To understand the physiological relevance of these transcript alterations in vivo, the expression of cell cycle mRNAs was assessed in cultures of isolated fetal subventricular cells, which include endogenous NSC. Similar expression levels for 6 out of 10 transcripts were found, including down regulation of the proliferation marker Ki67 and cell cycle regulator Cdc2a. This largely validates the algorithm for selecting DMR candidates. The authors concluded that the presence of growth factors with ethanol alters cell cycle kinetics of neural stem cells at G1/S checkpoints through hypermethylation (Hicks et al. 2010). They further postulated that hypermethylation of G1/S regulators restricts feed forward mechanism to maintain the continuation of the cycle.
