Intralocus sexual conflict (IASC) prevents males and females from reaching their disparate phenotypic optima and is widespread, but little is known about its genetic underpinnings. In Rhizoglyphus robini, a mite species with alternative male morphs, elevated sexual dimorphism of the armoured fighter males (compared to more feminized scramblers males) was previously reported to be associated with increased IASC. Because IASC persists if gene expression patterns are correlated between sexes, we compared gene expression patterns of males and females from the replicate lines selected for increased proportion of fighter or scrambler males (F- and S-lines, respectively). Specifically, we tested the prediction that selection for fighter morph caused correlated changes in gene expression patterns in females. We identified 532 differentially expressed genes (FDR < 0.05) between the F-line and S-line males. Consistent with the prediction, expression levels of these genes also differed between females from respective lines. Thus, significant proportion of genes differentially expressed between sexually selected male phenotypes showed correlated expression levels in females, likely contributing to elevated IASC in F-lines reported in a previous study.

This work was supported by the Foundation for Polish Science, International PhD Projects Programme co-financed by the European Regional Development Fund within the project MPD/2009-3/5, “Environmental stress, population viability and adaptation”, KNOW RNA Research Centre in Poznań 01/KNOW2/2014, and the Jagiellonian University (DS/WBiNoZ/INoS/762/14). The bulb mite genome analyses were supported by HHMI International Early Career Scientist Program (55007424), the MINECO (BFU2012-31329 and BFU2015-68723-P), Spanish Ministry of Economy and Competitiveness Centro de Excelencia Severo Ochoa 2013-2017 grant (SEV-2012-0208), Secretaria d'Universitats i Recerca del Departament d'Economia i Coneixement de la Generalitat’s AGAUR program (2014 SGR 0974), and the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013, ERC grant agreement (335980_EinME).