以“末端修饰法”构建人基因组的酵母人工染色体克隆

Construction of Human Genomic YAC Clones with "Terminal Modification

采用“末端修饰法”修饰酵母人工染色体（YAC）载体与基因组插入片段的酶切末端，并优化各个实验参数，成功地得到了4000多个YAC片段的克隆群，转化率为400～500转化子／μgDNA。经随机抽样初步鉴定：80％的阳性克隆能检出人工染色体，插入片段的大小范围为150～750kb，平均为450kb。载体连接实验检测表明，末端修饰法能有效防止“共连接”的发生。

A human YAC genomic pool with more than 4 000 clones was constructed by means of 'terminal modification' of YAC vector and genomic inserts, as well as optimization of rele-vant experimental pararneters. The transformation rate is approximately 4OO^5OO transfor-mants per pg DNA. Preliminary characterization of randomly sampled clones demonstrates that YAC-specific inserts, in the average size of 450 kb and ranging 150~ 750 kb,were de-tected from 8O% of the clones. The vector ligation experiment indicates the efficient reduc-tion of 'coligation' by tertninal modification.