摘要:

AbstractA recombinant plasmid vector was constructed in which the bacterialLacZgene was placed under the control of aBombyx moribaculovirus early promoter. The vector proved to be active in transfected cultured dipteran and lepidopteran cells. Co‐transfection carried out with this recombinant plasmid vector and a plasmid containing the hygromycin phosphotransferase gene followed by selection with the antibiotic hygromycin B, resulted in stable transformation of culturedDrosophila melanogasterSchneider 2 cells. Southern blot analysis of the host cell's genomic DNA in combination with chromosomalin situhybridization demonstrated that multiple copies of both plasmids were integrated in the host cell's genom

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1994.tb00139.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractVitellogenic carboxypeptidase is a 53 kDa yolk protein produced by the fat body of the female mosquito,Aedes aegypti, in response to a blood meal. Its expression is sex‐, stage‐ and tissue‐specific and is identical to that of the major yoik protein, vitellogenin. The gene is intronless and two alleles have been cloned and sequenced, including more than 1.5 kb on both sides of the coding region. A capsite consensus recently identified as an arthropod initiator is present at the start site of transcription. Upstream of this capsite is a 16 bp imperfect palindrome repeated four times showing strong homology to defined hormone‐response elements. In addition, a region that closely resembles the fat body enhancer and double sex binding site from theDrosophilayolk protein genes and several potential fat body‐specific regulatory protein binding sites w

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1994.tb00140.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractSegments of nicotinic acetylcholine receptor α sub‐unit genes have been isolated from a panel of insect species by polymerase chain reaction, using degenerate oligonucleotide primers designed to recognize conserved regions of theDrosophila melanogasterALS and SAO genes. The amplified segments encode elements of typical a‐subunits anticipated to play roles in ligand binding and ion channel formation. Each is also clearly either ALS or SAD‐like. The predicted protein sequences display extremely high levels of conservation (over 85% for each subtype) even though derived from very distantly related insect s

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1994.tb00141.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe phylogeny of the cryptic species complex of wasps in the genusNasoniawas inferred by analysis of nucleotide sequences of an rDNA internal transcribed spacer (ITS2) and the D2 region of 28S rDNA. Phylogenetic analysis showed thatN. vitripennisdescended from a theoretical common ancestor with that of a lineage that diverged intoN. longicornisandN. giraulti.Differences in the ITS2 regions clearly distinguished two strains ofN. giraulti.Another member of theDibrachysGroup,Trichomalopsis dubius, was placed outside of theNasoniacomplex. The D2 region had a base substitution rate =2 times slower than the ITS2 region and was used to resolve the phylogenetic affiliation of an eulophid,Melittobia digitata, to the pteromalids. Tree topology of theNasoniacomplex was congruent with the phylogeny of a cluster ofWolbachiabacteria which infect these insects. The possible role of these bacteria in driving speciation is discussed.

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1994.tb00142.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractBy a differential screening of cDNA libraries made with RNAs present in differentiating imaginal wing discs ofBombyx mori, we have isolated clones whose expression is dramatically modified during the formation of the pupal wings. The RNAs corresponding to all but one of these clones are also transiently accumulated in the wing primordia during the last larvo‐larval moult and in response to 20‐hydroxyecdysone injections. If the injections are made to juvenilized larvae the expression of the same genes is stimulated but the range of the stimulation is reduced. It is suggested that inBombyx, cells of the wings reach the pupal stage of differentiation by steps corresponding to the phases during which high levels of ecdysteroids are pres

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1994.tb00143.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe primary and secondary structure of the internal transcribed spacers of ribosomal DNA (ITS1 and ITS2) and their utility for phylogenetic analysis of closely related species were examined using theAnopheles gambiaecomplex as a model. Restriction mapping revealed an unusual architectural feature in the ITS1 of several members of anAn. gambiaecryptic species complex. Multiple spacer lengths are prevalent inAn. merusandAn. melasand are due to variable numbers of a repeated 250 bp sequence. Secondary structure analysis indicated that the repeat forms a helix and loop that may be involved in rDNA processing. Intra‐and interspecific polymorphism within the species complex were further examined by DNA sequencing of forty‐eight ITS2 clones obtained by polymerase chain reaction from individuals of the five species. Interspecies variation in the approximately 426 bp ITS2 sequence ranged between 0.4% and 1.6%; intraspecies variation ranged from 0.07% inAn. arabiensisto 0.43% inAn. gambiae.lntraindividual variation ranged from 0% in four individuals to a high of 0.4% in oneAn. quadriannulatusspecimen. None of the variants were shared between species. The low level of variation supports the hypothesis that species of the complex evolved recen

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1994.tb00144.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY