摘要:

AbstractCodon usage was compiled for fourteen chromosomal genes and four retrotransposons from the mosquitoAnopheles gambiae. Variation exists among chromosomal genes in the degree of bias. The genes showing the highest bias are probably most highly expressed. In these genes, the base composition at the third codon position is much richer in G + C than is the overall coding sequence. Thus, codon usage is biased toward G‐ or C‐ending codons. Codon usage in each retrotransposon is quite different, not only from chromosomal genes but also from the other retrotransposons. Codon usage comparisons among homologous genes fromAn. gambiaeand two other Dipterans, the yellow fever mosquitoAedes aegyptiand the fruitflyDrosophila melanogaster, show that while there are similarities, particularly betweenAn. gambiaeandD. melanogasterin the preference for G‐and C‐ending codons, each species has evolved a distinct pattern of codo

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1993.tb00089.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe vitelline membrane ofDrosophilaeggs is composed of a family of proteins which are cross linked into an insoluble matrix with an overlying waxy layer that prevents desiccation. We present here three sets of experiments which show that integrity of the vitelline membrane requires the activity of thealpha methyl dopa hypersensitive (1(2)amdHoramd) gene in both egg chambers and follicle cells. We show that loss ofamdactivity either by dietary administration of inhibitors or in genetic mosaics of either the germ line or follicle cells leads to production of defective vitelline membranes and byin situhybridization, thatamdis expressed in both nurse cells and follicle cells. Theamdgene product is the first non‐structural protein gene described whose activity is required for vitelline membrane biosynthesis. Given its unique role in insects and its demonstrated sensitivity to dietary inhibitors, theamdgene product poses an attractive target for insect contro

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1993.tb00090.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe codon bias of twoAedesmosquito species was examined using a sign test. In general, there appeared to be some preference for C + G at the third base position, although this was not statistically significant. While amino acids such as phenylalanine and tyrosine clearly displayed biases, others such as valine and serine appeared to have little or no bias for any particular codon. Three homologous genes ofAedes aegyptiandDrosophila melanogasterwere compared using the chi‐square test and the codon bias of the two species compared.Drosophila melanogasterwas found to have a much stronger bias for C + G at the third base position compared toAedes. The implications and usefulness of the codon bias are discusse

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1993.tb00091.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractWe describe anin vitrosystem that will facilitate molecular analysis of the association between Lyme disease spirochetes and vector cells. We coculturedBorrelia burgdorfericontinuously with two tick cell lines, RAE25 (fromRhipicephalus appendiculatus) and IDE8 (fromIxodes scapularis). A clone isolated after twenty‐two passages with RAE25 cells had lost the largest (49 kb) plasmid, and probes containing information normally encoded on it, including genes for two surface proteins, hybridized to smaller plasmids. Spirochetes maintained with IDE 8 cells showed a new 43 kb plasmid that hybridized to a probe made from the 49 kb plasmid. After reisolation from hamsters, these spirochetes carried a large plasmid (100 kb) that hybridized with the 49 kb plasmid. These changes may illustrate a plasticity that enablesB. burgdorferito adapt to different environment

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1993.tb00092.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe usefulness of random amplified polymorphic DNA (RAPD) was examined as a potential tool to differentiate cryptic mosquito species. It proved to be a quick, effective means of finding genetic markers to separate two laboratory populations of morphologically indistinguishable African malaria vectors,Anopheles gambiaeandAn. arabiensis. In an initial screening of fiftyseven RAPD primers, 377 bands were produced, 295 of which differed between the two species. Based on criteria of interpretability, simplicity and reproducibility, thirteen primers were chosen for further screening using DNA from thirty individuals of each species. Seven primers produced diagnostic bands, five of which are described here. Some problematic characteristics of RAPD banding patterns are discussed and approaches to overcome these are suggested.

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1993.tb00093.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractWe have isolated and determined the nucleotide sequences for cDNA clones encoding glucose‐6‐phosphate dehydrogenase (G6PD) and 6‐phosphogluconate dehydrogenase (6PGD) from the medflyCeratitis capitata. The derived amino acid sequences for G6PD and 6PGD are presented and compared with G6PDs and 6PGDs from other species. The codon usage of the cDNA clones has little bias with the notable exceptions of arginine, glycine and leucine.The chromosomal location of the genes for 6PGD and G6PD were determined byin situhybridization to salivary gland polytene chromosomes. This localization orients a genetic map of enzymatic loci and illustrates a remarkable similarity in the intra chromosomal order of homologous genes betweenDrosophila melanogasterand m

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1993.tb00094.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractSeveral cDNA clones with similarity to α‐amylases have been characterized from a library made from adult female salivary gland RNA isolated from the vector mosquito,Aedes aegypti. The corresponding gene, designatedAmylase I (Amy I), is expressed specifically in the proximal‐lateral lobes of the adult female salivary gland, a pattern overlapping that of another gene,Mal I, involved in carbohydrate metabolism. The deduced amino acid sequence ofAmy Iindicates that this gene encodes a protein, approximate Mr= 81,500, that appears to be a novel member of the amylase gene family. The mosquito protein contains a putative signal peptide for secretion and several consensus sites for asparagine‐linked glycosylation. TheAmy Iprotein shows significant similarity to invertebrate and vertebrate amylases including the conservation of four reactive and substrate binding sites. However, the amino‐terminal region of theAmy‐Iprotein is unique to the mosquito. Similarity with theDrosophila melanogasterprotein is evident only after the first 260 amino acids in the mosquito sequence. The identification of this gene and its expression pattern adds to the observed relationship between spatial‐specific gene expression in the female salivary glands and the specific feeding mode of the ad

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1993.tb00095.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY