J of Cell Sci, v. 136, n. 10, jcs260828, abr. 2023
Artículo
en Inglés
| SES-SP, SESSP-IBPROD, SES-SP | ID: bud-4910
Genomic replication is a critical, regulated process that ensures accurate genetic information duplication. In eukaryotic cells, strategies have evolved to prevent conflicts between replication and transcription. Giardia lamblia, a binucleated protozoan, alternates between tetraploid and octoploid genomes during its cell cycle. Using single-molecule techniques like DNA combing and nanopore-based sequencing, we investigated the spatio-temporal organization of DNA replication, replication fork progression, and potential head-on replication-transcription collisions in Giardiatrophozoites. Our findings indicate that Giardiachromosomes are replicated from few active origins, which are widely spaced and exhibit faster replication rates compared to other protozoan parasites. Immunofluorescence assays revealed that around 20% of trophozoites show asynchronous replication between nuclei. Forksense and gene ontology analyses disclosed that genes in regions with potential head-on collisions are linked to chromatin dynamics, cell cycleregulation, and DNA replication/repair pathways, possibly explaining the observed asynchronous replication in part of the population. This study offers the first comprehensive view of replication dynamics in Giardia, the cause of giardiasis, a diarrheal disease impacting millions worldwide.