Studies On The Genetic Resources And DNA Markers Related To Its Body Color Of Plectorhynchus Cinctus

The genetic resources of Plectorhynchus cinctus were investigated usingisoenzyme electrophoresis, karyotype analysis and molecular marker. The mutant of Pcinctus was firstly reported, and the genetic and biological character differencbsbetween P cinctus and its mutant were studied, DNA markers related to the bodycolor of P. cinctus were aslo abstained. The results are as bellowi1. The genetic diversity of P cinctus in the cultured stock from Zhe-lin bay inGuangdong was analyzed. 48 samples were examined by polyacrylamid gelelectrophoresis (PAGE). Ainong the 26 loci in ll enzymes, four polymorphic lociwere found. The meart level of polymophism was 15.4% and heterozygosity was0.047. With 34 random primers fOr RAPD-PCR, 197 infOrmative fragments wereobtained, including 45 variation fragments. The polymorphism and the meandtherence within the same stock were 22.84% and 0.077 respectively. The resultsindicated that the genetic diversity of P cinctus from Zhe-lin bay wereintermediate, compared with the other vertebrates.2. The genetic variations of two different cultured stock of P cinctus assessed byisoenzymes.The result indicated the stock of P cinctus from Zhe-lin bay showedhigher genetic diversity than that from Xiamen. The former lost one rare allele ofGCDHso. and the latter the four rare alleles of mSOD-11lo, mSOD--2,,.,, sMDHl2oand lDDH-2l38. All the above results implied the genetic resource had beendecline in both cultured stocks.3. The karyotype of the renal cell of Pcinclus was examined by PHA injection--airdrying method. The resu1t showed that the number of chromosome was 48, and4the karyotype formula was 2n=48=48t, NF=48, which was not in accordance withthe karyotype of the other three members of Pomadasyidae.4. 680 bp fragments of 16S rRNA gene in mtDNA in P cinctus and HaPatogenysnitens were amplified and digested with 5 restriction enzymes of Ecor I, Mse I 9Sac I, Pst' I and HindI1I. The results showed the fragment of 16SrRNA gene in Pcinctus was only digested by Mse I and the fragment in H nitens by Mse I andSac I. But the number of cleavage site of Mse I was dtherent betWeenP cinctusand H nitens. These differences could be used as the genetic marker to distigushPcinctus from H nitens.5. The fragment of l6S rRNA gene of P cinctus was sequenced, the region of 421bpwere compared with the same regions of the other three members ofPomadasyidae. The results proved that the dtherences of polymorphrism betweenP cinctus and the other three members were from 11.72% to 14.35%. There were105 polymorphic sites, 90 variation loci within the fOur species. Onehypervariable domain from 250bp to 274bp of 16S rRNA was fOund, and thehypervariable domain could be regarded as the DNA marker for the fOur species.6. UPGMA and MP molecular phylogenetic trees of the above four species inPomadasyidae were established by Phylip 3.0. Two molecular phylogenetic treesconsistent with each other. Two trees supported that both H nitens and P cinctusoriginated from one ancestor, but both Haemulon Sciurus and PomadaSySmaculates from another ancestor.7. Mutant of P cinctus was firstly found in Zhe-lin bay. It lost the body color of wildtype and was white in skin but black in eyes. The difference of biologicalcharacter between P cinctus and its mutant was analyzed. The results showed thatthere were differences in grow rate, movement, the compose and content of aminoacid in the muscle.8. 16S rRNA gene sequence analysis. PCR-RFLP. RAPD. MLP. ISSR and BSAtechniques were applied to study on the genetic difference between the P cinctusand its mutant. The results showed that P cinctus and its mutant shared high5genetic homology in mtDNA. Microsatellite DNA and genome DNA. The geneticsimilarity abtained from the different techniques were 96.61--98.57%, the geneticdtherence were 1.43--3.39%. 17 special DNA markers including 13 RAnDmarkers, 3 AFLP markers and 1 ISSR marker were...