Prenatal environment influence on adult phenotype development is partially mediated by epigenetics phenomena. Our previous study highlighted significant effects of the in-ovo injection of endocrine disruptors or a DNA methyltransferase inhibitor on quail development, significantly reducing their weight [1]. An increasing number of studies highlighted the transmission of epigenetics marks between generations following environmental exposure. However, there is much debate about their acquired transmission beyond the exposed generation. Recent studies revealed that non-genetics inheritance was probably present in avian species. In one of them [2], fertilized eggs were divided into two groups: one group injected with an endocrine disruptor, Genistein, and a non-injected control group. After three generations without any other injection, several traits were impacted by the ancestor treatment such as reproduction and behavioral traits. This pilot study highlighted the potential existence of transgenerational transmission of environmental effects in quails. To better understand the transgenerational transmission of these environmental effects, DNA methylation data were generated from blood samples of the third generation (WGBS and ONT). To analyse the DNA methylation state, we developed a bioinformatics pipeline in order to detect differential methylated cytosines (DMCs) affected by these transgenerational phenomena. We detected thousands of DMCs between both groups. A preliminary genetic analysis of the data suggests that most of these differentially methylated positions are related to genetic variability between both epilines, even if a mirror crossing was set up to reduce the genetic differences between both lines. In addition to these analyses, these data allowed us to perform a comparative analysis between the WGBS and ONT sequencing technologies for DNA methylation analysis. References [1] C. Cerutti, S. Leroux, D. Gourichon, Y. Labrune, I. David, T. Zerjal, V. Coustham, G. Devailly, F. Pitel. Short communication: Effects of in-ovo injection of endocrine disruptors and methylstransferase unhibitor on quail growth and egg-laying performances. Vol. 16, pp. :1751-7311, 2022. [2] S. Leroux, D. Gourichon, C. Leterrier, Y. Labrune, V. Coustham, S. Rivière, T. Zerjal, J.L. Coville, M. Morisson, F. Minvielle, F. Pitel. Embryonic environment and transgenerational effects in quail. Vol. 49, pp. :1297-9686, 2017.