Gene Expression Profile of CatSper3 and CatSper4 during Postnatal Development of Mouse Testis

Channel activities, particularly those of calcium channels, have vital roles in the process of sperm maturation, motility and sperm-egg interaction. A group of the recently discovered ion channels associated with these processes is four novel channel-like proteins known as CatSper (cation channel sperm) gene family. CatSper1 and CatSper2 show sperm specific expression patterns. However, neither CatSper1 nor CatSper2 have been shown to function as cation channels when transfected into cells, singly or together. It has been suggested that the known CatSper proteins require additional subunits and/or interaction partners to function. Using in silico gene identification and prediction techniques, two further members of the CatSper family, CatSper3 and CatSper4, have been identified. It has been hypothesized that the CatSper proteins may form a functional tetrameric channel. Based on these findings, we evaluated the temporal pattern of CatSper3 and CatSper4 genes during mouse testis development to assess any potential co-incidence of their expression with CatSper1 and CatSper2. In the present study, a total of 55 male BALB/c mice were categorized into 11 age groups: 1 day, 1 week, 2 weeks, 16, 18, 20, 22, 24 and 26 days, 1 month as well as adult mice. Testes were removed from each mouse, total RNA was extracted and RT-PCR was performed with specific primers for CatSper3, CatSper4 and beta-2-microglobin (as an internal control). Our results revealed that CatSper3 and CatSper4 genes are expressed predominantly at 3 week of age. The obtained data demonstrate that: 1) The expression of CatSper3 and CatSper4 in mouse is developmentally regulated. 2) There is a direct correlation between the temporary expressions of these genes and the other two members of the family, CatSper1 and CatSper2.