title: High risks of losing genetic diversity in an endemic Mauritian gecko: implications for conservation.
abstract: Genetic structure can be a consequence of recent population fragmentation and isolation, or a remnant of historical localised adaptation. This poses a challenge for conservationists since misinterpreting patterns of genetic structure may lead to inappropriate management. Of 17 species of reptile originally found in Mauritius, only five survive on the main island. One of these, Phelsuma guimbeaui (lowland forest day gecko), is now restricted to 30 small isolated subpopulations following severe forest fragmentation and isolation due to human colonisation. We used 20 microsatellites in ten subpopulations and two mitochondrial DNA (mtDNA) markers in 13 subpopulations to: (i) assess genetic diversity, population structure and genetic differentiation of subpopulations; (ii) estimate effective population sizes and migration rates of subpopulations; and (iii) examine the phylogenetic relationships of haplotypes found in different subpopulations. Microsatellite data revealed significant population structure with high levels of genetic diversity and isolation by distance, substantial genetic differentiation and no migration between most subpopulations. MtDNA, however, showed no evidence of population structure, indicating that there was once a genetically panmictic population. Effective population sizes of ten subpopulations, based on microsatellite markers, were small, ranging from 44 to 167. Simulations suggested that the chance of survival and allelic diversity of some subpopulations will decrease dramatically over the next 50 years if no migration occurs. Our DNA-based evidence reveals an urgent need for a management plan for the conservation of P. guimbeaui. We identified 18 threatened and 12 viable subpopulations and discuss a range of management options that include translocation of threatened subpopulations to retain maximum allelic diversity, and habitat restoration and assisted migration to decrease genetic erosion and inbreeding for the viable subpopulations.
authors: School of Biological Sciences, University of Bristol, Bristol, United Kingdom; NERC Biomolecular Analysis Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom; National Parks & Conservation Service, Reduit, Mauritius.
authors: Steeves
authors: S
authors: Buckland
authors: School of Biological Sciences, University of Bristol, Bristol, United Kingdom; Durrell Wildlife Conservation Trust, Jersey, Channel Islands; Mauritian Wildlife Foundation, Vacoas, Mauritius.
authors: Nik C
authors: NC
authors: Cole
authors: Durrell Institute of Conservation and Ecology, School of Anthropology and Conservation, University of Kent, Kent, United Kingdom.
authors: Jim J
authors: JJ
authors: Groombridge
authors: NERC Biomolecular Analysis Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom.
authors: Clemens
authors: C
authors: Küpper
authors: NERC Biomolecular Analysis Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom.
authors: Terry
authors: T
authors: Burke
authors: NERC Biomolecular Analysis Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom.
authors: Deborah A
authors: DA
authors: Dawson
authors: National Parks & Conservation Service, Reduit, Mauritius.
authors: Laura E
authors: LE
authors: Gallagher
authors: School of Biological Sciences, University of Bristol, Bristol, United Kingdom.
authors: Stephen
authors: S
authors: Harris
mesh_terms: D025041:Animal Migration; D000818:Animals; D003247:Conservation of Natural Resources; D004272:DNA, Mitochondrial / Q000737:chemistry; D056727:Endangered Species; D053476:Extinction, Biological; D014644:Genetic Variation; D005838:Genotype; D008116:Lizards / Q000235:genetics* / Q000502:physiology; D008436:Mauritius; D018895:Microsatellite Repeats; D010802:Phylogeny; D011156:Population Density; D011157:Population Dynamics; D060047:Reproductive Isolation
chemical_list: D004272:DNA, Mitochondrial