bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complete base sequence for the mitochondrial large subunit ribosomal RNA of the gypsy moth Lymantha dispar(L.)
Authors: Davis R. E. , Kelly T. J. , Masler E. P. , Thyagaraja B. S. , Rote C. A. , Imberski R. B. 
Published: December 2007

AbstractA 1355 bp sequence (accession number L32141) isolated from a gypsy moth (Lymantria dispar) cDNA library showed 68–74% sequence identity to mitochondrial large subunit ribosomal RNA (mt IrRNA) sequences of Locusta migratoria, Apis mellifera, Aedes albopictus, Anopheles gambiae and two Dros‐ophila species. A comparison of the primary sequences of the mt IrRNAs from the above insects in four orders and from Esherichia coli demonstrated regions of conservation which presumably correspond to regions of functional and/or structural homology. A secondary structure for the gypsy moth mt IrRNA sequence was derived based on the proposed secondary structures of Drosophila yakubaand Aedes albopictus mt IrRNAs (Gutell & Fox, Nucleic Acid Res 16 (Suppl.), r175‐r269, 1988). This sequence was found to hybridize to about 10–15% of the clones in several (eleven) gypsy moth cDNA libraries.
An analysis of secondary spread by putative clones of Sitobion avenae within a Hampshire wheat field using the multilocus (GATA)4 probe
Authors: Barro P. J. De , Sherratt T. N. , Carvalho G. R. , Nicol D. , Iyengar A. , Maclean N. 
Published: December 2007

AbstractGrain aphids (Sitobion avenae (F.)) were collected from forty‐four wheat ears in a Hampshire field at three times during the growing season. On each occasion, individual aphids were profiled using the multilocus (GATA)4 probe. During the full head emergence and full anthesis growth stages of wheat, each ear generally supported a genetically distinguishable aphid colony which consisted of genetically indistinguishable individuals (putative clones). This information strongly suggests that individual ears were colonized by single immigration events. By the late milky ripe stage, most ears supported two or more such clones. The total number of clones declined and the spatial separation of identical clones increased markedly over the duration of the study, which strongly suggests that secondary spread rather than increased immigration was responsible for the increased clonal diversity of ears. In addition, the profiles of individual S. avenae became more alike as the season progressed and samples became dominated by particular clones indicating either differential survival or reproduction among clones.
Sequence analysis of the D1 and D2 regions of 28S rDNA in the hornet (Vespa crabro) (Hymenoptera, Vespinae)
Authors: Schmitz J. , Moritz R. F. A. 
Published: December 2007

AbstractThe two variable domains D1 and D2 near the 5 end of the 28S ribosomal RNA gene (large subunit rRNA) have been sequenced for Vespa crabro. The sequence was aligned to corresponding rDNA regions of the wasp species Nasonia vitripennis, Melittobia digitata and the fruit fly Drosophila melanogaster. We analysed the nucleotide composition and sequence similarity for the different regions of the investigated sequences and present the inferred secondary structure of Vespa crabro.
Why do pupating insects lack an activity for the repair of uracil‐containing DNA? One explanation involves apoptosis
Authors: Deutsch W. A. 
Published: December 2007

AbstractAlthough uracil‐DNA glycosylases were at one time considered to be ubiquitous in nature, this DNA repair activity is notably absent in Drosophila melanogaster and other pupating insects. On the other hand, a nuclease has been identified in Drosophila that is specific for uracil‐containing DNA, but curiously the expression of this activity is restricted to late larval stages of development. Since the nuclease activity is only detected near the time of histolysation, we began questioning the possible role uracil might play in the events associated with the eventual DNA degradation that is involved in the metamorphotic process. The results of these studies have provided us with a molecular model for pupating insects that contains all the necessary elements to program cells for their ultimate death, and in so doing, shows why uracil‐DNA glycosylases would be incompatible with our proposed pathway for apoptosis.
Identification of a mariner element from the tsetse fly, Glossina palpalis palpalis
Authors: Blanchetot A. , Gooding R. H. 
Published: December 2007

AbstractIn the present study, the polymerase chain reaction was used initially to demonstrate the presence of mariner sequences in seven species/subspecies of tsetse flies. ONA hybridization experiments show mariner sequences to be dispersed within the tsetse genome and that there are large variations in copy numbers among the various taxa. A genomic library was used to isolate and characterize a full‐length mariner element from G. p. palpalis. The results indicate that this element is 1257 bp in length, flanked by two 32 bp inverted repeats differing at only one position, and belongs to the mellifera subfamily. The nucleotide sequence that is translated into a reading frame of 337 amino acids requires the introduction of two frame shifts and one stop codon to maximize sequence homology with a mariner element from Drosophila erecta. Based on this evidence, we conclude that the G. p. palpalis mariner element clearly represents a non‐functional transposable element and that the protein product is not an active transposase.
Mosquito sensitivity to a scorpion neurotoxin expressed using an infectious Sindbis virus vector
Authors: Higgs S. , Olson K. E. , Klimowski L. , Powers A. M. , Carlson J. O. , Possee R. D. , Beaty B. J. 
Published: December 2007

AbstractThe scorpion, Androctonus australis Hector, produces an insect‐specific toxin (AaHIT) encoded by the Scotox gene. To assess the toxicity of AaHIT for mosquitoes, we have taken a novel approach to express the Scotox gene in vivo. We have engineered a double subgenomic Sindbis (dsSIN) virus that contains the Scotox gene in the viral genome and intrathoracically inoculated the virus (TE/3'2J/Scotox) into mosquitoes (Aedes aegypti, Ae. triseriatus and Culex pipiens), houseflies (Musca domestica) and ticks (Dermacentor andersoni). Mosquitoes, which normally show no pathologic effects from Sindbis (SIN) virus infections, died 1–5 days after infection with TE/3'2J/Scotox virus. Neither flies nor ticks were killed. The mosquitocidal action of AaHIT in mosquitoes makes AaHIT a potential candidate for inclusion in molecular‐based methods of mosquito control. The expression of an arthropod gene in vivo demonstrates the utility of dsSIN expression vectors for future use to examine and potentially disrupt endogenous gene functions in mosquitoes.
Microsatellite DNA and isozyme variability in a West African population of Anopheles gambiae
Authors: Lanzaro G. C. , Zheng L. , Toure Y. T. , Traore S. F. , Kafatos F. C. , Vernick K. D. 
Published: December 2007

AbstractMicrosatellites are defined as tracts of tandemly repeated short DNA sequences. Polymorphisms in this class of DNA are currently being used to generate a genetic map of the mosquito Anopheles gambiae. In the present study we explore the potential of microsatellites as a tool for studying the genetic structure of natural populations of this malaria vector. Genetic polymorphism at twenty enzyme coding gene loci and eleven microsatellite DNA loci was surveyed in a population of An. gambiae from Mali, West Africa. All of the microsatellite loci surveyed were polymorphic, as compared to 40% of the isozyme loci. The mean heterozygosity for the isozyme loci was only 0.097 (±0.0035), but for the microsatellite loci it was 0.732 (±0.060). The pattern of variability was very different between isozymes and microsatellites. Typically, at an isozyme locus a single allele occurred at a frequency ≥0.75, whereas at microsatellite loci the most common allele had a frequency <0.50. We conclude that micro‐satellites provide a rich source of genetic polymorphisms for the study of the population genetics of An. gambiae and are in many ways superior to isozymes for this purpose. We discuss the potential for utilizing genetically mapped microsatellite loci to explore the effect of chromosomal inversions on the distribution of genetic polymorphisms in An. gambiae.
Organization and expression of the hemolin gene, a member of the immunoglobulin superfamily in an insect, Manduca sexta
Authors: Wang Y. , Willott E. , Kanost M. R. 
Published: December 2007

AbstractHemolin is a protein from the immunoglobulin (Ig) superfamily found so far in the haemolymph of two lepidopteran insect species, Hyalophora cecropia and Manduca sexta. Injection of bacteria into these insects induces the expression of hemolin. We have isolated the hemolin gene from M. sexta and determined its DNA sequence and transcription start site. The hemolin gene is 3127 bp long and contains six exons. The only correspondence between exons and the four Ig domains of hemolin is in domain 4, which is encoded by exon 6. Southern blot analysis indicates that there is one copy of the hemolin gene in the M. sexta genome. Analysis of the 5'‐flanking sequence of the hemolin gene resulted in identification of potential regulatory sequences. Hemolin mRNA accumulated in haemocytes, as well as fat body, in response to injection of larvae with bacteria. Hemolin was detected by immunocytochemistry in only one of the five morphological haemocyte types in M. sexta, the granular cells.
CYP6B3: a second furanocoumarin‐inducible cytochrome P450 expressed in Papilio polyxenes
Authors: Hung Chien‐Fu , Harrison T. L. , Berenbaum M. R. , Schuler M. A. 
Published: December 2007

AbstractCytochrome P450 monooxygenases in the larvae of Papilio polyxenes (black swallowtail) (Lepidoptera: Papilionidae) are capable of detoxifying linear and angular furanocoumarins found in their host plants. The CYP6B1 locus, which is transcriptionally induced in these larvae in response to xanthotoxin, encodes a P450 that principally metabolizes linear furanocoumarins such as xanthotoxin and bergapten. We have now cloned CYP6B3 cDNA derived from a second locus that is evolutionarily related to the CYP6B1 locus. Reverse transcription‐PCR Southern analyses have demonstrated that CYP6B3 transcripts are expressed in response to a wider range of linear and angular furanocoumarins but at lower abundance than CYP6B1 transcripts. Whereas CYP6B1 transcripts are expressed at a low detectable level in uninduced control larvae and at high levels in xanthotoxin‐induced larvae, CYP6B3 transcripts are nearly undetectable in control larvae and are highly induced by xanthotoxin and bergapten (linear furanocoumarins) as well as by angelicin and sphondin (angular furanocoumarins). The fact that these two CYP6B loci are differentially regulated by these four furanocoumarins indicates that P. polyxenes has adapted to the presence of the wide range of furanocoumarins in its host plants by diversifying its P450 isozyme structures and its furanocoumarin‐responsive regulatory cascades.
Toward a physical map of Aedes aegypti
Authors: Brown S. E. , Menninger J. , Difillipantonio M. , Beaty B. J. , Ward D. C. , Knudson D. L. 
Published: December 2007

AbstractLabelled recombinant cosmids were used as in situ hybridization probes to Aedes aegypti metaphase chromosomes. The cosmid probes yielded paired signals, one on each arm of sister chromatids, and they were ordered along the three chromosomes. In total, thirty‐seven different probes were mapped to the three chromosomes of Ae. aegypti (2n = 6): twenty‐eight to chromosome 1, six to chromosome 2, and six to chromosome 3. These results represent an initial stage in the generation of a physical map of the Ae. aegypti genome.
Amplification of complete insect mitochondrial genome in two easy pieces
Authors: Roehrdanz R. L. 
Published: December 2007

AbstractThe entire insect mitochondrial genome has been amplified in just two PCR reactions. ‘Universal’ insect primers and techniques to optimize amplification of long PCR products were used to obtain segments of the mitochondrial genomes of Helicoverpa zea and Heliothis virescens (Lepidoptera) ranging in size from 3.7 kb to 14 kb or about 25% to over 85% of a typical 16 kb mtDNA. Overlapping pairs of fragments contain the complete mtDNA sequence.
Replication and expression of a recombinant Sindbis virus in mosquitoes
Authors: Rayms‐Keller A. , Powers A. M. , Higgs S. , Olson K. E. , Kamrud K. I. , Carlson J. O. , Beaty B. J. 
Published: December 2007

AbstractA recombinant Sindbis virus, TE/3'2J/ANTI‐S, containing LaCrosse virus small segment cDNA in antisense orientation, was inoculated into Aedes triseriatus mosquitoes. Virus replication and LAC‐ANTI‐S RNA expression were analysed temporally and spatially. TE/3'2J/ANTI‐S virus titre peaked at 5.0 log10 TCID50 in heads 6–9 days post infection (p.i.) and decreased to 3.4 log10 TCID50 by 37 days p.i. Salivary glands contained 4.4 log10 TCID50 of 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 of Aedes and Culex mosquitoes.
Drosophila melanogaster mitochondrial DNA: completion of the nucleotide sequence and evolutionary comparisons
Authors: Lewis O. L. , Farr C. L. , Kaguni L. S. 
Published: December 2007

AbstractThe nucleotide sequence of the regions flanking the A + T region of Drosophila melanogaster mitochondrial 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 the D. melanogaster mitochondrial genome. The circular mtDNA of D. melanogaster varies 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 of D. yakuba. D. melanogaster mtDNA exhibits an extreme bias in base composition; it comprises 82.2% deoxyadenylate and thymidylate residues as compared to 78.6% in D. yakuba mtDNA. 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 genes.
Analysis of mosquito genome structure using graphical genotyping
Authors: Severson D. W. , Kassner V. A. 
Published: December 2007

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 mosquito Aedes aegypti. Two substrains selected for susceptibility and refractoriness, from a strain highly susceptible to the filarial worm parasite Brugia 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 influencing B. malayi susceptibility in A. aegypti. Graphical genotyping also provided perspectives on some features of genome structure in A. aegypti. It suggested the presence and location of a genetic lethal on chromosome 3 and possible inversion polymorphisms associated with each of the three A. aegypti chromosomes.
Comparison of preservation techniques for DNA extraction from hymenopterous insects
Authors: Dillon N. , Austin A. D. , Bartowsky E. 
Published: December 2007

AbstractTwo species of parasitic wasp, Venturia canescens and Leptomastix dactylopii, were killed and preserved by various methods used for Hymenoptera and in mass‐collecting devices. Total genomic DNA was subsequently extracted and a 524 bp fragment of the mitochondrial 16s ribosomal RNA gene amplified by PCR. Results for these techniques were compared with that for fresh material and museum specimens. Material from ‐80°C, 100% ethanol, air‐drying in a desiccator, and critical‐point dried from alcohol all yielded good results after short and long‐term storage, as did specimens from ethylene glycol but not formalin (the latter two being commonly used in pitfall and flight intercept traps). Specimens killed in ethyl acetate vapour and air‐dried yielded very degraded DNA which did not successfully PCR. The use of this killing agent is a likely reason for previous reports of inconsistent results obtained from museum specimens, and the now widespread use of critical‐point drying of wasps and other insects from alcohol is advocated as a potential source of DNA from rare taxa.
Aedes aegypti midgut early trypsin is post‐transcriptionally regulated by blood feeding
Authors: Noriega F. G. , Pennington J. E. , Barillas‐Mury C. , Wang X. Y. , Wells M. A. 
Published: December 2007

AbstractEarly trypsin is a female‐specific protease present in the Aedes aegypti midgut during the first hours after ingestion of a blood meal. Early trypsin gene expression was studied by Northern blot analysis. The early trypsin mRNA, absent in larvae, pupae and newly emerged females, reaches detectable levels at 24 h post‐emergence and attains a maximum level at an adult age of 4–7 days. After the first week there is a decrease in the steady‐state level of the transcript, but it remains readily detectable for up to a month after emergence. Despite the high levels of early trypsin mRNA present in the midgut of the unfed female, translation of the early trypsin mRNA occurs only after a blood or a protein meal. Early trypsin mRNA levels rapidly decrease during the first 24 h after feeding, but the steady‐state level of the transcript rises again at the end of the blood digestion cycle (60 h), as the mosquito prepares for a second blood meal.
Isolation and characterization of three serine protease genes in the mosquito Anopheles gambiae
Authors: Sldén‐Kiamos I. , Skavdis G. , Rubio J. , Papagiannakis G. , Louis C. 
Published: December 2007

AbstractThree genes encoding serine proteases (SpGA, Sp6T and Sp8T) were isolated from the malaria mosquito An, gambiae. The proteins that are conceptually translated from these genes contain all amino acids that have been described for this class of proteolytic enzymes, namely the His, Asp and Ser residues at the active site, and the six cysteine residues that form the three disulphide bridges in invertebrate serine proteases. The genes are expressed at low levels and the transcripts were detected only by PCR. Analysis of the nucleotide sequences of the three genes and their pattern of expression indicate that none of the genes code for digestive enzymes, but rather that the proteins have features of the tethered type of serine proteases.
Precise limitation of concerted evolution to ORFs in mosquito Hsp82 genes
Authors: Benedict M. Q. , Levine B. J. , Ke Z. X. , Cockburn A. F. , Seawright J. A. 
Published: December 2007

AbstractTwo Hsp82 genes were isolated from the malaria vector Anopheles albimanus in a single lambda phage clone. The two genes are in a head‐to‐head arrangement separated by approx. 0.9 kbp. Northern hybridizations and 5' RACE demonstrate that both genes are transcribed, have moderate levels of constitutive transcription, and are also heat‐inducible with maximum transcript accumulation occurring after 40°C heat shocks. Both genes have typical heat‐shock promoters and conserved intron boundaries in the untranslated leaders. The open reading frames are 99.6% identical differing in only nine silent nucleotide positions in the 2166 bp ORFs. However, precisely outside the ORFs, the flanking DNA of the two genes shows no evidence of common derivation. The high degree of identity between the two ORFs appears to be a result of gene conversion occurring by a process similar to that previously suspected in the A. albimanus Hsp70 genes and several D. melanogaster genes arranged as palindromes. This process probably involves a stem‐loop intermediate and is restricted in extent by flanking sequence divergence. These Hsp82 genes clearly demonstrate the extreme precision with which gene conversion can lead to proteincoding‐region homogeneity yet allow flanking DNA divergence.
Phylogeny of fourteen Culex mosquito species, including the Culex pipiens complex, inferred from the internal transcribed spacers of ribosomal DNA
Authors: Miller B. R. , Crabtree M. B. , Savage H. M. 
Published: December 2007

AbstractRibosomal DNA sequence divergence in the internal transcribed spacer regions (ITS‐1 and ITS‐2) was examined for fourteen species and four subgenera (sixty‐two clones) in the mosquito genus Culex (Diptera: Culicidae). A neighbour‐joining tree produced with Kimura 2‐parameter distances showed that each of the four subgenera was monophyletic at confidence probabilities of 70–99%. Culex (Lutzia) formed the sister group of Cx. (Culex). Two major clades, a Cx. pipiens complex‐Cx. torrentium assemblage and a Cx. restuans‐Cx, salinarius‐cx. erythrothorax assemblage, formed monophyletic groups. Cx. torrentium was closely related to members of the Cx, pipiens complex. Phylogenetic analysis of ITS‐1 and ITS‐2 sequences from members of the Cx. pipiens complex separated populations from northern latitudes and southern latitudes, but did not support the traditional taxa as monophyletic units.
Mosquito dopa decarboxylase cDNA characterization and blood‐meal‐induced ovarian expression
Authors: Ferdlg M. T. , Li J. , Severson D. W. , Christensen B. M. 
Published: December 2007

AbstractDopa decarboxylase (DDC) functions in insect cate‐cholamine biochemistry to produce materials essential for cross‐linking reactions that result in tanning and/or melanitation, including tanning of the mosquito egg chorion and encapsulation of parasites. We have cloned Ddc from the mosquito, Aedes aegypti, and studied its expression in response to blood‐feeding, which initiates events necessary for egg maturation in mosquitoes. The Ae. aegypti Ddc cDNA was isolated via heterologous screening using a clone from Drosophila melanogaster. A resulting 1.87 kilobase (kb) clone was sequenced to reveal an open reading frame of 1464 bp, as well as 5′‐ and 3′‐untranslated segments. The inferred amino acid sequence of this clone shares 81% identity with the published Drosophila Ddc cDNA, including complete identity with twenty‐four contiguous amino acids encompassing the pyridoxal‐5‐phosphate cofactor binding domain. Analysis of an F2 intercross population derived from a parental cross between two Ae. aegypti strains (Hamburg and Moyo‐In‐Dry) allowed us to map Ddc to a locus on linkage group 2. Expression studies demonstrated the presence of a 2.1 kb message, the majority of which occurs in the ovaries where Ddc‐specific mRNA is up‐regulated in response to Ingestion of a blood meal. The potential for egg‐tanning in anautogenous mosquitoes as a model for understanding specific genetic events in the regulation of catecholamine metabolism is addressed.