cDNA cloning and expression of two Ki-ras genes in the flounder, Platichthys flesus, and analysis of hepatic neoplasms.
The screening of a flounder cDNA library with a partial sequence of ras gene from flounder (exons 1 and 2) allowed the isolation of two complete cDNA sequences (ras1 and ras2) highly homologous to human Ki-rasb genes. ras1 and ras2 sequences have an homology of 77.3% indicating that they represent two distinct genes, which differ particularly in their 3 regions. ras1 and ras2 intron 1 sequencing revealed an homology of only 50%, confirming that they represent two different genes. Both genes encode for a 188 amino-acid protein, a size characteristic of Ki-rasb proteins. ras1 protein has the stronger homology to the human Ki-rasb protein (99% identity) and ras2 presents a 85.5% of homology. Two transcripts of respectively 2 and 2.8 kb were identified by northern blots with either ras1 or 2 probes. Preneoplastic and neoplastic livers collected from 14 flounder did not present any mutation on the ras2 gene.
Vincent-Hubert
F
F
Département Polluants Chimiques-IFREMER, Nantes, France. fvincent@ifremer.fr
D018248:Adenoma, Liver Cell / Q000235:genetics / Q000662:veterinary*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000662:veterinary*; D003001:Cloning, Molecular; D018076:DNA, Complementary; D005260:Female; D005432:Flounder / Q000235:genetics*; D015870:Gene Expression; D011905:Genes, ras; D006801:Humans; D006965:Hyperplasia; D007438:Introns; D008113:Liver Neoplasms / Q000235:genetics / Q000662:veterinary*; D008969:Molecular Sequence Data; D010053:Ovary / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D018076:DNA, Complementary