红脐鳞地衣基因组文库的构建

摘要

地衣是真菌和一种或多种光合微生物形成的稳定的共生联合体,既是先锋生物,又是敏感生物.环境的变化及生境的片断化,使得许多地衣种类处于濒危状态.保护珍稀濒危地衣物种的方法包括地衣体的移植,地衣中菌藻的分离培养及基因组文库的构建等.本研究用改进的CTAB方法提取基因组总DNA,以Lamb-da GEM-11为载体,构建了红脐鳞(Rhizoplaca chrysoleuca)的基因组文库,文库中同时含有该地衣共生菌与共生藻的DNA.该文库包含8.5×105个重组子,插入片段的平均大小为19kb.文库的容量约为红脐鳞单倍体基因组的100倍.该基因组文库的构建为保护稀有与濒危地衣物种提供了一个新的途径,并可进一步开展有关地衣的分子操作研究,如地衣冰核蛋白的异源表达等.%Lichens are stable symbiotic association comprised of a fungus and one or more photosynthetic microorganisms.Some methods were used to protect the rare and endangered lichens, which included transplanting thalli, separating and culturing fungi, algae and/or cyanobacteria, and constructing the genomic DNA library. As a main means of conservation of rare and endangered lichens, the feasible procedures of constructing the genomic DNA library of lichens were developed. A genomic DNA library of Rhizoplaca chrysoleuca (including both mycobiont and phycobiont) was constructed using the phage Lambda GEM-11 as a vector. The library consisted of 8.5 × 105 clones with an average insert size of about 19 kb. The capacity of this library was about 100 times the equivalent of the sum of haploid genomes of alga and lichen-forming fungus in R. chrysoleuca. Lichens generally grow too slowly for many kinds of laboratory manipulations and for effective conservation of rare and endangered species. Our studies make it possible to do some of those important experimental researches.