GSE178437
Dynamics of small non-coding RNAs in bovine scNT embryos through the maternal-to-embryonic transition [non-coding RNA]
The efficiency of somatic cell nuclear transfer (scNT) for production of viable offspring is relatively low as compared to in vitro fertilization (IVF), presumably due to deficiencies in epigenetic reprogramming of the donor cell genome. Such defects may also involve the population of small non-coding RNAs (sncRNAs), which are important during early embryonic developmeNT.The objective of this study was to examine dynamic changes in relative abundance of sncRNAs during the maternal-to embryonic transition (MET) in bovine embryos produced by scNT as compared to IVF by using RNA sequencing. When comparing populations of miRNA in scNT versus IVF embryos, only miR-2340, miR-345, and miR34a were differentially expressed in morulae, though many more miRNAs were differentially expressed when comparing across developmental stages. Also of interest, distinct populations of piwi-interacting like RNAs (pilRNAs) were identified in bovine embryos prior to and during embryonic genome activation (EGA) as compared bovine embryos post EGA and differentiated cells. Overall, sncRNA sequencing analysis of preimplantation embryos revealed largely similar profiles of sncRNAs for IVF and scNT embryos at the 2-cell, 8-cell, morula and blastocyst stages of developmeNT.However, these sncRNA profiles, including miRNA, piRNA and tRNA fragments, were notably distinct prior to and after completion of the MET. Overall design: Small non-coding RNA (sncRNA) profiles (focused in microRNAs, piwi-like RNAs, and transfer RNA fragments) of bovine oocytes; fibroblasts; and embryos produced via in vitro fertilization or somatic cell nuclear transfer at 2-cell, 8-cell, morula, and blastocyst developmental stages and blastocyst-derived cells.  Initially, four pools of 20 2-cell, 8-cell, morula, and blastocyst stage embryos were collected at 2, 3, 6, and 8 days post-IVF or scNT.