Improving the Golden-headed lion tamarin breeding schemes by establishing founder relatedness through combined microsatellite maker and pedigree analysis

To conserve a self-sustaining captive population, the population must be genetically managed to minimize loss of genetic diversity, inbreeding and adaptation to captivity. Accurate genetic management of a captive population relies mostly on pedigree analysis. However, the majority of the pedigrees in captive breeding programs are far from perfect for various reasons. Most importantly, founders are assumed to be unrelated, often resulting in an overestimation of the genetic diversity present in a population. The captive population of the Golden-headed lion tamarin, Leontopithecus chrysomelas, which is endemic to the Atlantic forest of South-Bahia and threatened with extinction, has grown in the last decades from 46 founders to a size of approximately 220 animals in the EEP. The pedigree is known for about 98% and the genetic diversity retained is estimated on a good 97% of the source population. However, the Golden-headed lion tamarins were imported from Brazil in small groups for which mutual relatedness was unknown. The main objectives of this study were to estimate the genetic relationship between the GHLT founders and to resolve gaps in the pedigree of the captive GHLT population. We used 21 microsatellite marker loci to infer genetic relatedness among 95 captive individuals in the first generations. Tissue samples were collected post-mortem and for live animals non-invasive hair samples were used for DNA extraction. Pedigree and molecular data were combined into one estimator of relatedness by weighing method developed by Bomcke & Gengler (2009). Integration of the relatedness estimates was completed through the use of the program PMx. The changes in mean inbreeding (F), mean kinship (MK), founder genome equivalents, and GD were assessed. Using these values we aimed to improve the breeding schemes and to make a more accurate evaluation of the current genetic status of the population.