Meeting Abstract
Rodents use their keen sense of smell to navigate their environment, find food and mates, recognize conspecifics, and avoid danger. Furthermore, rodents are described as having large olfactory receptor repertoires in order to support their specialization in olfactory behaviors. However, among rodents, relatively little work has documented the olfactory receptor repertoires outside of traditional rat and mouse laboratory models. We examined the composition of the olfactory receptor repertoire of the African giant pouched rat (Cricetomys ansorgei), a Muroid rodent distantly related to mice and rats. The pouched rat is notable as it has a relatively large cortex and large olfactory bulbs compared to sympatric rodents of a similar size. This anatomical elaboration of their olfactory system has been postulated to support their olfactory behavior, which includes their use as ‘biodetectors’ in applied olfactory tasks. We hypothesized that in addition to anatomical elaboration, the pouched rat would have an expanded olfactory receptor repertoire, to further support their olfactory behaviors. We identified 1145 functional olfactory genes and 260 pseudogenes in the pouched rat genome. This repertoire is similar in size and composition to mice and rats, but has several family-specific expansions. Whether these expansions provide the pouched rat a specialized ability to detect particular odors remains an open question. We also identified 99 orthologous genes conserved among four rodent species, and 167 genes conserved within Muroidea, suggesting a conserved Muroid-specific olfactory receptor repertoire. Our data suggest that the pouched rat is capable of a suite of specialized olfactory behaviors with a typical Muroid olfactory receptor repertoire.
