Expression pattern of olfactory receptor genes in human cumulus cells as an indicator for competent oocyte selection

Abstract

Odorant or olfactory receptors are mainly localized in the olfactory epithelium for the perception of different odors.Interestingly, many ectopic olfactory receptors with low expression levels have recently been found in nonolfactory tissues to involve inlocal functions. Therefore, we investigated the probable role of the olfactory signaling pathway in the surrounding microenvironmentof oocyte. This study included 22 women in intracytoplasmic sperm injection cycle. The expression of olfactory target molecules incumulus cells surrounding the growing and mature oocytes was evaluated by Western blotting and real-time polymerase chain reaction.Additionally, integrated bioinformatics analyses were carried out and 6 ectopic olfactory receptors were selected for further evaluation.The initiation of olfactory transduction cascade in cumulus cells of competent oocytes was confirmed by analyzing the expression ofadenylyl cyclase type 3 and olfactory market protein. Moreover, the expression pattern of the selected olfactory receptors was evaluatedand OR10H2 was selected due to a high level of expression in mature fertile oocytes. We suggested that OR10H2 could be consideredas a reliable biomarker for oocyte selection in assisted reproduction technique programs. However, further studies are required toelucidate the role of olfactory transduction cascade in embryo quality and implantation.