Exploring a gene co-expression network throughout the trypanosoma cruzi life cycle

Trypanosoma cruzi, the causative agent of American trypanosomiasis (Chagas disease), is a protozoan parasite with a complex life involving multiple developmental stages in both its triatomine vector and mammalian host. Each stage is characterized by distinct morphological and functional traits. Intriguingly, T. cruzi exhibits polycistronic transcription, relying predominantly on post-transcriptional mechanisms for gene regulation.

To delve deeper into the molecular aspects of this regulation, we performed gene co-expression network (GCN) analysis using transcriptomic data spanning all life-cycle stages of T. cruzi, offering insights into the coordinated expression patterns of functionally Linked gene groups. We examined the global network properties, identifying overrepresented functional pathways and highly connected hub genes. Additionally, we explored potential regulatory mechanisms within each module, focusing on conserved motifs in the 3' untranslated regions (3'UTRs) of co-expressed genes.

Our approach led to the identification of thirteen distinct co-expressed gene modules, each enriched in specific biological processes, including metabolism, pathogenesis, chromatin regulation, cytoskeleton modulation, and cellular movement. Finally, our study highlighted hub genes within each module. Combining a guilt-by-association approach with structural alignments and HMM-HMM profile comparisons, we assigned putative functions to previously uncharacterized proteins. Motif analysis of 3'UTR sequences in co-expressed genes revealed conserved elements and potential regulatory protein factors.

GCN analysis is a powerful tool for studying gene expression regulation. Our findings provide new insights into the regulatory networks of T. cruzi, identifying key genes and mechanisms underlying coordinated gene expression.