Mutations in the glutamine synthetase I (gsI) gene produce embryo‐lethal female sterility inDrosophila melanogaster

摘要

AbstractA female‐sterile mutation(fs(2) PM11‐19)was recovered in a screen for P‐M hybrid dysgenesis induced mutations uncovered by a deletion of region 21B and was identified as an allele of the gene encoding theDrosophilaglutamine synthetase I (GSI) mitochondrial isozyme.Molecular analysis has shown thatfs(2)PM11‐19contains a 5 kb insert within 500 bp upstream of the transcriptional start site of thegsIgene. Mutant flies have extremely low levels ofgsltranscription and GSI activity. A pre‐existing deficiency(Df(2L) netpm1) with a breakpoint near the transcription start site was also found to be a female‐sterile allele ofgsl.All eggs laid byPM11‐19homozygous females, as well as by females heterozygous for this mutation and a deletion or any of several recessive lethal alleles of thegslgene, fail to hatch. We conclude that an adequate level of maternally supplied GSI activity is necessary in the early stages ofDrosophilaembryonic development. © 1992 W