摘要:

AbstractA 14 kb region of genomic DN A containing the X‐linkedAnopheles gambiaeeye colour gene,white, was cloned and sequenced. Genomic clones containing distinctwhite+ alleles were polymorphic for the insertion of a small transposable element in intron 3, and differed at 1% of nucleotide positions compared. Sequence was also determined from a rare 2914 bp cDNA. Comparison of cDNA and genomic sequences established an intron‐exon structure distinct fromDrosophila white.Despite a common trend inAnophelesandDrosophilaof weak codon bias given low levels of gene expression, codon usage byAnopheles gambiae whitewas strongly biased. Overall amino acid identity between the predicted mosquito and fruitfly proteins was 64%, but dropped to 14% at the amino terminus. To correlate phenotypically white‐eyed strains ofA. gambiaewith structural lesions inwhite, five available strains were analysed by PCR and Southern blotting. Although these strains carried allelic mutations, independently generated by gamma radiation (three strains) or spontaneous events (two strains), nowhitelesions were detected. Significantly, anothernon‐allelicX‐linked mutation, causing an identical white‐eyed phenotype, has been correlated with a structural defect in the clonedwhitegene (Benedictet al., 1995). Taken together, these observations suggest that the white‐eyed mutants analysed in the present study carry mutations in a second eye colour gene and are most

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1995.tb00027.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractInsect mitochondrial genome (mtDNA) analysis is a powerful tool for the study of population genetics and phylogenetics. In the past few years primer sequences for the PCR amplification of various insect mtDNA genes have been published. The objectives of this study were (1) present new primer sequences for six insect mitochondrial genes and (2) test primers designed in our laboratory and some previously published primers on a wide range of insects to determine if amplification of the target fragment could be obtained. The primers for the amplification of the two ribosomal RNA gene (16S and 12S rRNA) fragments are universal for insects and related groups; the primers for NADH5 and NADH4 dehydrogenase gene fragments and cytochrome c oxidase I gene fragment are applicable broadly.

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1995.tb00028.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractCytoplasmic incompatibility is caused in various insects by intracellular infection with rickettsia‐like microorganisms of the genusWolbachia.In JapanLaodelphax striatellusshows unidirectional cytoplasmic incompatibility between northeastern and southwestern populations. In this study, nine natural populations ofL. striatelluscollected from central Japan, including the geographic boundary between the two cytotype populations, were analysed forWolbachiainfection by PCR using primers specific toWolbachia16S rDNA. The geographic pattern of the infection rates of the southwestern (high) and the northeastern (low or zero) populations broadly resembled that of a previous study of incompatibility. In populations which originated from the boundary regions between the southwestern and northeastern populations, the infected and uninfected cytotypes coexisted. It is suggested that in some populations ofL. striatellus, which formerly had been uninfected withWolbachia, the infection property has changed to the infected. Based on our results, we conclude that the distribution ofWolbachia‐infectedL. striatelluspopulations have spread northeasterly during the last 12 ye

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1995.tb00029.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractA recombinant Sindbis virus, TE/3'2J/ANTI‐S, containing LaCrosse virus small segment cDNA in antisense orientation, was inoculated intoAedes triseriatusmosquitoes. Virus replication and LAC‐ANTI‐S RNA expression were analysed temporally and spatially. TE/3'2J/ANTI‐S virus titre peaked at 5.0 log10TCID50in heads 6–9 days post infection (p.i.) and decreased to 3.4 log10TCID50by 37 days p.i. Salivary glands contained 4.4 log10TCID50of virus 6 days p.i.; titres were lower in other organs. LAC‐ANTI‐S RNA levels paralleled virus titre. SIN E1 antigen was detected in many mosquito organ systems, but in specific cells and tissues of some organs. TE/3'2J/ANTI‐S virus exhibited different cellular tropisms in salivary glands ofAedesand

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1995.tb00030.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractMolecular characterization of the paternal‐sex‐ratio (PSR) chromosome inNasonia vitripennis(Hymenoptera: Pteromalidae) has led to the isolation of a dispersed repetitive element. The element is a LTR‐containing retrotransposon which has been namedNATE(NAsonia Transposable Element).NATEhas direct terminal repeats and has an internal amino acid sequence similar to reverse transcriptases of other retroelements. Phylogenetic analysis indicatesNATEis a member of theGypsy/Ty3group of retrotransposons, and represents the first isolated from Hymenoptera. Five closely related copies ofNATEwere isolated from the PSR chromosome, but cross‐hybridizing elements were not detected on the autosomes ofN. vitripennis.Strongly cross‐hybridizing elements were, however, detected in two otherNasoniaspecies. This observed distribution ofNATEis interesting, because the supernumerary PSR chromosome may be derived from the genome of a sibling species ofN. vi

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1995.tb00031.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe nucleotide sequence of the regions flanking the A + T region ofDrosophila melanogastermitochondrial DNA (mtDNA) has been determined. Included are the genes encoding the transfer RNAs for valine, isoleucine, glutamine and methionine, the small ribosomal RNA and the 5'‐coding sequences of the large ribosomal RNA and NADH dehydrogenase subunit II. This completes the nucleotide sequence of theD. melanogastermitochondrial genome. The circular mtDNA ofD. melanogastervaries in size among different populations largely due to length differences in the control region (Fauron&Wolstenholme, 1976; Fauron&Wolstenholme, 1980a, b); the mtDNA region we have sequenced, combined with those sequenced by others, yields a composite genome that is 19,517 bp in length as compared to 16,019 bp for the mtDNA ofD. yakuba. D. melanogastermtDNA exhibits an extreme bias in base composition; it comprises 82.2% deoxyadenylate and thymidylate residues as compared to 78.6% inD. yakubamtDNA. All genes encoded in the mtDNA of both species are in identical locations and orientations. Nucleotide substitution analysis reveals that tRNA and rRNA genes evolve at less than half the rate of protein coding gene

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1995.tb00032.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractRestriction fragment length polymorphism (RFLP) markers provide effective tools for establishing the genotype at many loci for individual mosquitoes. RFLP genotypes can be organized to provide information concerning parental origin or the allelic configuration of various chromosome segments. Whole genome genotypic information for individuals can be represented in a simple graphic format, termed graphical genotyping. In this study, RFLP markers were used to demonstrate the utility of using graphical genotyping to easily and quickly evaluate the entire genome of the mosquitoAedes aegypti.Two substrains selected for susceptibility and refractoriness, from a strain highly susceptible to the filarial worm parasiteBrugia malayi, were compared. Graphical genotyping provided a mechanism to rapidly evaluate genome structure both within and between the two substrains with a simple visual analysis. This information was used in related studies to identify a new locus influencingB. malayisusceptibility inA. aegypti.Graphical genotyping also provided perspectives on some features of genome structure inA. aegypti.It suggested the presence and location of a genetic lethal on chromosome 3 and possible inversion polymorphisms associated with each of the threeA. aegyptichromosomes.

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1995.tb00033.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY