Leptin M, Bogaert T, Lehmann R, Wilcox M
MRC Laboratory of Molecular Biology, Cambridge, England.
Cell. 1989 Feb 10;56(3):401-8. doi: 10.1016/0092-8674(89)90243-2.
The Drosophila position-specific (PS) antigens are homologous to the vertebrate fibronectin receptor family, or integrins. A Drosophila gene required for embryonic morphogenesis, l(1)myospheroid, codes for a product homologous to the beta subunit of the vertebrate integrins. l(1)myospheroid mutants die during embryogenesis. We show here that they lack the beta subunit of the PS antigens. In the absence of the beta subunit in mutant embryos, the PS alpha subunits are not expressed on the cell surface. We conclude that the l(1)myospheroid phenotype represents the lack-of-function phenotype for these Drosophila integrins. In wild-type embryos, PS antigens are found at the interface between mesoderm and ectoderm, and later mainly at the attachment sites of muscles to the epidermis and gut. Together these results indicate that during embryogenesis, Drosophila integrins are used to attach mesoderm to ectoderm, and are required for the proper assembly of the extracellular matrix and for muscle attachment.
果蝇位置特异性（PS）抗原与脊椎动物纤连蛋白受体家族或整合素同源。胚胎形态发生所需的一个果蝇基因，l(1)肌球样蛋白，编码一种与脊椎动物整合素β亚基同源的产物。l(1)肌球样蛋白突变体在胚胎发育期间死亡。我们在此表明它们缺乏PS抗原的β亚基。在突变胚胎中缺乏β亚基的情况下，PSα亚基不在细胞表面表达。我们得出结论，l(1)肌球样蛋白表型代表这些果蝇整合素的功能缺失表型。在野生型胚胎中，PS抗原存在于中胚层和外胚层之间的界面，随后主要存在于肌肉与表皮和肠道的附着部位。这些结果共同表明，在胚胎发育过程中，果蝇整合素用于将中胚层附着于外胚层，并且是细胞外基质正确组装和肌肉附着所必需的。
