bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determinants of intracolonial relatedness inPogonomyrmex rugosus(Hymenoptera; Formicidae): mating frequency and brood raids
Authors: Gadau J. , Strehl C.‐P. , Oettler J. , Hölldobler B. 
Published: June 2003

AbstractThe genusPogonomyrmexis one of three ant genera with aneffective mating frequency(me) > 2.0. We developed microsatellites to determinemeforP. rugosusbecause mating frequency ofP. rugosuswas known only from observational data which do not allow an estimate ofme. We genotyped 474 workers from 20 colonies for two microsatellite loci. Observed mating frequencies ranged from 3 to 12 andmeforP. rugosuswas 4.71. Observed patriline frequencies were significantly different from the expected patriline frequencies generated with a simulated data set under the assumption of equal patriline representation. The available mating frequency data and phylogenetic information of the genusPogonomyrmexsuggest that multiple mating is the ancestral state in the North AmericanPogonomyrmex sensu stricto. EstablishedP. rugosuscolonies raid and destroy smaller conspecific colonies. During these raids ant workers were observed carrying pupae and larvae from the raided colony into the nest of the raiding colony. However, it was not clear whether raided brood emerged in the raiding colony and were subsequently recruited into the work force (intraspecific slavery) or were used as food (predation). Our analyses indicate 6 of 14 field colonies contained foreignP. rugosusworkers (43%). The range of the intracolonial frequency of foreign workers collected directly from the nest entrance was between 4 and 28%.
Hybridization andRorippa austriaca(Brassicaceae) invasion in Germany
Authors: Bleeker W. 
Published: June 2003

AbstractIntrogressive hybridization between the invasiveRorippa austriacaand the nativeR. sylvestrisin Germany has been studied using chloroplast DNA (trnL intron) and amplified fragment length polymorphism. Three hybrid zones between the invasive and native species were located in the Ruhr Valley (Mülheim) and at the River Main near Würzburg (Randersacker, Winterhausen). In each hybrid zone hybridization was indicated by additivity of region‐specific amplified fragment length polymorphism markers proving independent hybridization events. The hybrids were either morphologically intermediate (R. × armoracioides) or were close toR. sylvestris. ThetrnL intron ofR. austriacais characterized by a species‐specific deletion. This diagnostic chloroplast marker ofR. austriacawas detected in three individuals ofR. sylvestrisproviding evidence for introgression of the invasive chloroplast into the native species. Bidirectional introgression ofR. austriacamarkers intoR. sylvestrisand ofR. sylvestrismarkers intoR. austriacawas detected in the amplified fragment length polymorphism analysis. Some of the invasiveR. austriacapopulations showed high within‐population variation. A possible association among introgression, within‐population variation and invasion success is discussed. The morphologically intermediate hybridR. × armoracioidesis currently spreading in northern Germany. It forms large populations without its parent speciesR. austriacaandR. sylvestris. It is concluded that hybridization between invasiveR. austriacaand nativeR. sylvestrismay lead to the evolution of a new invasive speciesR. × armoracioides.
Wolbachiaand genetic variability in the birdnest blowflyProtocalliphora sialia
Authors: Baudry E. , Bartos J. , Emerson K. , Whitworth T. , Werren J. H. 
Published: June 2003

AbstractWolbachiaare widespread cytoplasmically inherited bacteria that induce various reproductive alterations in host arthropods, including cytoplasmic incompatibility (CI), an incompatibility between sperm and egg that typically results in embryonic death. CI has been invoked as a possible mechanism for reproductive isolation and speciation in arthropods, by restricting gene flow and promoting maintenance (and evolution) of genetic divergence between populations. Here we investigate patterns ofWolbachiainfection and nuclear and mitochondrial differentiation in geographical populations of the birdnest blowflyProtocalliphora sialia. Blowflies in western North America are infected with two A‐groupWolbachia, with some individuals singly and others doubly infected. Individuals in eastern North America mostly show single infections with a B‐groupWolbachia.Populations in the Midwest are polymorphic for infections and show A‐ or B‐group infection. There is a low level of mitochondrial divergence and perfect concordance of mitochondrial haplotype with infection type, suggesting that twoWolbachia‐associated selective sweeps of the mitochondrion have occurred in this species. Amplified fragment length polymorphism analysis of nuclear genetic variation shows genetic differentiation between the eastern–Midwestern and western populations. Both Midwestern and eastern flies infected with A‐Wolbachiashow eastern nuclear genetic profiles. Current results therefore suggest thatWolbachiahas not acted as a major barrier to gene flow between western and eastern–Midwestern populations, although some genetic differentiation between A‐Wolbachiainfected and B‐Wolbachiainfected individuals in eastern–Midwestern populations cannot be ruled out.
AFLP utility for population assignment studies: analytical investigation and empirical comparison with microsatellites
Authors: Campbell David , Duchesne Pierre , Bernatchez Louis 
Published: June 2003

AbstractIndividual‐based population assignment tests have thus far mainly relied on the use of microsatellite loci. However, the logistic difficulty of screening large numbers of loci required to reach sufficient statistical power hampers the usefulness of microsatellites in situations of weak population structuring. Amplified fragment length polymorphisms (AFLP) represents an alternative for overcoming this logistical issue as the technique allows the user to characterize a much larger number of loci with a comparable analytical effort. In this study, an assignment test based on maximum likelihood for dominant markers was used to investigate the potential usefulness of AFLP for population assignment. We also compared assignment success achieved with AFLP with that obtained using microsatellites in a case study of low population differentiation involving whitefish (Coregonus clupeaformis) sympatric ecotypes. The analytical investigation showed that the minimum number of AFLP loci required to reach an assignment success of 95% stood within values that are easily achievable in many situations. This also showed how assignment success varied according to the number of AFLP loci used, their absolute frequency and their frequency differential and sampling errors, as well as the number of putative source populations. The case study showed that given a comparable analytical effort in the laboratory, AFLP were much more efficient than the microsatellite loci in discriminating the source of an individual among putative populations. AFLP resulted in higher assignment success at all levels of stringency and the log‐likelihood differences between populations obtained with AFLP for each individual were much larger than those obtained with microsatellites. These results indicate that research involving individual‐based population assignment methods should benefit importantly from the use of AFLP markers, especially in systems characterized by weak population structuring.
Parentage assignment detects frequent and large‐scale dispersal in water voles
Authors: Telfer S. , Piertney S. B. , Dallas J. F. , Stewart W. A. , Marshall F. , Gow J. L. , Lambin X. 
Published: June 2003

AbstractEstimating the rate and scale of dispersal is essential for predicting the dynamics of fragmented populations, yet empirical estimates are typically imprecise and often negatively biased. We maximized detection of dispersal events between small, subdivided populations of water voles (Arvicola terrestris) using a novel method that combined direct capture–mark–recapture with microsatellite genotyping to identify parents and offspring in different populations and hence infer dispersal. We validated the method using individuals known from trapping data to have dispersed between populations. Local populations were linked by high rates of juvenile dispersal but much lower levels of adult dispersal. In the spring breeding population, 19% of females and 33% of males had left their natal population of the previous year. The average interpopulation dispersal distance was 1.8 km (range 0.3–5.2 km). Overall, patterns of dispersal fitted a negative exponential function. Information from genotyping increased the estimated rate and scale of dispersal by three‐ and twofold, respectively, and hence represents a powerful tool to provide more realistic estimates of dispersal parameters.
Fine‐scale genetic structure of two carabid species with contrasted levels of habitat specialization
Authors: Brouat C. , Sennedot F. , Audiot P. , Leblois R. , Rasplus J.‐Y. 
Published: June 2003

AbstractUsing microsatellite markers, we compared the genetic structure of populations of two carabid species, one described as a generalist (commonly found in forest and in open habitats) and the other known as a forest specialist. Both species were sampled in the same forest plots, which were separated from each other by either open or forested areas. At the local scale considered (13.6 km separating the most distant plots), genetic differentiation was substantial for both species studied, but populations of the forest specialist Carabus punctatoauratus appeared to be more spatially structured than those of C. nemoralis. Isolation by distance analyses showed that nonforested areas are partial barriers to gene flow for both species studied, although more clearly for the forest specialist. Between and within forests, dispersal capacity of the generalist C. nemoralis was shown to be higher than that of the specialist C. punctatoauratus.
The evolution of extreme shell shape variation in the land snailAinohelix editha: a phylogeny and hybrid zone analysis
Authors: Teshima Hiroaki , Davison Angus , Kuwahara Yasuhiro , Yokoyama Jun , Chiba Satoshi , Fukuda Tatsuya , Ogimura Hideo , Kawata Masakado 
Published: June 2003

AbstractAinohelix edithafrom Hokkaido, Japan, exhibit great geographical variation in their shell morphology. In particular,A. edithain two quite separate locations, Shimamaki and Samani, are striking because they are extremely flat and have a sharp keel, whereas at adjacent sites the shells are globular or depressed‐globular. We used mitochondrial 16S rRNA and nuclear ITS‐2 sequences to infer a phylogeny among 47 snails from 29 locations. Snails from the two keeled‐flat populations clustered separately in the phylogeny, suggesting that this unusual shell form could have evolved independently. A morphological analysis of shells collected along a transect between keeled‐flat and globular snail sites showed a cline for shell shape and the angle of the keel. Two different mtDNA lineages were found across the transect, with a cline for an ITS‐2 single nucleotide polymorphism. Together, the results may suggest a lack of reproductive isolation between keeled‐flat and globular snails, with possible introgression by hybridization.
Latitudinal divergence of common frog (Rana temporaria) life history traits by natural selection: evidence from a comparison of molecular and quantitative genetic data
Authors: Palo J. U. , O'Hara R. B. , Laugen A. T. , Laurila A. , Primmer C. R. , Merilä J. 
Published: June 2003

AbstractThe relative roles of natural selection and direct environmental induction, as well as of natural selection and genetic drift, in creating clinal latitudinal variation in quantitative traits have seldom been assessed in vertebrates. To address these issues, we compared molecular and quantitative genetic differentiation between six common frog (Rana temporaria) populations along an approximately 1600 km long latitudinal gradient across Scandinavia. The degree of population differentiation (QST ≈ 0.81) in three heritable quantitative traits (age and size at metamorphosis, growth rate) exceeded that in eight (neutral) microsatellite loci (FST = 0.24). Isolation by distance was clear for both neutral markers and quantitative traits, but considerably stronger for one of the three quantitative traits than for neutral markers.QSTestimates obtained using animals subjected to different rearing conditions (temperature and food treatments) revealed some environmental dependency in patterns of population divergence in quantitative traits, but in general, these effects were weak in comparison to overall patterns. Pairwise comparisons ofFSTandQSTestimates across populations and treatments revealed that the degree of quantitative trait differentiation was not generally predictable from knowledge of that in molecular markers. In fact, both positive and negative correlations were observed depending on conditions where the quantitative genetic variability had been measured. All in all, the results suggest a very high degree of genetic subdivision both in neutral marker genes and genes coding quantitative traits across a relatively recently (< 9000 years) colonized environmental gradient. In particular, they give evidence for natural selection being the primary agent behind the observed latitudinal differentiation in quantitative traits.
Population size estimation in Yellowstone wolves with error‐prone noninvasive microsatellite genotypes
Authors: Creel Scott , Spong Goran , Sands Jennifer L. , Rotella Jay , Zeigle Janet , Joe Lawrence , Murphy Kerry M. , Smith Douglas 
Published: June 2003

AbstractDetermining population sizes can be difficult, but is essential for conservation. By counting distinct microsatellite genotypes, DNA from noninvasive samples (hair, faeces) allows estimation of population size. Problems arise because genotypes from noninvasive samples are error‐prone, but genotyping errors can be reduced by multiple polymerase chain reaction (PCR). For faecal genotypes from wolves in Yellowstone National Park, error rates varied substantially among samples, often above the ‘worst‐case threshold’ suggested by simulation. Consequently, a substantial proportion of multilocus genotypes held one or more errors, despite multiple PCR. These genotyping errors created several genotypes per individual and caused overestimation (up to 5.5‐fold) of population size. We propose a ‘matching approach’ to eliminate this overestimation bias.
Bimodal run distribution in a northern population of sockeye salmon (Oncorhynchus nerka): life history and genetic analysis on a temporal scale
Authors: Fillatre E. K. , Etherton P. , Heath D. D. 
Published: June 2003

AbstractLife history variation and genetic differentiation were analysed in sockeye salmon in Klukshu River, Yukon Canada over 7 years (1994–2000). Sockeye salmon return to the Klukshu River in two distinct runs, with a small ‘early run’ in June–August, and a larger ‘late run’ in August–September. A maximum likelihood test for clusters indicated that the return frequency distribution was bimodal in all the years analysed. Life history differences (fork length, sex ratio, age at maturity, fresh‐ and saltwater residency times) were found between the early and late runs; however, inconsistent patterns suggest that environmental effects outweigh, or strongly interact with, genetic effects for the life history characters evaluated. Analysis of variation at eight microsatellite loci showed that the early and late runs are genetically differentiated in all years examined (exact test).FSTestimates between runs within years were significantly greater than zero (range: 0.018–0.041) for all years except one (0.004). The genetic variance explained by early vs. late runs (2.27%) was twice the variance among years (1.16%) based on analysis of molecular variance. Our neighbour‐joining tree showed early and late runs generally clustering separately, indicating higher gene flow among the early or late run fish across years relative to between‐run gene flow. Two years did not fit the general clustering pattern; although the early and late runs in 1995 and 2000 were genetically differentiated, they clustered separately from the rest of the groups. We cannot offer a definitive explanation for these anomalies; however, an analysis of possible cryptic population structure in early and late runs indicated that at least a few fish strayed between the runs in each year, and the highest rate of mixing was in 1995 and 2000. Our data indicate that the runs are at least partially reproductively isolated as a result of temporal and/or spatial isolating mechanisms. Such reproductive isolation has important implications for conservation and management of the Klukshu sockeye salmon, and make them an evolutionarily interesting group because of parallels with incipient speciation.
The role of environment in shaping the genetic diversity of the subalpine mosquito, Aedes rusticus (Diptera, Culicidae)
Authors: David J. P. , Huber K. , Failloux A. B. , Rey D. , Meyran J. C. 
Published: June 2003

AbstractThe relative involvement of larval dietary tolerance to the leaf‐litter toxic polyphenols in shaping population genetic structure of the subalpine mosquito Aedes rusticus was examined. This was compared with other parameters such as geographical range, type of vegetation surrounding the breeding site, and occurrence of annual larvicidal treatments. Population genetic structure was analysed at 10 presumed neutral polymorphic isoenzyme loci. Toxicological comparisons involved standard bioassays performed on larvae fed on toxic decomposed leaf litter. Significant overall genetic differentiation was observed among the 22 studied populations and within the five defined geographical groups. Analysis of molecular variance revealed an absence of relation between genetic and environmental parameters, genetic variance being essentially found within populations. This suggested that the larval dietary tolerance to the toxic leaf litter and the other studied parameters poorly influence population genetic structure. The local adaptation of subalpine mosquito populations to the surrounding vegetation thus appears as a labile trait. Such a dynamic adaptation is also suggested by the correlation between geographical and toxicological distances and the correlation between dietary tolerance to the leaf‐litter toxic polyphenols and annual larvicidal treatments.
Genetic identification of two sibling species ofLutzomyia longipalpis(Diptera: Psychodidae) that produce distinct male sex pheromones in Sobral, Ceará State, Brazil
Authors: Maingon R. D. C. , Ward R. D. , Hamilton J. G. C. , Noyes H. A. , Souza N. , Kemp S. J. , Watts P. C. 
Published: June 2003

AbstractLutzomyia longipalpis, the main sandfly vector for New World visceral leishmaniasis is a complex of an as yet undefined number of sibling species. At present, there is no consensus on the status (single species vs. species complex) of Brazilian populations. We applied five microsatellite loci to test the hypothesis thatL. longipalpisoccurs as two sympatric cryptic species in Sobral, Ceará State, Brazil as predicted by male sex pheromone chemotypes described previously for field specimens from this site [S‐9‐methyl‐germacrene‐B(9MGB) and a cembrene compound]. Abdominal spot morphology corresponds with pheromone type at this locality (9MGB in ‘1 spot’ males and cembrene in ‘2 spot’ males). Genotype data from 190 wild‐caughtL. longipalpisspecimens collected in October 1999 and April 2001 were used to estimate genetic differentiation between the two sex pheromone populations and sampling dates. No significant (P > 0.05) genetic differences were found between the 1999 and 2001 9MGB samples (θ = 0.018;RST = −0.005), and genetic differentiation was low between the cembrene collections (θ = 0.037,P < 0.05;RST = −0.043,P > 0.05). By contrast, highly divergent allelic frequencies (largely at two microsatellite loci) corresponded to significant (P > 0.05) genetic differentiation (θ = 0.221;RST = 0.215) for all comparisons between samples with different pheromones. When pheromone samples were pooled across sample date, genetic differentiation was high (θ = 0.229;P < 0.001;Nem = 0.84). The allele frequency distribution at each of the five microsatellite loci was similar for males and females from the two collection years. Two of these loci showed highly divergent allele frequencies in the two sex pheromone populations. This was reflected in the highly significant genetic differentiation obtained from the male genotypes, between populations producing different pheromones (θ = 0.229–0.268;P < 0.0001 for the 2001 and θ = 0.254–0.558;P < 0.0001 for the 1999 collections, respectively). Similar results were obtained when the females, assigned to a pheromone type, were included in the analysis. Both a Bayesian analysis of the data set and a population assignment test provided strong evidence for two distinct populations corresponding to pheromone type. Given its genotype, the probability of assigning a 9MGB male to the original 9MGB population was 100% once the two years’ collections were pooled. For cembrene‐producing ‘2 spot’ males this probability although still high, was lower than for 9MGB males, at 86%. This microsatellite data together with previously reported reproductive isolation between the two Sobral populations confirm that premating barriers are important in speciation ofL. longipalpis.
The use of nuclear and mitochondrial single nucleotide polymorphisms to identify cryptic species
Authors: Belfiore N. M. , Hoffman F. G. , Baker R. J. , Dewoody J. A. 
Published: June 2003

AbstractThere is growing interest in the use of single nucleotide polymorphisms for evolutionary and population genetics. We tested the efficacy of one of the available single nucleotide polymorphism techniques, single‐base extension, in distinguishing four cryptic species of Microtus. Sequence data were available for these species at nuclear and mitochondrial loci and their identity could be independently confirmed using karyotypes. We found that the development and optimization of single nucleotide polymorphisms required extensive effort, and that the method accurately identified the correct nucleotide at single nucleotide polymorphism sites ≈ 90% of the time at the conserved nuclear locus. Correct identification rates were much lower at the highly variable mitochondrial locus.
The phylogeography of dusky dolphins (Lagenorhynchus obscurus): a critical examination of network methods and rooting procedures
Authors: Cassens I. , Van Waerebeek K. , Best P. B. , Crespo E. A. , Reyes J. , Milinkovitch M. C. 
Published: June 2003

AbstractWe investigated the phylogeography and evolutionary history of dusky dolphins (Lagenorhynchus obscurus) using DNA sequences of the full mitochondrial cytochromebgene in 124 individuals from the putative stocks off Peru, Argentina and Southwest Africa. While genetic differentiation within oceans is surprisingly low, there is no evidence for recent female gene flow between Atlantic and Pacific waters. Highest genetic variability in terms of sequence divergence and number of haplotypes is found in the Atlantic. Our analyses also indicate that the eastern South Pacific dusky dolphins stock should be considered a separate management unit. Given the high level of mortality experienced by the Peruvian dusky dolphin in local fishery activities, these findings have important implications for an objective management of the species. Furthermore, we analysed our mitochondrial sequence data with several widely used network estimation and rooting methods. The resulting intraspecific gene genealogies and rooting inferences exhibited substantial differences, underlying the limitations of some algorithms. Given that scientific hypotheses and management decisions depend strongly on inferred tree or network topologies, there is a clear need for a systematic comparative analysis of available methods. Finally, the present study indicates that (i) the dusky and the Pacific white‐sided dolphins are sister species and (ii) not only the Westwind Drift hypothesis but also other models of dispersion are compatible with the current geographical distribution of dusky dolphins.