Developing germ cells in mouse testis express pheromone receptors

Abstract

Pheromone receptors are expressed in the accessory olfactory system, which is vital for non-specific chemical communication and for sexual behavior. Under the hypothesis that some of the pheromone molecules released from female reproductive organs might regulate sperm chemotaxis or chemokinesis, we examined whether the V1R type pheromone receptor mRNAs are expressed in developing germ cells. By a reverse transcription-PCR method, we obtained nine kinds of cDNA fragments belonging to the receptor family. In situ hybridization analysis in testicular sections using probes of testicular pheromone receptors (TVRs) revealed that TVR mRNAs were expressed by spermatids. TVRs were also expressed in the accessory olfactory organ. In the testis, hybridization signals were localized in subsets of the seminiferous tubules, suggesting that TVRs were expressed by selective subsets of the spermatids. In situ hybridization study suggests also that each sperm expresses multiple pheromone receptors. The testicular pheromone receptors might have an important role in the maturation and/or migration of sperm. ß

Functional characterization of a mouse testicular olfactory receptor and its role in chemosensing and in regulation of sperm motility

“…This expression during limited stages of spermatids is similar to the expression pattern of some members of the spermatid chemoreceptor family (a family of rat ORs) in the testis (Walensky et al, 1998). This contrasts with the report by Tatsura et al (Tatsura et al, 2001) that TOR9, an OR family member, is expressed in 90% of seminiferous tubules. The large difference between the expression patterns could be attributed to differences between OR genes or to differences in hybridization conditions.…”

G Protein-Coupled Receptor Genes in the FANTOM2 Database

“…Nevertheless, it is intriguing that some of the odorant or pheromone receptor genes are expressed in testis and certain neonate tissues in which the odorant receptors appear to have no biological function. This observation is consistent with the previous reports (Parmentier et al 1992;Thomas et al 1996;Tatsura et al 2001) and raises a possibility that the sensory receptors could be involved not only in olfactory sensing, but also in reproduction or development. Moreover, it is well characterized that each olfactory neuron expresses only one odorant receptor gene (Buck 2000).…”

Female choice and the MHC

“…This has been observed in humans [46,57], mice [19,66,67], rats [66,68] and dogs [47]. In line with this, the product of a particular OR gene is expressed on a variable number (w5-40%) of spermatozoa within a given ejaculate in humans, mice and dogs [18,19,69].…”