title: Synaptonemal complex analysis of a reciprocal translocation, rcp(20;24) (q17;q25), in a subfertile bull.
abstract: A reciprocal translocation was identified in a subfertile artificial insemination bull. Somatic chromosome investigation of G-banded metaphases demonstrated a 60,XY,rcp(20;24)(q17;q25) karyotype for the carrier. Synaptonemal complex analysis of the translocation by electron microscopy revealed an irregular pairing behavior of the chromosome axes involved, which resulted in a variety of configurations at pachytene. Not only was the expected quadrivalent configuration present, but also a trivalent plus univalent and two heteromorphic bivalents. Most common was an incompletely or completely paired quadrivalent configuration, which was non-homologously paired. XY association with the multivalent was seen only rarely. Histological analysis of testicular tissue showed meiotic arrest in some tubules. However, the semen picture was normal.
authors.affiliation: Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala.
authors.forename: D A
authors.initials: DA
authors.lastname: Villagómez
authors.forename: M
authors.initials: M
authors.lastname: Andersson
authors.forename: I
authors.initials: I
authors.lastname: Gustavsson
authors.forename: L
authors.initials: L
authors.lastname: Plöen
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000235:genetics*; D007248:Infertility, Male / Q000235:genetics / Q000662:veterinary*; D007621:Karyotyping; D008297:Male; D012661:Semen; D012671:Seminiferous Tubules / Q000473:pathology; D013090:Spermatocytes / Q000473:pathology; D013573:Synaptonemal Complex; D014178:Translocation, Genetic