Postnatal changes in the calcium binding proteins of mouse testis.

Abstract

To define the changes in calcium-binding proteins (CBPs) of mouse testis during postnatal development, testicular protein extracts were analyzed by mobility shift after Ca2+ binding (MSACB) in the 2-dimensional SDS-PAGE. In the adult testis extracts, 29 kinds of protein spots showed mobility shift in the gel containing Ca2+. Among them, 2 spots showed nonspecific mobility shift and 4 spots showed Zn2+ shift. Drastic changes in expression of high-Mr CBPs (Mr > 25 kDa) were observed in testis 3 weeks after birth, suggesting that their expressions were developmentally changed. There was no obvious difference in the qualitative patterns of CBP between 4-week-old testis and adult testis. There was a large mass of CBPs (Mr = 20-25 kDa) expressed constitutively in testis throughout the postnatal development. Degree of MSACB (Mr on the diagonal line/Mr of shifted point in Ca2+ gel) of each spot was in the range of 1.1-1.7 in 12% acrylamide gel. These results suggest that changes in CBPs of testis are closely related with progression of spermatogenesis in mouse testis.