Simoncini L, Block M L, Moody W J
Department of Zoology, University of Washington, Seattle 98195.
Science. 1988 Dec 16;242(4885):1572-5. doi: 10.1126/science.2849207.
The development of electrophysiological properties of isolated, identified ascidian blastomeres was followed from the fertilized egg to the neurula, and the stage at which cells of different lineages first express different functional ion channel populations was determined. Little has been known about such events because of the difficulties of making voltage-clamp recordings from small embryonic cells and of identifying their developmental fates in dissociated preparations. The problem of small cell size was circumvented by using the whole-cell patch clamp, and identification was facilitated by the use of a species of ascidian, Boltenia villosa, in which endogenous pigment marks cells of specific developmental fates. Within approximately 3 hours after gastrulation, muscle-lineage blastomeres in these embryos developed a voltage-dependent calcium current while surrounding blastomeres of other lineages did not. At about the same time, all cells developed delayed outward potassium currents and lost the inwardly rectifying potassium currents present at earlier stages.
对分离出的、已鉴定的海鞘卵裂球从受精卵到神经胚阶段的电生理特性发育进行了跟踪研究，并确定了不同谱系的细胞首次表达不同功能离子通道群体的阶段。由于从小胚胎细胞进行电压钳记录以及在解离制剂中确定其发育命运存在困难，此前人们对这些事件了解甚少。通过使用全细胞膜片钳技术规避了小细胞尺寸的问题，并且通过使用一种海鞘Boltenia villosa促进了鉴定，在这种海鞘中，内源性色素标记特定发育命运的细胞。在原肠胚形成后约3小时内，这些胚胎中的肌肉谱系卵裂球产生了电压依赖性钙电流，而其他谱系的周围卵裂球则没有。大约在同一时间，所有细胞都产生了延迟外向钾电流，并失去了早期存在的内向整流钾电流。
