Research Projects

Genomic plasticity, such as aneuploidy and copy number variations, is one of the major adaptive strategies used by unicellular eukaryotes like fungi and protists to cope with environmental challenges. While chromosomal abnormalities are usually deleterious for multicellular organisms and contribute to conditions like genetic disorders and cancer, unicellular eukaryotes such as Saccharomyces cerevisiae, Candida albicans, Giardia intestinalis, and Cryptococcus neoformans naturally display remarkable tolerance to chromosomal instability [1], [2], [3]. Recently, protozoan parasites, such as Trypanosoma and Leishmania, have emerged as unique models for studying aneuploidy due to their tolerance to extreme genomic instability. Studies have shown that genomic plasticity in these parasites contributes to rapid adaptation to environmental stresses through changes in gene dosage and may have an impact on both virulence and the development of drug resistance [4], [5], [6]. However, the molecular mechanisms by which these parasites selectively regulate the transcript levels of individual genes on aneuploid chromosomes remain largely unknown [7], [8]. Gene expression in Leishmania parasites is unique compared to most eukaryotes, as they lack canonical RNA polymerase II promoters and, therefore, rely on polycistronic transcription, where regulation of gene expression occurs post-transcriptionally [9]; [10]. It is suggested that RNA-binding proteins (RNPs) that interact with individual mRNAs may play a central role in selective protein expression and thus contribute to tolerance of genome instability. RNPs recognize specific sequences or structural motifs in mRNA untranslated regions (UTRs) and influence their stability, localization, or translation [11], [12], [13], [14]. In wild yeast (Saccharomyces cerevisiae), an RNA-binding protein, Sad1, was found to aid aneuploidy tolerance [15], while in Leishmania braziliensis, two RNA-binding proteins, namely SCD6 and RBP42, were recently identified that mediate differential gene expression [16]. The same class of RNP, RBP42, was also found to regulate cellular energy metabolism in Trypanosoma brucei [17]. This project aims to elucidate how the Leishmania parasites tolerate genome instability by identifying key RNPs in Leishmania donovani using computational tools and validating their roles by gene knockouts and next-generation sequencing (WGS and RNAseq) analyses. The functional impacts of each RBP knockout on post-transcriptional gene regulation, particularly under stress-induced genomic instability, will be studied. Ultimately, this study aims to enhance our understanding of genome plasticity in Leishmania and may reveal novel factors involved in stress response and drug resistance.