[A comparison of the characteristics of chromosome nondisjunction in the first maturation division of mouse oocytes heterozygous for balanced structural rearrangements of the chromosomes].

Peculiarities of non-disjunction of chromosomes in the first meiosis of maturation of oocytes in mice heterozygous in the Robertsonian and nonuniform reciprocal translocations have been determined. Mice, heterozygous in one Robertson's translocation, had general frequency of chromosomal non-disjunction in the 1st meiosis of oocyte maturation equal to 17%; by two Robertsonian translocations the total frequency of genetically deficient oocytes amounted to about 77%, in case of unequal reciprocal translocation--to 50%. In two latter cases genetic disturbances were due to unbalanced euploid chromosome sets.