Zagris N, Chung A E, Stavridis V
Department of Biology, University of Patras, Greece.
Int J Dev Biol. 2000 Oct;44(7):815-8.
The expression patterns of laminin alpha1 and beta1 genes were examined by In situ hybridization of their mRNAs in the early chick embryo from the blastoderm at stage X (morula) to the 10-somite stage. The laminin alpha1 and beta1 transcripts were found in abundance in the chick blastoderm at stage X before initiation of synthesis of the protein. Laminin polypeptides were detected shortly thereafter in embryos at stage XIII (blastula). The expression of the laminin transcripts was intense in the epiblast and in the hypoblast of embryos at stage XIII. During gastrulation (stage HH3-4), the laminin (alpha1 and beta1 cRNAs gave strong signals in the cells ingressing through the primitive streak, in the migrating mesenchymal cells and the cells of the lower layer. The expression of laminin alpha1 and beta1 genes was restricted to specific cell populations later in development. At the neurula stage (stage HH5-6), the expression of laminin transcripts was low in epithelial ectoderm and strong in chordamesoderm neural ectoderm and may implicate important developmental roles for laminin in the morphogenetic movements of neural plate bending during primary neurulation. At the 10-somite stage (stage HH10-11), the (alpha1 and beta1 cRNAs gave no signals in the neural tube, notochord, and ectoderm. The alpha1 and beta1 cRNAs gave strong signals in neural crest cells and this may indicate that the neural crest cells can produce laminin. The alpha1 cRNAs gave strong signals in the dermamyotome and no signal in the sclerotome of somites, and intense signals in the pronephric tubules. The laminin expression pattern in somites may show transient expression of the alpha1 and/or expression of a distinct alpha1 isoform in the sclerotome. The selective expression of laminin alpha1 and beta1 subunits which shows a developmentally regulated, tissue specific distribution suggests potential roles for different members of the same subfamily of genes in the developing chick embryo.
通过对层粘连蛋白α1和β1基因的mRNA进行原位杂交，研究了其在早期鸡胚中的表达模式，鸡胚发育阶段从X期（桑椹胚）的胚盘到10体节期。在蛋白质合成开始之前，X期鸡胚胚盘中就大量存在层粘连蛋白α1和β1转录本。此后不久，在XIII期（囊胚）胚胎中检测到层粘连蛋白多肽。在XIII期胚胎的上胚层和下胚层中，层粘连蛋白转录本的表达强烈。在原肠胚形成期（HH3 - 4期），层粘连蛋白（α1和β1 cRNAs）在通过原条进入的细胞、迁移的间充质细胞和下层细胞中发出强信号。层粘连蛋白α1和β1基因的表达在发育后期局限于特定细胞群体。在神经胚期（HH5 - 6期），层粘连蛋白转录本在上皮外胚层中表达低，在脊索中胚层神经外胚层中表达强，这可能暗示层粘连蛋白在初级神经胚形成过程中神经板弯曲的形态发生运动中起重要的发育作用。在10体节期（HH10 - 11期），α1和β1 cRNAs在神经管、脊索和外胚层中无信号。α1和β1 cRNAs在神经嵴细胞中发出强信号，这可能表明神经嵴细胞可以产生层粘连蛋白。α1 cRNAs在生皮节中发出强信号，在体节的生骨节中无信号，在原肾小管中发出强信号。体节中层粘连蛋白的表达模式可能显示α1的瞬时表达和/或生骨节中不同α1同工型的表达。层粘连蛋白α1和β1亚基的选择性表达呈现出发育调控的、组织特异性的分布，这表明同一基因亚家族的不同成员在发育中的鸡胚中可能具有潜在作用。
