| Summary: | 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.
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