荞麦不同种间BW10KD过敏蛋白基因序列比较

Comparison of BW10KD allergen protein gene sequences among different buckwheat species

荞麦过敏蛋白(BW10KD)与变应原病人的血清免疫球蛋白(immunoglobulin E,IgE)有强烈反应。通过对属于8个荞麦种和1个变种的58个收集系中的BW10KD过敏蛋白基因保守片段进行差异分析与系统进化关系研究,为探讨BW10KD基因的结构功能及其在不同种间的进化奠定了基础,并为发生在物种基因DNA水平的微尺度的变异与进化研究中提供新的分析方法。用设计的特异引物进行扩增,所得序列与已报道过敏蛋白编码基因序列相似性达99%。各收集系间进行序列比对,得到307个排列位点(不含缺失位点),其中单型不变位点150个,多态位点S为157个(含简约信息位点数101个和单型可变位点56个)。整个序列突变位点Eta为201个。选择特定分类群内变异小、分类群间变异大的19个位点进行系统聚类分析得到清晰的种系关系图。金荞、细柄野荞、硬枝万年荞聚在一起,暗示其具有较保守的BW10KD过敏蛋白基因序列;栽培甜荞与野甜荞亲缘关系近,其次与左贡野荞较近缘;毛野荞与大野荞彼此较近缘;栽培苦荞与野苦荞亲缘关系最近,与毛野荞和大野荞亲缘关系次之。

Buckwheat allergy protein （BW10KD） has a strong reaction to allergic patients＂ serum IgE. The objectives of this study were to deposit information on structure and function of BW10KD gene and evolution possibility of different species, and to provide a new method for analyzing DNA variation occurred in different species. The conserved sequence of BWIOKD gene was amplified in 58 buckwheat entries （Fagopyrum Mill） belonging to 8 species and a variant species. The phylogenic trees were constructed according to sequence blast results. The amplified sequence sharing 99% homology to the known sequence of allergy protein gene. A total of 306 arrangement sites were identified in the 58 entries, excluding deletion and insertion loci. Among them, there were 150 invariable （monomorphie） sites and 157 polymorphie （segregating） sites, including 101 parsimony informative sites and 56 singleton variable sites. There were 201 mtttations on Eta site in the whole sequence. Based on data of 19 sites with small variation within taxa and large variation among taxa, the phylogenie relationship was clear among different entries. The sequences of BWIOKD gene were highly conserved in F. cymosum, Egracilipes, and F. urophyllum, showing their close relationships. Cultivated common buckwheat was primarily clustered with its wild type, and further grouped with F. zuogongense. Species F. pilus and F. megaspartanium were involved in the same clade, which was continuously clustered with the group containing cultivated tartary buckwheat and its wild type.