This is supporting data for an article in which we describe a protocol for the generation of sequence-ready libraries for population epigenomics studies. The protocol is a streamlined version of the Assay for transposase accessible chromatin with high-throughput sequencing (ATAC-seq) that provides a positive display of accessible, presumably euchromatic regions. The protocol is straightforward and can be used with small individuals such as daphnia and schistosome worms, and probably many other biological samples of comparable size, and it requires little molecular biology handling expertise. In "Agarose picture.Tif" the left lane shows the 100 bp size marker, first 10 bands from down to top: 100bp, 200bp, 300bp, 400bp, 500bp, 600bp, 700bp, 800bp, 900bp and 1kbp. Produced at IHPE (http://ihpe.univ-perp.fr/)

This work was performed with the support of LabEx CeMEB, an ANR « Investissements d'avenir » program (ANR-10-LABX-04-01) and the RTP Epigenetics in Ecology and Evolution (RTP3E). R.A. and C.G. were supported by the Wellcome Trust Strategic award 107475/Z/15/Z. C.G. and A.M. received support from JSPS grant S17087.