Joos T O, Whittaker C A, Meng F, DeSimone D W, Gnau V, Hausen P
Max-Planck-Institut für Entwicklungsbiologie, Abt. V, Tübingen, FRG.
Mech Dev. 1995 Apr;50(2-3):187-99. doi: 10.1016/0925-4773(94)00335-k.
The full length sequence of the Xenopus integrin alpha 5 subunit is reported. Analysis of cloned cDNA fragments reveals that alternative polyadenylation of alpha 5 mRNA occurs in the embryo. Furthermore, a variant form of the alpha 5 mRNA is expressed which encodes an integrin alpha 5 subunit with a truncated cytoplasmic domain. Integrin alpha 5 mRNA and protein are expressed in oocytes, eggs and throughout development. Spatial expression of alpha 5 mRNAs is first detected by whole mount in situ hybridization in presumptive neural crest cells and in the somitic mesoderm from the midgastrula stage onwards. In contrast, the alpha 5 protein is present on newly formed plasma membranes beginning at first cleavage. During neurulation, the integrin alpha 5 subunit disappears from the outer layer of the ectoderm, the notochord and the neural tube and accumulates in the sensorial layer of the ectoderm, the somites and the neural crest cells. These results provide evidence for the position specific regulation of alpha subunit expression in early vertebrate embryos.
报道了非洲爪蟾整联蛋白α5亚基的全长序列。对克隆的cDNA片段的分析表明，α5 mRNA在胚胎中存在可变聚腺苷酸化现象。此外，还表达了一种α5 mRNA的变体形式，其编码具有截短细胞质结构域的整联蛋白α5亚基。整联蛋白α5 mRNA和蛋白在卵母细胞、卵以及整个发育过程中均有表达。通过整体原位杂交，在原肠胚中期开始，首先在推定的神经嵴细胞和体节中胚层中检测到α5 mRNA的空间表达。相反，α5蛋白从第一次卵裂开始就出现在新形成的质膜上。在神经胚形成过程中，整联蛋白α5亚基从外胚层的外层、脊索和神经管消失，并在外胚层的感觉层、体节和神经嵴细胞中积累。这些结果为早期脊椎动物胚胎中α亚基表达的位置特异性调控提供了证据。
