The floor plate is sufficient for development of the sclerotome and spine without the notochord
The floor plate is sufficient for development of the sclerotome and spine without the notochord
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DOI：
10.1016/j.mod.2010.11.005
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发表时间：
2011-01-01
影响因子：
2.6
通讯作者：
Yamamura, Ken-ichi
中科院分区：
文献类型：
--
作者：
Ando, Takashi;Semba, Kei;Yamamura, Ken-ichi
丹福斯的短尾(SD)小鼠是一种影响脊柱发育的半显性突变。虽然脊索在胚胎9.5天时完全退化，但脊柱一直存在到腰部，提示底板可以替代脊索的功能。我们先前通过基因诱变建立了突变的小鼠品系SKT(GT)，并鉴定了新基因SKT，它被定位在SD基因座远端0.95 cM处。利用可以利用SktGt等位基因监测脊索发育和SD基因座基因分型的事实，我们评估了+-+/+-SKT(GT)、SD-+/+-+、SD-SKT(GT)/+-+、SD-SKT(GT)/+-SKT(GT)、SD-+/SD-+和SD-SKT(GT)/SD-SKT(GT)胚胎的脊椎、脊索、体节、底板和菌核的发育。在具有C57BL/6遗传背景的SD纯合子突变体中，第6胸椎的脊柱被截断，这比以前报道的更严重。脊索退变前，底板和硬骨节发育到体节水平，剩余椎体数目与底板和硬骨节的发育程度相一致。硬骨节的缺陷和随后的脊椎发育不是由于躯体发育失败造成的。综上所述，这些结果表明，脊索在退化前诱导了底板的发育，在没有脊索的情况下，剩余的底板足以维持体节分化为硬节和脊椎。(C)2010爱思唯尔爱尔兰有限公司。保留所有权利。
Danforth's short-tail (Sd) mouse is a semi-dominant mutation affecting the development of the vertebral column. Although the notochord degenerates completely by embryonic day 9.5, the vertebral column exists up to the lumber region, suggesting that the floor plate can substitute for notochord function. We previously established the mutant mouse line, Skt(Gt), through gene trap mutagenesis and identified the novel gene, Skt, which was mapped 0.95 cM distal to the Sd locus. Taking advantage of the fact that monitoring notochordal development and genotyping of the Sd locus can be performed using the SktGt allele, we assessed the development of the vertebra, notochord, somite, floor plate and sclerotome in +-+/+-Skt(Gt), Sd-+/+-+, Sd-Skt(Gt)/+-+, Sd-Skt(Gt)/+-Skt(Gt), Sd-+/Sd-+ and Sd-Skt(Gt)/Sd-Skt(Gt) embryos. In Sd homozygous mutants with a C57BL/6 genetic background, the vertebral column was truncated in the 6th thoracic vertebra, which was more severe than previously reported. The floor plate and sclerotome developed to the level of somite before notochord degeneration and the number of remaining vertebrae corresponded well with the level of development of the floor plate and sclerotome. Defects to the sclerotome and subsequent vertebral development were not due to failure of somitogenesis. Taken together, these results suggest that the notochord induced floor plate development before degeneration, and that the remaining floor plate is sufficient for maintenance of differentiation of the somite into the sclerotome and vertebra in the absence of the notochord. (C) 2010 Elsevier Ireland Ltd. All rights reserved.