一个血清抑制基因的克隆

Cloning of a Gene Inhibited by Serum Medium

比较血清培养细胞和血清饥饿细胞的基因表达差异 ,获得了一段血清饥饿细胞中特异表达的cDNA序列 ,以此序列出发 ,通过搜索表达序列标签 (EST) ,拼接出完整的基因序列 ,通过PCR分段克隆获得全长cDNA序列 .该基因全长 5 4 2 9bp ,编码框预测有 791个氨基酸残基 .GenBank搜索 ,该基因与已有的细胞周期调控基因没有同源性 .所以 ,该基因是一个新的与细胞周期有关的基因 (GenBank接受号 :AY0 5 0 16 9) .由于该基因最初发现在无血清培养条件下表达 ,故叫血清抑制基因 (seruminhibitgene,Si 1基因 ) .

Comparing the gene expression difference between normal cultured cells and serum starvation cells with DD-PCR method, a cDNA fragment, which expresses increase under serum starvation, was obtained. According to this cDNA fragment, the full gene cDNA was obtained primarily by searching and splicing the EST sequences, then was cloned by PCR and sequenced. The size of this gene is 5 429 bp and it codes a peptide containing 791 amino acid residues. It is not homologous with known genes that related to cell cycle. So, this gene may be a new cell cycle-related gene (GenBank: AY050169). It was named as serum inhibition gene (Si-1) according to its expression inhibited under serum existing.