Stewart-Scott I A, Bruère A N
J Hered. 1987 Jan-Feb;78(1):37-40. doi: 10.1093/oxfordjournals.jhered.a110304.
In an analysis of the chromosomes in 1556 metaphase II figures from 26 translocation-carrying rams and 84 figures from 3 normal rams (54, XY), there were no hypermodal cells in the normal rams but 35 such cells in the translocation rams, giving mean aneuploid frequencies of 3.92 percent, 4.29 percent, and 5.29 percent for the rams heterozygous for 1, 2, and 3 translocations, respectively. The translocation chromosome in the heterozygous state was found to segregate evenly during meiosis. Although the effect of heterozygosity was to increase the aneuploid frequency of the ram it is seen that the frequency in all translocation-carrying rams is low and it is thought that these cells are eliminated during spermatogenesis and therefore do not reduce the fertility of the sheep.
在对26只携带易位的公羊的1556个中期II细胞和3只正常公羊（54，XY）的84个细胞进行染色体分析时，正常公羊中没有超数细胞，但易位公羊中有35个这样的细胞，对于分别携带1个、2个和3个易位的杂合公羊，其非整倍体平均频率分别为3.92%、4.29%和5.29%。发现杂合状态下的易位染色体在减数分裂过程中均匀分离。虽然杂合性的影响是增加公羊的非整倍体频率，但可以看出，所有携带易位的公羊中的频率都很低，并且认为这些细胞在精子发生过程中被消除，因此不会降低绵羊的生育力。
