Organization and promoter analysis of the zebrafish (Danio rerio) interferon gene.
Interferon plays important roles in confronting viral infections as the first line of defense. For the purpose of understanding the molecular mechanism which controls transcription of the interferon gene, we cloned and sequenced the interferon promoter region of the zebrafish interferon gene and characterized its activity using firefly luciferase transient transfection expression assays. Different fragments of the zebrafish interferon 5'-flanking region were transfected into ZFL cells. In these cell lines, maximum promoter activity was located in 2.2 kb of the zebrafish interferon 5' flanking region of the ZFL cell line. In this study, we investigated whether the viral replicative intermediate double-stranded RNA (herein we used synthetic polyinosinic-polycytidylic acid [poly(I):poly(C)] modifies the effects of interferon on gene expression. For this purpose, all zebrafish interferon promoter fragments were treated with either 1, 10, or 100 microg/ml poly(I):poly(C). The results showed that after treatment with 10 microg/ml poly(I):poly(C), high promoter activity was observed in the -2.2-kb interferon promoter fragment. Several putative transcription factors were shown in the promoter region, including IRF-1, C/EBP, NFkappaB, and GATA-1. Further study of the in vivo expression of the interferon promoter during development was carried out in transgenic zebrafish expressing an interferon promoter-driven green fluorescent protein (GFP) encoding the GFP cDNA transgene. Morphological studies of transgenic zebrafish indicated that the interferon promoter-driven GFP transcripts appeared in the yolk, head, and lymphoid organs. These results indicate that the interferon promoter is active in a tissue-specific manner, and suggest that the interferon promoter plays an important role in virus resistance during teleost growth.
Chen
Jyh-Yih
JY
Marine Research Station, Institute of Zoology, Academia Sinica, Jiaushi, Ilan, Taiwan, Republic of China.
You
Yung-Kang
YK
Chen
Jian-Chyi
JC
Huang
Tzou-Chi
TC
Kuo
Ching-Ming
CM
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D002478:Cells, Cultured; D018076:DNA, Complementary / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007372:Interferons / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D041681:NIH 3T3 Cells; D011066:Poly C / Q000235:genetics; D011069:Poly I / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012330:RNA, Double-Stranded / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D015027:Zebrafish / Q000196:embryology / Q000235:genetics* / Q000254:growth & development
D018076:DNA, Complementary; D012330:RNA, Double-Stranded; D014157:Transcription Factors; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D011069:Poly I; D011066:Poly C; D007372:Interferons