Organization of a cluster of four chorion genes in Drosophila and its relationship to developmental expression and amplification☆

[摘要] Fourchoriongenes,codingforlow-molecular-weightproteinsproducedchieflytowardtheendofchoriogenesis,areclusteredwithin6kbofDNAinregion66D.Allfourgenesamplifytothesameextentduringdevelopment,butarenotequallyexpressedintoRNA.ThequantitativeaswellastemporaldifferencesinRNAaccumulationindicatethat,inadditiontocoordinateamplification,choriogenesisentailstheregulatedexpressionofindividualgenes.Ifthisregulationoperatesthroughdifferentialtranscription,itmayberelatedtotheorganizationofgenesinindividual,directlyorientedtranscriptionunits,asopposedtothedivergent,coordinatelyexpressedgenepairscharacteristicofthesilkmothchorionlocus.DNaseIhypersensitivesitesflankallthreechoriongenesexamined.Onlyonegene,s15-1,showsabimodaltemporalprofileofRNAaccumulation,thefirstpeakofwhichmaypossiblyindicatealinkbetweentranscriptionandtheonsetofamplification.

[学科分类] 生物科学（综合）