Molecular cloning and genomic structure of a gene encoding interferon regulatory factor in the pufferfish (Fugu rubripes)

Interferon regulatory factors (IRFs) are a large family of transcription fa ctors involved in regulating the transcriptional response of vertebrates to interferons and viral infection. In this report we describe the cloning an d genomic organization of an IRF gene from the pufferfish (Fugu rubripes). The fugu IRF gene spans 2.7 kb from the transcription start site to the pol yadenylation signal. It consists of 10 exons and 9 introns and encodes a pr otein of 296 amino acids. The overall amino acid sequence of fugu IRF displ ays 55% identity to flounder IRF and approximately 44% identity to avian an d mammalian IRF-1 and IRF-2. On the basis of the genomic structure and the absence of a transcriptional repression domain, we conclude that the fugu I RF is a member of the IRF-1 family. The fugu IRF gene is expressed in a wid e range of tissues. While a single transcript of 1.4 kb was detected in mos t tissues, several larger transcripts generated using alternative polyadeny lation signals were found in the gills.