Molecular Analysis of Genes Expressed in the Liver

• Main Authors: Ting, Man-Chun, 丁曼君
• Other Authors: Lan-Yang Ch'ang, Ching-Ping Tseng
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/23393194124402248379

碩士 === 國立交通大學 === 生物科技研究所 === 86 === Liver is a vital organ in humans and play many essential physiological rolesin metabolism and detoxification. The gene expression pattern of the liver is expected to be complex. In this study, we employed two new techniques, namely the complexityreductionanalysis and bioinformatics, to investigate genes expressed in thefetal and adult livers. The expression of genes that are developmentallyregulated were also examined in established human hepatoma cell lines. Fromthe profiles of fingerprinted expressed genes, a total of 220 fetal liver cDNAfragments were isolated, cloned, and sequenced. Extensive database search of188 unique sequences revealed that 167 fragments had matches greater than 90%in the databases. The remaining 21 expressed sequences of no matches found in the Human Genome Index (HGI) were potentially novel. All but 4 were confirmedas human genes by the reveres transcription-polymerase chain reaction(RT-PCR)using cDNA templates prepared from the normal fetal and adult livers and thehepatoma cell lines and by the Northern blot analysis. Of the 17 potential human genes, 6 were expressed predominantly in the fetal liver and a half of which showed an elevated level of expression in Hep-G2 cells. Four genes were expressed at a higher level in the adult tissue and their expression appeared to be down-regulated in the hepatoma cell lines. The expression of the remaining 7 genes was not modulated. Expression of these genes in human fetal and adult tissues was also examined by the Northern blot analysis. Both the tissues-restricted expression patterns and multiple transcripts of the same gene were observed. In addition, electronic cloning was performed on the computer by assembling the expressed sequence and its overlaping fragments in the databases into a contig.