摘要:

Synaptonemal complex analysis by electron microscopy of a trisomy 28 in a male horse demonstrated a trivalent or a bivalent plus a univalent in primary spermatocytes. Two of the chromosomes making up the trivalent were, most often, completely paired with each other and only partially paired or associated with the third one. Half of the spermatocytes analysed demonstrated heterologous pairing or association between the free axis of the trivalent and the sex bivalent. The pairings remained, to a large extent, into diakinesis-metaphase I. In most pachytene cells one autosomal bivalent showed proximal asynapsis and paired often, heterologously, with the trivalent or the sex bivalent. The horse demonstrated azoospermy, which was due, at least in part, to degeneration at both the spermatocyte and spermatid levels.

ISSN:1424-8581    

DOI:10.1159/000133408

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The chromosomal locations of the rabbit genes for the α and β subunits of phosphorylase kinase (PHKA and PHKB) were determined by in situ hybridization using rabbit cDNA probes. Our results localize PHKA to the X chromosome at the proximal end of the long arm, near the centromere, and PHKB to the same location on chromosome 5. These assignments support previously reported homoeologies of rabbit and human chromosome

ISSN:1424-8581    

DOI:10.1159/000133409

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Wild male house mice Mus musculus domesticus were collected from the hybrid zone between the John o’Groats race (2n = 32) and the standard race (2n = 40) in northern Scotland. Meiosis in both homozygotes (2n = 32, 36, and 40) and single Robertsonian heterozygotes (2n = 33, 35, and 37) was found to be orderly. At prophase/metaphase I in heterozygotes, a trivalent was formed from the metacentric and two homologous acrocentrics. At pachytene, this trivalent usually had a single side arm at the position of the centromeres, as a result of nonhomologous pairing of the acrocentrics. This side arm persisted into diplotene. Generally only a single chiasma was formed between each acrocentric and the metacentric. Ana-phase I nondisjunction frequencies were estimated as 1.5% for the homozygotes and 2.7% for the heterozygotes. The extent of germ cell death between the pachytene and round spermatid stages was 18 % greater in heterozygotes than in homozygotes. Our results concur with previous studies which indicate that single Robertsonian heterozygotes in wild house mice have near-normal fertilit

ISSN:1424-8581    

DOI:10.1159/000133410

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Biotinylated chromosome-specific probes were prepared from flow-sorted pig chromosomes 1 13,18, X, and Y using the degenerate oligonucleotide-primed polymerase chain reaction. Probes prepared in this way can be used to confirm the identity of chromosomes in the bivariate pig flow karyotype and in pig × mouse somatic cell hybrids

ISSN:1424-8581    

DOI:10.1159/000133411

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000133412

出版商:S. Karger AG    

年代:1992

数据来源: Karger