Identification of FAD2 and FAD3 genes in Brassica napus genome and development of allele-specific markers for high oleic and low linolenic acid contents
Identification of FAD2 and FAD3 genes in Brassica napus genome and development of allele-specific markers for high oleic and low linolenic acid contents
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DOI：
10.1007/s00122-012-1863-1
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发表时间：
2012-08-01
影响因子：
5.4
通讯作者：
Zhou, Yongming
中科院分区：
文献类型：
--
作者：
Yang, Qingyong;Fan, Chuchuan;Zhou, Yongming
油菜去芥酸后，提高油酸（C18：1）和亚麻酸（C18：3）含量是油菜品质育种的主要目标之一。脂肪酸去饱和酶基因FAD 2和FAD 3是控制C18：1和C18：3含量的主效基因。然而，双二倍体B中两个基因家族的基因组结构和基因座分布并不一致。到目前为止，人们对油菜的认识还不完全。在本研究中，B的A和C基因组中的FAD 2和FAD 3基因的所有拷贝。通过生物信息学分析和广泛的分子克隆，鉴定了甘蓝型油菜及其两个二倍体祖先种芜菁和甘蓝。B中存在两个FAD 2基因。rapa和B.甘蓝中存在FAD 2基因，B中存在4个拷贝。油菜。在二倍体和双二倍体物种中分别鉴定出3个和6个拷贝的FAD 3基因。通过对一个双单倍体群体中高C18：1含量和低C18：3含量性状的QTL定位和相关基因的分子克隆，研究了这两个性状的遗传控制。位于A5染色体上的BnaA.FAD2.a是决定C18：1高含量的主效QTL。发现BnaA.FAD2.a基因座中的缺失突变，其代表B中高油酸变异的先前未鉴定的等位基因。油菜种在DH群体和SW山核桃中，C18：3含量低的主要原因是位于A4和C4染色体上的两个QTL。此外，BnaA.FAD3.b和BnaC.FAD3.b中的几个单碱基对变化被鉴定为导致低C18：3含量的表型。根据遗传作图结果和已鉴定的序列，开发了FAD 2和FAD 3基因的等位基因特异性标记。特别是FAD 3等位基因的单核苷酸扩增多态性标记被证明是一种可靠的SNP标记类型，用于明确鉴定双二倍体B中C18：3含量不同的基因型。油菜。
Modification of oleic acid (C18:1) and linolenic acid (C18:3) contents in seeds is one of the major goals for quality breeding after removal of erucic acid in oilseed rape (Brassica napus). The fatty acid desaturase genes FAD2 and FAD3 have been shown as the major genes for the control of C18:1 and C18:3 contents. However, the genome structure and locus distributions of the two gene families in amphidiploid B. napus are still not completely understood to date. In the present study, all copies of FAD2 and FAD3 genes in the A- and C-genome of B. napus and its two diploid progenitor species, Brassica rapa and Brassica oleracea, were identified through bioinformatic analysis and extensive molecular cloning. Two FAD2 genes exist in B. rapa and B. oleracea, and four copies of FAD2 genes exist in B. napus. Three and six copies of FAD3 genes were identified in diploid species and amphidiploid species, respectively. The genetic control of high C18:1 and low C18:3 contents in a double haploid population was investigated through mapping of the quantitative trait loci (QTL) for the traits and the molecular cloning of the underlying genes. One major QTL of BnaA.FAD2.a located on A5 chromosome was responsible for the high C18:1 content. A deleted mutation in the BnaA.FAD2.a locus was uncovered, which represented a previously unidentified allele for the high oleic variation in B. napus species. Two major QTLs on A4 and C4 chromosomes were found to be responsible for the low C18:3 content in the DH population as well as in SW Hickory. Furthermore, several single base pair changes in BnaA.FAD3.b and BnaC.FAD3.b were identified to cause the phenotype of low C18:3 content. Based on the results of genetic mapping and identified sequences, allele-specific markers were developed for FAD2 and FAD3 genes. Particularly, single-nucleotide amplified polymorphisms markers for FAD3 alleles were demonstrated to be a reliable type of SNP markers for unambiguous identification of genotypes with different content of C18:3 in amphidiploid B. napus.