Abstract
The ultrastructure of whole X-Y pairs has been reconstructed by serial sectioning and model building. Seven X-Y pairs were completely reconstructed and the lengths of the cores of the sex chromosomes were measured. These X-Y pairs corresponded to zygonema, early, middle and late pachynema. Special regions of the X-Y pair were reconstructed from thinner sections. — It has been shown that two cores exist in the sex pair during the cited stages, and that their lengths and morphology are rather constant in specific stages. The long core averages 8.9 μ in length and the short core is 3.5 μ long. Both cores have a common end region in which a synaptonemal complex is formed from zygonema up to midpachynema. This synaptonemal complex shortens progressively up to mid-pachynema and at late pachynema becomes obliterated. Each core has a free end touching the nuclear membrane. During mid-pachynema an anomalous synaptonemal complex is developed on most of the length of the long core. This complex is asymmetric and disappears at late pachynema. The meaning of the cores and the complexes are discussed, and the existence of a homologous region in the X-Y pair of the mouse is interpreted to be proved.
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References
Coleman, J. R., Moses, M. J.: DNA and the fine structure of synaptic chromosomes in the domestic rooster (Gallus domesticus). J. Cell Biol. 23, 63–78 (1964).
Ford, E. H., Woollam, D. H.: The fine structure of the sex vesicle and sex chromosome association in spermatocytes of mouse, golden hamster and field vole. J. Anat. (Lond.) 100, 787–799 (1966).
Meyer, G. F.: Possible correlation between submicroscopic structure of meiotic chromosomes and crossing-over. Third Europ. Conference on Electron Microscopy, B, 461–462 (1964).
Moens, P. B.: The structure and function of the synaptonemal complex in Lilium longiflorum sporocytes. Chromosoma (Berl.) 23, 418–451 (1968).
—: The fine structure of meiotic chromosome pairing in the triploid Lilium tigrinum. J. Cell Biol. 40, 273–279 (1969).
Moses, M. J.: The relation between the axial complex of meiotic prophase chromosomes and chromosome pairing in a salamander (Plethodon cinereus). J. biophys. biochem. Cytol. 4, 633–638 (1958).
—: Cytology and cell physiology (G. Bourne, ed.), p. 423–568. New York: Academic Press 1964.
Moses, M. J.: Synaptonemal complex. Ann. Rev. Genet. 2, 363–412 (1968).
Ohno, S., Kaplan, W., Kinosita, R.: Heterochromatic regions and nucleolus organizers in chromosomes of the mouse, Mus musculus. Exp. Cell Res. 13, 358–364 (1957).
— On the end-to-end association of the X and Y chromosomes of Mus musculus. Exp. Cell Res. 18, 282–290 (1959).
—, Lyon, M. F.: Cytological study of Searle's X-autosome translocation in Mus musculus. Chromosoma (Berl.) 16, 90–100 (1965).
— Weiler, C.: Relationship between large Y-chromosome and side-by-side pairing of the X-Y bivalent observed in the Chinese hamster, Cricetus griseus. Chromosoma (Berl.) 13, 106–110 (1962).
Peacock, W. J.: Chromosome replication. In: Intern. Symp. on Genes and Chromosomes. Structure and Function. Nat. Cancer Inst. Monogr. 18, 101–131. Bethesda: National Cancer Institut 1965.
Rhoades, M. M.: Meiosis. In: The cell (J. Brachet and A. Mirsky, ed.), vol. III, p. 1–75. New York: Academic Press 1961.
Reader, C., Solari, A. J.: The histology and cytology of the seminiferous epithelium of the mouse with Searle's X-autosome translocation. Acta physiol. lat.-amer. (in press).
Roth, T. F.: Changes in the synaptinemal complex during meiotic prophase in mosquito oocytes. Protoplasma 61, 346–386 (1966).
Sachs, L.: The possibilities of crossing-over between the sex chromosomes of the house mouse. Genetica (s'Gravenhage) 27, 309–322 (1955).
Schin, K. S.: Core-Strukturen in den meiotischen und post-meiotischen Kernen der Spermatogenese von Gryllus domesticus. Chromosoma (Berl.) 16, 436–452 (1965).
Sheridan, W. F., Barrnett, R. J.: Cytochemical studies on chromosome ultrastructure. J. Ultrastruct. Res. 27, 216–229 (1969).
Sjöstrand, F. J., In: Electron microscopy of cells and tissues. I. Instrumentation and techniques. New York: Academic Press 1967.
Solari, A. J.: The morphology and the ultrastructure of the sex vesicle in the mouse. Exp. Cell Res. 36, 160–168 (1964).
—: The evolution of the ultrastructure of the sex chromosomes (sex vesicle) during meiotic prophase in mouse spermatocytes. J. Ultrastruct. Res. 27, 289–305 (1969a).
—: Changes in the sex chromosomes during meiotic prophase in mouse spermatocytes. In: Nuclear physiology and differentiation. Genetics, Suppl. 61, 113–120 (1969b).
—, Tres, L.: The localization of nucleic acids and the argentaffin substance in the sex vesicle of mouse spermatocytes. Exp. Cell Res. 47, 86–96 (1967a).
—: The ultrastructure of the human sex vesicle. Chromosoma (Berl.) 22, 16–31 (1967b).
—— The three-dimensional reconstruction of the X-Y pair of human spermatocytes. J. Cell Biol. (in press).
Sotelo, J. R., Wettstein, R.: Electron microscope study on meiosis. The sex chromosome in spermatocytes, spermatids and oocytes of Gryllus argentinus. Chromosoma (Berl.) 15, 389–415 (1964).
Stern, H., Hotta, Y.: DNA synthesis in relation to chromosome pairing and chiasma formation. In: Nuclear physiology and differentiation. Genetics, Suppl. 61, 27–39 (1969).
Wettstein, R., Sotelo, J. R.: Electron microscopical serial reconstruction of the spermatocyte I nuclei at pachytene. J. de Microsc. 6, 557–576 (1967).
Wolstenholme, D. R., Meyer, G.: Some facts concerning the nature and formation of axial core structures in spermatids of Gryllusdomesticus. Chromosoma (Berl.) 18, 272–286 (1966).
Woollam, D. H., Ford, E. H., Millen, J.: The attachment of pachytene chromosomes to the nuclear membrane in mammalian spermatocytes. Exp. Cell Res. 42, 657–661 (1966).
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Solari, A.J. The spatial relationship of the X and Y chromosomes during meiotic prophase in mouse spermatocytes. Chromosoma 29, 217–236 (1970). https://doi.org/10.1007/BF00326080
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DOI: https://doi.org/10.1007/BF00326080