Differential gene expression in porcine oviduct during the oestrous cycle

The oviduct undergoes changes under the influence of steroid hormones during the oestrous cycle. However, the molecular mechanisms underlying oviductal regulation are not fully understood. The aim of the present study was to identify the gene expression profile of the porcine oviduct in different stages of the cycle using microarray technology. A systematic study was performed on animals at four different stage: prepubertal gilts, and sows in the preovulatory, postovulatory and luteal phase of the oestrous cycle. The porcine oviduct expressed a total of 4929 genes. Moreover, significant differences in the expression of several genes were detected as the oestrous cycle progressed. Analysis of the differentially expressed genes indicated that a total of 86, 89 and 15 genes were upregulated in prepubertal gilts, preovulatory and luteal sows respectively compared with levels observed in postovulatory sows. Moreover, 80, 51 and 64 genes were downregulated in prepubertal, preovulatory and luteal animals respectively compared with the postovulatory sows. The concentrations of 10 selected transcripts were quantified by real-time reverse transcription-polymerase chain reaction to validate the cDNA array hybridisation data. Conversely, for some genes, localisation of corresponding protein expression in the oviduct was analysed by immunohistochemistry (i.e. cholecystokinin, glutathione peroxidase 2, mucin 1, phosphatidylethanolamine binding protein 4 and tachykinin 3) and mass spectrometry analysis of oviductal fluid allowed identification of peptides from all five proteins. The results of the present study demonstrate that gene expression in the porcine oviduct is clearly regulated during the oestrous cycle, with some oviductal proteins that could be related to several reproductive processes described here for the first time.