Assessment of genetic diversity and inbreeding in the EAZA gibbon conservation breeding programmes using a novel panel of cross species microsatellites

We have developed a panel of 12 autosomal microsatellite loci to measure levels of genetic diversity and inbreeding within the EAZA gibbon conservation breeding programmes. Estimates of genetic diversity and inbreeding within captive populations are usually determined from studbook data. The assumption of unrelated founders in these calculations may be erroneous, resulting in inaccurate appraisals of populations. Genetic testing of individuals provides quantitative data to directly measure relatedness and inform on the genetic diversity of populations. Our panel of microsatellite loci successfully produced profiles in all species of gibbon tested (n=11 species, across three genera), offering excellent cross-species utility. Loss of alleles was observed for all examined EAZA populations across generations, and loss of heterozygosity was observed for all populations, except Nomascus leucogenys. Deviation from Hardy-Weinberg equilibrium was detected for the Symphalangus syndactylus EAZA population (P<0.002), but for no others. We were also able to compare the diversity of the EAZA gibbons with independent samples held at The University of Tokyo. This revealed unique alleles for each species in both sets of samples, indicating higher genetic diversity in wild populations, and lower in captive populations. Our data demonstrate the advantage of direct genetic testing to assess breeding populations, quickly highlighting where intervention may be necessary. These tools will assist gibbon conservation breeding programmes by providing robust information on the genetic diversity of populations, which can be used to guide future breeding decisions.