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Yoshizaki S, Akahori H, Umemura T, Terada T, Takashima Y, Muto Y. Genome-wide analyses reveal genes subject to positive selection in Toxoplasma gondii. Gene 2019; 699:73-79. [PMID: 30858136 DOI: 10.1016/j.gene.2019.03.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 03/05/2019] [Accepted: 03/06/2019] [Indexed: 10/27/2022]
Abstract
Toxoplasma gondii is an important protozoan pathogen that infects many wild and domestic animals and causes infections in immunocompromised humans. However, there has been little investigation of the molecular evolutionary trajectories of this pathogenic protozoa using comparative genomics data. Here, we employed a comparative evolutionary genomics approach to identify genes that are under site- and lineage-specific positive selection in nine strains of T. gondii, including two closely related species, Neospora caninum and Hammondia hammondi. Based on the analyses of five coccidian core genomes, 4.5% of the 5788 core genome genes showed strong signals for positive selection in the site model. In addition, the branch-site model analyses in the nine T. gondii core genomes indicated that 2 to 20 genes underwent significant positive selection along each lineage leading to T. gondii strains. Many of the protein products encoded by the positively selected genes are secretory or surface proteins that have previously been implicated in host pathogenesis. The adaptive changes in these positively selected genes might be related to dynamic interactions between the host immune systems and might play a crucial role in the infection and pathogenic processes of T. gondii.
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Affiliation(s)
- Sumio Yoshizaki
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, 1-1, Yanagido, Gifu 501-1193, Japan; Department of Nursing, Heisei College of Health Sciences, 180 Kurono, Gifu 501-1131, Japan
| | - Hiromichi Akahori
- Department of Functional Bioscience, Gifu University School of Medicine, 1-1, Yanagido, Gifu 501-1193, Japan
| | - Toshiaki Umemura
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Tomoyoshi Terada
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, 1-1, Yanagido, Gifu 501-1193, Japan; Department of Functional Bioscience, Gifu University School of Medicine, 1-1, Yanagido, Gifu 501-1193, Japan
| | - Yasuhiro Takashima
- Department of Veterinary Parasitology, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan; Center for Highly Advanced Integration of Nano and Life Sciences, Gifu University (G-CHAIN), 1-1 Yanagido, Gifu 501-1193, Japan
| | - Yoshinori Muto
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, 1-1, Yanagido, Gifu 501-1193, Japan; Department of Functional Bioscience, Gifu University School of Medicine, 1-1, Yanagido, Gifu 501-1193, Japan.
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de Araujo CB, Calderano SG, Elias MC. The Dynamics of Replication in Trypanosoma cruzi Parasites by Single-Molecule Analysis. J Eukaryot Microbiol 2018; 66:514-518. [PMID: 30076751 DOI: 10.1111/jeu.12676] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 07/03/2018] [Accepted: 07/20/2018] [Indexed: 12/12/2022]
Abstract
Here, we investigated the features of replication in Trypanosoma cruzi epimastigotes based on fork speed progression, which is influenced by distinct features such as DNA polymerase rate, susceptibility to DNA damage and repair, secondary structures, transcription and chromatin state. Although T. cruzi exhibits a mean fork speed (2.05 ± 0.10 kb/min) very similar to other trypanosomatids, we found that the majority of DNA molecules replicated more slowly, with a frequency distribution approximately 1 kb/min. This frequency distribution analysis provides more information about the replication profile of this organism.
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Affiliation(s)
- Christiane B de Araujo
- Laboratorio Especial de Ciclo celular, Instituto Butantan, Av Vital Brasil, 1500, São Paulo, 05503-900, Brazil.,Center of Toxins, Immune Response and Cell Signaling (CeTICS), Instituto Butantan, Av Vital Brasil, 1500, São Paulo, 05503-900, Brazil
| | - Simone G Calderano
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Instituto Butantan, Av Vital Brasil, 1500, São Paulo, 05503-900, Brazil.,Laboratório de Parasitologia, Instituto Butantan, Av Vital Brasil, 1500, São Paulo, 05503-900, Brazil
| | - Maria Carolina Elias
- Laboratorio Especial de Ciclo celular, Instituto Butantan, Av Vital Brasil, 1500, São Paulo, 05503-900, Brazil.,Center of Toxins, Immune Response and Cell Signaling (CeTICS), Instituto Butantan, Av Vital Brasil, 1500, São Paulo, 05503-900, Brazil
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Reis-Cunha JL, Valdivia HO, Bartholomeu DC. Gene and Chromosomal Copy Number Variations as an Adaptive Mechanism Towards a Parasitic Lifestyle in Trypanosomatids. Curr Genomics 2018; 19:87-97. [PMID: 29491737 PMCID: PMC5814966 DOI: 10.2174/1389202918666170911161311] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 03/14/2017] [Accepted: 04/18/2017] [Indexed: 12/21/2022] Open
Abstract
Trypanosomatids are a group of kinetoplastid parasites including some of great public health importance, causing debilitating and life-long lasting diseases that affect more than 24 million people worldwide. Among the trypanosomatids, Trypanosoma cruzi, Trypanosoma brucei and species from the Leishmania genus are the most well studied parasites, due to their high prevalence in human infections. These parasites have an extreme genomic and phenotypic variability, with a massive expansion in the copy number of species-specific multigene families enrolled in host-parasite interactions that mediate cellular invasion and immune evasion processes. As most trypanosomatids are heteroxenous, and therefore their lifecycles involve the transition between different hosts, these parasites have developed several strategies to ensure a rapid adaptation to changing environments. Among these strategies, a rapid shift in the repertoire of expressed genes, genetic variability and genome plasticity are key mechanisms. Trypanosomatid genomes are organized into large directional gene clusters that are transcribed polycistronically, where genes derived from the same polycistron may have very distinct mRNA levels. This particular mode of transcription implies that the control of gene expression operates mainly at post-transcriptional level. In this sense, gene duplications/losses were already associated with changes in mRNA levels in these parasites. Gene duplications also allow the generation of sequence variability, as the newly formed copy can diverge without loss of function of the original copy. Recently, aneuploidies have been shown to occur in several Leishmania species and T. cruzi strains. Although aneuploidies are usually associated with debilitating phenotypes in superior eukaryotes, recent data shows that it could also provide increased fitness in stress conditions and generate drug resistance in unicellular eukaryotes. In this review, we will focus on gene and chromosomal copy number variations and their relevance to the evolution of trypanosomatid parasites.
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Affiliation(s)
- João Luís Reis-Cunha
- Universidade Federal de Minas Gerais, Laboratório de Imunologia e Genômica de Parasitos, Instituto de Ciências Biológicas, Belo Horizonte, Brazil
| | - Hugo O. Valdivia
- Universidade Federal de Minas Gerais, Laboratório de Imunologia e Genômica de Parasitos, Instituto de Ciências Biológicas, Belo Horizonte, Brazil
- Centro de Investigaciones Tecnológicas, Biomédicas y Medioambientales, Callao, Peru
| | - Daniella Castanheira Bartholomeu
- Universidade Federal de Minas Gerais, Laboratório de Imunologia e Genômica de Parasitos, Instituto de Ciências Biológicas, Belo Horizonte, Brazil
- Centro de Investigaciones Tecnológicas, Biomédicas y Medioambientales, Callao, Peru
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Machado-Silva A, Cerqueira PG, Grazielle-Silva V, Gadelha FR, Peloso EDF, Teixeira SMR, Machado CR. How Trypanosoma cruzi deals with oxidative stress: Antioxidant defence and DNA repair pathways. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2016; 767:8-22. [DOI: 10.1016/j.mrrev.2015.12.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 12/22/2015] [Accepted: 12/23/2015] [Indexed: 02/06/2023]
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