The full length cDNA of a prion protein (PrP) encoding gene of guppy (Poecilia reticulata) and the corresponding ge-nomic DNA were cloned. The cDNA was 2245 bp in length and contained an open reading frame (ORF) of 15...The full length cDNA of a prion protein (PrP) encoding gene of guppy (Poecilia reticulata) and the corresponding ge-nomic DNA were cloned. The cDNA was 2245 bp in length and contained an open reading frame (ORF) of 1545 bp encoding a pro-tein of 515 amino acids,which held all typical structural characteristics of the functional PrP. The cloned genomic DNA fragment corresponding to the cDNA was 3720 bp in length,consisting of 2 introns and 2 exons. The 5’ untranslated region of cDNA origi-nated from the 2 exons,while the ORF originated from the second exon. Although the gene was transcribed in diverse tissues in-cluding brain,eye,liver,intestine,muscle and tail,its transcript was most abundant in the brain. In addition,the transcription of the gene was enhanced by 5 salinity,implying that it was associated with the response of guppy to saline stress.展开更多
Sarcopterygians is an important vertebrate clade that includes crossopterygians and tetrapods.Crossopterygians are lobe-finned fish that include lungfish and coelacanths.Tetrapods include amphibians,reptiles,avians an...Sarcopterygians is an important vertebrate clade that includes crossopterygians and tetrapods.Crossopterygians are lobe-finned fish that include lungfish and coelacanths.Tetrapods include amphibians,reptiles,avians and mammals.To compare the interferon regulatory factor 1 (irf-1) gene structure and to explore phylogenetic relationships among sarcopterygians,we cloned the cDNA sequence of irf-1 from lungfish and compared it with irf-1 orthologs in other sarcopterygian species.The lungfish is a primitive sarcopterygian that occupies a very important position in vertebrate phylogeny.Interferon regulatory factors (IRFs) are a family of proteins involved in innate immunity.To date,11 IRF family members have been reported.All IRFs share homology in the first 115 amino acids,which encompasses a DNA binding domain containing a characteristic repeat of 5 tryptophan residues separated by 10-18 amino acids.IRF-1 and IRF-2 were the first members of this family to be reported and they have a very important role in innate immunity.However,studies of the irf-1 and irf-2 genes are mostly confined to mammals;very few non-mammalian irf-1 genes have been reported.Consistent with the irf-1 gene sequences already published,the first 345 nucleotides of lungfish irf-1 are highly conserved.At the carboxyl terminal a C-terminal transactivating region motif and an interferon associated domain (IAD2) were identified.417 million years separate the present from the closest common ancestor of lungfish and tetrapods;however,the irf-1 genes among sarcopterygians are highly conserved and have very obvious phylogenetic relationships.Also the interrelationship tree of sarcopterygians,based on IRF-1 amino acid sequences,is identical with trees produced using other data,such as morphological characteristics or mitochondrial gene sequences.展开更多
基金the Key Laboratory of Freshwater Germplasm and Biotechnology of Chinese Ministry of Agriculture,Yangtze River Fisheries Research Institute,Chinese Academy of Fishery Sciences (LFB20070601)the Key Laboratory of Mariculture of Chinese Ministry of Education,Ocean University of ChinaNational High Technology Research and Development Program of China (2007AA09Z427)
文摘The full length cDNA of a prion protein (PrP) encoding gene of guppy (Poecilia reticulata) and the corresponding ge-nomic DNA were cloned. The cDNA was 2245 bp in length and contained an open reading frame (ORF) of 1545 bp encoding a pro-tein of 515 amino acids,which held all typical structural characteristics of the functional PrP. The cloned genomic DNA fragment corresponding to the cDNA was 3720 bp in length,consisting of 2 introns and 2 exons. The 5’ untranslated region of cDNA origi-nated from the 2 exons,while the ORF originated from the second exon. Although the gene was transcribed in diverse tissues in-cluding brain,eye,liver,intestine,muscle and tail,its transcript was most abundant in the brain. In addition,the transcription of the gene was enhanced by 5 salinity,implying that it was associated with the response of guppy to saline stress.
基金supported by the National Key Basic Research Program of China (HCV2009CB522500)
文摘Sarcopterygians is an important vertebrate clade that includes crossopterygians and tetrapods.Crossopterygians are lobe-finned fish that include lungfish and coelacanths.Tetrapods include amphibians,reptiles,avians and mammals.To compare the interferon regulatory factor 1 (irf-1) gene structure and to explore phylogenetic relationships among sarcopterygians,we cloned the cDNA sequence of irf-1 from lungfish and compared it with irf-1 orthologs in other sarcopterygian species.The lungfish is a primitive sarcopterygian that occupies a very important position in vertebrate phylogeny.Interferon regulatory factors (IRFs) are a family of proteins involved in innate immunity.To date,11 IRF family members have been reported.All IRFs share homology in the first 115 amino acids,which encompasses a DNA binding domain containing a characteristic repeat of 5 tryptophan residues separated by 10-18 amino acids.IRF-1 and IRF-2 were the first members of this family to be reported and they have a very important role in innate immunity.However,studies of the irf-1 and irf-2 genes are mostly confined to mammals;very few non-mammalian irf-1 genes have been reported.Consistent with the irf-1 gene sequences already published,the first 345 nucleotides of lungfish irf-1 are highly conserved.At the carboxyl terminal a C-terminal transactivating region motif and an interferon associated domain (IAD2) were identified.417 million years separate the present from the closest common ancestor of lungfish and tetrapods;however,the irf-1 genes among sarcopterygians are highly conserved and have very obvious phylogenetic relationships.Also the interrelationship tree of sarcopterygians,based on IRF-1 amino acid sequences,is identical with trees produced using other data,such as morphological characteristics or mitochondrial gene sequences.
