(15) Profiling of Small RNAs in Mouse Androgenetic Haploid Embryonic Stem Cells

Zhiming Han^1,4; Wenteng He²; Hongming Tang²; Yuanyuan Li³; Mingzhu Wang³; Yuanyuan Li¹; Jiayu Chen³; Shaorong Gao^2,3

1. State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China

2. Institute for Regenerative Medicine, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China

3. Clinical and Translation Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China

4. Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China

Abstract Text:

Mouse androgenetic haploid embryonic stem cells (mAG-haESCs) are haploid cells derived from mouse androgenetic haploid blastocysts, which have only one set of genomes inherited from sperm. mAG-haESCs can maintain pluripotency and propagate infinitely, similar to diploid embryonic stem cells (ESCs) (2n ESCs), under 2i culture conditions. mAG-haESCs can be utilized to uncover gene functions, especially those of genes with recessive effects, and to produce semi-cloned mice when injected into mature oocytes. However, mouse haploid cells undergo rapid diploidization during long-term culture in vitro and subsequently lose the advantages of haploidy. To investigate the mechanism of diploidization in mAG-haESCs, we compared the small RNAs (sRNAs) of mAG-haESCs, normal 2n ESCs (R1), and mouse round spermatids (mRS) with the same genetic background through high-throughput sequencing and identified distinct sRNA profiles. The results showed that the sRNAs in mAG-haESCs and R1 were mainly microRNAs (miRNAs) with a small amount of piwi-interacting RNAs (piRNAs), while those in mRS were mainly piRNAs with fewer miRNAs. mAG-haESCs contained fewer piRNAs than R1, which is consistent with the unique piRNA metabolic process pathway of mAG-haESCs. mAG-haESCs have a unique sRNA signature compared to R1 and mRS in terms of the length distribution, sRNA type distribution, first-base distribution, and base position preference of known miRNAs. The results of the KEGG pathway analysis of the candidate target genes of the differentially expressed miRNAs indicated that mAG-haESCs have a unique miRNA expression profile with distinct impacts on the physiological processes of cell proliferation, apoptosis, and metabolism. Moreover, these differentially transcribed miRNAs play important regulatory roles in these pathways and may affect them by negatively regulating the expression of their target genes. In this study, we revealed the unique sRNA profile of mAG-haESCs and suggested that modulating the expression of miRNAs might mitigate the diploidization in mAG-haESCs. This study was supported by the National Key Research and Development Program of China (2019YFA0109900) to Z.H.