# Impact on the Leishmania mexicana transcriptome due to knockout of genes encoding orthologs of methyltransferases involved in m1A and m5C mRNA modifications

## TL;DR

This study investigates how removing genes for certain methyltransferases affects gene expression and differentiation in Leishmania mexicana parasites.

## Contribution

The study reveals novel biological roles of TRMT61A and NSUN2 orthologs in regulating the Leishmania transcriptome.

## Key findings

- Gene deletion altered L. mexicana differentiation patterns.
- TRMT61A affects nucleotide metabolism, translation, and protein folding.
- NSUN2 impacts nucleotide metabolism and DNA binding processes.

## Abstract

Chemical modifications of mRNAs constitute an alternative mechanism for gene expression regulation, which involves proteins responsible for adding, recognizing and removing these modifications. While orthologs of enzymes involved in adding m1A (TRMT6/TRMT61A) and m5C (NSUN2) modifications are present in trypanosomatid species, a clear understanding of their biological role in these parasites is necessary.

To shed light on this, we genetically manipulated the TRMT61A and NSUN2 protein-encoding genes in the Leishmania mexicana species using the CRISPR-Cas9 editing technique and analyzed the impact on cell growth and differentiation as well as the global gene expression profile.

Deletion of the genes investigated here caused changes in the normal pattern of L. mexicana differentiation, and functional analyses of differentially expressed genes in the mutants unveiled significant biological effects. For the TRMT61A gene, transcripts related to nucleotide metabolism, translation, protein folding and refolding were affected. For the NSUN2 genes, enrichment analysis indicated impacts on biological processes mostly related to nucleotide metabolism and DNA binding.

Our findings provide insights into the role of these methyltransferases orthologs in the regulation of trypanosomatid transcriptome, contributing to our understanding of gene expression control in this parasite.

The online version contains supplementary material available at 10.1186/s13071-025-06969-8.