Cloning And Sequence Analysis Of Ips Related Transcription Factors From Pinctada Fucata

In vitro somatic cell culture, the four transcription factors named Sox2, Oct4,c-Myc and KLF4can reprogram differentiated cells to an embryonic-like state, inanother name, induced pluripotent stem（iPS） cells. These factors can reprogramdifferentiated somatic cells to iPS cells, and they can also maintain the pluripotency ofstem cells.The gene sequences of c-Myc, Sox2and KLF4from Pinctada fucata was amplifiedby RACE PCR. The complete sequence of c-Myc gene was1585bp long and the openreading frame’s （ORF） length was1131bp which encoded a protein with376aminoacid residues. The analysis of protein structure showed c-Myc protein had theconservative HLH and Myc-N domains, which have the DNA-binding function.Sox2gene has the complete sequence of1908bp long and the990bp ORF whichencoded a protein with329amino acid residues. And the Sox2protein had theconservative HMG-box and Soxp domains, which have the DNA-regulation function.KLF4gene was2268bp long and the ORF was624bp long which encoded aprotein with207amino acid residues. And the KLF4protein had two zf-H2C2₂domains, which can bind DNA. Blast analysis indicated the three deduced amino acidsequences of the c-Myc, Sox2and KLF4genes from Pinctada fucata showed highhomology with proteins from Crassostrea gigas.RT-PCR result shows that the three genes were expressed in all six tissues fromPinctada fucata, those were mantle, foot, gonal, visceral mass, adductor muscle and gill.c-Myc, Sox2and KLF4are all very consevative tanscription factors involved in generegulation. It’s expectable that they were expressed in all tissues.Therefore, considering that the different functions of distinguished tissues, thegenes’ expression in different tissues should be distinguished too. So I carried on thereal time quantitative PCR, which gives an intuitive result of the relative expressionlevels of the genes in the central, submarginal and marginal zone of mantle for thecorrelations between mantle and biomineralization.It turns out that the genes expressed most in mantle centeral cells, less insubmarginal and least in maginal cells. I think it could be explained by the least differentiation of cells in mantle center, for the previous research has showed that thethree genes expressed more in early development of embryonic and express less in mostdifferentiated tissues. This experiment showed that cells in mantle central zone are inlow level of differentiation, and may have the potential to distinguished fates ofdifferentiation.Our research laid the foundation for study of iPS cells and transcriptional factorsfrom Pinctada fucata. It provided a new thought for the culture of mantle cells in vitrowhich will help the study of mechanism of nacre formation. The mantle central cellshave been proved to have a series of characteristics of stem cells, and could be thebreakthough of study of mechanism of nacre formation at celluar level.