【作者】 胡雷；

【导师】 胡春根； 姚家玲；

【作者基本信息】 华中农业大学 ， 植物学， 2010， 硕士

【摘要】 基因组印迹是一种非孟德尔遗传现象。它是指在配子或合子发生期间,来自亲本的等位基因或染色体产生专一性的加工修饰,导致后代体细胞中两个亲本来源的等位基因有不同的表达活性。印迹基因的特点就是基因的表达与否决定于其亲本来源,导致两个不同亲源的等位基因具有不同的表型效应,即具有亲源效应。在植物中已经发现了一些对早期胚乳发育的启动有重要作用并与亲本印记有关的基因,如拟南芥中的基因FERTILIZATION-INDEPENDENT ENDOSPERM(FIE)、FERTILIZATION-INDEPENDENT SEED1/MEDEA(FIS1/MEA)和EMF2这些基因编码的蛋白属于多梳家族蛋白(polycomb group protein, PcG)。玉米中的PcG类基因(FIE1、FIE2、Mez1、Mez2)也参与胚乳发育的调控。而水稻是世界主要的粮食作物之一,也是单子叶模式植物,其主要食用部分胚乳在胚胎发育过程中起着至关重要的作用。对水稻中PcG类基因(EMF,FIE2a,FIE2b,EZ1,EZ3)的研究,将有助于认识禾谷类作物胚乳发育的机制,并有潜在的育种价值。为了研究水稻胚乳中PcG类基因的印记模式,本试验通过两个方面的研究思路试图解决这个问题。一、对FIS类基因的启动子片段,用生物信息学分析其功能区段,并将启动子片段分别连上带有GFP和GUS两种不同标记基因的表达载体上。分离相关的启动子并尝试将启动子片段装入含有报告基因的启动子表达载体可以为转基因植株研究提供载体平台,这对精细研究FIS基因及调控胚乳发育的分子机制大有帮助。而这部分的实验也分别获得了相应的启动子GFP和GUS两套表达载体,为以后的研究打下基础。二、将粳稻品种日本晴和籼稻品种9311正反杂交,取授粉后一定时期内的花序材料剥离胚和胚乳,以此为材料分析胚和胚乳中多梳蛋白(polycomb group protein, PcG)的表达。通过这部分的实验发现大致可以判断FIE2b和EZ1两个基因在受精后一段时间内胚乳中的表达量是有增加的趋势。从某种程度上证明这两个基因与胚乳的发育相关,而与印迹也有很微妙的联系。更多还原

【Abstract】 Genomic imprinting is a genetic phenomenon by which certain genes are expressed in a parent-of-origin-specific manner. It is an inheritance process independent of the classical Mendelian inheritance. Imprinted genes are either expressed only from the allele inherited from the mother, or in other instances from the allele inherited from the father. Forms of genomic imprinting have been demonstrated in insects, mammals and flowering plants(eg. FIE、FIS1/MEA and EMF2 in Arabidopsis thaliana; FIE1、FIE2、Mezl and Mez2 in Zea mays).As one of the most important crops of the world, Oryza sativa is a model of monocotyledon plant. The endoperm is the main edible part of rice which takes a crucial role in the embryo development. It is useful to carry out some necessary researches on PcG genes of rice, because it is helpful to understand the mechanism of endosperm development in cereal which has a potential value in breeding.For the purpose of making clear the mechanism of PcG genes of rice. I try to make it clear in two different ways.In one hand,bioimformation method was used to analyst the promoter of PcG genes in rice. After that I construct the expression vector use two vector which contain GFP and GUS.In the other hand, positive and negative crossbreed was used to study the expressing of FIS class gene.After crossbreeding in 9311 and Nipponbare, I take inflorescences of rice after pollination, and separate the endsperm and embryo. Then by the tool of RT PCR, I can inspect the expression level of FIS class gene. And the result indicates that gene FIE2b and EZ1 maybe is related to genome imprinting.更多还原