D'Alessio M, Ramirez F, Suzuki H R, Solursh M, Gambino R
Department of Microbiology and Immunology, State University of New York-Health Science Center, Brooklyn, 11203.
Proc Natl Acad Sci U S A. 1989 Dec;86(23):9303-7. doi: 10.1073/pnas.86.23.9303.
We have isolated and characterized cDNA and genomic clones that specify a Paracentrotus lividus procollagen chain. The cDNAs code for 160 uninterrupted Gly-Xaa-Yaa triplets and a 252-amino acid carboxyl propeptide. Analysis of the deduced amino acid sequences indicated that the sea urchin polypeptide exhibits structural features that are characteristic of the fibril-forming class of collagen molecules. Partial characterization of two genomic recombinants revealed that the 3' end of the echinoid gene displays a complex organization that closely resembles that of a prototypical vertebrate fibrillar collagen gene. In situ and Northern (RNA) blot hybridizations established the size, time of appearance, and tissue distribution of the collagen transcripts in the developing sea urchin embryo. Collagen mRNA, approximately equal to 6 kilobases in size, is first detected in the forming primary mesenchyme cells of late blastulae where it progressively accumulates until the free swimming/feeding pluteus larval stage. Interestingly, collagen transcripts are also detected in the forming secondary mesenchyme cells of late gastrulae, and by the prism stage, their derivatives appear to be the most intensively labeled cells.
我们已经分离并鉴定了指定紫球海胆原胶原链的cDNA和基因组克隆。这些cDNA编码160个不间断的甘氨酸-任一氨基酸-任一氨基酸三联体和一个252个氨基酸的羧基前肽。对推导的氨基酸序列的分析表明，海胆多肽呈现出原纤维形成类胶原分子所特有的结构特征。对两个基因组重组体的部分鉴定显示，棘皮动物基因的3'端呈现出一种复杂的组织形式，与典型的脊椎动物原纤维胶原基因非常相似。原位杂交和Northern（RNA）印迹杂交确定了发育中的海胆胚胎中胶原转录本的大小、出现时间和组织分布。大小约为6千碱基的胶原mRNA首先在晚期囊胚形成的初级间充质细胞中被检测到，在那里它逐渐积累，直到自由游动/摄食的长腕幼虫阶段。有趣的是，在晚期原肠胚形成的次级间充质细胞中也检测到了胶原转录本，到棱柱幼虫阶段，其衍生物似乎是标记最强烈的细胞。
