An initial investigation of an alternative model to study rat primordial germ cell epigenetic reprogramming

• Grant number: 17/14606-9
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: September 01, 2017
• End date: February 28, 2018
• Field of knowledge: Biological Sciences - Morphology - Embryology
• Principal Investigator: Taiza Stumpp Teixeira
• Grantee: Taiza Stumpp Teixeira
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

Background: Primordial germ cells (PGC) are the precursors of the gametes. During pre-natal development, PGC undergo an epigenetic reprogramming when bulk DNA demethylation occurs. This has been widely studied in mice but not in rats probably due to the lack of genetic and molecular information available about germ cell development in this species when compared to mice. However, we have previously shown that the rat might be an interesting model to study germ cell development. In face of the difficulties of getting enough PGC for molecular studies, the aim of this study was to propose an alternative method to study rat PGC DNA methylation. Rat embryos were collected at 14, 15 and 19dpc for the analysis of DNMT1, DNMT3a and DNMT3b expression or at 16dpc for 5-Aza-CdR treatment in vitro. Results: DNMT1 was not detected in PGC at 14dpc but was present at 15 and 19dpc. DNMT3a and DNMT3b expression varied between them and according to the embryo age. The in vitro treatment of rat embryonic gonads with 1µM of 5-Aza-CdR lead to a loss of 5mC labelling and to the activation of Pax6 expression in PGC, but not in somatic cells, suggesting that 5-Aza-CdR promoted a PGC-specific global DNA hypomethylation. Conclusions: This study suggests that the protocol used here can be a potential method to study the wide DNA demethylation that takes place during PGC reprogramming. (AU)