Abstract
At metaphase of the first spermatocyte meiotic division in Ascaris lumbricoides var. suum the polymorphic bivalents are arranged at the equatorial plate peripheral to a central aggregate mass. The aggregate mass segregates to only one of the two daughter cells and thus behaves as a sex chromosome. The mass is comprised of two components: a granular chromatin that can be differentiated from the autosomes at metaphase I, and a condensed chromatin that has a similar morphology to the autosomes but is functionally differentiated at anaphase I. The condensed chromatin may be autosomes that have fused with the sex chromsomes and may be responsible for the segregation of the whole aggregate at anaphase I. Analysis of the origin of the mass is discussed and microtubular association in the movement of the mass is described.
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Literature
Boring, A.: A small chromosome in Ascaris megalocephala. Arch. Zellf. 4, 120–131 (1909)
Boveri, T.: Zellen-Studien II. Die Befruchtung und Teilung des Eies von Ascaris megalocephala. Jena: Fischer, 1888
Castle, W.: The heredity of sex. Bull. Mus. comp. Zool. Harvard 40, 189–218 (1903)
Edwards, C.: The sex-determining chromosome in Ascaris. Science 31, 514–515 (1910a)
Edwards, C.: The idiochromosome in Ascaris megalocephala and Ascaris lumbricoides. Arch. Zellf. 5, 422–429 (1910b)
Edwards, C.: The sex-chromosomes in Ascaris felis. Arch. Zellf. 7, 309–311 (1912)
Fiske, S.: An adaptation of Reynold's lead citrate stain for high resolution autoradiography. J. Microscopie 5, 355–360 (1966)
Geinitz, B.: Über Abweichungen bei der Eireifung von Ascaris. Arch. Zellf. 13, 588–633 (1915)
Goldstein, P.: Spermatogenesis and spermiogenesis in Ascaris suum. J. Morph. 154, 317–338 (1977)
Goldstein, P., Moens, P.B.: Karyotype analysis of Ascaris lumbricoides var. suum male and female pachytene nuclei by 3-D reconstruction from electron microscopy of serial sections. Chromosoma (Berl.) 58, 110–111 (1976)
Goodrich, H.: The maturation divisions in Ascaris incurva. Biol. Bull. 27, 147–150 (1914)
Goodrich, H.: The germ cells in Ascaris incurva. J. exp. Zool. 21, 61–100 (1916)
Herla, V.: Etude des variations de la mitose chez l'Ascaride megalocephale. Arch. Biol. 13, 423–519 (1895)
Jeffrey, E., Haertl, E.: The nature of certain so-called sex chromosomes in Ascaris. La Cellule 46, 237–245 (1938)
Kautzsch, G.: Studien über Entwicklungsanomalien bei Ascaris II. Arch. Entwick. mech. Organ. 35, 642–691 (1913)
Moens, P.B.: Serial sectioning in Electron Microscopy. Proc. Canad. Fed. Biol. Soc. 13, pp160 (1970)
Montgomery, T.: On the morphological differences of the chromosomes of Ascaris megalocephala. Arch. Zellf. 2, 66–75 (1909)
Mutafova, T.: Morphology and behaviour of sex chromosomes during meiosis in Ascaris suum. Z. Parasitenk. 46, 291–295 (1975)
Payne, F.: Some new types of chromosome distribution and their relation to sex. Biol. Bull. 16, 153–166 (1909)
Schaffner, J.: Chromosome difference in Ascaris megalocephala. Ohio Naturalist 9, 506–508 (1909)
Vassilev, I., Mutafova, T.: Comparative studies on the karyotype of Ascaris suum and Ascaris ovis. Z. Parasitenk. 43, 115–121 (1974)
Walton, A.: Ascaris canis (Werner) and Ascaris felis (Goeze). A taxonomic and a cytobiological comparison. Biol. Bull. 31, 364–372 (1916)
Walton, A.: The Oogenesis and early embryology of Ascaris canis J. Morph. 30, 537–603 (1917)
Walton, A.: The Spermatogenesis of Ascaris felis (Goeze). J. exp. Zool. 34, 189–201 (1921)
Zickler, D., Olson, L.: The synaptonemal complex and the spindle plaque during meiosis in yeast. Chromosoma (Berl.) 50, 1–23 (1975)
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Goldstein, P. Ultrastructural analysis of sex determination in Ascaris lumbricoides var. suum . Chromosoma 66, 59–69 (1978). https://doi.org/10.1007/BF00285816
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DOI: https://doi.org/10.1007/BF00285816