See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/309513614 Genetic structure and diversity in an isolated population of an endemic mole salamander (Ambystoma rivulare... Article in Genetica · December 2016 DOI: 10.1007/s10709-016-9935-9 CITATIONS READS 0 163 6 authors, including: Octavio Monroy-vilchis Martha M Zarco-González Universidad Autónoma del Estado de México … Universidad Autónoma del Estado de México … 79 PUBLICATIONS 584 CITATIONS 29 PUBLICATIONS 257 CITATIONS SEE PROFILE SEE PROFILE Daniel Martinez German D Mendoza Metropolitan Autonomous University Metropolitan Autonomous University 17 PUBLICATIONS 25 CITATIONS 303 PUBLICATIONS 1,908 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: COORDINADOR DEL CENTRO DE INVESTIGACIÓN EN CIENCAS BIOLÓGICAS APLICADAS View project Growth parameters of black spiny-tailed iguana (Ctenosaura pectinata). View project All content following this page was uploaded by Armando Sunny on 16 November 2016. The user has requested enhancement of the downloaded file. Genetica (2016) 144:689–698 DOI 10.1007/s10709-016-9935-9 Genetic structure and diversity in an isolated population of an endemic mole salamander (Ambystoma rivulare Taylor, 1940) of central Mexico 1 1 Rosa-Laura Heredia-Bobadilla • Octavio Monroy-Vilchis • 1 2 Martha M. Zarco-Gonza´lez • Daniel Martı´nez-Go´mez • 2 1 Germa´n David Mendoza-Martı´nez • Armando Sunny Received: 18 August 2016 / Accepted: 18 October 2016 / Published online: 28 October 2016 Ó Springer International Publishing Switzerland 2016 Abstract Human activities are affecting the distribution of values of effective population size, small inbreeding species worldwide by causing fragmentation and isolation coefficients, and low gene flow were also found. of populations. Isolation and fragmentation lead to popu- lations with lower genetic variability and an increased Keywords Mole salamander Á Conservation genetics Á chance of inbreeding and genetic drift, which results in a Micro-endemic species Á Microsatellites Á Conservation loss of biological fitness over time. Studies of the genetic structure of small and isolated populations are critically important for management and conservation decisions. Introduction Ambystoma rivulare is a micro-endemic Mexican mole salamander from central Mexico. It is found in the most Biodiversity of the planet is rapidly decreasing as a conse- ecologically disturbed region in Mexico, the Trans-Mexi- quence of human exploitation of land resources. Conse- can Volcanic Belt. The goal of this study of the population quences of decreased biodiversity include reduced species genetics of the micro-endemic mole salamander was to richness (Waltert et al. 2004; Ribeiro et al. 2009), a decline in provide information to be used as a basis for future genetic diversity (Frankham et al. 2005), and changes in the research and conservation planning of this species and distribution of fauna resulting from habitat loss (Ribeiro et al. other species of the Ambystoma genus in Mexico. The 2009; Sarukha´n et al. 2009). Loss of habitat can result in structural analysis found two subpopulations, one for each small, isolated, and fragmented populations. These popula- river sampled, with no signs of admixture and very high tions tend to have an increased chance of inbreeding as well levels of genetic differentiation. Medium to high levels of as less genetic variability due to a loss of alleles through heterozygosity and few alleles and genotypes were genetic drift (Frankham et al. 2005; Sunny et al. 2014a; observed. Evidence of an ancestral genetic bottleneck, low Rueda Zozaya et al. 2016), reducing their biological fitness over time (Lande 1988; Jehle and Arntzen 2002). In order to maintain sufficient levels of genetic variability for small, Electronic supplementary material The online version of this fragmented populations and ensure their long term survival, article (doi:10.1007/s10709-016-9935-9) contains supplementary studies of genetic variability must be conducted so that material, which is available to authorized users. management strategies can be improved (Frankham et al. 2005; Palsbøll et al. 2007; Bradshaw et al. 2010). & Octavio Monroy-Vilchis [email protected]; [email protected] Mexico is a biodiverse country which ranks fifth in the number of amphibian species (Parra-Olea et al. 1999;Frı´as- 1 Centro de Investigacio´n en Ciencias Biolo´gicas Aplicadas, Alvarez et al. 2008) with 377 species (AmphibiaWeb 2016), Universidad Auto´noma del Estado de Me´xico, Instituto of which 259 are endemic (Parra-Olea et al. 2014; Flores- literario # 100, Colonia Centro, CP 50000 Toluca, Estado de Me´xico, Mexico Villela and Garcı´a-Va´zquez 2014;AmphibiaWeb2016). However, Mexico also ranks fourth in world deforestation 2 Departamento de Produccio´n Agrı´cola y Animal, Universidad Auto´noma Metropolitana Xochimilco, Calz. Del Hueso 1100, rates (FAO 2006; Ellis and Porter-Bolland 2008), which Col. Villa Quietud, 04960 Mexico city, Mexico increases fragmentation and isolation of wildlife populations. 123 690 Genetica (2016) 144:689–698 The Trans-Mexican Volcanic Belt (TMVB) is one of the most grassland, near a sacred fir and pine forest (Abies religiosa ecologically disturbed regions in the country due to its near- and Pinus hartwegii), at an altitude of 3200 masl. The ness to highly urbanized cities (Sunny et al. 2015). Mexico sampling site is a recreational park with ecotourism also has 18 Ambystoma species, of which 16 are endemic activities, trout farming, and cattle and sheep grazing (Parra-Olea et al. 2014). Ambystoma rivulare is a micro-en- (Fig. 1). Tissue samples from 54 individuals were collected demic mountain mole salamander that inhabits slow-flowing in the first river, and from 32 individuals in the second streams within the TMVB, surrounded by Pinus hartwegii and river. In order to represent all maturity stages of A. rivulare Abies religiosa forest. It is found in streams located above in the data, tissue was obtained from both adults and larvae. 2800 m above sea level (masl) (Barriga-Vallejo et al. 2015). Sampling of larvae was limited ([10 %) and efforts were This species is endangered, along with most of the mole made to avoid sampling siblings. A total of 14 sampling salamanders of Mexico (SEMARNAT 2010; Parra-Olea sites were chosen after considering the characteristics of et al. 2012; Sunny et al. 2014a; IUCN 2016), largely due to different micro-environments presented by the rivers deforestation, pollution of rivers, and the introduction of (presence of ponds, flow rates, substrate type, amount of exotic species (Casas-Andreu et al. 2004; Beebee and vegetation, etc.). Individuals were captured with a fishing Griffiths 2005; Zambrano et al. 2010). However, there is net and a 2 mm2 tail clip was collected. This methodology little information on the current population trend and the is low-impact and does not affect the survival or growth of status of genetic variability of this species, except within the mole salamanders (Arntzen et al. 1999; Polich et al. the Special Reserve of the Monarch Butterfly (SRMB) 2013). Tissue samples were preserved in 90 % ethanol and (Parra-Olea et al. 2012). The IUCN categorizes this species then frozen at -20 °C until processing could be completed. as data deficient (Shaffer et al. 2008). Additionally, this All mole salamanders were released immediately at the species is found in one of the most fragmented and dis- point of capture. turbed areas of Mexico, where the environment has been heavily impacted by agriculture and urban settlements. In DNA extraction and microsatellite amplification fact, some of the largest metropolitan areas in Mexico are in the distribution range of A. rivulare (CONAPO 2010; DNA extraction was performed with a commercial kit Bryson et al. 2014; Sunny et al. 2015). (Vivantis GF-1 Tissue DNA extraction kit). Genomic DNA The aim of this study was to assess two small, frag- was used as a template for amplification of nine mented populations of A. rivulare found in the Nevado de microsatellite loci: At 52.2, At 52.10, At 52.143, At 60.3, Toluca Volcano (NTV) natural protected area, part of the At 52.115, At 52.6, At 52.34, At 52.20, and At 52.1 (Parra- TMVB, by examining their genetic diversity and structure, Olea et al. 2007). PCR reactions were performed in a level of inbreeding, current effective population size, and Techne thermocycler. Amplified products were multi- evidence for bottlenecks. The NTV was declared a natural plexed on an ABI Prism3730xl and sized in PEAK protected area in 1936, but lack of communication between SCANNER V1.0 (Applied Biosystems 2006) software the government and communal land holders prevented using ROX-500 as an internal size standard. Allele sizes proper implementation of protection laws. Consequently, were measured and binned with the software TANDEM the presence of human settlements, parks, trout farming, (Matschiner and Salzburger 2009). illegal logging and other human activities has continued to affect the biodiversity of this area (Candeau and Franco Microsatellite analysis 2007). Based on this species’ life history and the poor condition of the natural protected area, we expected to find Potential scoring errors and genetic structure low genetic variability, a high degree of genetic structure, small effective population sizes, and low gene flow in these The presence of null alleles and other genotyping errors populations. These results will provide valuable informa- was determined using the software MICROCHECKER tion for making management decisions to help preserve A. (Van Oosterhout et al. 2004). rivulare in the NTV. We used the software STRUCTURE 2.3.4 (Pritchard et al. 2000) to infer the population structure. Due to the lack of genetic structure found in previous studies, the Materials and methods results of exploratory analyses of these data (K = 10, K = 8, K = 5, K = 3, K = 2 and K = 1; results not Study site and population sampling shown), and the results of a Delta K (DK) Evanno plot (see results), we decided to explore values of K from 1 to 8.