Population structure and genetic diversity of Rana dalmatina in the Iberian Peninsula

Abstract

The increasing fragmentation of natural habitats may strongly affect patterns of dispersal and gene flow among populations, and thus alter evolutionary dynamics. We examined genetic variation at twelve microsatellite loci in the Agile frog (Rana dalmatina) from 22 breeding ponds in the Iberian Peninsula, the southwest limit of its range, where populations of this species are severely fragmented and are of conservation concern. We investigated genetic diversity, structure and gene flow within and among populations. Diversity as observed heterozygosities ranged from 0.257 to 0.586. The mean number of alleles was 3.6. Just one population showed a significant F IS value. Four populations show evidence of recent bottlenecks. Strong pattern of structure was observed due to isolation by distance and to landscape structure. The average degree of genetic differentiation among populations was F ST = 0.185. Three operational conservation units with metapopulation structure were identified. Additionally, there are some other isolated populations. The results reinforce the view that amphibian populations are highly structured even in small geographic areas. The knowledge of genetic structure pattern and gene flow is fundamental information for developing programmes for the preservation of R. dalmatina at the limits of its geographic distribution.

Novel genetic sex markers reveal high frequency of sex reversal in wild populations of the agile frog (Rana dalmatina) associated with anthropogenic land use

“…40 km; genetic structure at such small spatial scale in agile frogs is more likely the outcome of habitat fragmentation than isolation by distance (Lesbarrères, Primmer, Lodé, & Merilä, 2006, Sarasola‐Puente, Madeira, Gosá, Lizana, & Gómez‐Moliner, 2012). Highways pose migration barriers for agile frogs (Lesbarrères et al 2006, Sarasola‐Puente et al 2012); however, the distribution of main roads and highways between our study sites is more likely to reduce migration along a North/South cline than separating East from West (Figure 1). Taken together, we have little reason to expect an East/West population differentiation in our study.…”

Effects of natural and anthropogenic features on functional connectivity of anurans: a review of landscape genetics studies in temperate, subtropical and tropical species

“…Although roads, urbanization and land cover change lead to habitat fragmentation, there are a number of studies in the literature that tested the effect of habitat fragmentation in general, without specifying the factors affecting it. In populations of Rana dalmatina from Spain, fragmentation has affected southeastern populations, showing evidence of recent bottlenecks and decreases on gene flow due to isolation (Sarasola‐Puente et al ., 2012). In Ascaphus truei , low levels of genetic differentiation were detected in populations from fragmented forests, which could be the result of a delayed response of the populations to logging (Spear & Storfer, 2008).…”

Ampliación de la distribución de Rana dalmatina en Navarra

“…Las nuevas observaciones demuestran la existencia de individuos dispersos en el interior y la periferia de los territorios de las cuatro subpoblaciones originales, ampliándose notablemente el número de enclaves donde se reproduce R. dalmatina. Las incipientes diferencias genéticas detectadas entre poblaciones son consecuencia de su aislamiento (Sarasola-Puente et al, 2012), pudiendo estar presentes igualmente en los nuevos núcleos detectados en el Urumea y Bidasoa, lo que deberá ser comprobado en futuros análisis genéticos. Con los nuevos datos, las distancias en línea recta entre los núcleos poblacionales más cercanos de dos subpoblaciones vecinas fluctúan desde los 6 km en las de la Cuenca de Pamplona y La Barranca y los 25 km en las de Urumea-Bidasoa y La Barranca-Sierra de Cantabria (Tabla 3).…”