Clues on the dynamics of DNA replication in Giardia lamblia

Author(s)

Silva, Marcelo S. da ; Vitarelli, Marcela O. ; Viala, Vincent Louis ; Tsantarlis, Katherine ; Pires, David da Silva ; Franco, Thiago A. ; de Azevedo, Inacio L. M. J. ; Elias, Maria Carolina ; Tonelli, Renata R.

• Document type: Journal article
• Source: Journal of Cell Science; v. 136, n. 10, p. 13-pg., 2023-05-01.

Abstract

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 octaploid 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 Giardia trophozoites. Our findings indicate that Giardia chromosomes are replicated from only a few active origins, which are widely spaced and exhibit faster replication rates compared to those in other protozoan parasites. Immunofluorescence assays revealed that similar to 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 cycle regulation 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, which is the pathogen that causes giardiasis, a diarrheal disease impacting millions worldwide. (AU)

• FAPESP's process: 17/07693-2 - Functional dynamics of Orc1b protein during the life cycle of Trypanosoma
• Grantee: Marcela de Oliveira Vitarelli
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 20/10277-3 - Investigation of the role of inositol pyrophosphates (PP-IPs) in DNA repair pathways and telomere dynamics using trypanosomatids as a model
• Grantee: Marcelo Santos da Silva
• Support Opportunities: Scholarships in Brazil - Young Researchers
• FAPESP's process: 18/14432-3 - A network for an integrative biology in neglected diseases: bridging epigenetics, metabolism and cell cycle in pathogenic trypanosomatids
• Grantee: Ariel Mariano Silber
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 13/07467-1 - CeTICS - Center of Toxins, Immune-Response and Cell Signaling
• Grantee: Hugo Aguirre Armelin
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 14/24170-5 - DNA replication dynamics in Trypanosoma cruzi: licensing and replication rate characterization
• Grantee: Marcelo Santos da Silva
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 19/02918-1 - Bioengeneered 3D human intestine: use of silk "scaffolds" in studies of Giardia lamblia-host interaction
• Grantee: Renata Rosito Tonelli
• Support Opportunities: Regular Research Grants
• FAPESP's process: 20/00694-6 - How DNA replication contributes for the success of infection caused by Trypanosoma cruzi
• Grantee: Maria Carolina Quartim Barbosa Elias Sabbaga
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/50050-2 - How do common and diverged features of the replicative stress response shape the biology of TriTryp parasites?
• Grantee: Maria Carolina Quartim Barbosa Elias Sabbaga
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 19/10753-2 - Investigation on the role of inositol pyrophosphates (PP-IPs) in DNA repair pathways and telomere dynamics using trypanosomatids as a model
• Grantee: Marcelo Santos da Silva
• Support Opportunities: Research Grants - Young Investigators Grants