Duplication deficiency heterozygotes in Aedes aegypti

Abstract

Two types of duplication-deficiency heterozygotes have been discovered from a translocation stock of Aedes ae&ypti. The structural interchange involved one arm of chromosome 2 with chromosome 1 and the other arm with chromosome 3. Both types of dp-dfheterozygotes were deficient for a part of chromosome 2. But in one case a part of chromosome 1 and, in the other, a part of chromosome 3 was duplicated. During meiosis, chromosomes with a duplication usually formed homomorphic ring bivalents in a variable frequency. The remaining four chromosomes formed chain multiples. Ring multiples were never observed. In one heterozygote where chromosome 3 was involved in duplication, approximately 91 per cent of the cells showed a chiasma in one of the interstitial regions. The frequency of the interstitial chiasma corresponded with the expected equational segregation during first anaphase of meiosis.