The evidence for post-meiotic expression of a testis-specific isoform of a regulatory subunit of calcineurin using a monoclonal antibody.
The expression of a regulatory subunit of calcineurin (CaN beta) during rat spermatogenesis was examined in rat testes using a monoclonal antibody Va1. Results showed that a testis-specific isoform of CaN beta was expressed only 3 weeks after birth, when meiosis begins, and increased in amount depending on the maturation of spermatogenesis. The matured sperm, which consists of only post-meiotic cells, is most likely to have only the testis-specific isoform of CaN beta. The brain type isoform of CaN beta was not detected in rat sperm. Immunoblot analysis of testes from different rodent species by a monoclonal antibody Va1 showed that all rodent species examined had their own homologues corresponding to a testis-specific isoform of CaN beta in rats, although they showed distinctively different molecular weights on SDS-PAGE compared to the testis-specific isoform in rats. Each homologue was shown to be specifically expressed in post-meiotic phase of spermatogenesis, as was seen in rats.
Nishio
H
H
Department of Physiology, Kagawa Medical School, Japan.
Matsui
H
H
Moia
L J
LJ
Taketa
S
S
Miyamoto
K
K
Tokuda
M
M
Itano
T
T
Nakahara
S
S
Hatase
O
O
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000911:Antibodies, Monoclonal; D001921:Brain / Q000254:growth & development / Q000378:metabolism; D019703:Calcineurin; D002148:Calmodulin-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006168:Guinea Pigs; D015151:Immunoblotting; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism*; D046911:Macromolecular Substances; D008297:Male; D008540:Meiosis; D051379:Mice; D008970:Molecular Weight; D010749:Phosphoprotein Phosphatases / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D013091:Spermatogenesis / Q000502:physiology*; D013737:Testis / Q000254:growth & development / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D002148:Calmodulin-Binding Proteins; D007527:Isoenzymes; D046911:Macromolecular Substances; D019703:Calcineurin; D010749:Phosphoprotein Phosphatases