Satoh Noriyuki, Makabe Kazuhiro W, Katsuyama You, Wada Shuichi, Saiga Hidetoshi
Department of Zoology, Graduate School of Science, Kyoto University, Kyoto 606-01, Japan.
Department of Biology, Faculty of Science, Tokyo Metropolitan University, Hachioji 192-03, Tokyo, Japan.
Dev Growth Differ. 1996 Aug;38(4):325-340. doi: 10.1046/j.1440-169X.1996.t01-3-00001.x.
Ascidians have served as an appropriate experimental system in developmental biology for more than a century. The fertilized egg develops quickly into a tadpole larva, which consists of a small number of tissues including the epidermis, central nervous system with two sensory organs, nerve cord, endoderm, mesenchyme, notochord and muscle. Lineage of these embryonic cells is completely described up to the gastrula stage. These features of the ascidian embryo provide an opportunity to study the mechanisms underlying the differentiation of tissues in development. To understand the molecular basis of ascidian embryogenesis, cloning of various genes has been performed, including those that exhibit a lineage-associated expression pattern and those encoding transcription factors, which are expected to be involved in differentiation of tissues, lineage specification, axis formation and regionalization in developmental fields. Here, we present recent advances in the isolation and characterization of these genes. We emphasize the advantages of the ascidian embryo as an experimental system to study genetic circuitries that are required for cellular differentiation and morphogenesis.
一个多世纪以来，海鞘一直是发育生物学中合适的实验系统。受精卵迅速发育成蝌蚪幼虫，它由少量组织组成，包括表皮、带有两个感觉器官的中枢神经系统、神经索、内胚层、间充质、脊索和肌肉。这些胚胎细胞的谱系在原肠胚阶段之前已被完全描述。海鞘胚胎的这些特征为研究发育过程中组织分化的潜在机制提供了机会。为了理解海鞘胚胎发生的分子基础，人们已经进行了各种基因的克隆，包括那些呈现与谱系相关的表达模式的基因以及编码转录因子的基因，这些转录因子预计参与组织分化、谱系特化、轴形成以及发育领域的区域化。在此，我们展示了这些基因在分离和表征方面的最新进展。我们强调海鞘胚胎作为研究细胞分化和形态发生所需遗传回路的实验系统的优势。
