Genetic evaluation of the captive breeding program of the Persian wild ass

Abstract

During the last century, many species have become endangered and conservation in terms of captive breeding has been crucial for their survival. Classical management of captive species is based on recorded genealogies. However, if pedigrees are incomplete or inaccurate, it can bias the interpretation of the results obtained from analyses based on such data. In this investigation, 12 microsatellite loci were investigated to evaluate the studbook information of the critically endangered Persian wild ass, Equus hemionus onager. Relatedness and inbreeding coefficients were calculated in order to compare the same coefficients estimated from the recorded studbook. A significant correlation between coefficients obtained by microsatellites and the studbook validates the recorded studbook as a reasonable tool for future genetic management. Furthermore, a Bayesian-based method divided the captive onager population into four subgroups that indicate departure from random mating, and thus minor rotation of animals between zoos. Lastly, analyses for inferring past demographic changes revealed a gradual population decline and inbreeding over several generations. This may indicate a low genetic load in captive onagers as a consequence of some degree of purging. Consequently, the risk of inbreeding depression should currently be minimal in the captive breeding program. Therefore, it is recommended to increase the connectivity between the four subgroups of onagers in order to reduce the risk of demographic and genetic stochasticity. This study underlines the importance of using molecular markers to evaluate genetic management of captive breeding programs.

Ex situ conservation genetics: a review of molecular studies on the genetic consequences of captive breeding programmes for endangered animal species

“…An inbreeding coefficient calculated from studbook data was documented only in 18% of the studies. There were only three studies reporting a significant correlation between relatedness derived from studbook data (f) and the inbreeding coefficient (F IS ) (Nielsen et al 2007;Ruiz-Lopez et al 2009) or observed heterozygosity (H o ) (Ellegren 1999). Only four studies calculated the effective population size (N e ) of the captive population.…”

“…However, cumulative inbreeding will affect both measures. A correlation between both values is, therefore, intuitive and has been reported (Nielsen et al 2007). A comparison of both measures in a meta-analysis may provide valuable insights, but most of the hitherto published studies only mention f, even though genetic data was available.…”

Fundamental Studies of the Reproductive Biology of the Endangered Persian Onager (Equus hemionus onager) Result in First Wild Equid Offspring from Artificial Insemination1

“…The two challenges are the paucity of data for fundamental reproductive physiology of both genders of the subspecies and the isolated pockets of individuals or small groups that must be reproductively managed to avoid inbreeding [14][15][16][17]. The present study dealt with both issues, first by assessing seasonal endocrinology and ovarian morphology of the female as well as sperm quality and cryosensitivity of males.…”

Effectiveness of microsatellite and SNP markers for parentage and identity analysis in species with low genetic diversity: the case of European bison

“…In fact, in captive breeding, translocation and restocking programmes, substantial efforts are made to ensure that matings between close relatives are minimized. In cases in which animals have an unknown pedigree, molecular markers can be used to create a relative ranking of degrees of relatedness (Nielsen et al, 2007).…”