Differential effects of duplication-deficiency gametes from T (3;12) on embryonic development in the German cockroach.

Differential embryonic development, as seen within egg cases of the German cockroach, serves to distinguish matings of interchange heterozygotes from those of wild type. In T (3;12), one group of fertilized eggs ceases development during stage I of embryonic development; a second group, during stage VII. The frequency of the two groups correlates closely with that of adjacent-1 vs adjacent-2 disjunction. It also does not differ significantly from the expected frequency if zygotes fertilized by one of the two types of adjacent-1 gametes reach a more advanced stage of development than those of the other three types of duplication-deficiency gametes. The absence of a sex difference in the stages of embryonic death indicates that it makes little difference whether aneuploid gametes are of maternal or paternal origin.