拟南芥突变体tgd表型和分子生物学特性分析

主要研究1个由Ds插入所造成的大片段缺失拟南芥突变体tgd(ten gene deletion)．这个突变体来自于基因陷阱拟南芥突变体库．对这一突变体的后代卡那霉素抗性分离比分析和Southern杂交表明,只有1个Ds拷贝插入此突变体基因组中，但是Tail-PCR和随后用特异基因序列为引物的验证PCR证实在Ds插入过程中造成了30 kb基因片段的缺失．根据对拟南芥基因组序列的注释，这30 kb的序列中包含10个基因．这一多基因缺失突变体有多效性表型．整株表现为株型矮小，发育迟缓，根系不发达，极易失水而死，茎细弱，较短，花序不正常．其中,莲座叶的表型最为明显，突变体叶形较细，叶片较厚．为了研究这些基因在多效性表型产生中所发挥的功能，对来自ABRC种子库中所有基因的T-DNA插入突变体，即salk line的表型进行了分析，发现所有基因的T-DNA插入突变体均没有可见的表型．这一现象暗示,突变体tgd的表型是10个基因缺失的综合效应，但是10个基因的相互关系以及与tgd表型的相互关系仍有待于继续研究．

Phenotypic and Molecular Characterization of an Arabidopsis Mutant tgd

Here we report an Arabidopsisdeletion mutant tgd(ten gene deletion) with a pleiotropic phenotype. The mutant was derived from a library of Dsinsertion mutants, which contained a single copy of Dselement in the genome as determined by Kanamycin resistant segregation ratio of its offspring and Southern blot. The Tail-PCR and subsequent verification using specific primers revealed that a 30-kb length fragment, containing 10 genes in TAIR(Arabidopsis Information Resource) annotations, was knocked out by this Ds element insertion. This deletion mutant exerted a pleiotropic phenotype with dwarfish plantlet, slime and fragile shoot，underdeveloped roots, and narrow and thick leaves, which was the most apparent abnormality. To find out the candidate genes for this pleiotropic phenotype, we obtained and analyzed the salk lines of these genes from ABRC (Arabidopsis Biological Resource Center) stock, none of those lines demonstrated the observed phenotype, suggesting that the pleiotropic phenotype was a conjoint consequence of the 10 gene deletions instead of the effect of the deletion of each individual gene. The interactions of these 10 genes deserve further investigation.