The Role of Histone Modifications in Chromatin-Mediated Transcriptional Repression in the Protozoan Parasite Trichomonas vaginalis [ChIP-Seq]

Trichomonas vaginalis is an extracellular flagellated protozoan responsible for trichomoniasis, one of the most prevalent non-viral sexually transmitted infections. To persist in the host, T. vaginalis employs sophisticated gene regulation mechanisms to adapt to hostile environmental conditions. Although transcriptional regulation is crucial for this adaptation, the specific molecular mechanisms remain poorly understood. Epigenetic regulation, particularly through histone modifications, has emerged as a key modulator of gene expression. Our previous study demonstrated the role of histone modifications H3K4me3 and H3K27Ac in promoting active transcription. However, the full extent of epigenetic regulation in T. vaginalis remained unclear. In this study, we extend these findings by exploring the repressive role of two additional histone H3 modifications, H3K9me3 and H3K27me3. Genome-wide analysis reveals that these modifications are negatively correlated with gene expression, impacting not only protein-coding genes but also repeat genes and transposable elements. These findings offer new insights into the dual role of histone modifications in both activating and repressing gene expression, providing a more comprehensive understanding of epigenetic regulation in T. vaginalis. This expanded knowledge could inform the development of novel therapeutic strategies targeting the epigenetic machinery of this parasite. Chromatin immunoprecipitation followed by DNA sequencing (ChIP-seq) was performed to analyze histone modifications, including H3K4me3, H3K27ac, H3K9me3, and H3K27me3, in Trichomonas vaginalis cells.