Time filter

Source Type

Zurich, Sweden

Schultz J.K.,Hawaii Institute of Marine Biology | Marshall A.J.,University of Otago | Pfunder M.,Ecogenics GmbH

Threatened species often exhibit low genetic diversity as a result of selective sweeps, historical bottlenecks, or persistent small population size. Whereas selective sweeps create localized reduction of variation at a chromosome, population bottlenecks result in the loss of rare alleles throughout the genome. Heterozygosity is lost more slowly and is severely impacted only when populations are small for an extended period of time. We test the hypotheses of selective sweep, historical bottleneck and persistently small population size to explain extremely low genetic diversity in the critically endangered Hawaiian monk seal (Monachus schauinslandi). Of 163 microsatellite loci isolated from the species' genome, only 17 are polymorphic. Mapping 98 monomorphic and 12 polymorphic loci to 35 chromosomes throughout the dog genome, we reject the selective sweep hypothesis. Genotyping 2,423 Hawaiian monk seals at the 17 polymorphic loci plus a locus previously isolated from another pinniped species, we find evidence for a recent bottleneck (P = 0.04). This is consistent with historical records describing intense hunting in the 19th century; however, the bottleneck was not of sufficient severity and duration to explain the genome-wide depletion of genetic diversity (H O = 0.05; A = 1.1). Long-term population size restriction is a more likely explanation. Though at least two of the polymorphic loci appear to be candidates for selection, the low genetic diversity of the species may further threaten chances for survival of this critically endangered species in a changing world. © 2010 by the authors; licensee MDPI, Basel, Switzerland. Source

Ramstad K.M.,Victoria University of Wellington | Pfunder M.,Ecogenics GmbH | Robertson H.A.,Research and Development Group | Colbourne R.M.,Research and Development Group | And 3 more authors.
Conservation Genetics Resources

We present 14 microsatellite loci that were isolated from little spotted kiwi (LSK, Apteryx owenii). All loci cross-amplify in all kiwi species currently recognized except for one locus in a single species. Little spotted kiwi exhibited lower variation at these loci (mean number of alleles, H E) than other kiwi species, despite the markers having been developed for polymorphism in LSK and a far greater number of LSK genotyped than kiwi of other species. Reliable cross-species amplification and polymorphism make these markers promising new tools for the management of New Zealand's threatened kiwi. © Springer Science+Business Media B.V. 2010. Source

Ismail S.A.,ETH Zurich | Buser A.,Ecogenics GmbH | Uma Shaanker R.,University of Agricultural Sciences, Bangalore | Ravikanth G.,Ashoka Trust for Research in Ecology and the Environment | And 2 more authors.
Conservation Genetics Resources

Vateria indica (Dipterocarpaceae) is an economically and ecologically important canopy tree endemic to the Western Ghats, India. The species has undergone extensive habitat loss and overexploitation and is therefore listed as 'critically endangered' on the 2012 IUCN Red List. We developed ten polymorphic microsatellite loci for V. indica. In addition, we confirm cross amplification and variation in two loci isolated from the closely related but geographically disjunct species Vateriopsis seychellarum, previously published by Finger et al. Conserv Genet Resour, 2 (S1):309-311, (2010). The twelve microsatellite primers screened on 48 adult samples of V. indica had 5-11 alleles per locus (mean of 8. 5 per locus) with an average polymorphic information content of 0. 64 across loci. Expected heterozygosity ranged from 0. 44 to 0. 84. These markers will enable us to quantify population genetic diversity in habitat fragments and to study fine scale spatial genetic structure and contemporary gene flow. © 2012 Springer Science+Business Media Dordrecht. Source

Duwe V.K.,Free University of Berlin | Ismail S.A.,Free University of Berlin | Buser A.,Ecogenics GmbH | Sossai E.,Free University of Berlin | And 2 more authors.
Applications in Plant Sciences

Premise of the study: Microsatellite markers were developed to investigate population genetic structure in the threatened species Arnica Montana Methods and Results: Fourteen microsatellite markers with di-, tetra-, and hexanucleotide repeat motifs were developed for A. Montana using 454 pyrosequencing without and with library-enrichment methods, resulting in 56,545 sequence reads and 14,467 sequence reads, respectively. All loci showed a high level of polymorphism, with allele numbers ranging from four to 11 in five individuals from five populations (25 samples) and an expected heterozygosity ranging from 0.192 to 0.648 across the loci. Conclusions: This set of microsatellite markers is the first one described for A. Montana and will facilitate conservation genetic applications as well as the understanding of phylogeographic patterns in this species. © 2015 Houliston et al. Published by the Botanical Society of America. Source

Morgan E.J.,ETH Zurich | Maattanen K.,ETH Zurich | Kaiser-Bunbury C.N.,TU Darmstadt | Buser A.,Ecogenics GmbH | And 2 more authors.
Applications in Plant Sciences

Premise of the study: The evolutionarily and ecologically distinct coco de mer palm Lodoicea maldivica (Arecaceae) is endemic to two islands in the Seychelles. Before colonization of the islands by man, the endangered palm formed large monodominant stands, but its natural range is now restricted to four main populations and several patches of isolated individuals. Microsatellite markers were designed to investigate the genetic structure of the remaining natural populations of L. maldivica. Methods and Results: We developed 12 polymorphic and three monomorphic microsatellite markers for this species, with a mean number of alleles per locus of 13.2 (range 5-21) and expected heterozygosity values ranging from 0.31-0.91 for the polymorphic loci. Conclusions: These markers enable us to study the patterns of genetic diversity, contemporary seed dispersal, and the fine-scale spatial genetic structure of this important conservation flagship species. . Source

Discover hidden collaborations