Study On The Expression Characteristics And Localization Of Lcn5 In Goat Testis And Epididymidis

Lcn5, one member of Lipocalin family proteins, is closely related to male reproduction. Currently, studies reported on Lcn5 in reproductive organs are mainly in mice and rats. Considering the expression patterns of Lcn5 in reproductive organs of goat at different developmental stages has not been reported, the present research was to study the expression and localization of Lcn5 in testis and epididymis of goat at different developmental stage and its effects on the reproductive function of goats, which provided a theoretical basis for further study of Lcn5 about its regulatory mechanism in male animal reproduction.Epididymis and testis of goats at seven days,2,3,4,5,6,9 and 18 months of age and sperm of goat at 18 months of age were taken as the research object. We used the QRT-PCR and Western blot technology to analyse the relative expression level of Lcn5 mRNA and that of Lcn5 protein in testis and epididymis tissues of goat. Immunohistochemistry and immunofluorescence technology were used to analyse the localization of Lcn5. The main results were as follows:(1) QRT-PCR results showed that Lcn5 widely expressed in goats, In addition to the reproductive organs with a high expression level, the remaining organs all had a low expression level. The expression level in reproductive organs was as follows: Epididymidal caput> Epididymidal cauda> Epididymidal corpus> Testis. The expression of Lcn5 mRNA in Epididymidal caput, Epididymidal corpus and Epididymidal cauda of goat at different developmental stages gradually increased up to 5 months of age, then gradually decreased.(2) Western-blot results showed that the expression of Lcn5 protein in testis and epididymis were as follows: Epididymidal caput> Epididymidal cauda> Epididymidal corpus> Testis. The expression trend of Lcn5 protein in epididymis of goat at different months was consistent with that of Lcn5 mRNA and testis also showed the same trend.(3) Immunohistochemistry and immunofluorescence results showed that Lcn5 expressed both in goats testis and epididymis. Lcn5 expressed in spermatogonia and sperm cells in testis and rapidly increased in pseudostratified columnar epithelial cells, ciliated cells and the cytoplasm luminal fluid in the epididymis. Immunofluorescence results showed Lcn5 mainly expressed in the sperm acrosome end cap and the tail. The results of immunohistochemical optical density analysis of Lcn5 in testis and epididymis of goat at different months consisted with that of mRNA and western-blot results, suggesting Lcn5 may be related with spermatogenesis, maturation, capacitation and vibrant energy, and thus affect the male reproduction.