DORSAL-VENTRAL PATTERNING OF THE DROSOPHILA EMBRYO DEPENDS ON A PUTATIVE NEGATIVE GROWTH-FACTOR ENCODED BY THE SHORT GASTRULATION GENE
DORSAL-VENTRAL PATTERNING OF THE DROSOPHILA EMBRYO DEPENDS ON A PUTATIVE NEGATIVE GROWTH-FACTOR ENCODED BY THE SHORT GASTRULATION GENE
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DOI：
10.1101/gad.8.21.2602
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发表时间：
1994-11-01
影响因子：
10.5
通讯作者：
BIER, E
中科院分区：
文献类型：
--
作者：
FRANCOIS, V;SOLLOWAY, M;BIER, E
果蝇胚胎背部区域的模式形成取决于一小群合子作用基因的活性。dpp是该组中的关键基因，编码TGF-β样产物（Dpp），其已被提出作为形态发生原起作用，具有峰值水平的Dpp-特异性浆膜层（最背侧的细胞类型）和较低水平的Dpp-特异性背侧外胚层。短原肠胚形成基因也有助于形成背侧区域的图案，但与参与这一过程的其他基因不同，sog活性仅在腹侧细胞中需要。遗传证据表明sog的功能是拮抗dpp的活性。在这份报告中，我们提出了进一步的表型特征的sog突变体胚胎的背部和侧面地区，并描述了克隆的sog基因座。SOG在邻接DPP表达细胞的背侧区域的细胞的宽的横向条纹中表达。据预测，SOG编码具有内部信号序列和大的胞外结构域的蛋白质，所述胞外结构域包含由10个半胱氨酸残基的间隔限定的新基序的四个重复，所述新基序与血小板反应蛋白和原胶原中存在的结构域远相关。我们提出，这些半胱氨酸重复序列中的一个或多个可以通过主要Sog蛋白的蛋白水解裂解来释放。这些假定的可溶性Sog肽然后可以扩散到背侧区域以拮抗Dpp的活性，从而导致背侧领土细分为浆膜和背侧外胚层。
Pattern formation in the dorsal region of the Drosophila embryo depends on the activity of a small group of zygotically acting genes. dpp, a key gene in this group, encodes a TGF-beta-like product (Dpp) that has been proposed to function as a morphogen with peak levels of Dpp-specifying amnioserosa, the dorsal-most cell type, and lower Dpp levels specifying dorsal ectoderm. The short gastrulation gene also contributes to patterning the dorsal region, but unlike the other genes involved in this process, sog activity is only required in ventral cells. Genetic evidence indicates that sog functions to antagonize dpp activity. In this report we present further phenotypic characterization of sog mutant embryos in dorsal and lateral regions and describe the cloning of the sog locus. sog is expressed in a broad lateral stripe of cells that abuts the dorsal territory of dpp-expressing cells. sog is predicted to encode a protein with an internal signal sequence and a large extracellular domain containing four repeats of a novel motif defined by the spacing of 10 cysteine residues that is distantly related to domains present in thrombospondin and procollagen. We propose that one or more of these cysteine repeats can be liberated by proteolytic cleavage of the primary Sog protein. These putative soluble Sog peptides may then diffuse into the dorsal region to antagonize the activity of Dpp, leading to the subdivision of the dorsal territory into amnioserosa and dorsal ectoderm.