1Department of Anthropology, Yale University, 2Department of Anthropology, University of Pennsylvania, 3CECOAL, Conicet-Argentina
Thursday All day, Plaza Level
Numerous vertebrate studies have demonstrated a correlation between elevated levels of the pituitary hormone prolactin (PRL) in fathers compared to non-fathers. Knockout mouse studies have further implicated the prolactin receptor (PRLR), as a key component of this neuroendocrine pathway, which is associated with parental care behavior. Although paternal care is rare in the mammalian world, several platyrrhine primate taxa show high levels of paternal investment in offspring. In our study population, Azara’s owl monkeys (Aotus azarai) of northern Argentina, males exhibit extraordinarily high levels of care to infants residing within their social group. Thus, to explore the nexus between PRLR variation and paternal care behavior, we sequenced the entire PRLR gene and characterized intraspecific variation in 25 owl monkeys. In addition, we examined interspecific variation in PRLR by sequencing the locus in four phylogeographically diverse Aotus species, as well as 12 other platyrrhine and catarrhine taxa who contribute varying amounts of paternal care to their putative offspring. Our analysis revealed that the coding region of PRLR exhibits high levels of variation within the A. azarai population, the genus Aotus possesses unique lineage-specific amino acid changes, and the gene displays considerable variation among both platyrrhines and catarrhines. In fact, entire codons within PRLR have been deleted in several species. We further detected signatures of balancing selection that have maintained molecular diversity in the intracellular domain of PRLR mRNA. These findings suggests that functional changes in PRLR may have contributed to the uneven distribution of paternal care behaviors among extant primates
This research was supported by the University Research Fund and Department of Anthropology at the University of Pennsylvania, the Department of Biology at Haverford College, and the National Science Foundation (EFD: BCS-0621020). TGS further acknowledges the infrastructural support provided by the National Geographic Society.