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Histone post-translational modifications (PTMs) are epigenetic marks that play a critical role in the expression and maintenance of DNA, but they remain largely uninvestigated in non-model organisms due to technical challenges. To begin alleviating this issue, we developed a workflow for histone PTM analysis in the Mozambique tilapia (Oreochromis mossambicus), being a widespread and environmentally hardy fish, using mass spectrometry methods. By incorporating multiple protein digestion methods into the preparation of each sample, we reliably quantified 503 biologically relevant histone PTMs. All of these histone PTMs, collectively referred to as the global histone PTM landscape, were characterized in the gills, kidney, and testes of this fish. By comparing the global histone PTM landscape between the three tissues, we found that 90.46% of histone PTMs were tissue-dependent. The workflow and tools for histone PTM analysis described in this study are now publicly available and enable comprehensive investigation into the influence of environmental stress on histone PTMs in non-model organisms. Given the functionality and flexibility of histone PTMs, we anticipate that the study of histone PTMs in ecologically relevant contexts will provide ground-breaking insights into comparative physiology and evolution.
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Identification of histone post-translational modifications in three tissues of Mozambique tilapia (Oreochromis mossambicus)
Histone post-translational modifications (PTMs) are epigenetic marks that modify the state of chromatin and lead to alterations in gene expression. Advances in mass spectrometry have enabled the high-throughput analysis of histone PTMs without the need for prior knowledge of individual PTMs of interest. In this study, the global histone PTM landscape was analyzed in the gills, kidney, and testes of Mozambique tilapia (Oreochromis mossambicus) through tandem mass spectrometry using data dependent acquisition (DDA-LCMS2) and PTM mapping approaches. PTM assignment to a specific amino acid was validated using A-score and localization probability scores that are based on the detection of diagnostic MSMS ions. These values signify the robustness of PTM assignment to a specific residue within the protein sequence. For PTMs that were represented by both modified and unmodified versions of the corresponding peptide, the stoichiometry was calculated and compared between tissues. We have identified multiple types of histone PTMs and assigned them to specific residues in each tissue. These PTMs include acetylation, methylation, demethylation, trimethylation, phosphorylation/ dehydration, and ubiquitination. Our results indicate that the gills, kidney, and testes each display a unique profile of histone PTMs. These data provide a strong basis for the generation of spectral libraries that enable high-throughput quantitative analyses of histone PTM stoichiometry on a global scale in tilapia exposed to diverse environmental and developmental contexts.
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- Award ID(s):
- 1656371
- PAR ID:
- 10227706
- Date Published:
- Journal Name:
- SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY 2021 VIRTUAL ANNUAL MEETING
- Volume:
- P9
- Issue:
- 4
- Page Range / eLocation ID:
- 1
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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