bluuebunny/crossref_metadata_2025_split huggingface dataset:
Baculovirus immediate early gene promoter based expression vectors for transient and stable transformation of insect cells
Authors: Vulsteke V. , Janssen I. , Broeck J. Vanden , Loot A. De , Huybrechts R. 
Published: December 2007

AbstractA recombinant plasmid vector was constructed in which the bacterial LacZ gene was placed under the control of a Bombyx mori baculovirus 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 cultured Drosophila melanogaster Schneider 2 cells. Southern blot analysis of the host cell's genomic DNA in combination with chromosomal in situ hybridization demonstrated that multiple copies of both plasmids were integrated in the host cell's genome.
Phylogeny of the Nasonia species complex (Hymenoptera: Pteromalidae) inferred from an internal transcribed spacer (ITS2) and 28S rDNA sequences
Authors: Campbell B. C. , Steffen‐Campbell J. D. , Werren J. H. 
Published: December 2007

AbstractThe phylogeny of the cryptic species complex of wasps in the genus Nasonia was inferred by analysis of nucleotide sequences of an rDNA internal transcribed spacer (ITS2) and the D2 region of 28S rDNA. Phylogenetic analysis showed that N. vitripennis descended from a theoretical common ancestor with that of a lineage that diverged into N. longicornis and N. giraulti. Differences in the ITS2 regions clearly distinguished two strains of N. giraulti. Another member of the Dibrachys Group, Trichomalopsis dubius, was placed outside of the Nasonia complex. 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 the Nasonia complex was congruent with the phylogeny of a cluster of Wolbachia bacteria which infect these insects. The possible role of these bacteria in driving speciation is discussed.
Isolation of non‐LTR retrotransposon reverse transcriptase‐like sequences from phlebotomine sandflies
Authors: Booth D. R. , Ready P. D. , Smith D. F. 
Published: December 2007

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 the Drosophila I, 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 of transposon.
Expression of polydnavirus genes from the parasitoid wasp Cotesia kariyai m two noctuid hosts
Authors: Hayakawa Y. , Yazaki K. , Yamanaka A. , Tanaka T. 
Published: December 2007

AbstractDNA purified from polydnavirus particles isolated from the parasitoid wasp Cotesia kariyai contained 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 that C. kariyai virus (CkV) gene expression occurs species‐specifically, although viral DNA can be detected in ail tested tissues of the habitual host armyworm.
An estimate of the number of serine protease genes expressed in sheep blowfly larvae (Lucilia cuprina)
Authors: Elvin C. M. , Vuocolo T. , Smith W. J. M. , Eisemann C. H. , Riddles P. W. 
Published: December 2007

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 of L. 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 in Droso‐phila melanogaster larval gut cells.
Molecular identification and phylogeny of parasitic wasp species (Hymenoptera: Trichogrammatidae) by mitochondrial DNA RFLP and RAPD markers
Authors: Vanlerberghe‐Masutti F. 
Published: December 2007

AbstractMitochondrial DNA (mtDNA) restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD) were tested for their ability to discriminate between seven species of minute parasitic wasps belonging to the genus Trichogramma. They proved to be reliable species‐diagnostic molecular markers. Pairwise comparisons of the mtDNA restriction maps revealed considerable differentiation among the seven species. Percentage of common restriction sites ranged from 30% to 83%. Phylogenetic analyses performed either on the mtDNA nucleotide distance matrix or on the matrix of the restriction site‐state generated a tree congruent with those based on allozymes and morphology.RAPD procedures also revealed species‐specific banding patterns and seem promising for a rapid and easy identification of Trichogramma species. Moreover, for some Trichogramma species, RAPD banding patterns might be informative of the phylogenetic related ness.
Bombyx gene promoter analysis in transplanted silk gland transformed by particle delivery system
Authors: Horard B. , Mangé A. , Pelissier B. , Couble P. 
Published: December 2007

AbstractIn most, if not all non‐Drosophila insect systems, the study of gene regulation relies on in vitro analyses. With the aim of providing an in vivo assay, we developed an original protocol using the Bombyx mori silk gland, by which the functioning of cloned gene promoters can be efficiently measured. This consists of introducing DNA‐coated tungsten particles into isolated silk glands by ballistic methods, according to a modified protocol in which the DNA is maintained in a hydrated state. The treated organ is then grafted into the haemolymph cavity of a host larva before analysis of transgene expression. In these reconstituted physiological conditions more than half of the cells express the transfected gene construct, and expression is both promoter‐dependent and cell type‐specific.
Identification by rDNA‐PCR of Anopheles bwambae, a geothermal spring species of the An. gambiae complex
Authors: Townson H. , Onapa A. W. 
Published: December 2007

AbstractThe identification of the malaria vector Anopheles bwambaeby rDNA‐PCR is described. PCR primers that amplify a region of the intergenic spacer of rDN A of An. gambiae s.s. produce two diagnostic PCR products of 690 bp and 390 bp with An. bwambae.
Functional expression of insecticide‐resistant GABA receptors from the mosquito Aedes aegypti
Authors: Shotkoski F. , Lee H.‐J. , Zhang H.‐G. , Jackson M. B. , Ffrench‐Constant R. H. 
Published: December 2007

AbstractWe are interested in cloning insecticide resistance genes from vector mosquitos for use as selectable markers in their genetic transformation. As a first step towards this goal, we here report the functional homo‐muitimeric expression of a γ‐aminobutyric acid (GABA) receptor subunit gene, Resistance to dieldrin (Rdl), from the yellow fever mosquito Aedes aegypti in baculovirus‐infected insect cell lines. Replacement of alanine296 with a serine leads to approximately 100‐fold insensitivity to picrotoxin as previously observed in Drosophila. This shows not only that the mosquito GABA receptor cDNA is functional but also that it can be simply mutated to resistance. Strategies for incorporation of this cDNA into a minigene for the genetic transformation of mosquitoes are discussed.
of the aphid Schlechtendalia chinensis
Authors: Lai C.‐Y. , Baumann P. , Moran N. A. 
Published: December 2007

AbstractTwo DNA fragments (3941 and 7152 base pairs) from the procaryotic endosymbiont (Buchnera) of the aphid Schlechtendalia chinensis were cloned and sequenced. The smaller fragment contained trpEG and the larger fragment contained trpDC(F)BA, genes coding for enzymes of the tryptophan biosynthetic pathway which convert chorismate to tryptophan. Both of these gene clusters were present as one copy on the endosymbiont chromosome and probably constitute two transcription units. The deduced amino acid sequences of the proteins was 51–61% identical to the corresponding proteins were previously studied in Buchnera of the aphid Schizaphis graminum. In this endosymbiont, trpEG is amplified and located on a plasmid, whereas, in the endosymbiont of S. chinensis, as in other eubacteria, trpEG occurs as a single copy on the bacterial chromosome. Implications of these findings for the evolution of this mutualistic association are discussed.
Analysis of mitochondrial DNA and development of PCR‐based diagnostic molecular markers for Mediterranean fruit fly (Ceratitis capitata) populations
Authors: Gasparich G. E. , Sheppard W. S. , Han H.‐Y. , McPheron B. A. , Steck G. J. 
Published: December 2007

AbstractA 2.99 kb mtDNA fragment containing two variable restriction endonuclease sites (EcoRV and Xbal) was subcloned and sequenced from the Mediterranean fruit fly (Ceratitis capitata). This fragment represents approximately one‐fifth of the entire mitochondrial sequence. The sequence was aligned with the comparable region from Drosophila yakuba and Anopheles gambiae, resulting in 81.8% and 76.7% identity at the nucleotide level, and 77% and 67.7% identity, respectively, at the amino acid level. The sequenced region includes the complete genes for NADH dehydrogenase 4, NADH dehydrogenase 4L, NADH dehydrogenase 6, and transfer RNAs for proline, threonine and histidine, and part of the genes for NADH dehydrogenase 5 and cytochrome b. Oligonucleotide primers were designed to asymmetrically bracket each of two variable restriction endonuclease sites to allow PCR amplification and subsequent restriction endonuclease analysis of individual fly samples.
The Simulium damnosum species complex: phylogenetic analysis and molecular identification based upon mitochondrially encoded gene sequences
Authors: Tang J. , Toè L. , Back C. , Zimmerman P. A. , Pruess K. , Unnasch T. R. 
Published: December 2007

AbstractThe DNA sequence of portions of the 16s rRNA and the NADH dehydrogenase subunit 4 (ND4) genes were used to determine phylogenetic relationships in the Simulium damnosum s.l. species complex. Results suggested that at least two major clades existed in the S. damnosum species complex, and that members of the S. damnosum s.l. species complex were not closely related to North American Simulium species. The sequence variability of the ND4 gene was exploited to develop a method to distinguish the sibling species of the S. damnosum s.l. species complex, based on directed heteroduplex analysis of PCR products derived from the ND4 gene. This method was capable of classifying the six sibling species into at least five groups.
Unusually high frequency of (CT)n and (GT)n microsatellite loci in a yellowjacket wasp, Vespula rufa (L.) (Hymenoptera: Vespidae)
Authors: Thorén P. A. , Paxton R. J. , Estoup A. 
Published: December 2007

AbstractA high number of (GT)n and (CT)n microsatellites were isolated from a partial genomic library of a primitively eusocial wasp, Vespula rufa. On average, (GT)n and (CT)n repeats occur in the genome approximately every 8 kb and 2.5 kb respectively. This is the highest density of dinucleotide microsatellites reported in the literature. Predominant categories of repeats are imperfect and compound repeats for (GT)n microsatellites and perfect repeats for (CT)n microsatellites. Comparisons with other Hymenoptera and with mammalian species showed significant differences in the frequency distribution of these categories of repeats. Many (CT)n and (GT)n repeats are surrounded by various types of microsatellites, suggesting an associative distribution of short tandem repeats. A high level of intracolonial polymorphism is demonstrated with one microsatellite locus, showing that multiple mating of the queen occurs in V. rufa.
Cloning and characterization of the white gene from Anopheles gambiae
Authors: Besansky N. J. , Bedell J. A. , Benedict M. Q. , Mukabayire O. , Hilfiker D. , Collins F. H. 
Published: December 2007

AbstractA 14 kb region of genomic DN A containing the X‐linked Anopheles gambiae eye colour gene, white, was cloned and sequenced. Genomic clones containing distinct white+ 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 from Drosophila white. Despite a common trend in Anopheles and Drosophila of weak codon bias given low levels of gene expression, codon usage by Anopheles gambiae white was 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 of A. gambiae with structural lesions in white, 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), no white lesions were detected. Significantly, another non‐allelic X‐linked mutation, causing an identical white‐eyed phenotype, has been correlated with a structural defect in the cloned white gene (Benedict et 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 likely white+.
PCR‐based detection of Wolbachia, cytoplasmic incompatibility microorganisms, infected in natural populations of Laodelphax striatellus (Homoptera: Delphacidae) in central Japan: has the distribution of Wolbachia spread recently?
Authors: Hoshizaki S. , Shimada T. 
Published: December 2007

AbstractCytoplasmic incompatibility is caused in various insects by intracellular infection with rickettsia‐like microorganisms of the genus Wolbachia. In Japan Laodelphax striatellus shows unidirectional cytoplasmic incompatibility between northeastern and southwestern populations. In this study, nine natural populations of L. striatellus collected from central Japan, including the geographic boundary between the two cytotype populations, were analysed for Wolbachia infection by PCR using primers specific to Wolbachia 16S 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 of L. striatellus, which formerly had been uninfected with Wolbachia, the infection property has changed to the infected. Based on our results, we conclude that the distribution of Wolbachia‐infected L. striatellus populations have spread northeasterly during the last 12 years.
A review of the use of ribosomal DNA (rDNA) to differentiate among cryptic Anopheles species
Authors: Collins F. H. , Paskewitz S. M. 
Published: December 2007

AbstractCryptic species complexes are groups of closely related species that are difficult or impossible to distinguish by morphological traits. These complexes are known from a wide variety of arthropods and are common among the well‐studied, medically‐important insects. For example, many of the anopheline vectors of malaria parasites are members of cryptic species complexes. Complexes typically include both vector and non‐vector species, and two or more member species are often found sympatrically. Until the late 1950s, only two such Anopheles complexes were known, the A. gambiae complex from Africa and the A. maculipennis complex from Europe. Today, dozens of Anopheles cryptic species complexes are recognized, and accumulating evidence suggests that most important malaria vectors are likely to be members of such complexes.A variety of methods have been developed for identifying the species of individual specimens from these complexes, although until recently only those based on species‐specific allozymes and polytene chromosome inversions were widely used. The limitations inherent in these methods have been circumvented with DNA‐based procedures, which are especially useful because both sexes and all developmental stages can be identified, and DNA can be recovered from samples stored by a wide variety of simple methods. Several DNA‐based identification techniques have been developed, including hybridization assays based on species‐specific repeat sequences, and diagnostic PCR fragments produced either by the use of random PCR primers or by amplifying DNA with primers based on known species‐specific sequences. In this review we discuss the relative merits of different methods of cryptic species identification, with emphasis on the use of ribosomal DNA as a target for species‐diagnostic PCR assays.
Primary structure of ribosomal proteins S3 and S7 from Manduca sexta
Authors: Jiang H. , Wang Y. , Kanost M. R. 
Published: December 2007

AbstractWe have isolated from Manduca sexta full‐length cDNAs encoding proteins homologous to human ribosomal proteins S3 and S7. These are the first ribosomal protein sequences obtained from non‐Dipteran insects. M, sexta ribosomal protein S3 has a molecular mass of 26,715 Da. Ribosomal protein S7 has a mass 21,870 Da. Both are basic proteins, with abundant Lys and Arg residues that may interact with ribosomal RNA in the ribosome. Southern blot hybridization suggests the presence of single genes for both ribosomal proteins in the M. sexta genome. Alignments with other S3 and S7 sequences available in the database indicate regions of the ribosomal proteins that have been the most highly conserved in evolution and may point to important functional regions in the proteins. Ribosomal protein S3 appears to be more highly conserved than ribosomal protein S7. This may be due to greater constraints on the structure of S3 because of its dual functions in translation as a ribosomal protein and in DNA repair in the nucleus.
Identification and characterization of a RAPD‐PCR marker for distinguishing Asian and North American gypsy moths
Authors: Garner K. J. , Slavicek J. M. 
Published: December 2007

AbstractThe recent introduction of the Asian gypsy moth (Lymantria dispar L.) into North America has necessitated the development of genetic markers to distinguish Asian moths from the established North American population, which originated in Europe. We used RAPD‐PCR to identify a DNA length polymorphism that is diagnostic for the two moth strains. The polymorphism maps to an autosomal locus with codo‐minant Mendelian inheritance. DNA sequence analyses of the Asian and North American forms enabled development of locus‐specific primers so that this marker, designated FS‐1, will be useful for strain identification under varying conditions in different laboratories.
The sequence and structure of the meadow grasshopper (Chorthippus parallelus) mitochondrial srRNA, ND2, COl, COll ATPase8 and 9 tRNA genes
Authors: Szymura J. M. , Lunt D. H. , Hewitt G. M. 
Published: December 2007

AbstractThe nucleotide sequence of the mitochondrial ND2, COI, COll, ATPase8, srRNA and nine tRNA genes have been sequenced from two individuals of the meadow grasshopper Chorthippus parallelus. Comparisons are made to other insects for which the same regions are completely sequenced. Percentage A + T is found to be relatively low in C. parallelus though consistent with that of the other Orthopteran, Locusta migratoria. The relative number of substitutions observed in the different protein‐coding genes was analysed between pairs of insect species sharing different levels of relatedness. A clear change in this rate was observed between the within‐genus and between‐genera comparisons. This change is interpreted in terms of the functional constraints acting on these four different genes. The patterns seem to result from an early saturation of COl and COll genes with synonymous substitutions, and a tolerance of ND2 and ATPase8 function to high levels of amino acid replacements. This analysis highlights a need for further sequence studies and comparisons between taxa of different levels of divergence in order to understand the patterns of mtDNA evolution on which many evolutionary investigations are based.
Precise excision of TTAA‐specific lepidopteran transposons piggyBac (IFP2) and tagalong (TFP3) from the baculovirus genome in cell lines from two species of Lepidoptera
Authors: Fraser M. J. , Clszczon T. , Elick T. , Bauser C. 
Published: December 2007

AbstractTransposon mutagenesis of baculoviruses provides an ideal experimental system for analysis of the movement of a unique family of mobile element identified from lepidopteran genomes. Members of this family of short‐inverted‐repeat elements are characterized by their extreme Specificity for TTAA target sites. This report describes the analysis of excision events for two representatives of this family, tagalong (formerly TFP3) and piggysac (formerly IFP2). These elements were tagged with a polyhedrin/lacZ reporter gene and inserted back into the virus genome either by homologous recombination or by transposition. Revertants were selected based on a white plaque phenotype. Both elements excise in a precise fashion from their positions in the baculovirus genome in either TN‐368 cells or IPLB‐SF21 AE cells. The precise excision of these elements in infected IPLB‐SF21 AE cells occurs in the absence of either tagalong or piggysac element encoded functions. The common characteristics of both insertion and excision for these elements provides further validation for their inclusion In a single family of unique transposons.