Studies of l(3)c43hs1 a polyphasic, temperature-sensitive mutant of Drosophila melanogaster with a variety of imaginal disc defects☆

摘要

Theheat-sensitive,lethalmutationl(3)c43hs1(3a€“49.0)produceswidevarietyofdefectsintheimaginaldiscsofDrosophilamelanogaster.Atpermissivetemperatures(20?°Corlower),homozygotesareviable,butsterile.At22?°C,lethalityoccursduringthelatepupalstage,andat25?°Corhigher,lethalityoccursduringthethirdlarvalinstar.Theimaginal-discabnormalitiesobservedafterexposuretorestrictivetemperaturesinclude:deficienciesofheadstructures,duplicationsanddeficienciesoftheantenna,ahomeotictransformationofthearistatotarsus,duplicationsanddeficienciesofwingandhalterestructures,differentiationofamorphouscuticularmaterialinthewingblade,anincreaseinthenumberofsex-combteeth,anddisruptionofthenormalsegmentationofthetarsus.Exposureto27?°Cfor24hratdifferenttimesinthelifecyclerevealedthateachofthesedefectshasacharacteristictemperature-sensitiveperiod(TSP)duringthelarvalstages.InjectionofwingdiscsbeforeandaftertheirTSPshowedthatthemutationisexpressedautonomously.Theseresultsarediscussedinrelationtotherolethatthel(3)c43+geneplaysinthedevelopmentofimaginaldiscs.