Scentmarking communication in the female rat_C4PR_LIV

Chemical communication in mammals is in part mediated through the deposition of scent marks in the environment. Volatile and non-volatile moleculesin the scent marksconvey important information about the donor animal, such as sex, social and reproductive status,and stimulatea response in the receptor animal. In rodents, most of the work about deciphering the molecular composition of scent markshas been focused on mice. In rats, by contrast, knowledge is limitedand the molecular complexity of scent marks is not as well described as in mice. In particular, the sources and roles of proteins in scent marks are largely undefined, with even less knowledge when we consider female rats. We therefore conducted a global proteomic analysis of scent marks from femalerats (Rattus norvegicus)to define the protein composition and then we investigated the role of scent marks in sexual communication. Our study revealed that protein pattern inscent marks greatly differsfrom that in naturally voided urine, indicatinga different tissue of41origin. In particular, female scent marks are dominated by lipocalins, notablymajor urinary proteins, whereas urinary output of these proteins is almost imperceptible.Further analysis revealed that the most plausible source of the components in scent marks are the clitoral glands,implying a critical role of theseaccessory glands in sexual communication in the rat.