TY - JOUR
T1 - Expression and differential cell distribution of low-threshold Ca 2+ channels in mammalian male germ cells and sperm
AU - Treviño, Claudia L.
AU - Felix, Ricardo
AU - Castellano, Laura E.
AU - Gutiérrez, Carolina
AU - Rodríguez, Delany
AU - Pacheco, Judith
AU - López-González, Ignacio
AU - Gomora, Juan Carlos
AU - Tsutsumi, Victor
AU - Hernández-Cruz, Arturo
AU - Fiordelisio, Tatiana
AU - Scaling, Allison L.
AU - Darszon, Alberto
N1 - Funding Information:
Supported by grants from CONACyT to A.D., R.F. and J.C.G.; and from DGAPA (UNAM) to A.D., J.C.G., C.L.T. and A.H.-C and from TWAS to C.L.T. We thank X. Alvarado, R. Hernández, E. Mata, E. Bustos, A. Rondán and A. Marı́n for expert technical assistance. We thank also the Laboratorio Clı́nico y de Biogenética Eugenio Sue for allowing us to use the Hamilton-Thorne HTM-IVOS-12 sperm analysis system.
PY - 2004/4/9
Y1 - 2004/4/9
N2 - Numerous sperm functions including the acrosome reaction (AR) are associated with Ca2+ influx through voltage-gated Ca2+ (CaV) channels. Although the electrophysiological characterization of Ca2+ currents in mature sperm has proven difficult, functional studies have revealed the presence of low-threshold (CaV3) channels in spermatogenic cells. However, the molecular identity of these proteins remains undefined. Here, we identified by reverse transcription polymerase chain reaction the expression of CaV3.3 mRNA in mouse male germ cells, an isoform not previously described in these cells. Immunoconfocal microscopy revealed the presence of the three CaV3 channel isoforms in mouse spermatogenic cells. In mature mouse sperm only CaV3.1 and Ca V3.2 were detected in the head, suggesting its participation in the AR. CaV3.1 and CaV3.3 were found in the principal and the midpiece of the flagella. All CaV3 channels are also present in human sperm, but only to a minor extent in the head. These findings were corroborated by immunogold transmission electron microscopy. Tail localization of Ca V3 channels suggested they may participate in motility, however, mibefradil and gossypol concentrations that inhibit CaV3 channels did not significantly affect human sperm motility. Only higher mibefradil doses that can block high-threshold (HVA) CaV channels caused small but significant motility alterations. Antibodies to HVA channels detected Ca V1.3 and CaV2.3 in human sperm flagella.
AB - Numerous sperm functions including the acrosome reaction (AR) are associated with Ca2+ influx through voltage-gated Ca2+ (CaV) channels. Although the electrophysiological characterization of Ca2+ currents in mature sperm has proven difficult, functional studies have revealed the presence of low-threshold (CaV3) channels in spermatogenic cells. However, the molecular identity of these proteins remains undefined. Here, we identified by reverse transcription polymerase chain reaction the expression of CaV3.3 mRNA in mouse male germ cells, an isoform not previously described in these cells. Immunoconfocal microscopy revealed the presence of the three CaV3 channel isoforms in mouse spermatogenic cells. In mature mouse sperm only CaV3.1 and Ca V3.2 were detected in the head, suggesting its participation in the AR. CaV3.1 and CaV3.3 were found in the principal and the midpiece of the flagella. All CaV3 channels are also present in human sperm, but only to a minor extent in the head. These findings were corroborated by immunogold transmission electron microscopy. Tail localization of Ca V3 channels suggested they may participate in motility, however, mibefradil and gossypol concentrations that inhibit CaV3 channels did not significantly affect human sperm motility. Only higher mibefradil doses that can block high-threshold (HVA) CaV channels caused small but significant motility alterations. Antibodies to HVA channels detected Ca V1.3 and CaV2.3 in human sperm flagella.
KW - Acrosome reaction
KW - Ca channel
KW - Gossypol
KW - Mibefradil
KW - Sperm motility
UR - http://www.scopus.com/inward/record.url?scp=11144356559&partnerID=8YFLogxK
U2 - 10.1016/S0014-5793(04)00257-1
DO - 10.1016/S0014-5793(04)00257-1
M3 - Artículo
SN - 0014-5793
VL - 563
SP - 87
EP - 92
JO - FEBS Letters
JF - FEBS Letters
IS - 1-3
ER -