EVIDENCE THAT THE SEGREGATION-DISTORTION PHENOMENON IN DROSOPHILA INVOLVES CHROMOSOME BREAKAGE

Evidence that the segregation-distortion phenomenon in Drosophila involves chromosome breakage.

Biological parameters and the segregation distortion (SD) phenomenon in Drosophila melanogaster.

The relationship between some biological parameters (mortality, longevity, fertility, fecundity and sex ratio) and segregation of second chromosomes in heterozygous and homozygous SD males has been analyzed. The results obtained in SD/SD+ heterozygous males show: (1) their reduced fertility with respect to that of control males, (2) an alteration in the sex ratio in the SD+ progeny only, and (3...

Aging effect on the phenomenon of segregation distortion in Drosophila melanogaster.

EGREGATION Distorter (SD) is an element located in the centromeric region sof chromosome 2 of Drosophila mlanogaster. When a male carries SD in heterozygous condition, it transmits SD to its progeny in a great excess over the theoretical frequency of 50%. The SD system consists of three major elements: the SD locus itself which is the element causing segregation distortion; Activator of SD, Ac(...

Is the segregation distortion phenomenon in Drosophila due to recurrent active genetic transposition?

The Segregation distorter (SO) phenomenon in Drosophila melanogaster is characterized by the preferential recovery of Distorter second chromosomes in the progeny of heterozygous males. In some crosses, virtually all of the offspring of such males will carry the SD chromosome (compared to the expected 50% based on Mendelian segregation), and it is now known that the aberrant segregation ratios a...

On the Models of Segregation Distortion in DROSOPHILA MELANOGASTER.

The Segregation Distorter system of Drosophila melanogaster consists of two major elements, Sd and Rsp. There are two allelic alternatives of Rsp-sensitive (Rsp(s)) and insensitive (Rsp(i)); a chromosome carrying Rsp(i) is not distorted. According to the model proposed by Hartl (1973), these two elements interact to cause segregation distortion. For a sperm to complete the maturation process, i...