Glycan alterations in C.elegans surface mutants

描述（由申请人提供）：后生动物的发育需要产生多种细胞类型和复杂多细胞结构的形态发生。遗传学研究已经确定了糖基化和蛋白聚糖生物合成在发育信号中的作用。秀丽隐杆线虫是研究糖复合物在多细胞生物中作用的良好模式系统，也是寄生线虫的原型模型，因为其完整的基因组序列和发育的知识。在这项R2 I（探索/发展）资助申请中，我们希望探索C.优雅Srf-9、srf-8和srf-4（表面）是具有多个缺陷的单基因座突变体，包括不协调的运动、外阴突出、异常产卵以及有缺陷的交配囊和性腺形态，然而它们是基于它们的异位表面结合到与N-乙酰葡糖胺结合的凝集素而分离的。srf-9、srf-8和srf-4中的突变与lin-12基因中的突变相互作用，lin-12基因是介导细胞-细胞相互作用以在发育期间指定细胞命运的受体蛋白的LIN-12/NOTCH家族的成员。我们将测试的假设，srf-9，srf-8和srf-4基因参与的生物合成，翻译后加工或分泌的糖复合物，因此链接发育事件与糖复合物的表达。具体而言，拟议的工作将：1）通过角质层聚糖组分的结构表征来确定srf-9、srf-8和srf-4突变体中受影响的糖缀合物，2）通过使用单核苷酸多态性（SNP）作图和标记拯救实验的组合的分子克隆来鉴定srf-9、srf-8和srf-4基因。这些研究结果将为进一步研究这些基因在线虫C.优雅由于复杂的表型是几种人类遗传疾病的标志，包括一些影响糖基化的疾病，拟议的研究将建立使用C。作为人类糖基化障碍模型的秀丽线虫SRF突变体。

DESCRIPTION (provided by applicant): Development of metazoans requires the production of multiple cell types and the morphogenesis of complex multicellular structures. Genetic studies have established roles for glycosylation and proteoglycan biosynthesis in developmental signaling. The nematode Caenorhabditis elegans is a good model system to study the role of glycoconjugates in multicellular organisms as well as a prototypic model for parasitic nematodes because of the knowledge of its complete genomic sequence and development. In this R2 I (Exploratory / Developmental) grant application, we wish to explore a novel potential functional linkage between expression of glycoconjugates and developmental events in C. elegans. Srf-9, srf-8 and srf-4 (surface) are single loci mutants that have multiple defects, including uncoordinated movement, protruding vulva, abnormal egg laying, and defective copulatory bursae and gonad morphology, yet they were isolated based on their ectopic surface binding to a lectin which binds to N-acetylglucosamine. Mutations in srf-9, srf-8 and srf-4 interact with mutations in the lin-12 gene, which a member of the LIN- 1 2/NOTCH family of receptor proteins that mediate cell-cell interactions to specify cell fate during development. We will test the hypothesis that the srf-9, srf-8 and srf-4 genes are involved in the biosynthesis, post-translational processing or secretion of glycoconjugates, and therefore link developmental events with glycoconjugates expression. Specifically, the proposed work will: 1) Define the glycoconjugates affected in srf-9, srf-8 and srf-4 mutants, through the structural characterization of cuticle glycan fractions, 2) Identify the srf-9, srf-8 and srf-4 genes through molecular cloning using a combination of Single Nucleotide Polymorphism (SNP) mapping, and marker rescue experiments. The information derived from these studies will provide the tools to study the role of these genes in developmental events in the nematode C. elegans. Because complex phenotypes are the hallmark of several human genetic disorders, including some that affect glycosylation, the proposed studies will establish the feasibility of using C. elegans srf mutants as a model for glycosylation disorders in humans.