碩士 / 國立海洋大學 / 生物技術研究所 / 85 / The heterodimer complex of Ah receptor (AHR)- Ah receptor
nuclear translocator(ARNT) is an ubiquitous transcription factor
which mediates the expression of vertrbrate xenobiotic-response
genes, such as CYP1A1 and CYP1A2. AHR and ARNT also perform key
functions in murine embryo development. Both AHR and ARNT
factors share conserved function domains with PAS domain
families, such as Drosophila CNS-developing modulator, SIM, and
biological rhythm factor, PER. The xenobiotic, 2,3,7,8-TCDD,
strongly induces zebrafish CYP1A expression during
embryogenesis. Apparently, both AHR and ARNT factors are present
in fish embryosin form that can accurately respond to the proper
ligand to induce CYP1A. Wedpeculate these factors play similar
functional roles in fish development asthey do during
development of murine embryos. By using RT-PCR technique, we
haveobrained an ARNT-like cDNA fragment from the zebrafish
tissues. The deduced amino acid sequence derived from the
amplified cDNA fragment share significanthomology with the
respective mammalian ARNT PAS domain sequence. We found that
arnt-like gene is active during fish embryogenesis. The mRNA of
this specific arnt-like gene is also transcribed in oocyte as
maternal mRNA. By using the amplified cDNA fragment as a probe,
we have obtained a 1.6kb ARNT-like cDNA from a zebrafish
embryomic cDNA library. It contains an open reading frame which
encompasses 425 amino acid sequence. The encoded sequence shares
significant idenities with the mouse and rainbow trout ARNTs in
the bHLH-PAS domain region. However, this putative zebrafish
ARNT-like factor lacks a glutamine-rich transactivation domain
at its C-terminal region. By using the RT-PCR method, we have
revealed that this putative ARNT-like mRNA is
ubiquitouslyexpressed in a variety of tissues, including the
brain, eye, gill, liver,muscle, digestive gut, ovary and testis.
| Identifer | oai:union.ndltd.org:TW/085NTOU0108011 |
| Date | January 1997 |
| Creators | Wnag, Wen-Der, 王文德 |
| Contributors | Lin Fu-Pang, 胡清華 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 2 |
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