种内与种间非整倍性对甘蓝型油菜基因表达的扰乱

发布时间：2018-04-25 23:30

本文选题：甘蓝型油菜 + 萝卜　；参考：《华中农业大学》2016年博士论文

【摘要】：非整倍体(aneuploids)是指在一个物种正常染色体数(2n)的基础上个别染色体增加或丢失的个体或细胞,有种内与种间两种类型(intra-/interspecific aneuploids)。植物对非整倍性比动物具有较大的忍耐性,特别是异源多倍体可忍耐染色体丢失。前人获得的芸薹属异源四倍体种甘蓝型油菜(Brassica napus L.,2n=38,AACC)的一个缺体(2n=36)表现植株急剧变矮变小、大幅提早开花,但缺失染色体的“身份”有待确定。在本研究中,将该甘蓝型油菜缺体与甘蓝型油菜亲本杂交产生了单体,然后进行该缺体和单体与甘蓝型油菜亲本的叶片比较转录组分析,以揭示特定染色体的不同拷贝(0,1,2)对转录组的影响、确定与染色体丢失相关表型的分子机理。还进行了两个甘蓝型油菜—萝卜(Raphanus sativus L.,2n=18,RR)二体附加系(2n=40,AACC+1IIRR)与甘蓝型油菜和萝卜亲本的叶片比较转录组研究,以分析单条外源染色体对油菜基因表达的影响与互作。主要研究结果如下:1.甘蓝型油菜单体与缺体的转录组分析利用C染色体组特异的DNA重复序列为探针进行荧光原位杂交分析,显示缺体丢失的一对染色体属于C染色体组。从每条染色体的特定基因表达差异进一步显示在缺体中所丢失的染色体是甘蓝型油菜的C2染色体。单体和缺体的基因表达在全基因组范围内发生了改变,且绝大多数的差异表达基因(DEGs)是由C2染色体的不同拷贝(0,1)的反式作用效应所致,因直接由C2染色体的丢失导致的DEGs在单体和缺体中只占3.89%和8.22%。其他染色体上的上调表达基因数比下调表达基因数高,可能基因组通过提高某些基因的表达来响应C2染色体的丢失。在单体中比缺体中检测到更多的DEGs,显示单体的整个基因表达比缺体的受到更严重的扰乱。其余染色体上的基因表达受到不同的影响,可发现几个异常调节的区域,其内有集中分布的上调或下调基因。随着C2染色体的丢失,部分同源染色体A2的平均基因表达下降。尽管缺体与单体中DEGs数目相差很大,但GO注释的DEGs比例非常相近,进一步表明两个非整倍体有响应C2缺失的相似机制。与缺体较矮的株高和开花提早相符的是,缺体中与植物生长素有关的基因及控制开花有关基因的表达也发生相应改变,为与C2缺失有关的形态学差异提供了部分解释,尽管基因表达有时空性差异。2.甘蓝型油菜—萝卜二体附加系的转录组研究二体附加系BNR1与甘蓝型油菜(BN)间的差异表达基因数(DEGs)低于BNR2的;而与萝卜比较时则与BNR1的DEGs高于与BNR2的。附加系与亲本、两个附加系之间在差异倍数分布上有很大差异;与甘蓝型油菜相比时两个附加系中上调及下调基因分布均匀,大部分基因为非差异表达;而与萝卜比较则下调表达基因占了绝大部分。这些结果表明附加不同的萝卜染色体对附加系的基因表达有不同影响。附加系与甘蓝型油菜之间的差异表达基因在不同基因组及染色体上的分布存在差异。在BNR1与BN的比较中,A基因组上调表达基因和下调表达基因的基因总数相近、每条染色体上的上调与下调表达基因也非常接近。但C基因组上的下调表达基因总数为上调表达的3倍,每条染色体上的下调表达基因数都多于上调表达的基因数目,其中以C1、C3、C6最为明显。在BNR2与BN的比较中,A基因组的上调和下调表达基因总数也接近;C基因组下调表达的总体趋势并不明显,但C2、C3两条染色体的下调表达基因数仍远高于上调表达的基因数。大部分DEGs在染色体上表现随机分布,特别是在A染色体组上,但在一些C基因组的染色体上(C1,2,3,5,6)有上调或下调基因集中出现的大的区域。两个附加系与甘蓝型油菜之间的共同差异表达基因分析发现BNR1与BNR2间共享大约一半的DEGs(1103/2349),表明这些基因可能受非整倍化的影响较大。其中269个基因在两个附加系中上调表达,其中一部分基因与刺激/逆境响应相关。而共同下调的693个基因功能则主要集中在细胞、代谢及合成进程等。比较两个附加系与甘蓝型油菜间A与C基因组的部分同源基因的表达水平,在甘蓝型油菜中有3867个基因对表现部分同源表达的偏向性(1846对偏向A基因组、2021对偏向C基因组)。但两个附加系均比甘蓝型油菜亲本显现更多的偏向性表达,表明附加萝卜染色体后可增加甘蓝型油菜中A与C基因组的表达偏向性。甘蓝型油菜中的大多数偏向性表达在两个附加系中均得以保持,也存在只在两个附加系间共有的大量基因对,可能由外源染色体所引起。
[Abstract]:Aneuploidy (aneuploids) refers to individual or lost individuals or cells on the basis of the number of normal chromosomes (2n) of a species. There are two types of intraspecific and interspecific (intra-/interspecific aneuploids). Plants have greater tolerance to aneuploidy than animals, especially heterologous polyploidy can endure chromosome loss. One of the Brassica napus L., 2n=38, AACC of Brassica species (2n=36) obtained from Brassica species (2n=36) showed a sharp decrease in the plant and a large early flowering, but the "identity" of the missing chromosome remains to be determined. In this study, a single body was produced by the hybridization of the Brassica oleracea and Brassica napus. The leaf comparative transcriptional analysis of the deficient and monosomic and Brassica napus parents was carried out to reveal the effect of different copies of the specific chromosomes (0,1,2) on the transcriptional group and to determine the molecular mechanism of the phenotype associated with the chromosome loss. Two Brassica Raphanus (Raphanus sativus L., 2n=18, RR) was also carried out, and the 2n=40, AACC+1 (AACC+1) was also carried out. IIRR) study on the leaf comparative transcriptional group of Brassica napus and Brassica napus and radish parents to analyze the influence and interaction of single exogenous chromosome on rapeseed gene expression. The main results are as follows: 1. the transcriptional group of Brassica napus monosome and lack of body analysis using the specific DNA duplication sequence of C chromosome group as the probe for fluorescence in situ hybridization analysis, A pair of chromosomes showing missing body loss is a group of C chromosomes. The difference in the expression of specific genes from each chromosome further shows that the lost chromosomes in the missing body are the C2 chromosome of Brassica napus. The gene expression of the monomer and the missing body has changed in the whole genome, and the vast majority of the differential expression genes (DEGs) are It is caused by the trans action effect of different copies of the C2 chromosome (0,1). The number of up regulated genes on 3.89% and other chromosomes in the monomer and the other chromosomes is higher than that of the other chromosomes in the monomer and the missing body, which is caused by the loss of the C2 chromosome directly. The genome may respond to the loss of the C2 chromosome by increasing the expression of some genes. More DEGs was detected in the monomer than in the deficient body, indicating that the whole gene expression of the monomer was more severely disturbed than the missing body. The gene expression on the other chromosomes was affected differently, and several abnormal regions were found, with a centralized or down regulated basis. With the loss of the C2 chromosome, partial homologous staining was found. The average gene expression of the body A2 decreased. Although the number of DEGs in the deficient body was very different from the monomer in the monomer, the DEGs ratio of the GO annotation was very similar. It further indicated that the two aneuploidy had a similar mechanism to respond to the deletion of C2. The expression of the gene was also changed to provide a partial explanation for the morphological differences related to the C2 deletion. Although the gene expression has temporal and spatial differences, the transcriptional group of the.2. Brassica napus two body appended line studies the number of differentially expressed genes (DEGs) between the two body addition line BNR1 and the Brassica napus (BN) lower than that of the BNR2; and compared with the radish. While the DEGs of BNR1 was higher than that of BNR2, there was a great difference in the distribution of the difference multiplier between the additional lines and the parents and the two additional lines. When compared with the Brassica napus, the up-regulated and down regulated genes were evenly distributed, and most of the genes were undifferentiated. The results showed that the chromosomes of the additional radish had different effects on the gene expression of the additional lines. The distribution of differentially expressed genes between the additional lines and the Brassica napus was different in different genomes and chromosomes. In the comparison of the BNR1 and the BN, the total number of up-regulated and down regulated genes of the A genome was similar, and each stain was stained. The up-regulated and down-regulated genes on the body were also very close, but the number of down regulated genes on the C genome was 3 times up to up, and the number of down regulated genes on each chromosome was more than the number of up-regulated genes, of which C1, C3, and C6 were most obvious. In the ratio of BNR2 to BN, the A genome up-regulated and downregulated the total number of genes. The overall trend of down regulation of C genome is not obvious, but the number of down regulated genes in C2, C3 two chromosomes is still far higher than the number of up-regulated genes. Most of the DEGs is randomly distributed on the chromosomes, especially on the A chromosome group, but in some C genome chromosomes (C1,2,3,5,6) there are up or down gene concentration. The common differentially expressed gene analysis between two additional lines and Brassica napus found that BNR1 and BNR2 shared about half of DEGs (1103/2349), indicating that these genes may be affected by aneuploidy. 269 of them were expressed in two additional lines, some of which were associated with irritation / adversity. The 693 gene functions were mainly concentrated in cell, metabolism and synthesis process, and the expression level of the partial homologous genes between the A and C genomes between the two additional lines and Brassica napus was compared, and 3867 genes in the Brassica napus were biased (1846 pairs of A genomes, 2021 pairs). But the two additional lines were more biased than the Brassica napus parents, indicating that the added radish chromosomes could increase the expression bias of the A and C genomes in Brassica napus. Most of the biased expressions in Brassica napus were maintained in two additional lines and only between two additional lines. A large number of gene pairs may be caused by foreign chromosomes.

【学位授予单位】：华中农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S565.4

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