Meiosis and spermatogenesis in bulls heterozygous for a presumptive 1/29 Robertsonian translocation

D. N. Logue, M. J. A. Harvey
1978 Reproduction  
Bulls heterozygous for the 1/29 Robertsonian translocation showed normal mating behaviour, semen quality and spermatogenesis. The karyotypes of 90 offspring of one heterozygous bull were consistent with a normal 1:1 segregation of the translocation. There was no difference in overall chiasma frequency at diakinesis between heterozygous and normal bulls, and while a trivalent was noted at diakinesis the chiasma position within the No. 1 arm of the trivalent did not appear to be altered when
more » ... red with that found in the normal No. 1 bivalent. An increased frequency of aneuploid secondary spermatocytes at the second meiotic division (M II) was found in the heterozygous bulls, the rate of non-disjunction based on the proportion of hypermodal cells being raised from 2\m=.\8% in the normal to 6\m=.\4%in the heterozygous animals.
doi:10.1530/jrf.0.0540159 pmid:712704 fatcat:hh5vpomoy5b2pjaowqwjrsrnzi