bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vitelline membrane biogenesis in Drosophila requires the activity of the α‐methyl dopa hypersensitive gene (1(2)amd) in both the germline and follicle cells
Authors: Konrad K. D. , Wang Degui , Marsh J. L. 
Published: December 2007

AbstractThe vitelline membrane of Drosophila eggs 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 the alpha methyl dopa hypersensitive (1(2)amdH or amd) gene in both egg chambers and follicle cells. We show that loss of amd activity 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 by in situ hybridization, that amd is expressed in both nurse cells and follicle cells. The amd gene 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, the amd gene product poses an attractive target for insect control.
Codon preference of Aedes aegypti and Aedes albopictus
Authors: Argentine J. A. , James A. A. 
Published: December 2007

AbstractThe codon bias of two Aedes mosquito 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 of Aedes aegypti and Drosophila melanogaster were compared using the chi‐square test and the codon bias of the two species compared. Drosophila melanogaster was found to have a much stronger bias for C + G at the third base position compared to Aedes. The implications and usefulness of the codon bias are discussed.
Random amplified polymorphic DNA (RAPD) markers readily distinguish cryptic mosquito species (Diptera: Culicidae: Anopheles)
Authors: Wilkerson R. C. , Parsons T. J. , Albright D. G. , Klein T. A. , Braun M. J. 
Published: December 2007

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 gambiae and An. 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.
Characterization of a cDNA clone encoding a glycine‐rich cuticular protein of Tenebrio molitor: developmental expression and effect of a juvenile hormone analogue
Authors: Bouhin H. , Charles J.‐P. , Quennedey B. , Courrent A. , Delachambre J. 
Published: December 2007

AbstractThe complete sequence of a cDNA clone, isolated from epidermal mRNA of Tenebrio molitor using a monoclonal antibody raised against an adult‐specific cuticular antigen only present in the hard cuticle, was obtained after primer extension at the 5′ end. From this cDNA sequence, the deduced protein encompasses 199 amino acids (including a signal peptide) with a total molecular weight of 20.7 kDa. The protein exhibits a bipartite structure: glycine‐rich region located in its NH2‐terminal part and a carboxy‐terminal domain sharing homologies with other cuticular proteins of Orthoptera, Diptera and Lepidoptera. In‐situ hybridization analysis shows that the corresponding mRNA is present only in epidermal cells secreting the adult fibrous cuticle destined to become heavily sclerotized. In supernumerary pupae obtained after the application of the juvenile hormone analogue (JHA) to newly ecdysed pupae, the mRNA was undetectable, indicating that JHA can prevent the switch to the adult programme. However, in pupal‐adult intermediates, obtained when JHA is applied later, the mRNA is detected.
Genetic variability in the social bee Lasioglossum marginatum and a cryptic undescribed sibling species, as detected by DNA fingerprinting and allozyme electrophoresis
Authors: Blanchetot A. , Packer L. 
Published: December 2007

AbstractDNA fingerprints (DNAfp) were obtained for three widely separated samples of bee related to Lasioglossum marginatum using the M13 sequence as a probe. Bee samples were obtained from France (three localities separated by at most 20 km), Greece and India. All European populations exhibited almost identical profiles with similarity indices (S) of over 98% within a French sample, 94% among Greek bees and 90% between Greek and French bees. The DNAfp profiles of Indian bees showed more polymorphism (intrapopulation S= 77%) and were quite dissimilar to the European samples (S= 55% and 56% to French and Greek samples, respectively). The similarity between populations separated by over 2000 km is higher than among unrelated individuals within a population in two other bee species and the tsetse fly. Data from allozyme electrophoresis shows parallel variation to that obtained with DNAfp and the genetic differences between Indian and European samples are strikingly large (Indian and European populations shared no alleles at 14 out of 47 loci surveyed) such that no more than one species must be involved. Nonetheless, the samples are indistinguishable morphologically. We argue that chronically low effective population size in these species results in low levels of genetic variability and that this, combined with a genetic bottleneck during the speciation event and colonization of Europe, may have resulted in both the extremely low levels of DNAfp variation in European bees and the large number of fixed allelic differences between European and Indian samples. We conclude that DNAfp may be particularly useful as a tool to study population level phenomena in organisms with only moderate levels of DNAfp variability and that the Hymenoptera may be particularly appropriate model systems for such research.
Native and baculovirus‐expressed forms of the immunoprotective protein BM86 from Boophilus microplus are anchored to the cell membrane by a glycosylphosphatidyl inositol linkage
Authors: Richardson M. A. , Smith D. R. J. , Kemp D. H. , Tellam R. L. 
Published: December 2007

AbstractA glycoprotein (BM86) from the gut cells of the cattle tick Boophilus microplus, when used to vaccinate cattle, has been shown to protect cattle from tick infestation. A recombinant BM86 protein is the principal component of a novel tick vaccine currently under development. The nature of the anchorage of BM86 to tick gut epithelial cells has been investigated using BM86 from B. microplus and recombinant BM86 proteins expressed in insect cells using the baculovirus expression system. BM86 from B. microplus and a full length recombinant BM86 are shown to be anchored to the extracellular surface of tick gut epithelial cells and baculovirus‐infected insect cells, respectively by a glycosyl‐phosphatidyl inositol membrane anchor. A recombinant BM86 truncated by the removal of a hydrophobic region coding for thirty amino acids at the carboxy‐terminal end was secreted from baculovirus‐infected Sf9 cells. This secreted form of recombinant BM86 showed strong protective activity against ticks in cattle vaccinated with this protein.
Mediterranean fruit fly, Ceratitis capitata (Wiedemann), mitochondrial DNA: genes and secondary structures for six t‐RNAs
Authors: Frohlich D. R. , Robinson A. S. , Wells M. A. 
Published: December 2007

AbstractThe polymerase chain reaction was used to amplify six mitochondrial t‐RNAs for Ala, Arg, Asn, Ser, Glu and Phe between genes for mitochondrial NADH dehydrogenases 3 and 5. With respect to Drosophila yakuba the gene order and direction of transcription is completely conserved. Analysis of secondary structure shows complete conservation of the anticodon loops but a number of differences in the dihydrouridine and TψC loops with respect to Drosophila. However, differences are such that tertiary interactions that stabilize stacking are preserved. The use of the reported sequence in combination with PCR to explore population variability is discussed.
A glutathione S‐transferase gene of the vector mosquito, Anopheles gambiae
Authors: Reiss R. A. , James A. A. 
Published: December 2007

AbstractA cDNA (D7‐8B) 1456 nucleotides in length was isolated from an adult, female‐specific Anopheles gambiae library and identified as a member of the glutathione S‐transferase (GST) gene family by virtue of the inferred amino acid sequence. The gene, AgGST2‐1, specifies a protein that is 57% identical to the Drosophila melanogaster gene, DmGST‐2. The conceptual translation product also shows similarity to the jt family of vertebrate GSTs. Northern analysis reveals multiple and abundant transcription products in larval, pupal and adult RNA preparations. Southern analyses of genomic DNA and hybridizations in situ to polytene chromosomes both suggest that there are multiple members of the GST gene family in Anopheles gambiae.
Characterization of differences between whiteflies using RAPD‐PCR
Authors: Gawel N. J. , Bartlett A. C. 
Published: December 2007

AbstractThe B biotype of the sweetpotato whitefly, Bemisia tabaci (Gennadius) has caused over $200 million in crop damage in the US during 1992. The taxonomic classification of the A and B biotypes of B. tabaci is unclear. We used RAPD‐PCR to demonstrate DNA differences between the A and B biotypes of this insect. Ail twenty of the RAPD primers tested distinguished readily between the biotypes. DNA extracted from individual eggs and nymphs showed identical differences. RAPD‐based genetic similarity statistics indicate that these two biotypes of B. tabaci were no more similar to each other than to two other whitefly species: bayberry whitefly (Parabemisia myri‐cae) or banded winged whitefly (Trialeurodes abutilo‐nea). These results indicate that RAPD‐PCR may be useful in distinguishing closely related organisms, but may not be useful in determining higher classification of insects. Before the taxonomic status of B. tabaci biotypes A and B can be determined, results from other genetic, morphological and physiological examinations will have to be compared.
In Drosophila Kc cells 20‐OHE induction of the 60C β3 tubulin gene expression is a primary transcriptional event
Authors: Chapel S. , Sobrier M. L. , Montpied P. , Micard D. , Bruhat A. , Couderc J. L. , Dastugue B. 
Published: December 2007

AbstractIn Drosophila Kc cells, the 60C 03 tubulin transcription unit, whose expression is induced by 20‐hydroxy‐ecdysone (20‐OHE), has the same structure as in Drosophila. This gene is characterized by an unusual 5 intron of regulating importance, by an alternatively spliced second intron and by a long 3 transcribed but untranslated region. This gene codes for two β3 tubulin isoforms with one amino acid difference. We have established that β3 tubulin gene expression is transcriptionally regulated by the steroid hormone in a time and hormonal concentration‐dependent fashion, without requirement of protein synthesis. This implies that this transcriptional induction is a primary event and that this gene is probably a direct target for the 20‐OHE receptor.
Variation in the ribosomal RNA cistron among host‐adapted races of an aphid (Schizaphis graminum)
Authors: Black W. C. 
Published: December 2007

AbstractThe greenbug, Schizaphis graminum, is an aphid species that consists of races that can be separated based on morphology, life histories, cytogenetics, mitochondrial DNA RFLPs and virulence to plant culti‐vars. Variation in the greenbug rDNA multigene family was studied to determine the extent to which rDNA cistrons have diverged among and within races. A restriction map of the rDNA cistron was constructed. Probing DNA from different races with subclones from rDNA coding regions and internal spacers identified little variation. However, probing with subclones of the intergenic spacer (IGS) identified continuous length variation within and among races. Race specific patterns were identified. Within a race, almost continuous variation in total IGS length was detected and asexual lineages possessed distinct patterns useful in genetic fingerprinting studies.
The Hsp70 heat‐shock gene family of the mosquito Anopheles albimanus
Authors: Benedict M. Q. , Cockburn A. F. , Seawright J. A. 
Published: December 2007

AbstractFour Hsp70 genes of the malaria vector Anopheles albimanus were isolated from a genomic DNA library as two non‐overlapping clones each containing a pair of divergently transcribed genes having 75% DNA sequence similarity to the protein‐coding regions of the Drosophila metanogaster Hsp70genes. The clones were assigned to two loci on chromosome 2R by in situ hybridization. These clones hybridize strongly to heat‐shock but only weakly to non‐shocked mosquito RNA. The Hsp70 gene family of A. albimanus is undergoing concerted evolution probably by gene conversion. The general arrangement of the genes suggests that divergently transcribed pairs of genes at two loci is an ancient Dipteran arrangement predating the Nematocera/Cyclorrapha divergence.
The mitochondrial genome of the mosquito Anopheles gambiae: DNA sequence, genome organization, and comparisons with mitochondrial sequences of other insects
Authors: Beard C. B. , Hamm D. Mills , Collins F. H. 
Published: December 2007

AbstractThe entire 15,363 bp mitochondrial genome was cloned and sequenced from the mosquito Anopheles gambiae. With respect to the protein‐coding genes, rRN A genes and the control region, the gene order was identical to that reported for other insects. There were significant differences, however, in the position and orientation of specific tRNA loci. The overall nucleotide composition was heavily biased towards adenine and thymine, which accounted for 77.6% of all nucleotides. Comparisons were made with the mitochondrial genomes of other insects on the basis genome size and organization, DNA and putative amino acid sequence data, nucleotide substitutions, codon usage and bias, and patterns of AT enrichment.
Five major subfamilies of mariner transposable elements in insects, including the Mediterranean fruit fly, and related arthropods
Authors: Robertson H. M. , MacLeod E. G. 
Published: December 2007

AbstractWe have used a PCR assay to screen 404 insects and related arthropods for mariner elements using primers corresponding to amino acids conserved between the mariner elements of Drosophila mauritiana and a moth, Hyalophora cecropia. Potential mariner elements were detected in sixty‐three species, representing ten insect orders as well as a centipede and a mite. Phylogenetic analysis of the PCR fragment sequences from thirty species identifies five major subfamilies of mariners. Many species have representatives of multiple subfamilies in their genomes, and the Medfly is an extreme example with representatives of four subfamilies. Two instances of recent horizontal transfer of mariner elements include at least three species each. The widespread but sporadic distribution of mariner elements suggests they are excellent candidates for development as transformation vectors for non‐drosophilids.
Nuclear DNA sequence divergence between parapatric subspecies of the grasshopper Chorthippus parallelus
Authors: Cooper S. J. B. , Hewitt G. M. 
Published: December 2007

AbstractSequence data from a non‐coding nuclear DNA segment (CpnI‐1) was used to investigate the divergence between Spanish and French subspecies of the grasshopper Chorthippuspara/us which form a hybrid zone in the Pyrenees. The spatial distribution of eighteen Cpnl‐1 sequence haplotypes from eighteen French and fifteen Spanish populations and phylogenetic analyses using both distance and parsimony procedures provide strong evidence that the Py renean hybrid zone was formed by postglacial secondary contact and that the French subspecies arose by range expansion from a Balkan or Italian refugium. In addition, the data provide evidence for subdivision between grasshoppers from Northern Spain and those from Central and Pyrenean Spanish populations.
ALS and SAD‐like nicotinic acetylcholine receptor subunit genes are widely distributed in insects
Authors: Sgard F. , Obosi L A. , King L. A. , Windass J. D. 
Published: December 2007

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 the Drosophila melanogaster ALS 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 species.
Genes expressed during the differentiation of the pupal wings are also transiently expressed during the larval moult in Bombyx mori
Authors: Chareyre P. , Guillet C. , Besson M. T. , Fourche J. , Bosquet G. 
Published: December 2007

AbstractBy a differential screening of cDNA libraries made with RNAs present in differentiating imaginal wing discs of Bombyx 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 in Bombyx, cells of the wings reach the pupal stage of differentiation by steps corresponding to the phases during which high levels of ecdysteroids are present.
A family of U1 pseudogenes in Bombyx mori may be derived from an ancestral pseudogene
Authors: Vega L. R. , Amengual J. , Herrera R. J. 
Published: December 2007

AbstractSeven EMBL‐4 lambda clones containing U1 small nuclear RNA sequences were isolated from a Bombyx mori genomic 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 in B. 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 to reverse transcription.
A prokaryotic dnaA sequence in Drosophila melanogasten Wolbachia infection and cytoplasmic incompatibility among laboratory strains
Authors: Bourtzis K. , Nirgianaki A. , Onyango P. , Savakis C. 
Published: December 2007

AbstractUsing oligonucleotide primers derived from the aligned polypeptide sequences of several prokaryotic dnaA genes, we amplified from Drosophila melano‐gaster DNA a 557 bp fragment containing a single open reading frame. The predicted peptide sequence shows a significant similarity to previously characterized protein sequences that are encoded by the dnaA genes of several prokaryotes. The dnaA sequences are also detectable by PCR in DNA from Drosophila simulans and Nasonia vitripennis flies which are infected by a symbiotic bacterium assigned to the type species Wolbachia pipientis. A tetracycline treatment that eradicates bacterial parasites from insects, abolishes the dnaA sequences from Drosophila and Nasonia DNA. In addition, dnaA‐positive Drosophila melano‐gaster contain numerous rod‐shaped bacteria in embryos, which are abolished in subsequent generations after treatment with tetracycline. Combined with phylogenetic analysis of DnaA and 16S rRNA sequences, these results show that the dnaA cognate comes from Wolbachia. A survey of Drosophila stocks using PCR amplification of dnaA and 16S rRNA sequences showed that Wolbachia is widely spread among D. melanogaster laboratory strains but absent from several established strains of the Mediterranean fruit fly Ceratitis capitata. Evidence is also presented that presence of the bacterium can cause partial cytoplasmic incompatibility between infected and non‐infected D, melanogaster strains.
Analysis of the Anopheles gambiae genome using RAPD markers
Authors: Favia G. , Dimopouios G. , Louis C. 
Published: December 2007

AbstractRAPD analysis technique is used as a rapid and reliable tool for genome analysis in the malaria vector Anopheles gambiae. Using more than eighty different commercially available primers we identified more than sixty different DNA segments that were differentially amplified in different strains of An. gambiae s.s. and An. arabiensis. An estimate of the cytogenetic position of these markers is provided by their hybridization to divisional dot‐blot filters. Potentially useful RAPD markers can be cytogenetically mapped with more precision by in situ hybridization and, as they segregate as dominant markers in a Mendelian fashion, they can also be genetically mapped relative to other genes or rearrangements. Finally, we identified markers for their potential use in the identification of different mosquito strains.
Molecular analysis of ribosomal DNA from the aphid Amphorophora idaei and an associated fungal organism
Authors: Fenton B. , Birch A. N. E. , Malloch G. , Woodford J. A. T. , Gonzalez C. 
Published: December 2007

AbstractThe ribosomal DNA cistron from the large raspberry aphid, Amphorophora idaei (Hemiptera: Aphididae), has been mapped by restriction analysis. The results showed that the map of A. idaeiwas similar to those of the previously characterized aphids Schizaphis grami‐num and Acyrthosiphon pisum. An extra Bglti site was found in some of the ribosomal DNA intergenic spacer repeats in A. idaei. Using in‐situ hybridization to aphid mitotic chromosomes it was demonstrated that probes derived from this region mapped to the pair of X chromosomes and it was therefore aphid in origin. Polymerase chain reaction using conserved rDNA primers also detected significant amounts of a fungal genome in the DNA samples. Microscopic investigation showed that the external surface of A. idaei harboured fungal propagules, hyphae and yeast‐like organisms.
cDNA structure and characterization of a kinesin‐like protein from the silkworm Bombyx mori
Authors: Okano K. , Takada N. , Kobayashi M. , Maekawa H. 
Published: December 2007

AbstractWe have isolated a 1224 bp cDNA clone from a Bombyx mori embryonic cDNA library which contains sequences homologous to the kinesin‐like protein gene, ncd, which is required for distribution of chromosomes at meiosis in Drosophila melanogaster females. This clone includes both a microtubule motor and the ATP‐binding domains found in kinesin‐like proteins. The motor domain is classified in the group of the BimC and cut7, which have a role in spindle formation during mitosis of Aspergillus nidulans and Schizosaccharomyces pombe, respectively. However, the location of the domain at the carboxy terminus is not common in this family, except for ncd and KAR3.