Phenotypic divergence between broiler and layer chicken lines is regulated at the molecular level during development.

"finally we appreciate the foundation for agrarian studies luiz de queiroz (fealq) for their grant support to f c v data availability the dataset supporting the conclusions of this article is available in the european nucleotide archive (ena) repository (embl-ebi) under accession prjeb65907 [ http://www ebi ac uk/ena/data/view/ ]. data availability the dataset supporting the conclusions of this article is available in the european nucleotide archive (ena) repository (embl-ebi) under accession prjeb65907"

"Declarations Ethics approvalThe procedures involving animals were evaluated and approved by the Ethics Committee for the Use of Animals (CEUA, number 015/2016) from the Brazilian Agricultural Research Corporation – Embrapa Suínos e Aves. All procedures followed the guidelines by the Brazilian Council of Animal Experimentation and the ethical principles in animal research, according to FASS [38], the Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching. This study was carried out in compliance with the ARRIVE guidelines. Consent for publicationNot applicable. Conflict of interestThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Conflict of interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest."

"Funding This work was financially supported by the São Paulo Research Foundation (FAPESP, São Paulo, Brazil) through grant 14/08704-0 to L.L.C.; the maintenance of pure lines was provided by the Brazilian Agricultural Research Corporation - Embrapa (project no. 01.15.02.003.05.00 to M.C.L). We also acknowledge the National Council for Scientific and Technological Development (CNPq, Brasília, Brazil) for research fellowships awarded to R.E.C. (158979/2018-4), A.S.M.C., and L.L.C., as well as the Coordination for the Improvement of Higher Education Personnel (CAPES, Brasília, Brazil) for providing a fellowship to I.B.L. (Finance Code 001). Finally, we appreciate the Foundation for Agrarian Studies Luiz de Queiroz (FEALQ) for their grant support to F.C.V."