Chennan Shi1, Jingyi Zhang1, Zhengjie Yan1, Li Gao1, Chao Gao1, Wei Wu1, Jiayin Liu1, Yugui Cui2. 1. State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, Jiangsu Province, China. 2. State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, Jiangsu Province, China. cuiygnj@njmu.edu.cn.
Abstract
PURPOSE: To investigate the epigenetic safety of putrescine supplementation during in vitro maturation (IVM) to offspring. METHODS: Germinal vesicle oocytes retrieved from 12-week-old mice were randomly divided into two groups and cultured in IVM medium with or without 1 mmol/L putrescine for 16 h. Then, in vitro fertilization and embryo transplantation were conducted to produce the F1 offspring. The F1 mated with ordinary mice and bred the F2 offspring. The DNA methylation patterns in the brain and heart of F1 were investigated by reduced representation bisulfite sequencing. Imprinted gene expression levels of F1 oocytes were tested. The global methylation of F2 was examined by dot blot. RESULTS: The weight, organ coefficient, and histology were normal in the F1 and F2 offspring from the putrescine-treated oocytes. An overall methylation level of 31.23 to 32.53% was observed for all CpG sites in the brain and heart of the two groups. The DNA methylation patterns of the brain and heart in F1 were not altered in general, with subtle differences. The expression levels of imprinted genes including H19, Snrpn, Peg3, Igf2, and Igf2r did not statistically change. The global 5mC level of F2 was consistent with the control group. CONCLUSION: Putrescine supplementation during IVM did not directly affect the development, health, and reproduction, and did not affect the genome and global epigenetics of mouse offspring derived from those oocytes. The transient putrescine treatment for improving oocyte maturation shows its long-term safety of genome and epigenetics in the offspring of mice.
PURPOSE: To investigate the epigenetic safety of putrescine supplementation during in vitro maturation (IVM) to offspring. METHODS: Germinal vesicle oocytes retrieved from 12-week-old mice were randomly divided into two groups and cultured in IVM medium with or without 1 mmol/L putrescine for 16 h. Then, in vitro fertilization and embryo transplantation were conducted to produce the F1 offspring. The F1 mated with ordinary mice and bred the F2 offspring. The DNA methylation patterns in the brain and heart of F1 were investigated by reduced representation bisulfite sequencing. Imprinted gene expression levels of F1 oocytes were tested. The global methylation of F2 was examined by dot blot. RESULTS: The weight, organ coefficient, and histology were normal in the F1 and F2 offspring from the putrescine-treated oocytes. An overall methylation level of 31.23 to 32.53% was observed for all CpG sites in the brain and heart of the two groups. The DNA methylation patterns of the brain and heart in F1 were not altered in general, with subtle differences. The expression levels of imprinted genes including H19, Snrpn, Peg3, Igf2, and Igf2r did not statistically change. The global 5mC level of F2 was consistent with the control group. CONCLUSION: Putrescine supplementation during IVM did not directly affect the development, health, and reproduction, and did not affect the genome and global epigenetics of mouse offspring derived from those oocytes. The transient putrescine treatment for improving oocyte maturation shows its long-term safety of genome and epigenetics in the offspring of mice.
Authors: Audrey J Kindsfather; Megan A Czekalski; Catherine A Pressimone; Margaret P Erisman; Mellissa R W Mann Journal: Clin Epigenetics Date: 2019-11-26 Impact factor: 6.551