Molecular characterization of a mutable pigmentation phenotype and isolation of the first active transposable element from Sorghum bicolor
Molecular characterization of a mutable pigmentation phenotype and isolation of the first active transposable element from Sorghum bicolor
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DOI：
10.1073/pnas.96.26.15330
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发表时间：
1999-12-21
影响因子：
11.1
通讯作者：
Peterson, T
中科院分区：
文献类型：
--
作者：
Chopra, S;Brendel, V;Peterson, T
高粱籽粒果皮中红色素的积累受Y基因控制。Y的可变等位基因，命名为y-cs（y-糖果条纹），产生杂色果皮表型。利用玉米p1基因与高粱Y基因交叉杂交的探针，我们分离出含有大插入元件的y-cs等位基因。我们的研究结果表明，Y基因是MYB转录因子家族的成员。插入元件，命名为Candystripe 1（Cs 1），存在于Y基因的第二个内含子中，并具有CACTA转座子超家族的特征。Cs 1的大小为23，018 bp，由20 bp的末端反向重复序列邻接。它在Y基因内插入后产生3-bp靶位点重复，并从y-cs切除，在分析的两个病例中留下2-bp足迹。CS 1的切除拷贝的重新插入通过Southern杂交在每个测试的7个红色果皮回复系的基因组中鉴定。Cs 1是第一个从高粱中分离到的活性转座因子。我们的分析表明，CS 1同源序列存在于高粱和其他草，包括苏丹草，玉米，水稻，大刍草，甘蔗的低拷贝数。Cs 1的低拷贝数和高转座频率表明，该转座子可以被证明是一个有效的高粱基因分离工具。
Accumulation of red phlobaphene pigments in sorghum grain pericarp is under the control of the Y gene. A mutable allele of Y, designated as y-cs (y-candystripe), produces a variegated pericarp phenotype. Using probes from the maize p1 gene that cross-hybridize with the sorghum Y gene, we isolated the y-cs allele containing a large insertion element. Our results show that the Y gene is a member of the MYB-transcription factor family. The insertion element, named Candystripe1 (Cs1), is present in the second intron of the Y gene and shares features of the CACTA superfamily of transposons. Cs1 is 23,018 bp in size and is bordered by 20-bp terminal inverted repeat sequences. It generated a 3-bp target site duplication upon insertion within the Y gene and excised from y-cs, leaving a 2-bp footprint in two cases analyzed. Reinsertion of the excised copy of Cs1 was identified by Southern hybridization in the genome of each of seven red pericarp revertant lines tested. Cs1 is the first active transposable element isolated from sorghum. Our analysis suggests that Cs1-homologous sequences are present in low copy number in sorghum and other grasses, including sudangrass, maize, rice, teosinte, and sugarcane. The low copy number and high transposition frequency of Cs1 imply that this transposon could prove to be an efficient gene isolation tool in sorghum.