CLONING AND CHARACTERIZATION OF FULL LENGTH cDNAs OF TWO GENES RELATED TO PROTEIN BIOSYNTHESIS IN GYNOGENETIC GIBEL CARP

The SMART cDNA plasmid library was constructed from heartbeat stage embryos of gibel carp(Carassius auratus gibelio). Randomly selected clones from the library were sequenced and their homologies were analyzed. The full length cDNAs of two genes related to protein biosynthesis were obtained from the sequenced clones. One gene,gibel carp translation initiation factor 3 subunit 2,was named GTIF3-S2. It is 1280 bp in length and has an open reading frame of 975 nucleotide acids for encoding 325 amino acids. The deduced amino acid sequence has three WD domains. The gibel carp GTIF3-S2 was first reported fish translation initiation factor 3 subunit 2. Another gene,gibel carp translation elongation factor 1α, was named GEF-1α. It is 1784 bp in length and has an open reading frame of 1386 nucleotide acids encoding 462 amino acids. The open reading frame is between 82—1467 bp. RT-PCR analysis showed that the maternal mRNAs of the two genes were detected in matured eggs and in early developmental embryos. In embryonic development, the two genes began to transcribe from gastrula stage, and their expressions became stronger as the embryos developed. The two genes were detected to express strongly in most of the examined tissues of gibel carp,but weaker expressions were found in testis. Homology analysis indicated that there exists high evolutionary conservation in gibel carp GTIF3-S2 and GEF-1α. among different species, from animals to plants. Therefore, we conclude that gibel carp GTIF3-S2 and GEF-1α. are two excellent target genes for studies on evolutionary genetics and systematics among species.