委内瑞拉产地龙须菜藻红蛋白基因的克隆及其系统学研究

本文报道了红藻 Gracilaria lemaneiformis委内瑞拉株的藻红蛋白基因的部分序列 ,将所得序列与其它红藻 - Rhodella violacea,Polysiphonia boldii,Griffithsia monolis,Porphyra tenera,Porphyra yezoensis及青岛产龙须菜的相应序列对齐后 ,进行了系统学研究。结果显示 ,同一属的藻红蛋白 α和 β亚基之间的间隔序列 ,从长度到核苷酸序列均非常相似 ,而同一科不同属或同一目的科间的该序列有很大的不同 ;两不同产地龙须菜的 PE基因在 β亚基上的转换多于颠换 ,说明 β亚基比 α亚基保守 ;委内瑞拉来源龙须菜与青岛产地龙须菜可能不属于同一物种 ,应为同属不同种关系 ;由藻红蛋白基因所得的系统树包括 3个与建立在形态标准上的遗传位置一致的分支 ;藻红蛋白基因序列可用于种间及更高地位的分子系统研究。

Cloning of Phycoerythrin Genes of Gracilaria lemaneiformis (Rhodophyceae) from Venezuela and Its Phylogenic Studies

Partial nucleotide sequences of phycoerythrin (PE) of Venezuelan strain (lv) of Gracilaria lemaneiformis (GL) are documented in the present paper. By aligning the nucleotide with that of other red alga, Rhodella violacea (RV), Polysiphonia boldii (PB), Griffithsia monolis (GM), Porphyra tenera (PT), Porphyra yezoensis (PY), Aglaothamnion neglectum (AN) and Qingdao strain of GL(qd) , the molecular systematic relationship of them were surveyed. The similarity of both the spacer length and the nucleotide sequence of alfa and beta subunits of PE within a genus were exhibited, while there was great variety in different genera within the same family or interfamily of the same order. There were more transitions than transversions in the beta subunit of PE gene between the two Gracilaria strains, indicating that beta subunit is more conserved than alfa subunit. It is suggested that lv and qd may not belong to the same species. They may be different species of the same genus. The phylogenic tree derived by PE divides the taxa into three clades that correlate with the generic assignment based on morphological criteria. The sequence of PE genes is a useful tool for molecular phylogenic studies among different species and at higher taxonomic levels.