bluuebunny/crossref_metadata_2025_split huggingface dataset:
Site directed chromosomal marking of a fluorescent pseudomonad isolated from the phytosphere of sugar beet; stability and potential for marker gene transfer.
Authors: BAILEY M. J. , LILLEY A. K. , THOMPSON I. P. , RAINEY P. B. , ELLIS R. J. 
Published: April 2008

AbstractA plasmid‐free, non‐pathogenic, ribosomal RNA group 1 fluorescent pseudomonad, Pseudomonas fluorescens SBW25, was selected from the microflora of sugar beet (Beta vulgaris) and modified to contain constitutively expressed marker genes. By site directed homologous recombination a KX cassette [kanamycin resistance (kanτ) and catechol 2,3 dioxygenase (xylE)] and a ZY cassette [lactose utilization (lacZY, β‐galactosidase, lactose permease)] were introduced at least 1 Mbp apart on the 6.6 Mbp bacterial chromosome. Separate sites were selected to provide sensitive detection methods and allow assessments of marker gene stability of the genetically modified micro‐organism (GMM), SBW25EeZY6KX, when it colonized the leaves and roots of sugar beet plants following seed inoculation.
Genetic monogamy in single‐male groups of acorn woodpeckers, Melanerpes formicivorus
Authors: DICKINSON J. , HAYDOCK J. , KOENIG W. , STANBACK M. , PITELKA F. 
Published: April 2008

AbstractAcorn woodpeckers have one of the most complex social systems of any bird species. Breeding units range in size from monogamous pairs to groups of 15 birds that include multiple breeding males and females as well as nonreproductive helpers‐at‐the‐nest. Groups form when young remain at their natal nest to help their parents breed or when single‐sex coalitions of siblings disperse to fill a reproductive vacancy on another territory. Plural breeding and helping behaviour are thought to be favoured through indirect fitness benefits for individuals that would otherwise be unable to breed due to a shortage of reproductive vacancies on territories with acorn stores. We report the results of multi‐locus DNA fingerprinting of 51 offspring from 18 nests of 16 socially monogamous pairs of acorn woodpeckers. If socially monogamous females mate outside the pair‐bond, indirect fitness benefits for cobreeders and helpers will be significantly reduced. Monogamous pairs accounted for all but one of the 51 offspring we tested; the single exception was apparently sired by the putative father, but the putative mother was excluded from maternity. Our results indicate that individuals remaining on their natal territories as helpers are generally the genetic offspring of the pair they help. They also suggest that single‐sex coalitions offspring dispersing together from nests of socially monogamous pairs will be full‐siblings.
Molecular identification of six species of scale insects (Quadraspidiotus sp.) by RAPD‐PCR: assessing the field‐specificity of pheromone traps
Authors: FREY J. E. , FREY B. 
Published: April 2008

AbstractThe San‐José Scale Quadraspidiotus perniciosus (SJS) is a quarantine pest in Switzerland. Its occurrence is monitored by trapping males on glue traps treated with artificial female sex pheromone that is supposed to be species‐specific. However, large numbers of males were caught in locations where, for ecological reasons, this species was not expected to occur, suggesting that the pheromone is attractive for one or several otrter scale species. Because no morphological species determination key is described for males of this genus, it was not possible to test this hypothesis until now. We used randomly amplified polymorphic DNA (RAPD‐PCR) to establish a molecular identification key for six European Quadraspidiotus species. Because the glue used on the traps proved to be an excellent preservative, this key enabled us to identify males caught on pheromone traps in the field and to assess the species‐specificity of the SJS‐pheromone.
Field application of the polymerase chain reaction (PCR) to the detection and characterization of trypanosomes in Glossina longipalpis (Diptera: Glossinidae) in Côte d'Ivoire
Authors: SOLANO P. , ARGIRO L. , REIFENBERG J. M. , YAO YAO , DUVALLET G. 
Published: April 2008

AbstractThe Polymerase Chain Reaction (PCR) technique was used for the identification of natural trypanosome infections in Glossina longipalpis (Diptera: Glossinidae) in Côte d'Ivoire. A total number of 139 flies were examined microscopically for the presence of trypanosomes. Out of them 50 were detected positive and were subsequently prepared for the PCR using primers specific for Trypanosoma (Nannomonas) congolense of Savannah, Riverine‐Forest, Kilifi, and Tsavo types, T. (N.) simiae, T. (Duttonella) vivax and Trypanozoon. Almost 90% of the infections detected by the PCR were attributed to Nannomonas, especially T. congolense Savannah and Riverine‐Forest types, with many infections in which both of these two types were present T. simiae and T. vivax were also detected in some flies. The sequence specificity of the PCR products was confirmed by hybridization with parasite‐type specific DNA probes. Differences between parasitological and PCR results are discussed.
Limited polymorphism at major histocompatibility complex (MHC) loci in the Swedish moose A. alces
Authors: ELLEGREN H. , MIKK S. , WALLIN K. , ANDERSSON L. 
Published: April 2008

AbstractThe Swedish moose was analysed for genetic variability at major histocompatibility complex (MHC) class I and class II DQA, DQB and DRB loci using restriction fragment length polymorphism (RFLP) and single strand conformation polymorphism (SSCP) techniques. Both methods revealed limited amounts of polymorphism. Since the SSCP analysis concerned an expressed DRB gene it can be concluded that the level of functional MHC class II polymorphism, at least at the DRB locus, is low in Swedish moose. DNA fingerprinting was used to determine if the unusual pattern of low MHC variability could be explained by a low degree of genome‐wide genetic diversity. Hybridizations with two minisatellite probes gave similarity indices somewhat higher than the average for other natural population, but the data suggest that the low MHC variability cannot be explained by a recent population bottleneck. However, since minisatellite sequences evolve more rapidly than MHC sequences, the low levels of MHC diversity may be attributed to a bottleneck of more ancient origin. The selection pressure for MHC variability in moose may also be reduced and we discuss the possibility that its solitary life style may reduce lateral transmission of pathogens in the population.
Associations between physical isolation and geographical variation within three species of Neotropical birds
Authors: BRAWN J. D. , COLLINS T. M. , MEDINA M. , BERMINGHAM E. 
Published: April 2008

AbstractWe studied effects of physical isolation on geographical variation in mtDNA RFLP polymorphisms and a suite of morphological characters within three species of neotropical forest birds; the crimson‐backed tanager Ramphocelus dimidiatus, the blue‐gray tanager Thraupis episcopus, and the streaked saltator Saltator albicollis. Variation among populations within continuous habitat on the Isthmus of Panama was compared with that among island populations isolated for about 10000 years. Putative barriers to dispersal were influential, but apparent isolation effects varied by species, geographical scale, and whether molecular or morphological traits were being assessed. We found no geographical structuring among the contiguous, mainland sampling sites. Migration rates among the islands appeared sufficient to maintain homogeneity in mtDNA haplotype frequencies. In contrast, variation in external morphology among islands was significant within two of three species. For all species, we found significant variation in genetic and morphological traits between the island (collectively) and mainland populations. Interspecific variation in the effects of isolation was likely related to differential vagility. These data generally corroborate other studies reporting relatively great geographical structuring within tropical birds over short distances. Behaviourally based traits ‐ low vagility and high ‘sensitivity’ to geographical barriers ‐ may underlie extensive diversification within neotropical forest birds, but more extensive ecological and phylogeographic information are needed on a diverse sample of species.
Microsatellite differentiation between Phillip Island and mainland Australian populations of the red foxVulpes vulpes
Authors: LADE J. A. , MURRAY N. D. , MARKS C. A. , ROBINSON N. A. 
Published: April 2008

AbstractPredation by the red foxVulpes vulpesis believed to be threatening the little penguinEudyptula minoron Phillip Island in Victoria. Polymorphism at seven microsatellite loci was examined to estimate the extent of differentiation between Phillip Island and mainland populations ofV. vulpes. Loss of alleles has occurred on Phillip Island where foxes first appeared = 88 years ago compared with mainland populations. Genetic differentiation between the Phillip Island and mainland populations was high. The relatively high differentiation found between the two populations could be due to either low migration rates, the effect of the composition of founder animals or both effects. Further ecological and historical information about the populations is needed to explore the likely significance of these effects.
Detection and pattern of interspecific hybridization between Gliricidia sepium and G. maculata in Meso‐America revealed by PCR‐based assays
Authors: DAWSON I. K. , SIMONS A. J. , WAUGH R. , POWELL W. 
Published: April 2008

Abstract Gliricidia sepium provides a variety of products important for rural communities in tropical countries. Native populations in Meso‐America currently form an important source of seed for distribution to farmers, but concerns centre on mechanisms which may lead to their genetic erosion, including anthropogenic dispersal and subsequent introgression from the related species, G. maculata.Populations of Gliricidia were examined genetically using approaches based on the polymerase chain reaction to test for interspecific hybridization and introgression between G. sepium and G. maculata. Analysis involved 13 RAPD and two RFLP‐PCR markers which were identified to have species‐diagnostic distributions. Data from both approaches corresponded and indicated three locations where multilocus genotypes were consistent with an hybrid origin. Data at one of these sites was consistent with introgression following hybridization. The hybrid origin of populations was supported by the intermediate geographical location of these sites to ‘pure’ populations of each species. Analysis of maternally inherited organellar DNA, which involved the detection of SSCPs in mitochondrial DNA amplification products, allowed further delineation of genetic structure among Gliricidia populations. Mitochondrial data indicated a high degree of organelle differentiation between sampled locations and identified G. sepium‐ and G. maculata‐diagnostic haplotypes. This data supported the interpretation of genetic structure based on RAPDs and RFLP‐PCR. In addition, cytonuclear analysis allowed the directionality of gene transfer during the formation of hybrid populations to be described. Despite evidence for the occurrence of interspecific hybridization and introgression in Gliricidia, important resource populations of G. sepium on the Pacific coast appear to have retained their genetic integrity. Implications in terms of the conservation and utilization of genetic resources within the genus are discussed.
Amplified fragment length polymorphism (AFLP) fingerprinting of symbiotic fungi cultured by the fungus‐growing ant Cyphomyrmex minutus
Authors: MUELLER U. G. , LIPARI S. E. , MILGROOM M. G. 
Published: April 2008

AbstractA PCR‐based fingerprinting technique based on amplified fragment length polymorphisms (AFLP) is used to screen symbiotic fungi of the fungus‐growing ant Cyphomyrmex minutus for genetic differences. AFLP fingerprints reveal several fungal ‘types’ that (a) represent distinct clones propagated vegetatively by the ant, or (b) correspond to free‐living fungi that may be acquired by the ant. Fungal types identified by AFLP fingerprints correspond to vegetative‐compatibility groups established previously, suggesting that vegetative compatibility can be used as a crude indicator of genetic differences between fungi of C. minutus.
Microsatellite markers for the study of cetacean populations
Authors: VALSECCHI E. , AMOS W. 
Published: April 2008

AbstractMicrosatellites are one of the most important classes of nuclear genetic markers and offer many advantages for the study of marine mammals. Here we describe the isolation and characterization of 12 cetacean microsatellites which are then tested across 30 different cetacean species. For around half the species tested, five or more polymorphic loci were identified. Since many species were represented by only one or two specimens, this figure is likely to underestimate the usefulness of these markers. No relationship was found between microsatellite repeat length and proportion of species which gave polymorphic products.
RAPD analysis reveals low genetic variability in the endangered light‐footed clapper rail
Authors: NUSSER J. A. , GOTO R. M. , LEDIG D. B. , FLEISCHER R. C. , MILLER M. M. 
Published: April 2008

AbstractNumbers of light‐footed clapper rails Rallus longirostris levipes, an endangered bird inhabiting southern California salt marshes, have substantially declined from historic levels. RAPD (randomly amplified polymorphic DNA) analysis was employed to assess the genetic variability within and among four of the largest remaining light‐footed clapper rail populations. A single, larger population of the endangered Yuma clapper rail Rallus longirostris yumanensis was used for comparison.A total of 325 RAPD primers were tested on DNA from a subset of five clapper rails composed of a single representative for each of the four light‐footed clapper rail populations and a representative for the single Yuma clapper rail population. Of the 1338 amplified bands (loci) surveyed in these five representative birds, approximately 1% were polymorphic, indicating the level of differentiation across all loci is quite low. Nine primers yielding these 16 polymorphic bands were used to analyse 48 individuals from five populations. Five of these bands were polymorphic in both subspecies, six were polymorphic only within the light‐footed clapper rails, and five were polymorphic only within the Yuma clapper rail samples. Considering the few bands that were polymorphic among the light‐footed clapper rail populations, a surprisingly high level of population differentiation (GST=0.28) was found. This is in accord with the results of AMOVA analyses which show that a fairly high percentage of the limited variability among the rails is due to either differences between subspecies or differences between the light‐footed rail populations. Because inbreeding depression is suspected and overall genetic distances between populations are low, movement of light‐footed clapper rails from larger populations into smaller ones might be considered as a management strategy. Employing RAPDs as one of a series of assays is useful in revealing the population structure of genetically depauperate species.
Phylogeography and population structure of the Atlantic and Mediterranean green turtleChelonia mydas: a mitochondrial DNA control region sequence assessment
Authors: ENCALADA S. E. , LAHANAS P. N. , BJORNDAL K. A. , BOLTEN A. B. , MIYAMOTO M. M. , BOWEN B. W. 
Published: April 2008

AbstractMitochondrial (mt) DNA sequences were analysed to resolve the phylogeography and population genetic structure of Atlantic and Mediterranean populations of green turtles (Chelonia mydas). Analysis of sequence variation over 487 base pairs of the control (D‐loop) region identified 18 haplotypes among 147 individuals from nine nesting populations. Pairwise comparisons of haplotype frequencies distinguished most nesting colonies, indicating significant genetic differentiation among rookeries and a strong propensity for natal homing behaviour by nesting females. Comparison of control region sequence data to earlier restriction fragment length polymorphism (RFLP) data for the same individuals demonstrates approximately a sixfold higher substitution rate in the 5′ end of the control region. The sequence data provide higher resolution both in terms of the number of mtDNA genotype variants and the phylogeographic relationships detected within the Atlantic region, and reveal a gene genealogy that distinguishes two groups of haplotypes corresponding to (i) the western Caribbean and Mediterranean, and (ii) eastern Caribbean, South Atlantic and West Africa. The data suggest that phylogeographic patterns in the Atlantic Ocean may be interpreted in terms of female nest site fidelity and episodic dispersal events. The distribution of mtDNA haplotypes within the region is thus explained by the geological and climatic alternations (glacial and interglacial) over the last million years.
Genetic structure of the global population of banana black leaf streak fungus, Mycosphaerella fijiensis
Authors: CARLIER J. , LEBRUN M. H. , ZAPATER M. F. , DUBOIS C. , MOURICHON X. 
Published: April 2008

AbstractThe genetic structure of Mycosphaerella fijiensis populations around the world was examined using DNA restriction fragment length polymorphism (RFLP) markers. Allele frequencies at 19 nuclear RFLP loci were estimated in a sample of 136 M. fijiensis isolates from five geographical populations representative of banana‐producing areas (South‐East Asia including the Philippines and Papua New Guinea, Africa, Latin America and Pacific Islands). Within each population, gametic disequilibrium tests between the 19 nuclear RFLP loci were mainly non significant (P > 0.05), indicating that random sexual reproduction occurred in these populations. All M. fijiensis populations had a high level of genotypic and allelic diversity (H, gene diversity: 0.25–0.59). The highest levels of gene diversity were found in the two South‐East Asian populations (H: 0.57 and 0.59). Most of the alleles (> 88%) detected in Africa, Latin America and Pacific Islands populations were also detected in South‐East Asian populations. Furthermore, a high and significant (P < 0.05) level of genetic differentiation was observed among M. fijiensis geographical populations (overall estimate of Fst: 0.32). These results were consistent with the hypothesis that M. fijiensis originated in South‐East Asia and spread recently to other parts of the world. The level of allelic diversity in M. fijiensis populations from regions other than South‐East Asia was drastically reduced, indicating founder effects. The data also suggested rare occurrence of migration of M. fijiensis between continents.
Mating structure and nestmate relatedness in a communal bee,Andrena jacobi(Hymenoptera, Andrenidae), using microsatellites
Authors: PAXTON R. J. , THOREN P. A. , TENGÖ J. , ESTOUP A. , PAMILO P. 
Published: April 2008

AbstractComplex eusocial insect societies are generally matrifilial, suggesting kin selection has been of importance in their development. For simpler social systems, factors favouring their existence, in particular kin selection, have rarely been studied. Communal nesting is one of these simple social organizations, and is found in a diversity of insect species. To examine whether kin selection may play a role in the evolution and maintenance of communality, we estimated genetic relatedness of nestmate females of the facultatively communal bee,Andrena jacobi. Microsatellite loci were developed for this species and used to analyse individuals from two populations. Loci were variable, they were in heterozygote deficit and showed positive inbreeding coefficients. This may arise from nonrandom mating; previous observations (Paxton & Tengö 1996) indicate that a large proportion of females mate intranidally with nestmate males in their natal nests before first emerging. Nestmate relatedness was low, no different from zero for all loci in one population and for three of four loci in the other population. The large number of nestmates sharing a common nest (up to 594) may explain the low relatedness estimates, although relatedness was also independent of the number of females sharing a nest. Lack of inclusive fitness payoffs could constrain social evolution in this communal species.
Micro‐evolution in the weevil genus Larinus: the formation of host biotypes and speciation
Authors: BRIESE D. T. , ESPIAU C. , POUCHOT‐LERMANS A. 
Published: April 2008

AbstractData are presented on allozyme variation between 15 populations of the stenophagous capitulum weevil, Larinus cynarae, and three populations of its congener, L. latus, that had been collected throughout the northern mediterranean range of these species. A phenetic analysis of these data revealed no direct relationship between genetic variation and host‐plant association within L. cynarae, but there was a strong geographical structuring of allozyme patterns. Most of the genetic variation was due to differences between geographical regions and variation within these was small. Wright's FST values showed that Italian and Greek populations of L. cynarae were most distinct from L. latus, with southern Iberian, northern Spanish and French populations increasingly less so. This pattern was associated with a cline in the frequencies of certain alleles along this geographical arc from France to Greece. A phenogram of Nei's genetic distances indicated the close genetic relationship between the two species of Larinus and separated the populations of L. cynarae into three allopatric groups. These groups have different host‐plant spectra — dominated by Cynara cardunculus in Italy and Greece, Cynara humilis/Onopordum in southern Iberia and Onopordum spp. in France/Northern Spain — and can be considered to be host biotypes of L. cynarae. L. latus, which occurs in Greece and further east is also an Onopordum specialist. An analysis of the phylogeny of this group of Larinus indicates a primary separation into eastern (L. latus) and western (L. cynarae) taxa, with further branching of the L. cynarae lineage into the putative host‐biotypes. An hypothesis for the evolution of these taxa is given, based on the evolutionary history of host‐plant taxa and geographical constraints.
Chloroplast DNA phylogeography of the argan tree of Morocco
Authors: MOUSADIK A. EL , PETIT R. J. 
Published: April 2008

AbstractPolymorphisms in the chloroplast genome of the argan tree (Sapotaceae), an endemic species of south‐western Morocco, have been detected by restriction site studies of PCR‐amplified fragments. A total of 12 chloroplast DNA (cpDNA) and two mitochondrial DNA (mtDNA) fragments were amplified and digested with a single restriction enzyme (HinfI). Polymorphisms were identified in six of the cpDNA fragments, whereas no mtDNA polymorphisms were detected in a survey of 95 individuals from 19 populations encompassing most of the natural range of the species. The cpDNA polymorphisms allowed the identification of 11 haplotypes. Two lineages, one in the south‐east and the other in the north‐west, divide the range of the argan tree into two distinct areas. The level of genetic differentiation measured at the haplotype level (GSTc= 0.60) (i.e. with unordered haplotypes) was smaller than when phylogenetic relationships were taken into account (NSTc= 0.71‐0.74) (ordered haplotypes), indicating that population history must be considered in the study of the geographical distribution of cpDNA lineages in this species. If contrasted with the level of nuclear genetic differentiation measured in a previous study with isozymes (GSTn= 0.25), the results indicate a relatively high level of gene flow by seeds, or conversely a relatively low level of gene flow by pollen, as compared with other tree species. Goats and camels could have played an important role in disseminating the fruits of this tree.