Summary
Meiotic parthenogenesis of a type not previously described was found in Pulvinaria hydrangeae Steinweden. During diakinesis 8 bivalents were formed. At prometaphase the spindle was tripolar but anaphase I was bipolar and normal. After completion of division of the primary oocyte, the following sequence occurred: 1. polar body I divided, usually into 3 products; 2. the secondary oocyte divided to yield the egg pronucleus and polar body II; 3. the egg pronucleus divided into its two haploid products; and 4. the second polar body divided. The products of the egg pronucleus fused while dividing to restore the diploid chromosome number; this division may be equated to the first cleavage division. The products of the polar bodies did not take part in the formation of the embryo proper or the mycetocytes.
Among the embryos produced by females of two out of the three populations studied some of the embryos showed a heterochromatic chromosome set, characteristic of males in this and related families. The reproductive system of the females as well as the eggs did not contain any sperm; thus the male embryos were apparently produced parthenogenetically.
The euchromatic and heterochromatic chromosome sets were genetically identical, since they both originated from the egg pronucleus by mitosis. The heterochromatization of one set but not the other might be due in part to a previous difference in their position in the cytoplasm.
The females were completely homozygous yet they produced male and female embryos. Thus it appears that sex determination in the group does not depend on the segregation of genetic factors in either males or females.
In addition to male and female embryos, three types of degenerating embryos were observed. It is believed that these embryos were formed by polyploid somatic cells which invaded abnormal eggs and embryos and took over development.
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References
Brown, S. W.: Lecanoid chromosome behavior in three more families of the Coccoïdea (Homoptera). Chromosoma (Berl.) 10, 278–300 (1959).
Brown, S. W., and W. A. Nelson-Rees: Radiation analysis of a lecanoid genetic system. Genetics 46, 983–1007 (1961).
Hughes-Schrader, Sally: Cytology of coccids (Coccoïdea-Homoptera). Advanc. Genet. 2, 127–203 (1948).
James, H. C.: The effect of the humidity of the environment on sex ratios from over-aged ova of Pseudococcus citri (Risso) (Hemipt. Coccidae). Proc. roy. Ent. Soc. Lond., Ser. A, Gen. Ent. 13, 73–79 (1938).
Nelson-Rees, W. A.: A study of sex predetermination in the mealy bug Planococcus citri (Risso). J. exp. Zool. 144, 111–137 (1960).
—: Modification of theovary of the mealy bug Planococcus citri (Risso), due to aging. J. exp. Zool. 146, 85–111 (1961); - The effects of radiation damaged heterochromatic chromosomes on male fertility in the mealy bug, Planococcus citri (Risso). Genetics 47, 661–683 (1962).
Nur, U.: Sperms, sperm bundles and fertilization in a mealy bug, Pseudococcus obscurus Essig (Homoptera: Coccoïdea). J. Morph. 111, 173–199 (1962).
Pesson, P.: Description du male de Pulvinaria mesembryanthemi Vallot et observations biologiques sur cette espèce. (Hemipt. Coccidae). Soc. Ent. France Ann. 110, 71–77 (1941).
Schrader, F., and Sally Hughes-Schrader: Haploidy in Metazoa. Quart. Rev. Biol. 6, 411–438 (1931).
Seiler, J., and B. Gessner: Die automiktischen Vorgänge im Ei der tetraploid parthenogenetischen Solenobia triquetrella F. R. (Psychidae, Lepid.). Chromosoma (Berl.) 4, 91–107 (1950).
Suomalainen, E.: Beiträge zur Zytologie der parthenogenetischen Insekten. II. Lecanium hemisphaericum (Coccidae). Ann. Acad. Sci. fenn. A, 57, 1–30 (1940); - Parthenogenesis in animals. Advanc. Genet. 3, 193–253 (1950).
Theim, H.: Beitrag zur Parthenogenese und Phänologie der Geschlechter von Lecanium corni Bouche (Coccidae). Z. Morph. Ökol. Tiere 27, 294–324 (1933).
Thomsen, M.: Studien über die Parthenogenese bei einigen Cocciden und Aleurodiden. Z. Zellforsch. 5, 1–116 (1927); - Sex determination in Lecanium. Trans. IVth Int. Congr. Ent. 1929, p. 18–24.
Tremblay, E.: Osservazioni sulla cariologia e sulla simbiosi endocellulare di alcuni Coccini. Boll. Lab. Ent. Agr. Portici 19, 215–260 (1961).
White, M. J. D.: Animal cytology and evolution, 2nd edit. Cambridge: University Press 1954.
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Nur, U. Meiotic parthenogenesis and heterochromatization in a soft scale, pulvinaria hydrangeae (Coccoidea: Homoptera). Chromosoma 14, 123–139 (1963). https://doi.org/10.1007/BF00336754
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DOI: https://doi.org/10.1007/BF00336754