Study On The Safety And Efficacy Of Blastocyst Biopsy In Pre-implantation Genetic Diagnosis

The advent of gene targeting and transgenesis has fostered profound advances in biomedical research over the past several decades.O ver-expression or ablation of specific genes,coupled with approaches for tissue-and cell-specific modification,has allowed great strides to be made in the understanding of the genetic determinants of development and the genetic components of disease.Model organisms such as Drosophila,Caenorhabditis elegans and the laboratory mouse,have provided most of this information because of their relative ease of manipulation。However,the development and physiology of even the mo use is sometimes disparate from humans and new models must be developed to address questions unique to primate physiology。However,ZFN,TALEN,CRISPR/Cas9 three gene editing techniques have a certain off-target effect,So slect successful and effective gene editing embryos for transplantation,will undoubtedly is very improtent.We can use preimplantation genetic diagnosis to select effective gene editing embryos.Although preimplantation genetic diagnosis technology has been widely used to promote the use,the safety of the offspring born through this technique has not been conclusive.In this study,as for mouse,cutting zona pellucida,and then obtaining blastocyst trophoblast cells,cryopreservating blastocyst,transferring embryo in uterus of surrogate mother,as well as delivering offspring,recording its weight weekly,and reproductive capacity,all were done.Meanwhile,cynomolgus monkey embryos used to do the same program.The results are as follows:(1)Blastocyst rate of mouse embryos cut zona pellucida were 71.5%,and that in control without cut was 88.9%.The rate in cynomolgus monkey embryos cut was 65.0%,and that in control was 60.0%.Both of counterpartners showed no significantly different.(2)Mouse embryos,the rate of successfully obtaining blastocyst trophoblast cells in mouse blastocyst was 95.6%,and that in cynomolgus monkey blastocyst was 84.2%.(3)Mouse embryos,after frozen and thaw,success rate is 85.0%,and control is 83.3%.(4)The pregnancy rate of control mouse embryos without frozen and thaw was 75.0%,control mouse embryos and after frozen and thaw was 66.7%.PGD embryo without frozen and thaw was 58.3%,PGD with frozen and thaw was 50.0%.C ynomolgus monkey embryos,the pregnancy rate of control embryos is 42.9%,PGD embryos was 37.5%.(5)offspring of mouse from PDG embryos have normal development of weight.The average number of offspring in mouse from no n-PGD embryos was 12.27±0.42,and that in mouse from PGD embryos was 11.18±1.16,which shows that mouse from PGD embryos have normal reproductive capacity.In summary,preimplantation genetic diagnosis technology does not affect the pregnancy rate and birth rate.This provides valuable data for the safety assessment of human assisted reproductive technology and application of PGD in nonhuman primates.