Features of DNA Repair in the Early Stages of Mammalian Embryonic Development.

Evgenia V Khokhlova,Julia V Sopova,Elena I Leonova,Zoia S Fesenko

doi:10.3390/genes11101138

Evgenia V Khokhlova, Julia V Sopova + Show 2 more

Open Access

https://doi.org/10.3390/genes11101138

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Journal: Genes	Publication Date: Sep 27, 2020
Citations: 31	License type: CC BY 4.0

Affiliation: Institute of Cytology, St Petersburg University

Abstract

Cell repair machinery is responsible for protecting the genome from endogenous and exogenous effects that induce DNA damage. Mutations that occur in somatic cells lead to dysfunction in certain tissues or organs, while a violation of genomic integrity during the embryonic period often leads to death. A mammalian embryo’s ability to respond to damaged DNA and repair it, as well as its sensitivity to specific lesions, is still not well understood. In this review, we combine disparate data on repair processes in the early stages of preimplantation development in mammalian embryos.

Highlights

DNA repair during the early stages of embryonic development has one of the most significant effects on embryonic fate [1]
Some mRNAs are translated in the oocyte, while others remain in a polyadenylated form until fertilization, maintaining a pool of repair proteins until the embryo genome is activated [29]
The transformation of a fertilized oocyte into a zygote is an amazing process that occurs in the absence of transcription and depends on the mRNA accumulated in the oocyte during oogenesis

Summary

Introduction

DNA repair during the early stages of embryonic development has one of the most significant effects on embryonic fate [1]. It is believed that all major DNA repair pathways function in embryos. If the damage is too substantial, and it is impossible to repair the DNA, a proapoptotic pathway is activated, resulting in cell death [3]. Several reports have shown that early embryos and embryonic stem (ES) cells lack functional cell cycle control checkpoints, and DNA synthesis and cell division continue in the presence of damaged DNA. Ineffective activation of cell cycle checkpoints and suppression of apoptotic pathways in early embryos is associated with a shortened cell cycle, helping to ensure that the first embryonic cell division occurs, even under adverse conditions [4]. This review aims to analyze the literature and compare the role of repair systems at different stages of early mammalian embryonic development from the oocyte to the preimplantation blastocyst

Oocyte Repair

Repair at the Zygote Stage

Repair at the Cleavage and Blastocyst Stages

Embryonic Stem Cells

Conclusions