Molecular Cloning And Functional Characterization Of Duplicated Follistatin Genes In Grass Carp (Ctenopharyngodon Idellus)

Grass carp (Ctenopharyngodon idellus) in China is an important economicfish,which is one of China’s four everybody fish. As grass carp has relatively big bodyand long sexual maturation cycle, it is hard to breed superior strain in short time withthe conventional fashion. Explore the effect the function of the gene for aquatic animalsis the important content of the genetic breeding, from the genetic type breeding goodvarieties could be an effective and efficient way. Although the application of aquaticanimals is less, but there are certain application prospect.Follistatin (Fst) is an activin-binding protein that neutralizes the activity of activin.Fst also binds other members of the transforming growth factor-β (TGF-β) superfamily,including myostatin (MSTN). MSTN is currently found on skeletal muscle developmentand the growth of the negative regulation function inhibition strongest thing. Researchshows that Fst can restrain MSTN gene of negative regulation and restore the growth ofmuscles in MSTN and corresponding body before its channel with blocking.We reportherein on the isolation and characterization of duplicated FST genes (fst-1and fst-2) in afreshwater fish grass carp (Ctenopharyngodon idellus), which is an importantaquacultural species with a production of365tons in China in2008. Grass carp fst-1and fst-2cDNAs are1,341bp and1,376bp in length, respectively. Their ORF are969bp and1,053bp, which encode322and350amino acids, respectively. Like their humanand zebrafish orthologs, grass carp fst-1and fst-2mature peptides also contain fourregions: N-domain, Domain I, Domam II and Domain III, in which N-domain containssix cysteine groups, Domain I, Domain II, and Domain III each functional areas containing ten cysteine groups. When compared to human and zebrafish, grass carp fst-1and fst-2have more than85%similarity in the coding region. Both fst-1and fst-2mRNAs were detected by RT-PCR throughout the embryogenesis and showeddifferential expression patterns. In the normal state, the grass carp embryonicdevelopment in various stages of the fst-1expression level is more constant and thedifference was not significant. The fst-2until16hpf when they begin to express, but theexpression level was gradually decreased from16hpf to40hpf.By in situ hybridization,fst-1mRNAs was observed in in the brain, hindbrain and skeletal muscle at the outeredge of the section expression, whereas fst-2mRNAs were expressed mainly in thebrain and skeletal muscle. In adult fish, fst-1mRNAs were transcribed in multipletissues except in gill and intestine, while fst-2mRNAs were detected mainly in eyes andslow-swtich muscle. Further through microscopic injection fst-2gene in the grass carpembryos, the figure is there any significant change.It can lead to grass carp embryos inthe back to the yolk sac bending and tails become warped. When excess fst-1geneexpression of grass carp have obvious no shape change. In this study, Tgf2transposonmediates efficient transposition of the Fsts gene in carp, grass carp, bream. Breamtransgenic group compared with the control group length has been increased, theindividual variable larger. Preliminary results indicate that certain feasibility by increaseFsts protein to improve animal muscle production. Our results suggest that duplicatedFsts genes may play conserved and divergent roles in regulating grass carp growth anddevelopment.