The morphological sequence of XY pairing in the Norway rat Rattus norvegicus - PubMed (original) (raw)

The morphological sequence of XY pairing in the Norway rat Rattus norvegicus

A M Joseph et al. Chromosoma. 1984.

Abstract

The sequence of XY pairing at meiotic prophase in the Norway rat, Rattus norvegicus, has been studied in spread preparations of spermatocytes obtained from pubertal males. As in most mammals, sex chromosome pairing is delayed in relation to that of the autosomes. At one stage in pachytene, the Y is fully paired in synaptonemal complex association with about one-third of the X. Observation in spread preparations at pachytene and diplotene and in air-dried metaphase I preparations indicates that the long arm of the Y pairs with the short arm of the X. Pairing of the Y with both ends of the X is seen in about 4% of pachytene spermatocytes. The possibility that XY pairing in the rat may be nonhomologous (Ashley 1983) is considered, and the view is expressed that the XY synaptonemal complex may be incomplete in fine structural detail, thus not providing for the effective pairing required in true reciprocal recombination. The same mechanism that excludes crossing over from heterochromatic regions of autosomes may also operate to minimize or prevent crossing over in the sex pair of mammals.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Experientia. 1980 Aug 15;36(8):1014-5 - PubMed
    1. Chromosoma. 1973;42(2):145-62 - PubMed
    1. J Cell Sci. 1977 Jun;25:1-15 - PubMed
    1. Chromosoma. 1977 Mar 16;60(2):127-37 - PubMed
    1. Hum Genet. 1983;63(2):132-8 - PubMed

Publication types

MeSH terms

LinkOut - more resources