摘要:

AbstractTwo quantitative trait loci (QTL) affecting susceptibility of the mosquitoAedes aegyptito the filarial worm parasiteBrugia malayiwere identified using restriction fragment length polymorphism (RFLP) markers. The first locus, fsb[1,LF178], resides within a 10 cM interval on chromosome 1 and exhibits a recessive effect with respect to susceptibility. The second locus, fsb[2,LF98], resides within a 9 cM interval on chromosome 2 and exhibits an additive effect on susceptibility. Significant epistasis was detected between these loci, although the effect of fsb[2,LF98] was dependent on the genetic background of the mosquito strains. Suggestions for a standard QTL nomenclature are included.

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1994.tb00153.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractPhylogenetic analysis of 18S rDNA nucleotide sequences of hemipteran exemplars shows Sternorrhyncha (psyllids, whiteflies, aphids and scales) is monophyletic and forms a sister group to all other hemipterans (Euhemiptera). Whiteflies form a sister group to aphids and scales. Psyllids form a sister group to all other Sternorrhyncha. Primary structures of 18S rDNAs of all sternorrhynchans are exceptionally long (˜2200 to ˜2500 bp) due to internal expansions. These expansions are a synapomorphy of Sternorrhyncha; other hemipterans possess shorter 18S rDNAs (˜1900 to ˜1925 bp). The 18S rDNA of whiteflies is the longest recorded to date and has a base substitution rate of ˜3 times greater than Euhemiptera taxa examined. The relevance of these findings to the fossil record, feeding strategies, reproductive biologies, and geoclimatic distribution is discu

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1994.tb00154.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractReverse transcriptase‐like sequences (RTs) with amino acid motifs characteristic of non‐LTR retro‐transposons have been isolated from several medically important phlebotomine sandfly species. These sequences were amplified using the polymerase chain reaction (PCR) with primers based on conserved amino acid motifs present in previously described insect RTs. A further set of RTs were amplified using primers based on the conserved regions identified in phlebotomine RTs. The average similarity of the phlebotomine RTs to theDrosophilaI, F and R1Dm elements was 28–29% between the closest primers used. Phlebotomine RTs were 31–62% similar to each other, the most dissimilar sequences coming from the same species. Several amino acid residues were invariant in the ten phlebotomine RTs, including motif Q(F/Y)GF, conserved in other non‐LTR retrotransposons, but not in retrovirus or LTR retrotransposon RTs. The remarkable conservation of this distinctive domain of non‐LTR retrotransposon RTs suggests it has a vital and possibly unique role in the mode of reverse transcription of this class

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1994.tb00155.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractDNA purified from polydnavirus particles isolated from the parasitoid waspCotesia kariyaicontained double‐stranded closed circular molecules which were polydisperse in molecular weight. 2 days after viral injection into the host armyworm larvae viral DNA was detected in all tested larval tissues, including haemocytes, fat body, nerve cord and brain. Viral transcripts were also observed in all the tissues of virus‐injected larvae. The most specific tissue was haemocytes because more viral DNA and RNA was detected than in the other tissues. Viral transcripts were not detected in haemocytes of virus‐injected larvae of common cutworm. The present data suggest thatC. kariyaivirus (CkV) gene expression occurs species‐specifically, although viral DNA can be detected in ail tested tissues of the habitual host a

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1994.tb00156.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractA large and diverse family of serine protease genes was identified in first‐instar larval cDNA of the sheep blowfly(Lucilia cuprina).This complex repertoire of genes was identified via a PCR approach using highly degenerate primers based on structurally conserved regions which surround the active site His and Ser residues found in all serine proteases. PCR products from entire first‐instar larval cDNA, or from third‐instar larval salivary glands or cardia, generated using a microscale RT‐PCR method, were cloned into a plas‐mid vector. Comparison of the restriction fragment patterns of PCR products generated from the three different sources suggests a highly diverse tissue‐specific pattern of serine protease expression in this organism. Detailed analysis of the restriction fragment patterns of sixty‐nine randomly selected clones from entire first‐instar larvae revealed forty‐nine different classes of PCR product. Maximum likelihood analysis of these data indicate that between 125 and 220 different serine protease genes are expressed in first‐instar larvae ofL. cuprina.DNA sequence analysis of ten randomly‐selected clones, derived from the three tissue sources, indicated that all ten encoded serine protease gene fragments. A frequently occurring PCR product, generated from both first‐instar total cDNA and third‐instar cardia cDNA, showed 73% amino acid identity to a digestive protease expressed inDroso‐phila m

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1994.tb00157.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractSeven EMBL‐4 lambda clones containing U1 small nuclear RNA sequences were isolated from aBombyx morigenomic library. Six of the seven represent unique sequences. The six unique U1 sequences exhibit fixed point 3‐end truncation. Five out of the six clones share immediate 3‐end flanking sequences while two share 5‐end flanking sequences. Fixed point 3‐end truncation and a hierarchy of shared to unique diagnostic mutations may suggest a family of U1 pseudogenes generated from a reverse‐transcribed class II pseudogene inB. mori.An ancestral ‘master’ U1 pseudogene capable of RNA‐ and/or DNA‐mediated transposition may give rise to generations of U1 pseudogenes that include the original pseudogene's flanking sequences. Identical 3‐end truncation in some of these U1 sequences can be explained by RNA self‐priming due to intra‐strand binding prior

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1994.tb00158.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe fall armyworm moth,Spodoptera frugiperda, is a migratory species composed of sympatric corn and rice strains. The strains are indistinguishable in morphology but can be recognized by molecuiar markers. We have cloned and characterized seven monomer units of a repeated DNA sequence, called FR, which is found exclusively in the genome of the rice strain individuals. The 189 bp FR units are tandemly organized in arrays longer than 30 kb. Female individuals possess over 100‐fold more of the FR sequence than male individuals. The repeated sequence is not methylated at GGCC sites, and shows high sequence similarity among repeat unit

ISSN:0962-1075    

DOI:10.1111/j.1365-2583.1994.tb00159.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY