Rex M, Orme A, Uwanogho D, Tointon K, Wigmore P M, Sharpe P T, Scotting P J
Department of Biochemistry, University of Nottingham Medical School, Queen's Medical Centre, United Kingdom.
Dev Dyn. 1997 Jul;209(3):323-32. doi: 10.1002/(SICI)1097-0177(199707)209:3<323::AID-AJA7>3.0.CO;2-K.
The chick genes, cSox2 and cSox3, are members of a large family of genes that encode transcription factors. Previous studies have shown that these genes are predominantly expressed in the central nervous system during embryonic development. We show that cSox3 is expressed throughout the ectoderm that is competent to form nervous tissue before neural induction. The expression of cSox3 is lost from cells as they undergo gastrulation to form nonectodermal tissues; the transcription factor, Brachyury, appears in cells about to undergo gastrulation a short time before cSox3 transcripts are lost. Therefore, Brachyury expression may act functionally upstream of cSox3 downregulation. cSox3 expression is also lost from non-neuronal ectoderm shortly after the neural plate becomes morphologically apparent. cSox2 expression increases dramatically in the central nervous system as neural ectoderm is established. The appearance of cSox2 in neural ectoderm represents one of the earliest molecular responses to neural induction documented thus far.
鸡的基因cSox2和cSox3是一个编码转录因子的大基因家族的成员。先前的研究表明，这些基因在胚胎发育过程中主要在中枢神经系统中表达。我们发现，cSox3在神经诱导之前能够形成神经组织的整个外胚层中表达。随着细胞进行原肠胚形成以形成非外胚层组织，cSox3的表达从细胞中消失；转录因子Brachyury在cSox3转录本消失前不久出现在即将进行原肠胚形成的细胞中。因此，Brachyury的表达可能在功能上位于cSox3下调的上游。在神经板在形态上变得明显后不久，cSox3的表达也从非神经外胚层中消失。随着神经外胚层的建立，cSox2在中枢神经系统中的表达急剧增加。cSox2在神经外胚层中的出现代表了迄今为止记录的对神经诱导的最早分子反应之一。
