Meeting Abstract

P2-134   -   Influence of salinity stress on the histone post-translational modification landscape of Mozambique tilapia (Oreochromis mossambicus) Mojica, EA*; Kültz, D; University of California, Davis; University of California, Davis eajarett@ucdavis.edu

Histone post-translational modifications (PTMs) are epigenetic marks that can elicit heritable patterns of gene expression. Environmental parameters have been shown to alter the relative abundance of histone PTMs in cells, but few studies have examined this in non-model organisms. To investigate the ecological relevance of this phenomenon, we tested the hypothesis that salinity stress could influence the histone PTM landscape within three tissues of Mozambique tilapia (Oreochromis mossambicus). We exposed fish to three different salinity treatments designed to evoke large changes in plasma osmolality. Following salinity treatments, we collected the gills, kidney, and testes of each fish. Gills and kidneys were chosen to represent osmoregulatory organs, and testes were chosen to represent the germline where histone PTMs could potentially be passed to future generations. All collected tissues were processed for histone PTM analysis by enriching samples for histone proteins, digesting proteins into peptides, then analyzing peptides by liquid chromatography mass spectrometry (LCMS). Spectra obtained through data dependent acquisition (DDA-LCMS2) were used to build spectral libraries and DIA assay libraries specific to each tissue. Using the spectra obtained through data independent acquisition (DIA-LCMS2), the relative abundance of all histone PTMs were quantified in the program Skyline. Through these methods, we detected thousands of histone PTMs within each tissue of Mozambique tilapia. For each histone PTM, we calculated the effect of salinity stress on its relative abundance. Funded by NSF-IOS 1656371 and BARD IS-5358-21.