Moderate evidence for heritability in the duet contributions of a South American primate.

Acoustic signals are ubiquitous across mammalian taxa. They serve a myriad of functions related to the formation and maintenance of social bonds and can provide conspecifics information about caller condition, motivation and identity. Disentangling the relative importance of evolutionary mechanisms that shape vocal variation is difficult, and little is known about heritability of mammalian vocalizations. Duetting--coordinated vocalizations within male and female pairs--arose independently at least four times across the Primate Order. Primate duets contain individual- or pair-level signatures, but the mechanisms that shape this variation remain unclear. Here, we test for evidence of heritability in two call types (pulses and chirps) from the duets of captive coppery titi monkeys (Plecturocebus cupreus). We extracted four features--note rate, duration, minimum and maximum fundamental frequency--from spectrograms of pulses and chirps, and estimated heritability of the features. We also tested whether features varied with sex or body weight. We found evidence for moderate heritability in one of the features examined (chirp note rate), whereas inter-individual variance was the most important source of variance for the rest of the features. We did not find evidence for sex differences in any of the features, but we did find that body weight and fundamental frequency of chirp elements covaried. Kin recognition has been invoked as a possible explanation for heritability or kin signatures in mammalian vocalizations. Although the function of primate duets remains a topic of debate, the presence of moderate heritability in titi monkey chirp elements indicates duets may serve a kin recognition function.

Determination of major histocompatibility class I and class II genetic composition of the Caribbean Primate Center specific pathogen-free rhesus macaque (Macaca mulatta) colony based on massively parallel sequencing.

BACKGROUND: Knowledge of major histocompatibility complex (MHC) composition and distribution in rhesus macaque colonies is critical for management strategies that maximize the utility of this model for biomedical research. METHODS: Variation within the Mamu-A and Mamu-B (class I) and DRB, DQA/B, and DPA/B (class II) regions of 379 animals from the Caribbean Primate Research Center's (CPRC) specific pathogen free (SPF) colony was examined using massively parallel sequencing. RESULTS: Analyses of the 7 MHC loci revealed a background of Indian origin with high levels of variation despite past genetic bottlenecks. All loci exhibited mutual linkage disequilibria while conforming to Hardy-Weinberg expectations suggesting the achievement of mutation-selection balance. CONCLUSION: The CPRC's SPF colony is a significant resource for research on AIDS and other infectious agents. Characterizing colony-wide MHC variability facilitates the breeding and selection of animals bearing desired haplotypes and increases the investigator's ability to understand the immune responses mounted by these animals.

Population Genetic Structure of the Cayo Santiago Colony of Rhesus Macaques (Macaca mulatta).

The rhesus macaque population at Cayo Santiago increases annually and is in urgent need of control. In-depth assessments of the colony's population genetic and pedigree structures provide a starting point for improving the colony's long-term management program. We evaluated the degree of genetic variation and coefficients of inbreeding and kinship of the Cayo Santiago colony by using pedigree and short tandem repeat (STR) data from 4738 rhesus macaques, which represent 7 extant social groups and a group of migrant males. Information on each animal's parentage, sex, birth date, and date of death or removal from the island were used to generate estimates of mean kinship, kinship value, gene value, genome uniqueness (GU), founder equivalents (fe), and founder genome equivalents (fg). Pedigree and STR analyses revealed that the social groups have not differentiated genetically from each other due to male-mediated gene flow (that is, FST estimates were in the negative range) and exhibit sufficient genetic variation, with mean estimates of allele numbers and observed and expected heterozygosity of 6.57, 0.72, and 0.70, respectively. Estimates of GU, fe, and fg show that a high effective number of founders has affected the colony's current genetic structure in a positive manner. As demographic changes occur, genetic and pedigree matrices need to be monitored consistently to ensure the health and wellbeing of the Cayo Santiago colony.