Analysis of Developmental Changes in Avian DNA Methylation Using a Novel Method for Quantifying Genome-wide DNA Methylation

Abstract

Individual differentiated somatic cells and undifferentiated stem cells have common genome, although their functions or morphological characters are very different. These differences are derived from difference of gene expression pattern. DNA methylation is generally key factor of suppression of gene and its level is globally change during mammalian early development. But, in birds, whether genome-wide changes in DNA methylation occur during embryonic development is still unknown. Here, we show that genome-wide DNA methylation to assess occurrence during early chick embryonic development. We found that the methylation status at stage 1 was approximately 57%, after which it gradually decreases, reaching a minimum at stage 10 (33%). After stage 10, DNA methylation gradually increased. These results should contribute to clarify the epigenetic mechanisms in birds.