Zagris Nikolas, Chung Albert E, Stavridis Vassilis
Division of Genetics and Cell and Developmental Biology, Department of Biology, University of Patras, Patras, Greece.
Int J Dev Biol. 2005;49(1):65-70. doi: 10.1387/ijdb.041812nz.
The expression patterns of entactin and laminin gamma1 chain genes were examined by in situ hybridization of their mRNAs in the early chick embryo from stage X (morula) to stage HH10-11 (10-somites). The entactin and laminin gamma1 transcripts were found in abundance in the embryo at stage X. Entactin polypeptides were detected in embryos at stage X by immunoprecipitation. The expression of the laminin transcripts was intense and of entactin milder in the epiblast and in the hypoblast of embryos at stage XIII (blastula). During gastrulation (stage HH3-4), the laminin gamma1 and entactin cRNAs gave strong signals in the cells ingressing through the primitive streak, in the migrating mesenchymal cells and the cells of the lower layer. At the neurula stage (stage HH5-6), punctate groups of cells expressed laminin gamma1 strongly in the neural ectoderm, while the signal of expression was milder and more uniform in chordamesoderm. The entactin cRNAs gave a strong punctate pattern of mRNA expression in the neural ectoderm, in mesoderm and in endoderm in embryos at the late gastrula stage (HH4), but mRNA expression was mild in the neural plate and in mesoderm and gave no signal in endoderm and lateral ectoderm in embryos at stage HH6 (neurula). At the 10-somite stage, the laminin gamma1 cRNAs gave strong signals in the neural tube and in neural crest cells migrating along the neural tube ventrally and low signals in ectoderm, intense signals in the myotome and milder signals in the dermatome and sclerotome of somites and intense signals in the mesonephric tubules. The punctate pattern of entactin expression was notable in cells at all stages studied. Ubiquitous expression of laminin gamma1 and entactin genes during the morula and blastula stages becomes restricted to specific cell populations as the first cell commitments start.
通过对从X期（桑椹胚）到HH10 - 11期（10体节）的早期鸡胚中巢蛋白和层粘连蛋白γ1链基因的mRNA进行原位杂交，检测了它们的表达模式。在X期胚胎中大量发现了巢蛋白和层粘连蛋白γ1转录本。通过免疫沉淀在X期胚胎中检测到了巢蛋白多肽。在XIII期（囊胚）胚胎的上胚层和下胚层中，层粘连蛋白转录本的表达强烈，而巢蛋白的表达较弱。在原肠胚形成期（HH3 - 4期），层粘连蛋白γ1和巢蛋白的cRNA在通过原条迁入的细胞、迁移的间充质细胞和下层细胞中产生强信号。在神经胚期（HH5 - 6期），点状细胞群在神经外胚层中强烈表达层粘连蛋白γ1，而在脊索中胚层中表达信号较弱且更均匀。在原肠胚后期（HH4期）胚胎的神经外胚层、中胚层和内胚层中，巢蛋白cRNA产生强烈的点状mRNA表达模式，但在HH6期（神经胚）胚胎的神经板和中胚层中mRNA表达较弱，在内胚层和侧外胚层中无信号。在10体节期，层粘连蛋白γ1的cRNA在神经管和沿神经管腹侧迁移的神经嵴细胞中产生强信号，在外胚层中产生低信号，在体节的肌节中产生强信号，在皮节和生骨节中产生较弱信号，在中肾小管中产生强信号。在所有研究阶段的细胞中，巢蛋白表达的点状模式都很明显。随着最初的细胞分化开始，桑椹胚和囊胚阶段层粘连蛋白γ1和巢蛋白基因的普遍表达开始局限于特定的细胞群体。
