Expression of Oestrogen Receptor Alpha and Progesterone Receptor in Sow Oviducts after Different Artificial Insemination

Abstract

In pig production, different insemination methods which allow deposition of sperm in the uterine body (intrauterine insemination, IUI) and uterine horn (deep intrauterine insemination) have been applied in order to
reduce number of spermatozoa. Earlier studies reported that steroid hormones influenced the transportation of spermatozoa, ovum and embryos in the sow reproductive tract which was related to the presence of their specific receptors; oestrogen receptor alpha (ERα) and progesterone receptor (PR). Therefore, the present study aims to evaluate the immunolocalization of ERα and PR in different parts of sow oviducts, after different artificial insemination methods. Twelve sows were divided into 3 groups according to the different insemination methods, which were AI (n = 3), IUI (n = 4) and DIUI (n = 4). Percentage of ERα and PR immunostaining was evaluated by manual scoring and image analysis system. Results showed significantly higher percentage of positive staining in AI group compared with IUI and DIUI groups in the oviduct for ERα and PR. It has been demonstrated that oestrogen (E2) in boar semen can up-regulate steroid receptors in the pig reproductive tract. The small volume of semen used for IUI and DIUI groups might also influence the lower expression of these steroid receptors due to the lower amount of
E2. In conclusion, the different insemination methods regarding the volume of semen can have the effects on the expression of steroid receptors in the sow oviduct.