Characterization of Spindlin1 isoform2 in mouse testis.

AIM To investigate the expression of Spindlin 1 (Spin 1) isoform2 and assess its function in mouse testis. METHODS First, reverse-transcription polymerase chain reaction (RT-PCR) was used to determine whether Spin1 isoform2 is present in mouse testis. Then the expression patterns of the isoform between newborn and adult mice testes were compared by immunoblot analysis. Finally, the diversity of its localization in mice testes at different ages (days 0, 7, 14, 21, 28 and 60) was observed by immunohistochemistry. The localization of the protein in mouse sperm was also investigated by immunofluorescence. RESULTS The RT-PCR results show that Spin1 isoform2 is present in mouse testis. As shown by immunoblot analysis, the isoform was more highly expressed in adult testes compared with newborn testes. Interestingly, Spin1 isoform2 did not show up in the cytoplasm of primary spermatocytes until day 14. Also, the protein exists at the tail of the mouse sperm. CONCLUSION Spin1 isoform2 is a protein expressed highly in adult testis, which might be involved in spermatogenesis and could be necessary for normal sperm motility.