Research On Preimplantation Genetic Screening Of Embryos Based On Multiomics

With the advancement of technology,Medically Assisted Reproduction(MAR)has become widely prevalent,offering hope for healthy pregnancies to those struggling with infertility.However,Preimplantation Genetic Testing(PGT),one of the significant procedures in assisted reproduction,may impact the health and development of offspring due to its invasive nature.Given the potential increased risk of obstetric,perinatal,and congenital anomalies associated with MAR,a non-invasive method for preimplantation genetic screening is increasingly vital.Yet,the sensitivity,specificity,and detectable molecular markers of non-invasive preimplantation genetic testing(niPGT)in clinical practice remain unclear.Therefore,exploring the laws of niPGT and searching for some genes related to embryonic development from a multi-group perspective is essential for promoting the development of assisted reproductive technology.In this paper,218 human embryo samples were first used for single-cell whole genome amplification(WGA)sequencing,in which blastocoele fluid(BF)and spent culture medium(SCM)were used as sources of niPGT;At the same time,experimental materials derived from a whole blastocyst(WB),trophoblast ectoderm(TB),and inner cell mass(ICM)were used as PGTs to determine the changes in signals at the genomic level by different detection methods.Secondly,we collected the histological data of discarded human-assisted reproductive embryo culture broth from the public database,explored the molecular mechanisms detected in the discarded culture broth,and improved our understanding of niPGT;Finally,the critical genes obtained from the analysis were used to explore the vital role of early embryonic development in neural development.The aforementioned study offers a precise theoretical foundation to advance the investigation of niPGT in the realm of reproductive development and facilitates the utilization of assisted reproductive technology for the prevention and treatment of reproductive development disorders.The specific content and results of this paper are as follows:(1)Systematic analysis of mutation profiles in preimplantation genetic screening materials for embryosIn this experiment,218 in vitro fertilization embryos were collected from patients who received adjuvant pregnancy treatment from the Northwest Women’s and Children’s Hospital and met the inclusion criteria.Samples were taken from 5 locations,including spent culture medium(SCM),blastocoele fluid(BF),inner cell mass(ICM),trophectoderm biopsy(TB),and whole blastocyst(WB),for single-cell genomic amplification.We found that the genome-wide similarity between SCM and ICM is higher than that of BF.At the late stage of embryonic development,embryonic stem cells in ICM will differentiate into various organs and tissues,serving as the gold standard for genetic screening before embryo implantation and occupying an important position in assisted reproduction.Our research shows that the genome-wide similarity between SCM and ICM is even higher than that of WB and TB from the same embryo biopsy.Mutation genes detected in SCM are enriched in pathways related to neural development.This characteristic indicates that SCM provides a more effective preimplantation genetic screening detection material and a new reference point for screening suitable transplanted embryos using mutation gene testing.We conclude that SCM is a more potential genetic screening material for preimplantation embryos.(2)Identification of Neurodevelopment-Related Genes in SCM and Verification of the Reliability of niPGTBased on the full transcriptome sequencing data of human embryos using assisted reproductive technology from the NCBI database,a study on molecular markers that can be detected by niPGT was conducted.The samples were collected from the discarded culture medium(SCM)from five human blastocysts that were subsequently transferred or frozen on the fifth day after in vitro fertilization.The protein-coding genes in SCM were found to be mainly enriched in neurologically relevant pathways.Despite the lack of differentiation of embryonic stem cells into neurons on the fifth day of embryo culture,a large number of neurologically related genes have been transcribed,laying a foundation for the rapid thickening of the outer embryonic layer along the central axis to form a longitudinal neural plate,gradually forming a neural tube three weeks later.Moreover,these neurologically related genes on the fifth day of embryonic development are implicated in the metabolic pathway of Alzheimer’s disease.This result is consistent with the mechanism related to the regulation of neurodevelopment in the early stages of embryo development under natural reproductive conditions,thereby proving the reliability of niPGT using SCM as a testing material.(3)Analysis of ce RNA Regulatory Network of Neurodevelopment-Related Molecular Signals in SCMTo further explore certain mechanisms regulating neurodevelopment in the early stages of embryonic development,the identification of neurologically related differential m RNAs was firstly carried out.Subsequently,a differential m RNA-lnc RNA-pathway co-expression network and a differential miRNA-target gene-pathway network related to neurodevelopment were constructed in SCM.Finally,an lnc RNA-miRNA-m RNA network was built,and three key genes associated with neurodevelopment,namely EFNA1,EXT1,and SYT2,were discovered.EFNA1,a neurotrophic factor,is associated with cancer metastasis.Studies have shown that the more EFNA1 is transcribed,the easier it is for cancer to metastasize;EXT1 can lead to patients suffering from osteochondroma,where tumors compress nerves,causing mild mental retardation in patients;SYT2 may lead to neurodegeneration or dysfunction at the neuromuscular junction.Further validation is in line with the fact that the fifth day of embryo culture is a critical period for neurodevelopment.The reliability of SCM as a testing material was verified from multiple perspectives,which is of great significance for the promotion of assisted reproductive technology in the future.In conclusion,this paper systematically analyzes the differences between different pre-implantation genetic screening methods using bioinformatics methods,efficiently mines the deep-level genomic information of niPGT,provides strong theoretical basis and research direction for the future application and development of niPGT technology in the field of reproduction and development through empirical evidence of the effectiveness and necessity of pre-implantation genetic screening using assisted reproductive technology.At the same time,it also opens up a new path for the research and practice of preventing and treating reproductive development diseases using assisted reproductive technology.