structural changes of the homologues as a possible cause of abnormal disjunction in female mice heterozygous for robertsonian translocations同系物的结构变化的一个可能原因异常分离雌性老鼠杂合的罗伯逊的易位.pdf

Structural changes of the homologues as a possible cause of abnormal disjunction in female mice heterozygous for Robertsonian translocations A.O. RUVINSKY S.I. AGULNIK, A.I. AGULNIK D.K. BELYAEV Institute of Cytology and Genetics, Academy of Sciences of the USSR, Siberian Division, Novosibirsk-90, USSR Summary Mutations T, Fu and -haplotypePon chromosome 17 cause preferential transmission of the acrocentric homologues in the progeny of female mice heterozygotes for Robertsonian transloca- tions (Rb). The present results demonstrate that the influence of these mutations upon segregation is restricted to the Robertsonian translocations involving chromosome 17. Substitution of parts of chromosome 17 distal or proximal to the T locus did not alter the effect of this chromosome on the transmission rate of the homologue. The effects of these mutations, whether cis or trans with Rb, on the transmission were the same. It was established that wLub-IRb13Lubt+/++tffemales reveal significant segregation distortion. However, in the progeny of !6!!!M’f!’’!/+r females, chromosome segregation did not differ from that theoretically expected. Rb7/ T43H mothers transmitted the chromosome with the reciprocal translocation T43H to 70.9 % of their progeny. Thus data were obtained supporting the idea that structural changes of the chromosomes caused by mutations affect the segregation of the homologues in Rb heterozygous females. Key words : mice, Robertsonian translocation, chromosome segregation. Résumé Modifications de la structure des chromosomes ’. homologues : une cause possible de la disjonction a