Fig. 4. Wild-type CX37 produced large hemichannel currents in Xenopus oocytes, but 2-21 did not produce currents nor inhibited wild-type currents. (A-D) Hemichannel current traces from control oocytes (A), or oocytes expressing wild-type CX37 (B), 2-21 (C) or wild-type CX37 and 2-21 (D) elicited in zero divalent OR2 by a series of voltage steps held for 1 second from a holding potential of –40 mV in 10 mV steps. Control currents shown in A were obtained from an oocyte that was injected with 2 ng antisense oligonucleotide to endogenous connexin CX38 only. Although an oocyte injected with 10 ng cRNA encoding wild-type CX37 showed hemichannel currents (B), no currents were observed above background in oocytes injected with 10 ng 2-21 cRNA alone (C). Oocytes injected with 10 ng wild-type CX37 cRNA and 10 ng 2-21 cRNA showed hemichannel currents similar in magnitude to the currents observed in oocytes injected with wild-type CX37 cRNA. (E) Current-voltage relationships obtained from control oocytes (x), or oocytes injected with wild-type CX37 (), 2-21 (), or a 1:1 mixture of 2-21 and CX37 (). Data are shown as mean ± s.e.m.