bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic exchange in 2La inversion heterokaryotypes of Anopheles gambiae
Authors: Stump A. D. , Pombi M. , Goeddel L. , Ribeiro J. M. C. , Wilder J. A. , Torre A. D. , Besansky N. J. 
Published: September 2010

AbstractIn the malaria vector Anopheles gambiae, alternative arrangements of chromosome 2 (2La and 2L+a) vary in relative frequency along clines of aridity, suggesting the action of natural selection on targets within the inversion. Our long term goal of detecting such targets depends in part on the level of genetic exchange between arrangements. Accordingly, we estimated recombination rates on 2L from the backcross progeny of 2La/+a heterokaryotypes and as a control, from 2L+a homokaryotypes. In homokaryotypes, the recombination rate was uniform at ~2.0 centimorgans per megabase (cM/Mb). In heterokaryotypes, recombination within the rearranged region was reduced to < 0.5 cM/Mb, with slightly higher but nevertheless reduced levels (< 1.0 cM/Mb) flanking the rearrangement. Yet, gene exchange was recorded between nearly all markers, including those very near the distal inversion breakpoint. These results suggest that reduced recombination is a necessary but not sufficient mechanism for genetic isolation between alternative arrangements, and that the targets of natural selection can be identified against the different chromosomal backgrounds.
Molecular cloning of a GABA receptor subunit from Laodelphax striatella (Fallén) and patch clamp analysis of the homo‐oligomeric receptors expressed in a Drosophila cell line
Authors: Narusuye K. , Nakao T. , Abe R. , Nagatomi Y. , Hirase K. , Ozoe Y. 
Published: September 2010

AbstractA cDNA encoding a γ‐aminobutyric acid (GABA) receptor subunit was cloned from the small brown planthopper Laodelphax striatella. The L. striatella GABA receptor subunit was found to have high amino acid sequence similarity to the bd‐type splice variant of the Drosophila GABA receptor Rdl subunit and several other GABA receptor subunits, with identities of over 70%. The cDNA was inserted into the expression vector pAc5.1‐lac‐Hygro. Clonal cell lines stably expressing homo‐oligomeric L. striatella GABA receptors were generated by transfecting the vector into D.mel‐2 cells. Expression of functional GABA receptors in the cell lines was demonstrated by whole‐cell patch clamp recordings. GABA induced inward currents with an EC50 value of 29 µM and a Hill coefficient of 1.7. The GABA‐evoked responses reversed close to the Nernst equilibrium potential for chloride ions. The amplitudes of agonist‐induced currents were found to be in the order muscimol (100 µM) ≥ GABA (100 µM) > isoguvacine (100 µM) > cis‐4‐aminocrotonic acid (CACA) (100 µM) > 5‐(4‐piperidyl)‐3‐isoxazolol (4‐PIOL) (1 mM). Antagonists such as fipronil (100 nM), 4′‐ethynyl‐4‐n‐propylbicycloorthobenzoate (EBOB) (100 nM), dieldrin (100 nM) and SR95531 (gabazine) (1 µM) suppressed GABA‐induced currents. The functional expression of a GABA receptor from an agricultural pest presents a unique opportunity to discover new molecules active at this important target site.
Relish regulates expression of antimicrobial peptide genes in the honeybee, Apis mellifera, shown by RNA interference
Authors: Schlüns H. , Crozier R. H. 
Published: September 2010

AbstractRelationships of immune genes in adult honeybees (Apis mellifera) were investigated using RNA interference (RNAi). Quantitative RT‐PCR was applied to estimate gene expression and the extent of gene silencing. Relish is a transcription factor and forms an important part of the IMD signalling pathway. The expression of the immune gene Relish was significantly reduced by RNAi (ca. 70%). The proposed regulation of antimicrobial peptide genes by Relish could be established for abaecin and hymenoptaecin. These two genes showed a reduction in gene expression to the same extent as Relish. However, the antimicrobial peptide gene defensin‐1 was not affected which suggests defensin‐1 is regulated by a different signalling pathway.
X and Y chromosome inheritance and mixtures of rDNA intergenic spacer regions in Anopheles gambiae
Authors: Wilkins E. E. , Howell P. I. , Benedict M. Q. 
Published: September 2010

AbstractWe observed Anopheles gambiae sensu stricto stocks that contained both Mopti (M) and Savanna (S) rDNA intergenic spacers (IGS). ASEMBO1 male IGS sequences consistently had a mixture. A diagnostic M and S Hha I restriction enzyme site in these fragments was concordant with two SNPs associated with M and S. Standard M and S stocks demonstrated X‐chromosome‐only inheritance of the rDNA form, but the ASEMBO1 males showed X and Y chromosome linkage of mixed rDNA. The metaphase Y chromosomes of ASEMBO1 contained a significantly larger amount of DNA relative to the X than a standard S stock. Analysis of wild A. gambiae males from the putative location of origin of the ASEMBO1 stock did not detect the same pattern of polymorphism observed in the laboratory stock but did detect heterogeneous arrays including some missing a diagnostic Hha I restriction site. These results demonstrate that M and S IGS types can occur within the rDNA arrays of a chromatid in laboratory A. gambiae stocks, and some A. gambiae s.s. have rDNA on the Y chromosome.
The nicotinic acetylcholine receptor subunitsMdα5andMdβ3on autosome 1 ofMusca domesticaare not involved in spinosad resistance
Authors: Gao J.‐R. , Deacutis J. M. , Scott J. G. 
Published: September 2010

AbstractSpinosad is a relatively new insecticide that exerts its toxic action via nicotinic acetylcholine receptors (nAChRs). Spinosad resistance in house flies appears to be due to an altered target site. To evaluate the molecular basis of spinosad resistance, two nAChR subunit genes,Mdα5andMdβ3were cloned and characterized from an insecticide‐susceptible (aabys) and spinosad resistant (rspin) strain of the house fly,Musca domestica. TheMdα5andMdβ3cDNAs encode proteins of 781 and 432 amino acid residues, respectively. Phylogenetic analysis with insect nAChR subunits suggested that Mdα5 and Mdβ3 are most closely related to Dα5 and Dβ3 ofDrosophila melanogaster, respectively.Mdβ3is intronless, which is unique among all previously described nAChR genes. A‐to‐I RNA editing was found at 13 sites inMdα5, eleven of which resulted in amino acid substitutions. No evidence for A‐to‐I RNA editing was found inMdβ3.Mdα5expression, quantified by real time PCR, was 340‐ and 23‐fold higher in the head and thorax than in the abdomen.Mdβ3expression was more uniform, being only 2.4‐fold higher in the head and 1.4‐fold lower in the thorax, compared to the abdomen. There was no difference in the expression ofMdα5andMdβ3between the aabys and rspin strains. AlthoughMdα5andMdβ3both map to the same chromosome as spinosad resistance, there were no unique features of either gene in rspin, relative to the aabys strain. This suggests neitherMdα5norMdβ3is responsible for spinosad resistance in house flies.
Nuclear mitochondrial‐like sequences in ants: evidence from Atta cephalotes (Formicidae: Attini)
Authors: Martins J. , Solomon S. E. , Mikheyev A. S. , Mueller U. G. , Ortiz A. , Bacci M. 
Published: September 2010

AbstractNuclear mitochondrial‐like sequences (numts) are copies of mitochondrial DNA that have migrated to the genomic DNA. We present the first characterization of numts in ants, these numts being homologues to a mitochondrial DNA fragment containing loci the 3′ portion of the cytochrome oxidase I gene, an intergenic spacer, the tRNA leucine gene and the 5′ portion of the cytochrome oxidase II gene. All 67 specimens of Atta cephalotes (Hymenoptera: Formicidae: Attini) investigated had these homologues, which are within two monophyletic groups that we called numt1 and numt2. Numt1 and numt2 sequences are less variable than mitochondrial sequences and released from the severe purifying selection constraining the evolution of mitochondrial genes. Their formation probably involved bottlenecks related to two distinct transfer events of ancient and fast evolving mitochondrial DNA fragments to comparative slowly evolving nuclear DNA regions.
Profiling infection responses in the haemocytes of the mosquito, Aedes aegypti
Authors: Bartholomay L. C. , Mayhew G. F. , Fuchs J. F. , Rocheleau T. A. , Erickson S. M. , Aliota M. T. , Christensen B. M. 
Published: September 2010

AbstractPathogens that infect and/or are transmitted by mosquitoes typically are exposed to the body cavity, and to haemocytes circulating therein, during development or dissemination. Aedes aegypti haemocytes produce a range of immune response‐related gene products, and an endpoint response of phagocytosis and/or melanization that is temporally and structurally distinct for the invading pathogen. Expressed sequence tags were generated from haemocyte libraries and then used to design oligonucleotide microarrays. Arrays were screened with haemocyte material collected 1‐, 8‐ and 24‐h post‐inoculation with Escherichia coli or Micrococcus luteus bacteria. Data from these studies support the discovery of novel immune response‐activated genes, provide an expanded understanding of antimicrobial peptide biology and highlight the coordination of immune factors that leads to an endpoint response.
A mutation in the voltage‐gated sodium channel gene associated with pyrethroid resistance in Latin American Aedes aegypti
Authors: Saavedra‐Rodriguez K. , Urdaneta‐Marquez L. , Rajatileka S. , Moulton M. , Flores A. E. , Fernandez‐Salas I. , Bisset J. , Rodriguez M. , Mccall P. J. , Donnelly M. J. , Ranson H. , Hemingway J. , Black W. C. 
Published: September 2010

AbstractPyrethroids are commonly used as mosquito adulticides and evolution of resistance to these compounds is a major threat to public health. ‘Knockdown resistance’ to pyrethroids (kdr) is frequently caused by nonsynonymous mutations in the voltage‐gated sodium channel transmembrane protein (para) that reduce pyrethroid binding. Early detection of kdr is critical to the development of resistance management strategies in mosquitoes including Aedes aegypti, the most prevalent vector of dengue and yellow fever viruses. Brengues et al. described seven novel mutations in hydrophobic segment 6 of domain II of para in Ae. aegypti. Assays on larvae from strains bearing these mutations indicated reduced nerve sensitivity to permethrin inhibition. Two of these occurred in codons Iso1011 and Val1016 in exons 20 and 21 respectively. A transition in the third position of Iso1011 encoded a Met1011 replacement and a transversion in the second position of Val1016 encoded a Gly1016 replacement. We have screened this same region in 1318 mosquitoes in 32 additional strains; 30 from throughout Latin America. While the Gly1016 allele was never detected in Latin America, we found two new mutations in these same codons. A transition in the first position of codon 1011 encodes a Val replacement while a transition in the first position of codon 1016 encodes an Iso replacement. We developed PCR assays for these four mutations that can be read either on an agarose gel or as a melting curve. Selection experiments, one with deltamethrin on a field strain from Santiago de Cuba and another with permethrin on a strain from Isla Mujeres, Mexico rapidly increased the frequency of the Iso1016 allele. Bioassays of F3 offspring arising from permethrin susceptible Val1016 homozygous parents and permethrin resistant Iso1016 homozygous parents show that Iso1016 segregates as a recessive allele in conferring kdr. Analysis of segregation between alleles at the 1011 and 1016 codons in the F3 showed a high rate of recombination even though the two codons are only separated by a ~250 bp intron. The tools and information presented provide a means for early detection and characterization of kdr that is critical to the development of strategies for resistance management.
The Aedes aegypti genome: a comparative perspective
Authors: Waterhouse R. M. , Wyder S. , Zdobnov E. M. 
Published: September 2010

AbstractThe sequencing of the second mosquito genome, Aedes aegypti, in addition to Anopheles gambiae, is a major milestone that will drive molecular‐level and genome‐wide high‐throughput studies of not only these but also other mosquito vectors of human pathogens. Here we overview the ancestry of the mosquito genes, list the major expansions of gene families that may relate to species adaptation processes, as exemplified by CYP9 cytochrome P450 genes, and discuss the conservation of chromosomal gene arrangements among the two mosquitoes and fruit fly. Many more invertebrate genomes are expected to be sequenced in the near future, including additional vectors of human pathogens (see http://www.vectorbase.org), and further comparative analyses will become increasingly refined and informative, hopefully improving our understanding of the genetic basis of phenotypical differences among these species, their vectorial capacity, and ultimately leading to the development of novel disease control strategies.
A microarray‐based analysis of transcriptional compartmentalization in the alimentary canal of Anopheles gambiae (Diptera: Culicidae) larvae
Authors: Neira Oviedo M. , VanEkeris L. , Corena‐Mcleod M. D. P. , Linser P. J. 
Published: September 2010

AbstractThe alimentary canal of the larval mosquito displays a considerable degree of physiological compartmentalization among its different anatomical sub‐divisions (gastric caeca, anterior midgut, posterior midgut and hindgut). We performed a comparative microarray analysis in order to identify transcripts which are particularly enriched in each gut section. Based on the available annotation of the selected transcripts, we suggest that the metabolism and absorption of proteins and carbohydrates takes place mainly in the gastric caeca and posterior midgut, whereas the anterior midgut specializes in the metabolism and absorption of lipids. Transcripts encoding antimicrobial peptides were found to be enriched in the gastric caeca, and a high enrichment of transcripts associated with enzymes involved in xenobiotic detoxification was found in the anterior midgut. Furthermore, our data support the notion that the region encompassing the hindgut and Malpighian tubes plays important roles in avoiding the excretion of nutrients, as well as in xenobiotic detoxification.
Transcriptional analysis of the pheromone gland of the turnip moth, Agrotis segetum (Noctuidae), reveals candidate genes involved in pheromone production
Authors: Strandh M. , Johansson T. , Ahrén D. , Löfstedt C. 
Published: September 2010

AbstractMoths generally rely on pheromone communication for mate finding. The pheromone components of most moths are produced by a common pathway of fatty‐acid biosynthesis coupled with species‐specific modifications of the final products. Some genes involved in moth pheromone production have previously been described, whereas others remain to be characterized and thus the molecular mechanisms accounting for the production of species‐specific blends are far from understood. The turnip moth, Agrotis segetum, has a multicomponent pheromone, consisting of at least four components derived from palmitic and stearic acid. Different populations produce and respond to different pheromone blends, which makes this species an excellent model for research on genes and molecular mechanisms involved in moth pheromone production. For this purpose, we performed an expressed sequence tag (EST) analysis of two cDNA libraries, one representing the female pheromone gland and the other representing the remainder of the insect body. Among 2285 ESTs analysed altogether, we identified a unigene set of 707 putative gene representatives. The comparative distribution of those in the two libraries showed the transcriptomes of the tissues to be clearly different. One third of the gene representatives were exclusively found in the pheromone gland. From sequence homology to public database information we assigned putative functional roles for a majority of the unigenes and then compared functional profiles of the two tissues. In the set of ESTs more abundant in the pheromone gland library, we found homologues of an acyl‐CoA Δ11‐desaturase, a G‐protein subunit, a chemosensory protein as well as a juvenile hormone binding protein.
Sperm washing method alters the ability of seminal plasma proteins to revert the cold‐shock damage on ram sperm membrane
Authors: Pérez‐Pé R. , Muiño‐Blanco T. , Cebrián‐Pérez J. A. 
Published: September 2010

Prolonged exposure of spermatozoa to seminal plasma (SP) has been found to have adverse effects on sperm function. Therefore, the separation of mammalian spermatozoa from SP is a practice routinely used in the laboratory and in assisted reproductive technology application. We have previously shown that adsorption of seminal plasma proteins (SPP) to the sperm cell surface partially restores the functional characteristics of damaged spermatozoa, reproducing those of live cells. In the present report, we have compared the influence of two different semen washing methods, a dextran/swim‐up or a filtration procedure, on the SPP adsorption to the sperm surface, and on their ability to recover membrane integrity of cold‐shocked sperm.Seminal plasma proteins were added to cold‐shocked sperm samples obtained by both washing procedures. Adsorption of proteins to the sperm membrane surface was assessed by centrifugal counter‐current distribution (CCCD) in an aqueous two‐phase system, as well as membrane integrity being determined by fluorescence markers. The percentage of reversion of cold‐shock effect in the sample containing plasma proteins with respect to the control sample was determined by assessing the percentage of membrane‐intact spermatozoa, i.e. propidium iodide‐negative. The addition of 700 μg of SPP to the swim‐up damaged samples caused a 32% reversion, whereas the reversal percentage found with the same amount of SPP on filtered damaged samples was 10% (p < 0.05). Likewise, the loss of heterogeneity and the decrease in viability after the cold‐shock revealed by CCCD analysis were greatly reversed by the addition of SPP to sperm samples obtained by swim‐up. However, this restorative effect was again much lower when SPP were added to the cold‐shocked filtered sample. These results strongly suggest that the washing method influences the ability of SPP to recover membrane integrity of cold‐shocked sperm. Separation of spermatozoa by swim‐up accounts for higher viability recovery than that obtained by filtration washing.
Towards a biogeographic regionalization of the European biota
Authors: Rueda Marta , Rodríguez Miguel Á. , Hawkins Bradford A. 
Published: September 2010

AbstractAim  To determine if it is possible to generate analytically derived regionalizations for multiple groups of European plants and animals and to explore potential influences on the regions for each taxonomic group.Location  Europe.Methods  We subjected range maps of trees, butterflies, reptiles, amphibians, birds and mammals to k‐means clustering followed by v‐fold cross‐validation to determine the pattern and number of regions (clusters). We then used the mean range sizes of species in each group as a correlate of the number of regions obtained for each taxon, and climate and species richness gradients as correlates of the spatial arrangement of the group‐specific regions. We also included the pattern of tree clusters as a predictor of animal clusters in order to test the ‘habitat templet’ concept as an explanation of animal distribution patterns.Results  Spatially coherent clusters were found for all groups. The number of regions ranged from three to eight and was strongly associated with the mean range sizes of the species in each taxon. The cluster patterns of all groups were associated with various combinations of climate, underlying species richness gradients and, in the case of animals, the arrangement of tree clusters, although the rankings of the correlates differed among groups. In four of five groups the tree pattern was the strongest single predictor of the animal cluster patterns.Main conclusions  Despite a long history of human disturbance and habitat modification, the European biota retains a discernable biogeographic structure. The primary driver appears to be aspects of climate related to water–energy balance, which also influence richness gradients. For many animals, the underlying habitat structure, as measured by tree distributions, appears to have a strong influence on their biogeographic structure, highlighting the need to preserve natural forest formations if we want to preserve the historical signal found in geographic distributions.
Consensus on interprofessional collaboration in hospitals: statistical agreement of ratings from ethnographic fieldwork and measurement scales
Authors: Kenaszchuk Chris , Conn Lesley Gotlib , Dainty Katie , McCarthy Colleen , Reeves Scott , Zwarenstein Merrick 
Published: September 2010

AbstractRationale  Few methods are available for analysing psychometric properties of combined qualitative and quantitative data. While conventional reliability of measures – meaning reproducibility or consistency – may not be meaningful in small‐N research, in some health services studies agreement on perceptions arising from data generated by fieldwork and quantitative measures can be examined to good effect.Methods  We studied interprofessional collaboration (IPC) in seven hospitals. An ethnographer shadowed and conducted interviews with regulated health professionals in medicine wards. Concurrently, nurses completed the nurse–doctor relations subscale of the Nursing Work Index (NWI‐NDRS) and a new measurement scale for IPC with doctors in the domains of communication, accommodation, and isolation. After fieldwork, the ethnographer rank‐ordered hospital sites on IPC from 1 to 7 based on interpretation of the qualitative data. Mean‐scale scores were calculated for hospital sites and converted to ranks similarly. The Tinsley‐Weiss T‐index (Tinsley & Weiss, 1975) for agreement among rank orderings was calculated for dyadic combinations of fieldwork and measurement ranks.Results  Perfect agreement was obtained for the most liberal agreement definitions considered – differences of two rank positions – involving qualitative data agreement with IPC subscales for accommodation and isolation. Defining agreement as a difference of 1 rank at most, the T‐index was 0.77 for agreement between fieldworker and IPC accommodation and the same for NWI‐NDRS and IPC isolation.Conclusion  Qualitative data from fieldwork rankings were substantially in accord with the contemporary IPC scales, less so with the NWI‐NDRS. Qualitative data appear to be useful as an additional approach to confirming the validity of quantitative scale data in measuring a complex interpersonal relational construct.