薏苡胚油脂分子标记鉴定及遗传多样性分析

Identification of Embryo Oil Molecular Marker and Genetic Diversity Analysis of Coix

薏苡被誉为“世界禾本科之王＂。它作为药食两用植物，特别以薏苡中性油脂为主要有效成分，用于辅助抗癌的药物，已在美FDA获准Ⅲ期临床。利用34个多态性丰富的RAPD分子标记，分析了23份不同地理来源的薏苡种质的遗传多样性，结果获得405个多态性片段，通过UPGMA聚类分析法，23份供试薏苡资源被分为5种类型，分类结果与地理来源和种质系谱一致。薏苡胚油脂分子标记鉴定中，胚油脂含量检测发现23份种质平均值仅为3．47％，但LG013中却高达8．99％，同时，发现长度约为1050bp的片段为LG013的特有条带。经克隆和特异引物的鉴定，结果显示在600bp处LG013拥有特异性代表条带，可作为该品种鉴定和知识产权保护的重要依据。

Conformational changes of proteins play an important role in life processes.The protein plays its role often accompanied by a conformational change.Some diseases are caused by conformational change of protein,such as Alzheimer's disease andBSE(bovine spongiform encephalopathy),where a water-soluble protein becomes an insoluble protein fiber form.Knowing the process of conformational change of protein is very important to understand the properties of protein.However,finding the transition path of the protein conformational change from atomic scale is a big challenge.In this paper,we applied the zero-temperature string methods in protein conformational changes of polypeptide chain between 310-helix andα-helix.From different initial paths,we got different optimal paths and different transition states;the transition state with significant barriers is the configuration similar to the 310-helix.And we also applied the finite temperature string method to study the conformational change and got the transition path ensemble by using two sampling methods,namely Langevin dynamics and molecular dynamics.The result indicates the effectiveness of the finite tem perature string method when compared with the zero temperature string method.