Fosnaugh K, Fuller D, Loomis W F
Department of Biology, University of California, San Diego, La Jolla 92093.
Dev Biol. 1994 Dec;166(2):823-5. doi: 10.1006/dbio.1994.1362.
The integrity of spores formed by mutant strains of Dictyostelium discoideum lacking the major spore coat proteins, SP96, SP70, or SP60, was compared to that of wild-type strains. Single, double, and triple knock-out strains developed normally and produced spores which were indistinguishable from wild-type spores by light or electron microscopy. However, the mutant strains were susceptable to staining with the lectin, ricin A, which recognizes a galactose-rich polysaccharide that is normally hidden by overlying spore coat proteins. The intensity of staining with fluorescently labeled ricinA increased as the spore coat proteins were incrementally lost. While these results indicate that the major outer spore coat proteins are not essential for the construction of a multi-layered spore coat in Dictyostelium, they show that the spores are more porous which might make them at risk to predators before germination.
将盘基网柄菌缺乏主要孢子壁蛋白SP96、SP70或SP60的突变菌株形成的孢子的完整性与野生型菌株的孢子完整性进行了比较。单敲除、双敲除和三敲除菌株发育正常并产生孢子，通过光学显微镜或电子显微镜观察，这些孢子与野生型孢子没有区别。然而，突变菌株易被凝集素蓖麻毒蛋白A染色，该凝集素可识别一种富含半乳糖的多糖，这种多糖通常被上层的孢子壁蛋白所掩盖。随着孢子壁蛋白逐渐缺失，用荧光标记的蓖麻毒蛋白A染色的强度增加。虽然这些结果表明主要的外孢子壁蛋白对于盘基网柄菌多层孢子壁的构建不是必需的，但它们表明孢子的孔隙率更高，这可能使它们在萌发前面临被捕食者攻击的风险。
