Yazaki I, Dale B, Tosti E
Department of Cell and Developmental Biology, Stazione Zoologica, Villa Comunale, Naples, 80121, Italy.
Dev Biol. 1999 Aug 15;212(2):503-10. doi: 10.1006/dbio.1999.9354.
Using the whole-cell voltage-clamp technique we have studied electrical coupling and dye coupling between pairs of blastomeres in 16- to 128-cell-stage sea urchin embryos. Electrical coupling was established between macromeres and micromeres at the 16-cell stage with a junctional conductance (G(j)) of 26 nS that decreased to 12 nS before the next cleavage division. G(j) between descendants of macromeres and micromeres was 12 nS falling to 8 nS in the latter half of the cell cycle. Intercellular current intensity was independent of transjunctional voltage, nondirectional, and sensitive to 1-octanol and therefore appears to be gated through gap junction channels. There was no significant coupling between other pairs of blastomeres. Lucifer yellow did not spread between these electrically coupled cell pairs and in fact significant dye coupling between nonsister cells was observed only at the 128-cell stage. Since 1-octanol inhibited electrical communication between blastomeres at the 16- to 64-cell stage and also induced defects in formation of the archenteron, it is possible that gap junctions play a role in embryonic induction.
我们运用全细胞膜片钳技术，研究了16细胞至128细胞期海胆胚胎中卵裂球对之间的电偶联和染料偶联。在16细胞期，巨卵裂球和小卵裂球之间建立了电偶联，连接电导（G(j)）为26 nS，在下一次卵裂之前降至12 nS。巨卵裂球和小卵裂球后代之间的G(j)为12 nS，在细胞周期后半段降至8 nS。细胞间电流强度与跨连接电压无关，无方向性，且对1-辛醇敏感，因此似乎是通过间隙连接通道门控的。其他卵裂球对之间没有明显的偶联。荧光黄在这些电偶联的细胞对之间不会扩散，实际上，非姐妹细胞之间显著的染料偶联仅在128细胞期观察到。由于1-辛醇在16细胞至64细胞期抑制了卵裂球之间的电通讯，并且还诱导了原肠形成缺陷，因此间隙连接可能在胚胎诱导中发挥作用。
