Population genetics of the California National Primate Research Center’s (CNPRC) captive Callicebus cupreus colony

Abstract

The California National Primate Research Center (CNPRC) maintains a small colony of titi monkeys (Callicebuscupreus) for behavioral studies. While short tandem repeat (STR) markers are critical for the genetic management of the center’s rhesus macaque (Macacamulatta) breeding colony, STRs are not used for this purpose in the maintenance of the center’s titi monkey colony. Consequently, the genetic structure of this titi monkey population has not been characterized. A lack of highly informative genetic markers in titi monkeys has also resulted in scant knowledge of the species’ genetic variation in the wild. The purpose of this study was to develop a panel of highly polymorphic titi monkey STRs using a cross-species PCR amplification protocol that could be used for the genetic management of the titi monkey colony. We screened 16 STR primer pairs and selected those that generated robust and reproducible polymorphic amplicons. Loci that were found to be highly polymorphic, very likely to be useful for parentage verification, pedigree assessment, and for studying titi monkey population genetics, were validated using Hardy-Weinberg equilibrium and linkage disequilibrium analyses. The genetic data generated in this study were also used to directly assess the impact of a recent adenovirus outbreak on the colony’s genetic diversity. While the adenovirus epizootic disease caused significant mortality (19 deaths among the 65 colony animals), our results suggest that the disease exhibited little or no influence on the overall genetic diversity of the colony.

Evaluating the genetic status of a closed colony of titi monkeys (Callicebus cupreus) using multigenerational pedigrees

“…The low colony‐wide inbreeding and kinship values suggest that colony management strategies have been successful in reducing consanguinity by preventing pairing first‐degree relatives (ie, mating between an offspring and its parent or full‐sib) and second‐degree relatives (ie, mating between an individual and its grandparent, aunt/uncle or half‐sibling) as well as minimizing opportunities for matings between third‐degree relatives (ie, mating between an individual and its first cousin or a great‐grandparent). This selective breeding scheme has likely also resulted in estimates of negative FIS, an indication of the absence of inbreeding based on Callicebus ‐specific DNA markers . As comparisons of genetic diversity and inbreeding estimates prior to and after the viral epizootic disease that struck the CNPRC in May 2009, which killed 19 of the 74 colony animals, showed no loss of variability occurred among the surviving colony animals, the same breeding program to prevent increasing levels of inbreeding is still currently employed to manage the CNPRC C. cupreus colony.…”

“…This selective breeding scheme has likely also resulted in estimates of negative FIS, an indication of the absence of inbreeding based on Callicebus ‐specific DNA markers . As comparisons of genetic diversity and inbreeding estimates prior to and after the viral epizootic disease that struck the CNPRC in May 2009, which killed 19 of the 74 colony animals, showed no loss of variability occurred among the surviving colony animals, the same breeding program to prevent increasing levels of inbreeding is still currently employed to manage the CNPRC C. cupreus colony.…”

“…Founder metrics in the present study, however, indicate that the effects of genetic drift have not been effectively mitigated, resulting in the loss of some founder alleles. The lack of DNA samples from older animals, including colony founders, in Mendoza et al's study prevented the assessment effects of genetic drift in this colony and its impact on founder alleles. Going forward, colony managers should utilize pedigree metrics to rank breeding animals according to their GU values to increase founder genome representation and curb future genetic bottlenecks and allele loss.…”

“…However, the colony genetic structure and composition are not as well characterized, and therefore, these data are not rigorously used. A more complete understanding of the colony genetic structure is important for the population’s long‐term viability and productivity . Moreover, as differences in the genetic composition of captive‐bred animals influence their suitability in research, knowledge of the C. cupreus colony genetic structure will support the development of this species as an NHP model for research…”

“…A more complete understanding of the colony genetic structure is important for the population's long-term viability and productivity. 7 Moreover, as differences in the genetic composition of captive-bred animals influence their suitability in research, knowledge of the C. cupreus colony genetic structure will support the development of this species as an NHP model for research. 8,9 In 2014, an initiative was implemented to characterize the genetic structure and composition of the CNPRC C. cupreus colony using a panel of short tandem repeats (STRs).…”