A BKCa to Kv Switch During Spermatogenesis in the Rat Seminiferous Tubules

Abstract Spermatogenesis is a complex cellular event during which the diploid germ cells differentiate and divide by mitosis and meiosis at specific time points along the spermatogenic cycle to generate the haploid spermatozoa. For this complex event to go in an orderly manner, cell differentiation and division must be precisely controlled by signals arising from within and outside the seminiferous tubules. Changes in the membrane potential of the germ cells are likely to be an important part of the signaling mechanism. We have applied the whole-cell patch clamp technique to identify and characterize ion channels in different spermatogenic cells from immature and mature rat testes fractionated by discontinuous Percoll gradient. A voltage- and Ca2+- dependent, outwardly rectifying current with gating and pharmacologic properties resembling the large conductance K+ channels (BKCa) was recorded from the spermatogonia and primary spermatocytes. Another voltage-dependent, outwardly rectifying current that was ...