Germanguz Igal, Lev Dmitri, Waisman Tal, Kim Cheol-Hee, Gitelman Inna
Department of Virology and Developmental Genetics, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel.
Dev Dyn. 2007 Sep;236(9):2615-26. doi: 10.1002/dvdy.21267.
Twist genes code for regulatory bHLH proteins essential for embryonic development and conserved across the metazoa. There are four genes that constitute the zebrafish twist family: twist1a, twist1b, twist2--orthologs of the mammalian twist1 and twist2 genes; and twist3--a gene from a new clade that does not exist in mammals. Presented here are their embryonic mRNA expression profiles. The study extends the known conservation of twist developmental patterns in tetrapods to the fish, e.g., expression in cephalic neural crest, sclerotome and lateral plate mesoderm. Some other expression domains are unique, like hypochord and dorsal aorta; some, like the notochord, may be ancestral patterns retained from protochordates; and the expression in invaginating/migrating cells may have been retained from the jellyfish. Perhaps this is one of the more ancient functions of twist--conserved from diploblasts to humans--to facilitate cell movement.
Twist基因编码对胚胎发育至关重要且在整个后生动物中保守的调控性bHLH蛋白。斑马鱼的Twist家族由四个基因组成：twist1a、twist1b、twist2（哺乳动物twist1和twist2基因的直系同源物）；以及twist3（一个不存在于哺乳动物中的新进化枝的基因）。本文展示了它们的胚胎mRNA表达谱。该研究将已知的四足动物中Twist发育模式的保守性扩展到了鱼类，例如，在头部神经嵴、体节和侧板中胚层中的表达。其他一些表达域是独特的，如脊索和背主动脉；一些，如脊索，可能是从原索动物保留下来的祖先模式；而在内陷/迁移细胞中的表达可能是从水母保留下来的。也许这是Twist更古老的功能之一——从双胚层动物到人类都保守——促进细胞运动。
