X Chromosome Status In Androgenetic Haploid Embryo Development

Haploid stem cell have been widely used for gene modification and drug screening as a novel significant gene edition tool. It is easier to acquire homozygote of recessive gene by utilizing the spontaneously diploidization feature of haploid stem cells. What’s more, gene trap and enhancer trap can also be realized for searching novel gene and enhancer element. In mus musculus, the derivation of androgenetic haploid stem cell broad a new horizon of stem cells and became a new hotspot. However, the low efficiency of androgenetic haploid stem cell derivation ratio and poor quality of androgenetic haploid embryo limit its application foreground.To improve the quality of androgenetic haploid balstocyst and the efficiency of the androgenetic haploid stem cells derivation, we assessed the expression of Xist in the androgenetic haploid embryos during its development to blastocyst in vitro.The result showed that the blastocyst rate of androgenetic haploid embryo was 10%-14%, the time for the development to balstocyst stage varied from 3.5 day to 5.5 day. RNA-FISH results indicated that there was three pattern of Xist expression including negative embryos, mosaic embryos and positive embryos. Xist was actively expressed in the early developmental stage, but was silenced in these embryos which developed to blastocyst stage. Knockdown Xist expression by si RNA improved the quality of the blastocyst and the rate of outgrowth when seeded on the feeders, but did not improve the blastocyst rate. These results indicated that the expression of Xist is one of the factors for the unsatisfied quality of the androgenetic haploid blastocyst and the low efficency of androgenetic stem cell derivation.