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Population Genetic Study (population + genetic_study)
Selected AbstractsNovel polymorphic microsatellite markers developed in the cotton bollworm Helicoverpa armigera (Lepidoptera: Noctuidae)INSECT SCIENCE, Issue 5 2005YA-JIE JI Abstract A novel set of five polymorphic di- or trinucleotide microsatellite loci suitable for population genetic study were developed from an enriched genomic library for the pest insect cotton bollworm, Helicoverpa armigera, and cross-amplifiability of these and other published loci was tested in a closely related species, the tobacco budworm, H. assulta. The expected heterozygosity at these loci ranges from 0.62 to 0.91 in the cotton bollworm. The observed allele numbers varies from 4 to 12 in the limited number of individuals tested. Although a large proportion of cloned microsatellite sequences are present in multi-copy in the cotton bollworm genome, the overwhelming majority of the finalized polymorphic diallelic loci are tri-nucleotide microsatellites - an unexpected outcome, which should facilitate subsequent genotyping analysis. [source] Pronounced genetic diversity in tropical epiphyllous lichen fungiMOLECULAR ECOLOGY, Issue 10 2009ELISABETH BALOCH Abstract Lowland tropical habitats harbour an unexplored genetic diversity of epiphyllous fungi. In the shade of rainforest understoreys, lichenized fungi are specialized to an ephemeral habitat where they produce little vegetative biomass and develop reproductive structures early. In a first population genetic study of epiphyllous lichen fungi, we analysed the intraspecific genetic diversity of five leaf-colonizing lichen mycobiont species. Sampling focused on a lowland perhumid forest plot in Costa Rica, with additional collections from other localities throughout the country. In all species we detected sympatric occurrence of highly diverged haplotypes. Haplotypes belonging to distinct clades in networks were also found on the same leaf, clearly indicating multiple independent colonization events on single leaves. Despite the unusually high genetic diversity of these leaf-colonizing tropical fungi, we did not detect pronounced spatial structure of the haplotype distribution between geographical regions. The observed patterns suggest that the diversity of foliicolous lichens could be much higher than expected, with several cryptic genetic lineages within each morphologically characterized species. [source] Isolation and evaluation of 18 microsatellite markers in Siniperca chuatsi (Basilewsky)MOLECULAR ECOLOGY RESOURCES, Issue 6 2009GANGQIAO KUANG Abstract Eighteen novel microsatellite markers were isolated in the Chinese perch Siniperca chuatsi (Basilewsky) using the FIASCO method, from (AC/TG)n, (AG/TC)n, (AT/TA)n, (GATA/CTAT)n and (GATT/CTAA)n repeat genomic libraries. The number of alleles per locus ranged from two to eight in a sample of 30 individuals from a wild population. Observed heterozygosity was between 0.100 and 0.737. Seven loci showed significant deviation from Hardy,Weinberg equilibrium, null alleles were suggested at nine loci but no linkage disequilibrium between loci was detected. These loci could be useful in the population genetic study of S. chuatsi. [source] Demography of an Afrotropical passerine in a highly fragmented landscapeANIMAL CONSERVATION, Issue 1 2006M. Githiru Abstract Demographic attributes of discrete subpopulations of animals and plants that constitute a larger (meta)population network may affect the strength and direction of local population responses to habitat loss or degradation. To address this question in an Afrotropical context, we studied survival rates, population densities, sex ratios and age distributions in seven white-starred robin Pogonocichla stellata populations inhabiting differently sized forest remnants in a highly fragmented Kenyan landscape. Sex ratios were strongly male biased, especially during the non-breeding season, but the level of bias did not differ between age groups nor fragment sizes. Juvenile to adult ratios were smallest in the medium-sized fragment, but did not differ between the largest and smallest fragments. Low population density combined with a skewed sex ratio in the medium-sized fragment pointed towards a local scarcity of females, which was supported by the presence of unmated territorial males. Based on capture,recapture analysis, all populations were considered stable on average. When combining demographic patterns with those emerging from a recent population genetic study and removal experiment, our results support the notion that small populations inhabiting tiny habitat remnants may play an important role in augmenting the long-term survival of spatially structured populations. [source] Genetic variation in Irish pygmy shrews Sorex minutus (Soricomorpha: Soricidae): implications for colonization historyBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2009ALLAN D. MCDEVITT The status of the pygmy shrew (Sorex minutus L.) as a native or an introduced species in Ireland has been subject to much debate. To examine this and other aspects of the colonization history of the Irish pygmy shrew, genetic variation was determined in 247 pygmy shrews collected throughout Ireland, using mitochondrial control region sequences and five polymorphic microsatellite loci. Genetic diversity was low for both types of marker. The median-joining network for control region sequences was star-like, suggesting that the colonization of Ireland involved a small number of founders and rapid population expansion thereafter; this was supported by other statistics. Molecular dating with both mitochondrial DNA and microsatellite data is consistent with a human introduction. This would have been several thousand years ago; a recent colonization within historical times can be ruled out. This is the first detailed population genetic study of the pygmy shrew anywhere in its range. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 918,927. [source] | ||||||||||