Hopwood N D, Pluck A, Gurdon J B
Cancer Research Campaign Molecular Embryology Research Group, Department of Zoology, Cambridge, England.
Cell. 1989 Dec 1;59(5):893-903. doi: 10.1016/0092-8674(89)90612-0.
We have cloned a Xenopus cDNA related to the twist gene, which is required for mesodermal differentiation in Drosophila. Northern blots of dissected embryos and in situ hybridization show that the corresponding mRNA, called Xtwi, first appears in early gastrulae, and is present only in mesodermal cells. Within the mesoderm, Xtwi is expressed in the notochord and lateral plate, but not in the myotome; therefore there is a complementary pattern of Xtwi and muscle-specific gene expression in the mesoderm. Xtwi expression therefore marks the subdivision of the mesoderm. Xtwi is also activated a few hours later in the early development of the neural crest. This gene is thus expressed in response to two sequential early inductions in frog development.
我们克隆了一个与果蝇中胚层分化所需的twist基因相关的非洲爪蟾cDNA。对解剖后的胚胎进行的Northern印迹分析和原位杂交显示，相应的mRNA（称为Xtwi）首先出现在早期原肠胚中，并且仅存在于中胚层细胞中。在中胚层内，Xtwi在脊索和侧板中表达，但在体节中不表达；因此，中胚层中Xtwi和肌肉特异性基因的表达模式是互补的。因此，Xtwi的表达标志着中胚层的细分。在神经嵴的早期发育中，Xtwi也在数小时后被激活。因此，该基因是在青蛙发育过程中对两个连续的早期诱导作出反应而表达的。
