Study On The Transferr In Of Pingxiang Red-transparent Crucian Carp, Carassius Auratus Var. Pingxiangnesis

Pingxiang red-transpanent crucian carp,Carassius auratus var.Pingxiangnesis had been considered as a variant of wildness diploid spieces of crucian carp in Jiangxi Province.The sixth generation was successive produced by selective breeding for seven years.The fish had many good economic characters,such as fast growth,easily adaptable,rich nutrition,easily cultured,strong anti-resistance.It had been examined and authorized as a new aquaculture variety in the whole country.Transferrin of the fish was studied in this paper.The phenotypes of the TF was got by the method of Polyacrylamide gel electrophoresis(PAGE) and its molecular weights was analyzed through Sodium dodecyl sulfate(SDS) Polyacrylamide gel electrophoresis.In order to understand the genetic background of the fish and got more scientific data,the length TF-cDNA was produced by RT-PCR and RACE-PCR.The main researches were as follows:Firstly,12 specimens were collected for electrophoretic analysis.Polyacrylamide gel electrophoresis was carried out to separate TF.All electrophoretic phenotypes of TF were same;Two bands are observed,one of them denser,the other fainter and they were considered encoded by two co-dominant alleles.Sodium dodecyl sulfate Polyacrylamide gel electrophoresis was utilized to determine the molecular weights of TF and the result showed all the molecular weights were about 71KDa.The high homogeneity of TF might indicated the population were stable pure line and might prove the natural gynogenesis in this population.Results suggested that the TF may be a good genetic marker of gynogenesis for the fish.Secondly,in order to understand the TF molecular mechanism,the length TF-cDNA was produced by RT-PCR and RACE-PCR.The TF-cDNA was 2364 bp long,with an complete open reading frame(ORF),8-bp 5'UTR and a 355-bp 3'UTR. The cDNA encoded a 666 amino acid with a potential signal peptide,for which the splicing site was located between the 15th and 16th amino acid residues.The deduced molecular weight(Mw) of the mature(after cleavage of the signal peptide) was 71.9 kDa,which was consistent with data from SDS-PAGE analysis.No possible N-linked glycosylation site was found.There were 34 cysteine(Cys) residues in mature TF-cDNA.Result showed there was similar genetic background among the colour crucian carp A,the silver crucian carp E and the Pingxiang red-transparent crucian carp.Lastly,we made theoretic analysis of the secondary structure of TF-cDNA and proceeded to homology modeling to generate similar tertiary structures of TF-cDNA.