利用SAGE方法分析家蚕基因表达数目的初探

Preliminary Study on the Number of Expressed Genes of Silkworm by Using Serial Analysis of Gene Expression(SAGE) Method

SAGE(serial analysis of gene expression)是基因表达水平差异分析和大规模发现新基因的分子生物学技术。已构建了家蚕卵、幼虫、蛹、成虫等4个不同发育时期的SAGE表达库,经测序分别得到69 100、62 232、63 966和62 666个基因标签序列,其中特异标签数目依次为17 718、13 243、14 044和15 224。这些特异标签数目即为家蚕在这4个不同发育时期的基因转录本数量。根据测序数与获得标签的数量动态监测,发现测序的数目尚未达到饱和,因此基因转录本的数目还可能会有所增加。在上述研究的基础上,利用SAGE数据为基础,采用双倒数作图求最大值的方法,推测出了家蚕在4个不同发育时期的基因表达数目,同时也发现家蚕卵期的基因表达数目远远大于其它3个时期。

Serial analysis of gene expression （SAGE） is a powerful technique that allows large-scale analysis of gene expression and identification of new genes. Four SAGE libraries were generated for each of the four developmental stages of the silkworm, egg, larva, pupa and moth stage. Totally 69 100, 62 232, 63 966, and 62 666 tags were obtained from these SAGE libraries, respectively. Of which there were 17 718, 13 243, 14 044, and 15 224 unique tags, respectively. The unique tags sequenced were not reached to saturation. By using the linear equations derived from the reciprocals of the total SAGE tags and unique SAGE tags, the maximal number of expressed silkworm genes in each of the four developmental stages. And the number of genes expressed in the egg stage was much more larger than that in the other three stages.