Abstract
In male mealybugs (Pseudococcide: Homoptera) the set of chromosomes of paternal origin becomes heterochromatic (H) and genetically inactive in early embryogenesis. During spermatogenesis the two sets segregate and only the meiotic products with the euchromatic (E) set form sperm. Individuals of Pseudococcus affinis (Maskell) may carry a B chromosome (B) which is usually heterochromatic. During prophase I of spermatogenesis, however, the B becomes even less condensed than the E set and usually segregates with the E set. We have previously shown that natural populations of P. affinis contain genotypes that can reduce the rate of transmission (k) of Bs from more than 0.9 to less than 0.1. We now demonstrate that these genotypes suppress k either by enhancing or by preventing the decondensation of the B, which in turn affects the position of the B on the metaphase plate and its segregation. We also demonstrate that radiation-induced fragment of the B, and a piece of a B which has been translocated onto a piece of an H chromosome, retain their characteristic pattern of condensation and thus that the condensation of the B is not controlled by one or a few cis-acting centers or loci.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Baker BS, Carpenter ATC, Esposito MS, Esposito RE, Sandler L (1976) The genetic control of meiosis. Annu Rev Genet 10:53–134
Bianchi NO (1982) Gene controlled condensation in individual chromosomes. Experientia 38:792–794
Brown SW (1959) Lecanoid chromosome behavior in three more families of the Coccoidea (Hemiptera). Chromosoma 10:278–300
Brown SW, Nelson-Rees WA (1961) Radiation analysis of a lecanoid genetic system. Genetics 46:983–1007
Doerfler W (1983) DNA methylation and gene activity. Annu Rev Biochem 52:93–124
Dorn R, Heymann S, Lindigkeit R, Reuter G (1986) Suppressor mutation of position-effect variegation in Drosophila melanogaster affecting chromatin properties. Chromosoma 93:398–403
Gartler SM, Riggs AD (1984) Mammalian X-chromosome inactivation. Annu Rev Genet 17:155–190
Gatti M, Smith DA, Baker BS (1983) A gene controlling condensation of heterochromatin in Drosophila melanogaster. Science 221:83–85
Hughes-Schrader S (1948) Cytology of coccids (Coccoidea: Homoptera). Adv Genet 2:127–203
Klein AS, Eckhardt RA (1976) The DNAs of the A and B chromosomes of the mealybug, Pseudococcus obscurus. Chromosoma 57:333–340
Nelson-Rees WA (1962) The effects of radiation damaged heterochromatic chromosomes on male fertility in the mealy bug, Planococcus citri (Risso). Genetics 47:661–683
Nelson-Rees WA (1963) New observations on lecanoid spermatogenesis in the mealybug Planococcus citri. Chromosoma 14:1–17
Nur U (1962) A supernumerary chromosome with an accumulation mechanism in the lecanoid genetic system. Chromosoma 13:249–371
Nur U (1967) Reversal of heterochromatization and the activity of the paternal chromosome set in the male mealybug. Genetics 56:375–389
Nur U (1969) Harmful B chromosomes in a mealybug; additional evidence. Chromosoma 28:280–297
Nur U (1970) Translocation between eu- and heterochromatic chromosomes and spermatocytes lacking a heterochromatic set in male mealybugs. Chromosoma 29:42–61
Nur U, Brett BLH (1985) Genotypes suppressing meiotic drive of a B chromosome in the mealybug, Pseudococcus obscurus. Genetics 110:73–92
Nur U, Brett BLH (1987) Control of meiotic drive of B chromosomes in the mealybug, Pseudococcus affinis (obscurus). Genetics 115:499–510
Nur U, Brown SW, Beardsley JW (1987) Evolution of chromosome number in mealybugs (Pseudococcidae: Homoptera). Genetica 74:53–60
Scarbrough K, Hattman S, Nur U (1984) Relationship of DNA methylation level to the presence of heterochromatin in mealybugs. Mol Cell Biol 4:599–603
Schrader F (1921) The chromosomes of Pseudococcus nipae. Biol Bull 40:259–270
Schrader F (1923) A study of the chromosomes in three species of Pseudococcus. Arch Zellforsch 17:45–62
Smith DA, Baker BS, Gatti M (1985) Mutations in genes encoding essential mitotic functions in Drosophila melanogaster. Genetics 110:671–688
Snow R (1963) Hydrochloric acid-carmine as a stain for chromosomes in squash preparations. Stain Technol 38:9–13
White MJD 61973) Animal cytology and evolution, 3rd edn. Cambridge University Press, Cambridge, p 961
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Nur, U., Brett, B.L.H. Genotypes affecting the condensation and transmission of heterochromtic B chromosomes in the mealybug Pseudococcus affinis . Chromosoma 96, 205–212 (1988). https://doi.org/10.1007/BF00302359
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00302359