, Shoela RA, Tomaszewski JP, Mirmira RB, Gosain AK. The Morphogenesis of Cranial Sutures in Zebrafish. PLoS ONE. 2016;11: e0165775.
Schell U, Hehr A, Feldman GJ, Robin NH, Zackai EH, de Die-Smulders C, et al. Mutations in FGFR1 and FGFR2 cause familial and sporadic Pfeiffer syndrome. Hum Mol Genet. 1995;4:323–8.
Farrow EG, Davis SI, Mooney SD, Beighton P, Mascarenhas L, Gutierrez YR, et al. Extended mutational analyses of FGFR1 in osteoglophonic dysplasia. Am J Med Genet A. 2006;140:537–9.
Duszynski RJ, Topczewski J, LeClair EE. Divergent requirements for fibroblast growth factor signaling in zebrafish maxillary barbel and caudal fin regeneration. Dev Growth Differ. 2013;55:282–300.
ZFIN Publication: Thisse et al., 2008 [Internet]. [cited 2024 Feb 15]. Available from: https://zfin.org/ZDB-PUB-080227-22.
Paudel S, Gjorcheska S, Bump P, Barske L. Patterning of cartilaginous condensations in the developing facial skeleton. Developmental Biology. 2022;486:44–55. https://doi.org/10.1016/j.ydbio.2022.03.010. Involvement of FGF signaling in PCC formation.
Wilkie AO, Slaney SF, Oldridge M, Poole MD, Ashworth GJ, Hockley AD, et al. Apert syndrome results from localized mutations of FGFR2 and is allelic with Crouzon syndrome. Nat Genet. 1995;9:165–72.
Reardon W, Winter RM, Rutland P, Pulleyn LJ, Jones BM, Malcolm S. Mutations in the fibroblast growth factor receptor 2 gene cause Crouzon syndrome. Nat Genet. 1994;8:98–103.
Ibrahimi OA, Zhang F, Eliseenkova AV, Linhardt RJ, Mohammadi M. Proline to arginine mutations in FGF receptors 1 and 3 result in Pfeiffer and Muenke craniosynostosis syndromes through enhancement of FGF binding affinity. Hum Mol Genet. 2004;13:69–78.
Fonseca R, Costa-Lima MA, Cosentino V, Orioli IM. Second case of Beare-Stevenson syndrome with an FGFR2 Ser372Cys mutation. Am J Med Genet A. 2008;146A:658–60.
Przylepa KA, Paznekas W, Zhang M, Golabi M, Bias W, Bamshad MJ, et al. Fibroblast growth factor receptor 2 mutations in Beare-Stevenson cutis gyrata syndrome. Nat Genet. 1996;13:492–4.
Ledwon JK, Turin SY, Gosain AK, Topczewska JM. The expression of fgfr3 in the zebrafish head. Gene Expr Patterns. 2018;29:32–8.
Rousseau F, Bonaventure J, Legeai-Mallet L, Pelet A, Rozet JM, Maroteaux P, et al. Mutations in the gene encoding fibroblast growth factor receptor-3 in achondroplasia. Nature. 1994;371:252–4.
Bellus GA, McIntosh I, Smith EA, Aylsworth AS, Kaitila I, Horton WA, et al. A recurrent mutation in the tyrosine kinase domain of fibroblast growth factor receptor 3 causes hypochondroplasia. Nat Genet. 1995;10:357–9.
Naski MC, Wang Q, Xu J, Ornitz DM. Graded activation of fibroblast growth factor receptor 3 by mutations causing achondroplasia and thanatophoric dysplasia. Nat Genet. 1996;13:233–7.
Wilkes D, Rutland P, Pulleyn LJ, Reardon W, Moss C, Ellis JP, et al. A recurrent mutation, ala391glu, in the transmembrane region of FGFR3 causes Crouzon syndrome and acanthosis nigricans. J Med Genet. 1996;33:744–8.
Muenke M, Gripp KW, McDonald-McGinn DM, Gaudenz K, Whitaker LA, Bartlett SP, et al. A unique point mutation in the fibroblast growth factor receptor 3 gene (FGFR3) defines a new craniosynostosis syndrome. Am J Hum Genet. 1997;60:555–64.
Makrythanasis P, Temtamy S, Aglan MS, Otaify GA, Hamamy H, Antonarakis SE. A novel homozygous mutation in FGFR3 causes tall stature, severe lateral tibial deviation, scoliosis, hearing impairment, camptodactyly, and arachnodactyly. Hum Mutat. 2014;35:959–63.
Sun X, Zhang R, Chen H, Du X, Chen S, Huang J, et al. Fgfr3 mutation disrupts chondrogenesis and bone ossification in zebrafish model mimicking CATSHL syndrome partially via enhanced Wnt/β-catenin signaling. Theranostics. 2020;10:7111–30. https://doi.org/10.7150/thno.45286. Role of FGFR3 during the viscerocranium development.
Hall C, Flores MV, Murison G, Crosier K, Crosier P. An essential role for zebrafish Fgfrl1 during gill cartilage development. Mech Dev. 2006;123:925–40.
Moosa S, Wollnik B. Altered FGF signalling in congenital craniofacial and skeletal disorders. Semin Cell Dev Biol. 2016;53:115–25.
Wilkie AOM, Johnson D, Wall SA. Clinical genetics of craniosynostosis. Curr Opin Pediatr. 2017;29:622–8.
Meyers GA, Orlow SJ, Munro IR, Przylepa KA, Jabs EW. Fibroblast growth factor receptor 3 (FGFR3) transmembrane mutation in Crouzon syndrome with acanthosis nigricans. Nat Genet. 1995;11:462–4.
Slaney SF, Oldridge M, Hurst JA, Moriss-Kay GM, Hall CM, Poole MD, et al. Differential effects of FGFR2 mutations on syndactyly and cleft palate in Apert syndrome. Am J Hum Genet. 1996;58:923–32.
de Planque CA, Wall SA, Dalton L, Paternoster G, Arnaud É, van Veelen M-LC, et al. Clinical signs, interventions, and treatment course of three different treatment protocols in patients with Crouzon syndrome with acanthosis nigricans. J Neurosurg Pediatr. 2021;28:425–31.
Schmetz A, Schaper J, Thelen S, Rana M, Klenzner T, Schaumann K, et al. FGF9-Associated Multiple Synostoses Syndrome Type 3 in a Multigenerational Family. Genes. 2023;14:724.
Di Rocco F, Biosse Duplan M, Heuzé Y, Kaci N, Komla-Ebri D, Munnich A, et al. FGFR3 mutation causes abnormal membranous ossification in achondroplasia. Hum Mol Genet. 2014;23:2914–25.
Biosse Duplan M, Komla-Ebri D, Heuzé Y, Estibals V, Gaudas E, Kaci N, et al. Meckel’s and condylar cartilages anomalies in achondroplasia result in defective development and growth of the mandible. Hum Mol Genet. 2016;25:2997–3010.
Toydemir RM, Brassington AE, Bayrak-Toydemir P, Krakowiak PA, Jorde LB, Whitby FG, et al. A novel mutation in FGFR3 causes camptodactyly, tall stature, and hearing loss (CATSHL) syndrome. Am J Hum Genet. 2006;79:935–41.
Cornille M, Dambroise E, Komla-Ebri D, Kaci N, Biosse-Duplan M, Di Rocco F, et al. Animal models of craniosynostosis. Neurochirurgie. 2019;65:202–9.
Zhao X, Erhardt S, Sung K, Wang J. FGF signaling in cranial suture development and related diseases. Front Cell Dev Biol. 2023;11:1112890.
Valenti MT, Marchetto G, Mottes M, Dalle CL. Zebrafish: A Suitable Tool for the Study of Cell Signaling in Bone. Cells. 2020;9:1911.
Truong BT, Artinger KB. The power of zebrafish models for understanding the co-occurrence of craniofacial and limb disorders. Genesis. 2021;59: e23407.
Li K, Fan L, Tian Y, Lou S, Li D, Ma L, et al. Application of zebrafish in the study of craniomaxillofacial developmental anomalies. Birth Defects Research. 2022;114:583–95.
Howe K, Clark MD, Torroja CF, Torrance J, Berthelot C, Muffato M, et al. The zebrafish reference genome sequence and its relationship to the human genome. Nature. 2013;496:498–503.
Duncan KM, Mukherjee K, Cornell RA, Liao EC. Zebrafish models of orofacial clefts. Dev Dyn. 2017;246:897–914.
Mork L, Crump G. Zebrafish Craniofacial Development: A Window into Early Patterning. Curr Top Dev Biol. 2015;115:235–69.
Choe CP, Choi S-Y, Kee Y, Kim MJ, Kim S-H, Lee Y, et al. Transgenic fluorescent zebrafish lines that have revolutionized biomedical research. Lab Anim Res. 2021;37:26. Includes list of transgenic lines for studying skeletal development.
Liu K, Petree C, Requena T, Varshney P, Varshney GK. Expanding the CRISPR Toolbox in Zebrafish for Studying Development and Disease. Front Cell Dev Biol. 2019;7:13.
Itoh N, Konishi M. The zebrafish fgf family. Zebrafish. 2007;4:179–86.
Beenken A, Mohammadi M. The FGF family: biology, pathophysiology and therapy. Nat Rev Drug Discov. 2009;8:235–53.
Jen Y-HL, Musacchio M, Lander AD. Glypican-1 controls brain size through regulation of fibroblast growth factor signaling in early neurogenesis. Neural Dev. 2009;4:33.
Keil S, Gupta M, Brand M, Knopf F. Heparan sulfate proteoglycan expression in the regenerating zebrafish fin. Dev Dyn. 2021;250:1368–80.
Norton WHJ, Ledin J, Grandel H, Neumann CJ. HSPG synthesis by zebrafish Ext2 and Extl3 is required for Fgf10 signalling during limb development. Development. 2005;132:4963–73.
Sugano Y, Lardelli M. Identification and expression analysis of the zebrafish orthologue of Klotho. Dev Genes Evol. 2011;221:179–86.
Mangos S, Amaral AP, Faul C, Jüppner H, Reiser J, Wolf M. Expression of fgf23 and αklotho in developing embryonic tissues and adult kidney of the zebrafish. Danio rerio Nephrol Dial Transplant. 2012;27:4314–22.
Ogura Y, Kaneko R, Ujibe K, Wakamatsu Y, Hirata H. Loss of αklotho causes reduced motor ability and short lifespan in zebrafish. Sci Rep. 2021;11:15090.
Singh AP, Sosa MX, Fang J, Shanmukhappa SK, Hubaud A, Fawcett CH, et al. αKlotho Regulates Age-Associated Vascular Calcification and Lifespan in Zebrafish. Cell Rep. 2019;28:2767-2776.e5.
Eswarakumar VP, Lax I, Schlessinger J. Cellular signaling by fibroblast growth factor receptors. Cytokine Growth Factor Rev. 2005;16:139–49.
Piotrowski T, Schilling TF, Brand M, Jiang Y-J, Heisenberg C-P, Beuchle D, et al. Jaw and branchial arch mutants in zebrafish II: anterior arches and cartilage differentiation. Development. 1996;123:345–56.
Schilling TF, Piotrowski T, Grandel H, Brand M, Heisenberg CP, Jiang YJ, et al. Jaw and branchial arch mutants in zebrafish I: branchial arches. Development. 1996;123:329–44.
Keer S, Cohen K, May C, Hu Y, McMenamin S, Hernandez LP. Anatomical Assessment of the Adult Skeleton of Zebrafish Reared Under Different Thyroid Hormone Profiles. Anat Rec. 2019;302:1754–69.
Cubbage CC, Mabee PM. Development of the cranium and paired fins in the zebrafish Danio rerio (Ostariophysi, Cyprinidae). J Morphol. 1996;229:121–60.
Weigele J, Franz-Odendaal TA. Functional bone histology of zebrafish reveals two types of endochondral ossification, different types of osteoblast clusters and a new bone type. J Anat. 2016;229:92–103.
Schilling TF, Kimmel CB. Segment and cell type lineage restrictions during pharyngeal arch development in the zebrafish embryo. Development. 1994;120:483–94.
Kague E, Gallagher M, Burke S, Parsons M, Franz-Odendaal T, Fisher S. Skeletogenic fate of zebrafish cranial and trunk neural crest. PLoS ONE. 2012;7: e47394.
Araya C, Ward LC, Girdler GC, Miranda M. Coordinating cell and tissue behavior during zebrafish neural tube morphogenesis. Dev Dyn. 2016;245:197–208.
Köntges G, Lumsden A. Rhombencephalic neural crest segmentation is preserved throughout craniofacial ontogeny. Development. 1996;122:3229–42.
Jovelin R, Yan Y, He X, Catchen J, Amores A, Canestro C, et al. Evolution of developmental regulation in the vertebrate FgfD subfamily. J Exp Zool Pt B. 2010;314B:33–56.
Okada K, Takada S. The second pharyngeal pouch is generated by dynamic remodeling of endodermal epithelium in zebrafish. Development. 2020;147:dev194738.
Kimmel CB, Miller CT, Moens CB. Specification and Morphogenesis of the Zebrafish Larval Head Skeleton. Dev Biol. 2001;233:239–57.
Leerberg DM, Hopton RE, Draper BW. Fibroblast Growth Factor Receptors Function Redundantly During Zebrafish Embryonic Development. Genetics. 2019;212:1301–19.
Gebuijs L, Wagener FA, Zethof J, Carels CE, Von Den Hoff JW, Metz JR. Targeting fibroblast growth factor receptors causes severe craniofacial malformations in zebrafish larvae. PeerJ. 2022;10:e14338. https://doi.org/10.7717/peerj.14338. Studies of the simple, double and triple CrisPR/Cas9 lof fgfrs zebrafish.
Arman E, Haffner-Krausz R, Chen Y, Heath JK, Lonai P. Targeted disruption of fibroblast growth factor (FGF) receptor 2 suggests a role for FGF signaling in pregastrulation mammalian development. Proc Natl Acad Sci USA. 1998;95:5082–7.
Deng CX, Wynshaw-Boris A, Shen MM, Daugherty C, Ornitz DM, Leder P. Murine FGFR-1 is required for early postimplantation growth and axial organization. Genes Dev. 1994;8:3045–57.
Reifers F, Walsh EC, Léger S, Stainier DY, Brand M. Induction and differentiation of the zebrafish heart requires fibroblast growth factor 8 (fgf8/acerebellar). Development. 2000;127:225–35.
Walshe J, Mason I. Fgf signalling is required for formation of cartilage in the head. Dev Biol. 2003;264:522–36.
Crump JG, Maves L, Lawson ND, Weinstein BM, Kimmel CB. An essential role for Fgfs in endodermal pouch formation influences later craniofacial skeletal patterning. Development. 2004;131:5703–16.
Vitelli F. Tbx1 mutation causes multiple cardiovascular defects and disrupts neural crest and cranial nerve migratory pathways. Hum Mol Genet. 2002;11:915–22.
Liu Y-H, Lin T-C, Hwang S-PL. Zebrafish Pax1a and Pax1b are required for pharyngeal pouch morphogenesis and ceratobranchial cartilage development. Mechanisms of Development. 2020;161:103598. https://doi.org/10.1016/j.mod.2020.103598. FGF signaling and pharyngeal pouches.
Blentic A, Tandon P, Payton S, Walshe J, Carney T, Kelsh RN, et al. The emergence of ectomesenchyme. Dev Dyn. 2008;237:592–601.
Yang S, Xu X, Yin Z, Liu Y, Wang H, Guo J, et al. nkx2.3 is responsible for posterior pharyngeal cartilage formation by inhibiting Fgf signaling. Heliyon. 2023;9:e21915.
Heubel BP, Bredesen CA, Schilling TF, Le Pabic P. Endochondral growth zone pattern and activity in the zebrafish pharyngeal skeleton. Developmental Dynamics. 2021;250:74–87. https://doi.org/10.1002/dvdy.241. Endochondral ossification in zebrafish.
Le Pabic P, Dranow DB, Hoyle DJ, Schilling TF. Zebrafish endochondral growth zones as they relate to human bone size, shape and disease. Front Endocrinol. 2022;13:1060187. https://doi.org/10.3389/fendo.2022.1060187. Review on New data regarding endochondral ossification in zebrafish.
Giffin JL, Gaitor D, Franz-Odendaal TA. The Forgotten Skeletogenic Condensations: A Comparison of Early Skeletal Development Amongst Vertebrates. JDB. 2019;7:4.
Sperber SM, Dawid IB. barx1 is necessary for ectomesenchyme proliferation and osteochondroprogenitor condensation in the zebrafish pharyngeal arches. Dev Biol. 2008;321:101–10.
Klüver N, Kondo M, Herpin A, Mitani H, Schartl M. Divergent expression patterns of Sox9 duplicates in teleosts indicate a lineage specific subfunctionalization. Dev Genes Evol. 2005;215:297–305.
Yan Y-L, Willoughby J, Liu D, Crump JG, Wilson C, Miller CT, et al. A pair of Sox: distinct and overlapping functions of zebrafish sox9 co-orthologs in craniofacial and pectoral fin development. Development. 2005;132:1069–83.
Giovannone D, Paul S, Schindler S, Arata C, Farmer DT, Patel P, et al. Programmed conversion of hypertrophic chondrocytes into osteoblasts and marrow adipocytes within zebrafish bones. eLife. 2019;8:42736.
McCarthy N, Sidik A, Bertrand JY, Eberhart JK. An Fgf-Shh signaling hierarchy regulates early specification of the zebrafish skull. Dev Biol. 2016;415:261–77.
Niu X, Zhang F, Ping L, Wang Y, Zhang B, Wang J, et al. vwa1 Knockout in Zebrafish Causes Abnormal Craniofacial Chondrogenesis by Regulating FGF Pathway. Genes. 2023;14:838.
Dash S, Trainor PA. Nucleolin loss of function leads to aberrant Fibroblast Growth Factor signaling and craniofacial anomalies. Development. 2022;149:dev200349. https://doi.org/10.1242/dev.200349. Regulation of fgf8 expression during chondrogenesis.
Ornitz DM, Legeai-Mallet L. Achondroplasia: Development, Pathogenesis, and Therapy. Dev Dyn. 2016 https://doi.org/10.1002/dvdy.24479.
Trueb B, Taeschler S. Expression of FGFRL1, a novel fibroblast growth factor receptor, during embryonic development. Int J Mol Med. 2006;17:617–20.
Kanther M, Scalici A, Rashid A, Miao K, Van Deventer E, Fisher S. Initiation and early growth of the skull vault in zebrafish. Mech Dev. 2019;103578. https://doi.org/10.1016/j.mod.2019.103578.
Li N, Felber K, Elks P, Croucher P, Roehl HH. Tracking gene expression during zebrafish osteoblast differentiation. Dev Dyn. 2009;238:459–66.
Kim Y-I, Lee S, Jung S-H, Kim H-T, Choi J-H, Lee M-S, et al. Establishment of a Bone-Specific col10a1:GFP Transgenic Zebrafish. Mol Cells. 2013;36:145–50.
Behr B, Longaker MT, Quarto N. Craniosynostosis of coronal suture in twist1 mice occurs through endochondral ossification recapitulating the physiological closure of posterior frontal suture. Front Physiol. 2011;2:37.
Mitchell LA, Kitley CA, Armitage TL, Krasnokutsky MV, Rooks VJ. Normal Sagittal and Coronal Suture Widths by Using CT Imaging. AJNR Am J Neuroradiol. 2011;32:1801–5.
Aldawood ZA, Mancinelli L, Geng X, Yeh S-CA, Di Carlo R, Leite CT, et al. Expansion of the sagittal suture induces proliferation of skeletal stem cells and sustains endogenous calvarial bone regeneration. Proc Natl Acad Sci U S A. 2023;120:e2120826120.
Debnath S, Yallowitz AR, McCormick J, Lalani S, Zhang T, Xu R, et al. Discovery of a periosteal stem cell mediating intramembranous bone formation. Nature. 2018;562:133–9.
Wilk K, Yeh S-CA, Mortensen LJ, Ghaffarigarakani S, Lombardo CM, Bassir SH, et al. Postnatal Calvarial Skeletal Stem Cells Expressing PRX1 Reside Exclusively in the Calvarial Sutures and Are Required for Bone Regeneration. Stem Cell Reports. 2017;8:933–46.
Zhao H, Feng J, Ho T-V, Grimes W, Urata M, Chai Y. The suture provides a niche for mesenchymal stem cells of craniofacial bones. Nat Cell Biol. 2015;17:386–96.
Teng CS, Ting M-C, Farmer DT, Brockop M, Maxson RE, Crump JG. Altered bone growth dynamics prefigure craniosynostosis in a zebrafish model of Saethre-Chotzen syndrome. Elife. 2018;7: e37024.
Blümel R, Zink M, Klopocki E, Liedtke D. On the traces of tcf12: Investigation of the gene expression pattern during development and cranial suture patterning in zebrafish (Danio rerio). PLoS ONE. 2019;14: e0218286.
Grova M, Lo DD, Montoro D, Hyun JS, Chung MT, Wan DC, et al. Models of cranial suture biology. J Craniofac Surg. 2012;23:1954–8.
Kague E, Roy P, Asselin G, Hu G, Simonet J, Stanley A, et al. Osterix/Sp7 limits cranial bone initiation sites and is required for formation of sutures. Dev Biol. 2016;413:160–72.
Laue K, Pogoda H-M, Daniel PB, van Haeringen A, Alanay Y, von Ameln S, et al. Craniosynostosis and multiple skeletal anomalies in humans and zebrafish result from a defect in the localized degradation of retinoic acid. Am J Hum Genet. 2011;89:595–606.
Jeradi S, Hammerschmidt M. Retinoic acid-induced premature osteoblast-to-preosteocyte transitioning has multiple effects on calvarial development. Development. 2016;143:1205–16.
Tokumaru AM, Barkovich AJ, Ciricillo SF, Edwards MS. Skull base and calvarial deformities: association with intracranial changes in craniofacial syndromes. AJNR Am J Neuroradiol. 1996;17:619–30.
Li W, Wang M, Zhou R, Wang S, Zheng H, Liu D, et al. Exploring the interaction between FGF Genes and T-box genes among chinese nonsyndromic cleft lip with or without cleft palate case-parent trios. Environ and Mol Mutagen. 2019;60:602–6.
Tan J, Jones MLM, Teague WJ, Ranjitkar S, Anderson PJ. Craniofacial anomalies in a murine model of heterozygous fibroblast growth factor 10 gene mutation. Orthod Craniofacial Res. 2024;27:84–94.
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Pereur, R., Dambroise, E. Insights into Craniofacial Development and Anomalies: Exploring Fgf Signaling in Zebrafish Models. Curr Osteoporos Rep 22, 340–352 (2024). https://doi.org/10.1007/s11914-024-00873-3
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DOI: https://doi.org/10.1007/s11914-024-00873-3