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Reis-Cunha JL, Pimenta-Carvalho SA, Almeida LV, Coqueiro-Dos-Santos A, Marques CA, Black JA, Damasceno J, McCulloch R, Bartholomeu DC, Jeffares DC. Ancestral aneuploidy and stable chromosomal duplication resulting in differential genome structure and gene expression control in trypanosomatid parasites. Genome Res 2024; 34:441-453. [PMID: 38604731 PMCID: PMC11067883 DOI: 10.1101/gr.278550.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 03/14/2024] [Indexed: 04/13/2024]
Abstract
Aneuploidy is widely observed in both unicellular and multicellular eukaryotes, usually associated with adaptation to stress conditions. Chromosomal duplication stability is a tradeoff between the fitness cost of having unbalanced gene copies and the potential fitness gained from increased dosage of specific advantageous genes. Trypanosomatids, a family of protozoans that include species that cause neglected tropical diseases, are a relevant group to study aneuploidies. Their life cycle has several stressors that could select for different patterns of chromosomal duplications and/or losses, and their nearly universal use of polycistronic transcription increases their reliance on gene expansion/contraction, as well as post-transcriptional control as mechanisms for gene expression regulation. By evaluating the data from 866 isolates covering seven trypanosomatid genera, we have revealed that aneuploidy tolerance is an ancestral characteristic of trypanosomatids but has a reduced occurrence in a specific monophyletic clade that has undergone large genomic reorganization and chromosomal fusions. We have also identified an ancient chromosomal duplication that was maintained across these parasite's speciation, named collectively as the trypanosomatid ancestral supernumerary chromosome (TASC). TASC has most genes in the same coding strand, is expressed as a disomic chromosome (even having four copies), and has increased potential for functional variation, but it purges highly deleterious mutations more efficiently than other chromosomes. The evidence of stringent control over gene expression in this chromosome suggests that these parasites have adapted to mitigate the fitness cost associated with this ancient chromosomal duplication.
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Affiliation(s)
- João L Reis-Cunha
- York Biomedical Research Institute, Department of Biology, University of York, York YO10 5DD, United Kingdom;
| | - Samuel A Pimenta-Carvalho
- Instituto de Ciências Biológicas, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Laila V Almeida
- Instituto de Ciências Biológicas, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Anderson Coqueiro-Dos-Santos
- Instituto de Ciências Biológicas, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Catarina A Marques
- The Wellcome Centre for Integrative Parasitology, School of Infection and Immunity, University of Glasgow, Glasgow G12 8TA, United Kingdom
| | - Jennifer A Black
- The Wellcome Centre for Integrative Parasitology, School of Infection and Immunity, University of Glasgow, Glasgow G12 8TA, United Kingdom
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, 14049-900, Brazil
| | - Jeziel Damasceno
- The Wellcome Centre for Integrative Parasitology, School of Infection and Immunity, University of Glasgow, Glasgow G12 8TA, United Kingdom
| | - Richard McCulloch
- The Wellcome Centre for Integrative Parasitology, School of Infection and Immunity, University of Glasgow, Glasgow G12 8TA, United Kingdom
| | - Daniella C Bartholomeu
- Instituto de Ciências Biológicas, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Daniel C Jeffares
- York Biomedical Research Institute, Department of Biology, University of York, York YO10 5DD, United Kingdom
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Vitarelli MDO, Franco TA, Pires DDS, Lima ARJ, Viala VL, Kraus AJ, de Azevedo IDLMJ, da Cunha JPC, Elias MC. Integrating high-throughput analysis to create an atlas of replication origins in Trypanosoma cruzi in the context of genome structure and variability. mBio 2024; 15:e0031924. [PMID: 38441981 PMCID: PMC11005370 DOI: 10.1128/mbio.00319-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 02/09/2024] [Indexed: 03/07/2024] Open
Abstract
Trypanosoma cruzi is the etiologic agent of the most prevalent human parasitic disease in Latin America, Chagas disease. Its genome is rich in multigenic families that code for virulent antigens and are present in the rapidly evolving genomic compartment named Disruptive. DNA replication is a meticulous biological process in which flaws can generate mutations and changes in chromosomal and gene copy numbers. Here, integrating high-throughput and single-molecule analyses, we were able to identify Predominant, Flexible, and Dormant Orc1Cdc6-dependent origins as well as Orc1Cdc6-independent origins. Orc1Cdc6-dependent origins were found in multigenic family loci, while independent origins were found in the Core compartment that contains conserved and hypothetical protein-coding genes, in addition to multigenic families. In addition, we found that Orc1Cdc6 density is related to the firing of origins and that Orc1Cdc6-binding sites within fired origins are depleted of a specific class of nucleosomes that we previously categorized as dynamic. Together, these data suggest that Orc1Cdc6-dependent origins may contribute to the rapid evolution of the Disruptive compartment and, therefore, to the success of T. cruzi infection and that the local epigenome landscape is also involved in this process.IMPORTANCETrypanosoma cruzi, responsible for Chagas disease, affects millions globally, particularly in Latin America. Lack of vaccine or treatment underscores the need for research. Parasite's genome, with virulent antigen-coding multigenic families, resides in the rapidly evolving Disruptive compartment. Study sheds light on the parasite's dynamic DNA replication, discussing the evolution of the Disruptive compartment. Therefore, the findings represent a significant stride in comprehending T. cruzi's biology and the molecular bases that contribute to the success of infection caused by this parasite.
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Affiliation(s)
- Marcela de Oliveira Vitarelli
- Cell Cycle Laboratory, Butantan Institute, Av. Vital Brazil, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, Av. Vital Brazil, São Paulo, Brazil
| | | | | | | | - Vincent Louis Viala
- Biochemistry Laboratory, Butantan Institute, Av. Vital Brazil, São Paulo, Brazil
| | - Amelie Johanna Kraus
- Division of Experimental Parasitology, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität in Munich, Planegg-Martinsried, Germany
- Biomedical Center, Division of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universität in Munich, Planegg-Martinsried, Germany
| | | | - Julia Pinheiro Chagas da Cunha
- Cell Cycle Laboratory, Butantan Institute, Av. Vital Brazil, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, Av. Vital Brazil, São Paulo, Brazil
| | - Maria Carolina Elias
- Cell Cycle Laboratory, Butantan Institute, Av. Vital Brazil, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, Av. Vital Brazil, São Paulo, Brazil
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3
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Genome-scale RNA interference profiling of Trypanosoma brucei cell cycle progression defects. Nat Commun 2022; 13:5326. [PMID: 36088375 PMCID: PMC9464253 DOI: 10.1038/s41467-022-33109-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/31/2022] [Indexed: 11/21/2022] Open
Abstract
Trypanosomatids, which include major pathogens of humans and livestock, are flagellated protozoa for which cell cycle controls and the underlying mechanisms are not completely understood. Here, we describe a genome-wide RNA-interference library screen for cell cycle defects in Trypanosoma brucei. We induced massive parallel knockdown, sorted the perturbed population using high-throughput flow cytometry, deep-sequenced RNAi-targets from each stage and digitally reconstructed cell cycle profiles at a genomic scale; also enabling data visualisation using an online tool ( https://tryp-cycle.pages.dev/ ). Analysis of several hundred genes that impact cell cycle progression reveals >100 flagellar component knockdowns linked to genome endoreduplication, evidence for metabolic control of the G1-S transition, surface antigen regulatory mRNA-binding protein knockdowns linked to G2M accumulation, and a putative nucleoredoxin required for both mitochondrial genome segregation and for mitosis. The outputs provide comprehensive functional genomic evidence for the known and novel machineries, pathways and regulators that coordinate trypanosome cell cycle progression.
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Lee KJ, Li Z. The CRK2-CYC13 complex functions as an S-phase cyclin-dependent kinase to promote DNA replication in Trypanosoma brucei. BMC Biol 2021; 19:29. [PMID: 33568178 PMCID: PMC7876812 DOI: 10.1186/s12915-021-00961-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 01/15/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Faithful DNA replication is essential to maintain genomic stability in all living organisms, and the regulatory pathway for DNA replication initiation is conserved from yeast to humans. The evolutionarily ancient human parasite Trypanosoma brucei, however, lacks many of the conserved DNA replication factors and may employ unusual mechanisms for DNA replication. Neither the S-phase cyclin-dependent kinase (CDK) nor the regulatory pathway governing DNA replication has been previously identified in T. brucei. RESULTS Here we report that CRK2 (Cdc2-related kinase 2) complexes with CYC13 (Cyclin13) and functions as an S-phase CDK to promote DNA replication in T. brucei. We further show that CRK2 phosphorylates Mcm3, a subunit of the Mcm2-7 sub-complex of the Cdc45-Mcm2-7-GINS complex, and demonstrate that Mcm3 phosphorylation by CRK2 facilitates interaction with Sld5, a subunit of the GINS sub-complex of the Cdc45-Mcm2-7-GINS complex. CONCLUSIONS These results identify the CRK2-CYC13 complex as an S-phase regulator in T. brucei and reveal its role in regulating DNA replication through promoting the assembly of the Cdc45-Mcm2-7-GINS complex.
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Affiliation(s)
- Kyu Joon Lee
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Ziyin Li
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, 77030, USA.
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Briggs EM, Marques CA, Reis-Cunha J, Black J, Campbell S, Damasceno J, Bartholomeu D, Crouch K, McCulloch R. Next-Generation Analysis of Trypanosomatid Genome Stability and Instability. Methods Mol Biol 2021; 2116:225-262. [PMID: 32221924 DOI: 10.1007/978-1-0716-0294-2_15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Understanding the rate and patterns of genome variation is becoming ever more amenable to whole-genome analysis through advances in DNA sequencing, which may, at least in some circumstances, have supplanted more localized analyses by cellular and genetic approaches. Whole-genome analyses can utilize both short- and long-read sequence technologies. Here we describe how sequence generated by these approaches has been used in trypanosomatids to examine DNA replication dynamics, the accumulation of modified histone H2A due to genome damage, and evaluation of genome variation, focusing on ploidy change.
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Affiliation(s)
- Emma M Briggs
- Institute of Infection, Immunity and Inflammation, The Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Catarina A Marques
- Institute of Infection, Immunity and Inflammation, The Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Joao Reis-Cunha
- Departamento de Parasitologia, Universidade Federal de Minas Gerais-Instituto de Ciências Biológicas, Belo Horizonte, Brazil
| | - Jennifer Black
- Institute of Infection, Immunity and Inflammation, The Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Samantha Campbell
- Institute of Infection, Immunity and Inflammation, The Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Jeziel Damasceno
- Institute of Infection, Immunity and Inflammation, The Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Daniella Bartholomeu
- Departamento de Parasitologia, Universidade Federal de Minas Gerais-Instituto de Ciências Biológicas, Belo Horizonte, Brazil
| | - Kathryn Crouch
- Institute of Infection, Immunity and Inflammation, The Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Richard McCulloch
- Institute of Infection, Immunity and Inflammation, The Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK.
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Damasceno JD, Marques CA, Black J, Briggs E, McCulloch R. Read, Write, Adapt: Challenges and Opportunities during Kinetoplastid Genome Replication. Trends Genet 2020; 37:21-34. [PMID: 32993968 PMCID: PMC9213392 DOI: 10.1016/j.tig.2020.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 12/31/2022]
Abstract
The genomes of all organisms are read throughout their growth and development, generating new copies during cell division and encoding the cellular activities dictated by the genome’s content. However, genomes are not invariant information stores but are purposefully altered in minor and major ways, adapting cellular behaviour and driving evolution. Kinetoplastids are eukaryotic microbes that display a wide range of such read–write genome activities, in many cases affecting critical aspects of their biology, such as host adaptation. Here we discuss the range of read–write genome changes found in two well-studied kinetoplastid parasites, Trypanosoma brucei and Leishmania, focusing on recent work that suggests such adaptive genome variation is linked to novel strategies the parasites use to replicate their unconventional genomes. Polycistronic transcription dominates and shapes kinetoplastid genomes, inevitably leading to clashes with DNA replication. By harnessing the resultant DNA damage for adaptation, kinetoplastids have huge potential for dynamic read–write genome variation. Major origins of DNA replication are confined to the boundaries of polycistronic transcription units in the Trypanosoma brucei and Leishmania genomes, putatively limiting DNA damage. Subtelomeres may lack this arrangement, generating read–write hotspots. In T. brucei, early replication of the highly transcribed subtelomeric variant surface glycoprotein (VSG) expression site may ensure replication-transcription clashes within this site to trigger DNA recombination, an event critical for antigenic variation. Leishmania genomes show extensive aneuploidy and copy number variation. Notably, DNA replication requires recombination factors and relies on post-S phase replication of subtelomeres. Evolution of compartmentalised DNA replication programmes underpin important aspects of genome biology in kinetoplastids, illustrating the consolidation of genome maintenance strategies to promote genome plasticity.
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Affiliation(s)
- Jeziel D Damasceno
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, G12 8TA, UK.
| | - Catarina A Marques
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, G12 8TA, UK
| | - Jennifer Black
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, G12 8TA, UK
| | - Emma Briggs
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, G12 8TA, UK; Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Richard McCulloch
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, G12 8TA, UK.
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Damasceno JD, Marques CA, Beraldi D, Crouch K, Lapsley C, Obonaga R, Tosi LR, McCulloch R. Genome duplication in Leishmania major relies on persistent subtelomeric DNA replication. eLife 2020; 9:58030. [PMID: 32897188 PMCID: PMC7511235 DOI: 10.7554/elife.58030] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 09/07/2020] [Indexed: 12/20/2022] Open
Abstract
DNA replication is needed to duplicate a cell’s genome in S phase and segregate it during cell division. Previous work in Leishmania detected DNA replication initiation at just a single region in each chromosome, an organisation predicted to be insufficient for complete genome duplication within S phase. Here, we show that acetylated histone H3 (AcH3), base J and a kinetochore factor co-localise in each chromosome at only a single locus, which corresponds with previously mapped DNA replication initiation regions and is demarcated by localised G/T skew and G4 patterns. In addition, we describe previously undetected subtelomeric DNA replication in G2/M and G1-phase-enriched cells. Finally, we show that subtelomeric DNA replication, unlike chromosome-internal DNA replication, is sensitive to hydroxyurea and dependent on 9-1-1 activity. These findings indicate that Leishmania’s genome duplication programme employs subtelomeric DNA replication initiation, possibly extending beyond S phase, to support predominantly chromosome-internal DNA replication initiation within S phase.
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Affiliation(s)
- Jeziel Dener Damasceno
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
| | - Catarina A Marques
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
| | - Dario Beraldi
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
| | - Kathryn Crouch
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
| | - Craig Lapsley
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
| | - Ricardo Obonaga
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Luiz Ro Tosi
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Richard McCulloch
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
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Damasceno JD, Reis-Cunha J, Crouch K, Beraldi D, Lapsley C, Tosi LRO, Bartholomeu D, McCulloch R. Conditional knockout of RAD51-related genes in Leishmania major reveals a critical role for homologous recombination during genome replication. PLoS Genet 2020; 16:e1008828. [PMID: 32609721 PMCID: PMC7360064 DOI: 10.1371/journal.pgen.1008828] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 07/14/2020] [Accepted: 05/05/2020] [Indexed: 12/12/2022] Open
Abstract
Homologous recombination (HR) has an intimate relationship with genome replication, both during repair of DNA lesions that might prevent DNA synthesis and in tackling stalls to the replication fork. Recent studies led us to ask if HR might have a more central role in replicating the genome of Leishmania, a eukaryotic parasite. Conflicting evidence has emerged regarding whether or not HR genes are essential, and genome-wide mapping has provided evidence for an unorthodox organisation of DNA replication initiation sites, termed origins. To answer this question, we have employed a combined CRISPR/Cas9 and DiCre approach to rapidly generate and assess the effect of conditional ablation of RAD51 and three RAD51-related proteins in Leishmania major. Using this approach, we demonstrate that loss of any of these HR factors is not immediately lethal but in each case growth slows with time and leads to DNA damage and accumulation of cells with aberrant DNA content. Despite these similarities, we show that only loss of RAD51 or RAD51-3 impairs DNA synthesis and causes elevated levels of genome-wide mutation. Furthermore, we show that these two HR factors act in distinct ways, since ablation of RAD51, but not RAD51-3, has a profound effect on DNA replication, causing loss of initiation at the major origins and increased DNA synthesis at subtelomeres. Our work clarifies questions regarding the importance of HR to survival of Leishmania and reveals an unanticipated, central role for RAD51 in the programme of genome replication in a microbial eukaryote.
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Affiliation(s)
- Jeziel D. Damasceno
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, United Kingdom
- * E-mail: (JDD); (RM)
| | - João Reis-Cunha
- Laboratório de Imunologia e Genômica de Parasitos, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brasil
| | - Kathryn Crouch
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, United Kingdom
| | - Dario Beraldi
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, United Kingdom
| | - Craig Lapsley
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, United Kingdom
| | - Luiz R. O. Tosi
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo; Ribeirão Preto, SP, Brazil
| | - Daniella Bartholomeu
- Laboratório de Imunologia e Genômica de Parasitos, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brasil
| | - Richard McCulloch
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, United Kingdom
- * E-mail: (JDD); (RM)
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9
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de Araujo CB, da Cunha JPC, Inada DT, Damasceno J, Lima ARJ, Hiraiwa P, Marques C, Gonçalves E, Nishiyama-Junior MY, McCulloch R, Elias MC. Replication origin location might contribute to genetic variability in Trypanosoma cruzi. BMC Genomics 2020; 21:414. [PMID: 32571205 PMCID: PMC7310030 DOI: 10.1186/s12864-020-06803-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 06/05/2020] [Indexed: 11/29/2022] Open
Abstract
Background DNA replication in trypanosomatids operates in a uniquely challenging environment, since most of their genomes are constitutively transcribed. Trypanosoma cruzi, the etiological agent of Chagas disease, presents high variability in both chromosomes size and copy number among strains, though the underlying mechanisms are unknown. Results Here we have mapped sites of DNA replication initiation across the T. cruzi genome using Marker Frequency Analysis, which has previously only been deployed in two related trypanosomatids. The putative origins identified in T. cruzi show a notable enrichment of GC content, a preferential position at subtelomeric regions, coinciding with genes transcribed towards the telomeres, and a pronounced enrichment within coding DNA sequences, most notably in genes from the Dispersed Gene Family 1 (DGF-1). Conclusions These findings suggest a scenario where collisions between DNA replication and transcription are frequent, leading to increased genetic variability, as seen by the increase SNP levels at chromosome subtelomeres and in DGF-1 genes containing putative origins.
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Affiliation(s)
- Christiane Bezerra de Araujo
- Laboratório de Ciclo Celular, Instituto Butantan, São Paulo, Brazil.,Center of Toxins, Immune Response and Cell Signaling (CeTICS), Instituto Butantan, São Paulo, Brazil
| | - Julia Pinheiro Chagas da Cunha
- Laboratório de Ciclo Celular, Instituto Butantan, São Paulo, Brazil. .,Center of Toxins, Immune Response and Cell Signaling (CeTICS), Instituto Butantan, São Paulo, Brazil.
| | - Davi Toshio Inada
- Laboratório de Ciclo Celular, Instituto Butantan, São Paulo, Brazil.,Center of Toxins, Immune Response and Cell Signaling (CeTICS), Instituto Butantan, São Paulo, Brazil
| | - Jeziel Damasceno
- The Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Alex Ranieri Jerônimo Lima
- Laboratório de Tecnologia Biomolecular - Bioinformática, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | | | - Catarina Marques
- The Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Evonnildo Gonçalves
- Laboratório de Tecnologia Biomolecular - Bioinformática, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Milton Yutaka Nishiyama-Junior
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Instituto Butantan, São Paulo, Brazil.,Laboratório Especial de Toxinologia Aplicada, Instituto Butantan, São Paulo, Brazil
| | - Richard McCulloch
- The Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Maria Carolina Elias
- Laboratório de Ciclo Celular, Instituto Butantan, São Paulo, Brazil. .,Center of Toxins, Immune Response and Cell Signaling (CeTICS), Instituto Butantan, São Paulo, Brazil.
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Abstract
In all kingdoms of life, DNA is used to encode hereditary information. Propagation of the genetic material between generations requires timely and accurate duplication of DNA by semiconservative replication prior to cell division to ensure each daughter cell receives the full complement of chromosomes. DNA synthesis of daughter strands starts at discrete sites, termed replication origins, and proceeds in a bidirectional manner until all genomic DNA is replicated. Despite the fundamental nature of these events, organisms have evolved surprisingly divergent strategies that control replication onset. Here, we discuss commonalities and differences in replication origin organization and recognition in the three domains of life.
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Affiliation(s)
- Babatunde Ekundayo
- Quantitative Biology, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Franziska Bleichert
- Quantitative Biology, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- * E-mail:
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11
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Abstract
Trypanosomes have complex life cycles within which there are both proliferative and differentiation cell divisions. The coordination of the cell cycle to achieve these different divisions is critical for the parasite to infect both host and vector. From studying the regulation of the proliferative cell cycle of the Trypanosoma brucei procyclic life cycle stage, three subcycles emerge that control the duplication and segregation of ( a) the nucleus, ( b) the kinetoplast, and ( c) a set of cytoskeletal structures. We discuss how the clear dependency relationships within these subcycles, and the potential for cross talk between them, are likely required for overall cell cycle coordination. Finally, we look at the implications this interdependence has for proliferative and differentiation divisions through the T. brucei life cycle and in related parasitic trypanosomatid species.
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Affiliation(s)
- Richard J. Wheeler
- Nuffield Department of Medicine, University of Oxford, Oxford OX1 3SY, United Kingdom
| | - Keith Gull
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Jack D. Sunter
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, United Kingdom
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Glover L, Marques CA, Suska O, Horn D. Persistent DNA Damage Foci and DNA Replication with a Broken Chromosome in the African Trypanosome. mBio 2019; 10:e01252-19. [PMID: 31289179 PMCID: PMC6747728 DOI: 10.1128/mbio.01252-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 06/06/2019] [Indexed: 02/06/2023] Open
Abstract
Damaged DNA typically imposes stringent controls on eukaryotic cell cycle progression, ensuring faithful transmission of genetic material. Some DNA breaks, and the resulting rearrangements, are advantageous, however. For example, antigenic variation in the parasitic African trypanosome, Trypanosoma brucei, relies upon homologous recombination-based rearrangements of telomeric variant surface glycoprotein (VSG) genes, triggered by breaks. Surprisingly, trypanosomes with a severed telomere continued to grow while progressively losing subtelomeric DNA, suggesting a nominal telomeric DNA damage checkpoint response. Here, we monitor the single-stranded DNA-binding protein replication protein A (RPA) in response to induced, locus-specific DNA breaks in T. brucei RPA foci accumulated at nucleolar sites following a break within ribosomal DNA and at extranucleolar sites following a break elsewhere, including adjacent to transcribed or silent telomeric VSG genes. As in other eukaryotes, RPA foci were formed in S phase and γH2A and RAD51 damage foci were disassembled prior to mitosis. Unlike in other eukaryotes, however, and regardless of the damaged locus, RPA foci persisted through the cell cycle, and these cells continued to replicate their DNA. We conclude that a DNA break, regardless of the damaged locus, fails to trigger a stringent cell cycle checkpoint in T. brucei This DNA damage tolerance may facilitate the generation of virulence-enhancing genetic diversity, within subtelomeric domains in particular. Stringent checkpoints may be similarly lacking in some other eukaryotic cells.IMPORTANCE Chromosome damage must be repaired to prevent the proliferation of defective cells. Alternatively, cells with damage must be eliminated. This is true of human and several other cell types but may not be the case for single-celled parasites, such as trypanosomes. African trypanosomes, which cause lethal diseases in both humans and livestock, can actually exploit chromosomal damage to activate new surface coat proteins and to evade host immune responses, for example. We monitored responses to single chromosomal breaks in trypanosomes using a DNA-binding protein that, in response to DNA damage, forms nuclear foci visible using a microscope. Surprisingly, and unlike what is seen in mammalian cells, these foci persist while cells continue to divide. We also demonstrate chromosome replication even when one chromosome is broken. These results reveal a remarkable degree of damage tolerance in trypanosomes, which may suit the lifestyle of a single-celled parasite, potentially facilitating adaptation and enhancing virulence.
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Affiliation(s)
- Lucy Glover
- Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Catarina A Marques
- Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Olga Suska
- Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - David Horn
- Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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Briggs E, Hamilton G, Crouch K, Lapsley C, McCulloch R. Genome-wide mapping reveals conserved and diverged R-loop activities in the unusual genetic landscape of the African trypanosome genome. Nucleic Acids Res 2018; 46:11789-11805. [PMID: 30304482 PMCID: PMC6294496 DOI: 10.1093/nar/gky928] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/25/2018] [Accepted: 10/05/2018] [Indexed: 01/09/2023] Open
Abstract
R-loops are stable RNA-DNA hybrids that have been implicated in transcription initiation and termination, as well as in telomere maintenance, chromatin formation, and genome replication and instability. RNA Polymerase (Pol) II transcription in the protozoan parasite Trypanosoma brucei is highly unusual: virtually all genes are co-transcribed from multigene transcription units, with mRNAs generated by linked trans-splicing and polyadenylation, and transcription initiation sites display no conserved promoter motifs. Here, we describe the genome-wide distribution of R-loops in wild type mammal-infective T. brucei and in mutants lacking RNase H1, revealing both conserved and diverged functions. Conserved localization was found at centromeres, rRNA genes and retrotransposon-associated genes. RNA Pol II transcription initiation sites also displayed R-loops, suggesting a broadly conserved role despite the lack of promoter conservation or transcription initiation regulation. However, the most abundant sites of R-loop enrichment were within the regions between coding sequences of the multigene transcription units, where the hybrids coincide with sites of polyadenylation and nucleosome-depletion. Thus, instead of functioning in transcription termination the most widespread localization of R-loops in T. brucei suggests a novel correlation with pre-mRNA processing. Finally, we find little evidence for correlation between R-loop localization and mapped sites of DNA replication initiation.
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Affiliation(s)
- Emma Briggs
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK
| | - Graham Hamilton
- Glasgow Polyomics, University of Glasgow, Wolfson Wohl Cancer Research Centre, Garscube Estate, Switchback Rd, Bearsden, G61 1QH, UK
| | - Kathryn Crouch
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK
| | - Craig Lapsley
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK
| | - Richard McCulloch
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK
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Almeida LV, Coqueiro-Dos-Santos A, Rodriguez-Luiz GF, McCulloch R, Bartholomeu DC, Reis-Cunha JL. Chromosomal copy number variation analysis by next generation sequencing confirms ploidy stability in Trypanosoma brucei subspecies. Microb Genom 2018; 4. [PMID: 30256189 PMCID: PMC6249438 DOI: 10.1099/mgen.0.000223] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Although aneuploidy usually results in severe abnormalities in multicellular eukaryotes, recent data suggest that it could be beneficial for unicellular eukaryotes, such as yeast and trypanosomatid parasites, providing increased survival under stressful conditions. Among characterized trypanosomatids, Trypanosoma cruzi, Trypanosoma brucei and species from the genus Leishmania stand out due to their importance in public health, infecting around 20 million people worldwide. The presence of aneuploidies in T. cruzi and Leishmania was recently confirmed by analysis based on next generation sequencing (NGS) and fluorescence in situ hybridization, where they have been associated with adaptation during transmission between their insect vectors and mammalian hosts and in promoting drug resistance. Although chromosomal copy number variations (CCNVs) are present in the aforementioned species, PFGE and fluorescence cytophotometry analyses suggest that aneuploidies are absent from T. brucei. A re-evaluation of CCNV in T. b gambiense based on NGS reads confirmed the absence of aneuploidies in this subspecies. However, the presence of aneuploidies in the other two T. brucei subspecies, T. b. brucei and T. b. rhodesiense, has not been evaluated using NGS approaches. In the present work, we tested for aneuploidies in 26 T. brucei isolates, including samples from the three T. brucei subspecies, by both allele frequency and read depth coverage analyses. These analyses showed that none of the T. brucei subspecies presents aneuploidies, which could be related to differences in the mechanisms of DNA replication and recombination in these parasites when compared with Leishmania.
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Affiliation(s)
- Laila Viana Almeida
- 1Departamento de Parasitologia, Universidade Federal de Minas Gerais - Instituto de Ciências Biológicas, Belo Horizonte, Brazil
| | - Anderson Coqueiro-Dos-Santos
- 1Departamento de Parasitologia, Universidade Federal de Minas Gerais - Instituto de Ciências Biológicas, Belo Horizonte, Brazil
| | - Gabriela F Rodriguez-Luiz
- 1Departamento de Parasitologia, Universidade Federal de Minas Gerais - Instituto de Ciências Biológicas, Belo Horizonte, Brazil
| | - Richard McCulloch
- 2University of Glasgow, Wellcome Centre for Molecular Parasitology, Glasgow, UK
| | - Daniella Castanheira Bartholomeu
- 1Departamento de Parasitologia, Universidade Federal de Minas Gerais - Instituto de Ciências Biológicas, Belo Horizonte, Brazil
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