Studies on the female - sterile phenotype of l ( l ) su ( f ) ts 76 a , a temperature - sensitive allele of the suppressor of forked mutation in Drosophila melanogaster

A new allele of the suppressor of forked [su(f)] mutation in Drosophila melanogaster has been found and designated l(l)su(f). It is temperature-sensitive for suppression of forked (/) and has additional temperature-sensitive phenotypes of lethality, female sterility, and abnormal bristle formation at 29 °C. It closely resembles two other conditional alleles of su(f), l{l)su(f) and I{l)ts726. Female sterility at 29 °C is characterized by both disorganized egg chambers in the ovarioles and also chorion-deficient oocytes. Both of these abnormalities may be the result of premature follicle cell death. The observations on l{l)su(f) ts76a a r e consistent with the proposal that the similar allele, l(J)ts726, is a cell-lethal mutation specifically affecting mitotically active cells.