Comparison of the effects of vitrification and slow freezing on the growth and development of offspring using a mouse model

Abstract

Comparison of the effects of vitrification and slow freezing on the growth and development of offspring using a mouse model Z.Y. Wang1,2,†,∗ , S. Chen3,† , W.J. Zhu1,2 , X.T. Shen1,2 , Y.B. Li1,2 , J.X. Zheng4,∗ 1Center for Reproductive Medicine, The First Affiliated Hospital, Sun Yat-sen University, 510080, Guangdong (P.R. China) 2The Key Laboratory for Reproductive Medicine of Guangdong Province, The First Affiliated Hospital, Sun Yat-sen University, 510080, Guangdong (P.R. China) 3Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital, Sun Yat-sen University, 510080, Guangdong (P.R. China) 4Department of Neurology, People’s Hospital of Yangjiang, 529500, Guangdong (P.R. China) Summary In this study, mouse embryos were used to compare the effects of vitrification and slow freezing on the physiology, normal spatial learning, cerebral development, and gene expression of offspring. 583 8-cell stage embryos were obtained from 60 female mice and randomly divided randomly into three groups: vitrified, slow frozen, and control groups. In the vitrified group, embryos were cryopreserved by using the vitrification technique. In the slow frozen group, embryos were frozen using the slow freezing technique. In the control group, the embryos were not frozen and were transferred. After thawing, birth rates, physiology, normal spatial learning, and cerebral development of offspring were compared among the three groups. The expression of fat and brain-associated genes were measured by RT-PCR (real-time quantitative polymerase chain reaction), Western blot, immunofluorescence staining, and immunohistochemistry. The weight of the offspring in the vitrified and slow frozen groups was higher (p < 0.05) than in the control group at 8 weeks. There were no differences in the other postnatal physiology and development parameters in the offspring from the three groups. There were no difference in the expression and distribution of two brain development-related proteins, glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP) in the offspring. The expression of two fat-associated genes, Fat mass and obesity-associated (FTO) and PPARγ co-activator-1 (PGC-1α), were higher in offspring from the frozen-thawed (slow frozen and vitrified) group than the control group. Slow freezing and vitrification embryo transfer techniques had no significant differences in postnatal physiology and development. Key words: Vitrification; Slow freezing; Gene expression; Offspring health; Mouse model.