拟南芥黄心突变体yh基因的图位克隆及分析

在研究光合作用相关基因的过程中，获得了一个叶片为黄心(yellow heart，yh)的突变株，与野生型拟南芥(Col 0)相比，其新生叶片发黄，突变表型由隐性单基因控制。采用图位克隆及其精细定位技术，将yh突变基因定位在1号染色体的INS1_55_342与INS1_56_34区间，物理距离约为676 kb。通过测序得知yh在At1g64790第44个内含子剪接处有4个碱基的缺失，导致内含子剪切位点的变化。RT PCR分析显示，该基因表达降低，是At1g64790基因的一个新等位突变。研究表明，yh突变体与叶绿体的发育相关，可为进一步探究植物叶绿体和叶片发育机制提供新的遗传材料。

Map based Cloning and Analysis of the yh Gene in Arabidopsis thaliana Yellow Heart Mutant

In the process of investigating the photosynthesis related genes, we obtained a recessive Arabidopsis thaliana mutant, yellow heart (yh). Compared with the wild type (Col 0) A. thaliana, yh mutant appeared a yellow heart phenotype in new leaves. With map based cloning strategy, the mutant gene yh was precisely mapped into the 676 kb chromosome interval between the molecular markers INS1_55_342 and INS1_56_34 on chromosome 1. The yh mutant has a 4 base deletion at the splice junction of the 44th intron, which result in a change in the splice site of the intron. RT PCR results have indicated that the expression of yh gene is knock down, and yh mutant is indeed a new allelic mutation in gene At1g64790. Based on study above, yh mutant may provide a new genetic material to explore the chloroplast and leaf development mechanisms.