Bakkers J, Semino C E, Stroband H, Kijne J W, Robbins P W, Spaink H P
Institute of Molecular Plant Sciences, Leiden University, Wassenaarseweg 64, 2333 AL Leiden, The Netherlands.
Proc Natl Acad Sci U S A. 1997 Jul 22;94(15):7982-6. doi: 10.1073/pnas.94.15.7982.
Derivatives of chitin oligosaccharides have been shown to play a role in plant organogenesis at nanomolar concentrations. Here we present data which indicate that chitin oligosaccharides are important for embryogenesis in vertebrates. We characterize chitin oligosaccharides synthesized in vitro by zebrafish and carp embryos in the late gastrulation stage by incorporation of radiolabeled N-acetyl-D-[U14C]glucosamine and by HPLC in combination with enzymatic conversion using the Bradyrhizobium NodZ alpha-1, 6-fucosyltransferase and chitinases. A rapid and sensitive bioassay for chitin oligosaccharides was also used employing suspension-cultured plant cells of Catharanthus roseus. We show that chitin oligosaccharide synthase activity is apparent only during late gastrulation and can be inhibited by antiserum raised against the Xenopus DG42 protein. The DG42 protein, a glycosyltransferase, is transiently expressed between midblastula and neurulation in Xenopus and zebrafish embryogenesis. Microinjection of the DG42 antiserum or the Bradyrhizobium NodZ enzyme in fertilized eggs of zebrafish led to severe defects in trunk and tail development.
几丁质寡糖的衍生物已被证明在纳摩尔浓度下对植物器官发生起作用。在此，我们展示的数据表明几丁质寡糖对脊椎动物的胚胎发生很重要。我们通过掺入放射性标记的N-乙酰-D-[U14C]葡糖胺以及结合使用慢生根瘤菌NodZα-1,6-岩藻糖基转移酶和几丁质酶的酶促转化，通过高效液相色谱法对斑马鱼和鲤鱼胚胎在原肠胚形成后期体外合成的几丁质寡糖进行了表征。还使用长春花悬浮培养的植物细胞对几丁质寡糖进行了快速灵敏的生物测定。我们表明几丁质寡糖合酶活性仅在原肠胚形成后期才明显，并且可以被针对非洲爪蟾DG42蛋白产生的抗血清抑制。DG42蛋白是一种糖基转移酶，在非洲爪蟾和斑马鱼胚胎发生的囊胚中期和神经胚形成之间短暂表达。在斑马鱼受精卵中显微注射DG42抗血清或慢生根瘤菌NodZ酶会导致躯干和尾巴发育出现严重缺陷。
