Epigenetic mapping of the somatotropic axis in Nile tilapia reveals differential DNA hydroxymethylation marks associated with growth

12 pages, 6 figures, 2 tables, supplementary material https://doi.org/10.1016/j.ygeno.2021.06.037.-- Data availability: The DNA hydroxymethylation dataset of this study is available in the SRA (NCBI) repository, under the accession number PRJNA665628. The RNA sequencing dataset of this study is available in the GEO (NCBI) repository, under the accession number GSE158910

In vertebrates, the somatotropic axis comprising the pituitary gland, liver and muscle plays a major role in myogenesis. Its output in terms of muscle growth is highly affected by nutritional and environmental cues, and thus likely epigenetically regulated. Hydroxymethylation is emerging as a DNA modification that modulates gene expression but a holistic characterization of the hydroxymethylome of the somatotropic axis has not been investigated to date. Using reduced representation 5-hydroxymethylcytosine profiling we demonstrate tissue-specific localization of 5-hydroxymethylcytosines at single nucleotide resolution. Their abundance within gene bodies and promoters of several growth-related genes supports their pertinent role in gene regulation. We propose that cytosine hydroxymethylation may contribute to the phenotypic plasticity of growth through epigenetic regulation of the somatotropic axis

This work was funded by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreements nos. 683210 and 812986) and by the Research Council of Norway under the Toppforsk programme (grant agreement no 250548/F20)

With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)

Peer reviewed