摘要:

AbstractA storage protein receptor was shown to be present in membranes of the pupal fat body ofSarcophaga peregrina, whereas membranes of the larval fat body contained a cryptic receptor. The molting hormone, 20‐hydroxyecdysone, was essential for activation of the cryptic receptor to bind and incorporate the storage protein. The active receptor in the pupal fat body membrane was a protein with a molecular mass of 120‐kdaltons. It was found that a 125‐kdalton protein, a cryptic receptor for storage protein, present in the larval fat body membrane was converted to an active receptor in the presence of 20‐hydroxyecdysone, without accompanying appreciable new protein sy

ISSN:0739-4462    

DOI:10.1002/arch.940030712

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractThe deposition and apolysis of insect cuticles have long been known to be regulated by ecdysone. Unsclerotized, chitin‐containing procuticles contain evolutionarily conserved, hydrophobic proteins that are soluble in solutions of denaturing agents. The pupal procuticle ofDrosophilais deposited by larval and imaginal epidermis starting 9 h after puparium formation when the ecdysone titer is low. Initially, a set of low molecular weight proteins (less than 25,000 daltons; low molecular weight pupal cuticle proteins = S‐PCPs) is synthesized. However, about the time of pupation, synthesis of S‐PCPs ceases, and high molecular weight proteins (greater than 50,000 daltons; H‐PCPs) are synthesized. In vitro experiments indicate that the initial formation of the procuticle with synthesis of the S‐PCPs requires a pulse of hormone followed by withdrawal (6 h with 20‐hydroxyecdysone, 1 μg/ml). The switch from synthesis of S‐PCPs to H‐PCPs is facilitated by a second, short pulse of 20‐hydroxyecdysone (0.1 μg/ml, 3 h). Ultrastructural localization demonstrates that the S‐PCPs are located only in the external lamellae of the procuticle, while the H‐PCPs are present only in internal lamellae. Developmental analyses with cloned genes indicate that cuticle protein genes are expressed during only one stage ofDrosophiladevelopment. Some of the genes encoding S‐PCPs are limited in their expression to larval (posterior) or imaginal (anterior) epidermis. Preliminary molecular analyses of the larval and pupal cuticle protein genes indicate that they are organized in different ways. For example, four larval genes exist in a cluster with divergent transcription, and one PCP gene, PCP‐GART, is located within an intr

ISSN:0739-4462    

DOI:10.1002/arch.940030713

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractSix major transcripts encoding the α, β, and γ subunits of the larval serum protein LSP‐1, the single subunit of the LSP‐2, and the P1 and P6 polypeptides appear sequentially in the fat body tissue during the third larval stage ofDrosophila melanogaster.Northern blot analysis shows that the transcription of the LSP‐2 and P1 mRNAs is restricted temporally to the third instar and the early phase of pupal development and spatially to the fat body tissue. The synthesis and/or accumulation of the LSP‐2 and P1 transcripts are differentially affected by mutations of thedorandoccloci of the 2B5 complex of genes involved in thetrans‐regulation of the activity of ecdysteroid‐responsive genes. Application of the P element‐mediated germ line transformation to the P1 gene shows that correct developmental expression of this gene requires no more than 1.5 kb of DNA sequences upstream from the

ISSN:0739-4462    

DOI:10.1002/arch.940030714

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractA new picture of gene and chromosome structure is emerging inDrosophilathat differs considerably from that largely derived from polytene chromosome banding patterns and saturation mutagenesis. In particular, gene transfer has enabled us to more clearly limit the functional unit of a number of genes. Gene regulation may be studied at the molecular level with such techniques. The possible complexity of regulatory elements that may pose problems in their analysis is discussed.

ISSN:0739-4462    

DOI:10.1002/arch.940030715

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940030701

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY