Cloning, Identification And Adaptive Evolution Analysis Of Cyclin G1 And Morg1 In Grass Crap (ctenopharyngodon Idellus)

Ctenopharyngodon idella cyclin G1(CCGN1) and MAPK orgnizer 1(Morg1) had been cloned from the liver and kideny grass crap cDNA library.Cyclin Gl,the atypical cyclin, has complex functions that not only participates in DNA replication but also play a role in the promotion of apoptosis and signal transduction.The full lengh the grass crap cyclin G1 was 2118bp, which contained a 5' untranslated region of 255bp and a 3'untranslated region of 963bp.The open reading frame was 256-1155bp, which could code a 299 amino acid polypeptide. N-lobe of grass carp cyclin G1 was a highly conserved region called cyclin box which can identify the corresponding cyclin-dependent protein kinase, C-lobe was a EGF_Lam domain that may have phosphorylation sites to regulate signal transduction. Grass carp cyclin G1 shared the homology of 90% with zebrafish, in addition, the homology of other fishes(Salmo salar, Poecilia reticulata) more than 70%, and 40%-63%.with amphibians, mammals. Phylogenetic tree analysis revealed cyclin G1 shared the highest homology with zebrafish.Morgl is a molecular scaffold protein which can affect or regulate cell growth, cell cycle or signal transduction by interacting with the MP1 (MEK partner-1). The full lengh the grass crap Morgl was 1402bp, which contained a 5'untranslated region of 204bp and a 3'untranslated region of 241bp.The open reading frame was 205-1161bP, which could code a 318 amino acid polypeptide. Grass carp Morgl contained seven WD40 repeats, N-lobe of grass carp Morgl was a Kazal-type serine protease inhibitor domain which regulates protease activity, C-lobe was a ZnF_UBP which participates in the ubiquitin cycle. Grass carp Morgl shared the homology of more than 90% with other fishes(Danio rerio, Salmo salar), in addition, the homology of amphibians and mammals more than 70%. Phylogenetic tree analysis revealed grass carp Morgl shared the highest homology with zebrafish.Codon-Substitution Models are statistical methods for detecting molecular adaptation. The models not only can indicate whether the genes of phylogeny under the postitive selection or not, but also forcast these codon sites under the postitive selection, which promote gene divergence and polymorphism. Using these models to analysis the molecular adaptation of cyclin G1 and Morgl genes, the results of adaptive evolutionary analysis indicated that amino acid sites of 26A,171A,225K in cyclin G1 protein were suffered the positive selection effect, we can not find positive selective sites in Morg1.