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Hörandl E. Apomixis and the paradox of sex in plants. ANNALS OF BOTANY 2024; 134:1-18. [PMID: 38497809 PMCID: PMC11161571 DOI: 10.1093/aob/mcae044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 03/15/2024] [Indexed: 03/19/2024]
Abstract
BACKGROUND The predominance of sex in eukaryotes, despite the high costs of meiosis and mating, remains an evolutionary enigma. Many theories have been proposed, none of them being conclusive on its own, and they are, in part, not well applicable to land plants. Sexual reproduction is obligate in embryophytes for the great majority of species. SCOPE This review compares the main forms of sexual and asexual reproduction in ferns and angiosperms, based on the generation cycling of sporophyte and gametophyte (leaving vegetative propagation aside). The benefits of sexual reproduction for maintenance of genomic integrity in comparison to asexuality are discussed in the light of developmental, evolutionary, genetic and phylogenetic studies. CONCLUSIONS Asexual reproduction represents modifications of the sexual pathway, with various forms of facultative sexuality. For sexual land plants, meiosis provides direct DNA repair mechanisms for oxidative damage in reproductive tissues. The ploidy alternations of meiosis-syngamy cycles and prolonged multicellular stages in the haploid phase in the gametophytes provide a high efficiency of purifying selection against recessive deleterious mutations. Asexual lineages might buffer effects of such mutations via polyploidy and can purge the mutational load via facultative sexuality. The role of organelle-nuclear genome compatibility for maintenance of genome integrity is not well understood. In plants in general, the costs of mating are low because of predominant hermaphroditism. Phylogenetic patterns in the archaeplastid clade suggest that high frequencies of sexuality in land plants are concomitant with a stepwise increase of intrinsic and extrinsic stress factors. Furthermore, expansion of genome size in land plants would increase the potential mutational load. Sexual reproduction appears to be essential for keeping long-term genomic integrity, and only rare combinations of extrinsic and intrinsic factors allow for shifts to asexuality.
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Affiliation(s)
- Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with herbarium), University of Göttingen, Göttingen, Germany
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2
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Brejová B, Hodorová V, Mutalová S, Cillingová A, Tomáška Ľ, Vinař T, Nosek J. Chromosome-level genome assembly of the yeast Lodderomyces beijingensis reveals the genetic nature of metabolic adaptations and identifies subtelomeres as hotspots for amplification of mating type loci. DNA Res 2024; 31:dsae014. [PMID: 38686638 PMCID: PMC11100356 DOI: 10.1093/dnares/dsae014] [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: 03/15/2024] [Revised: 04/22/2024] [Accepted: 04/29/2024] [Indexed: 05/02/2024] Open
Abstract
Lodderomyces beijingensis is an ascosporic ascomycetous yeast. In contrast to related species Lodderomyces elongisporus, which is a recently emerging human pathogen, L. beijingensis is associated with insects. To provide an insight into its genetic makeup, we investigated the genome of its type strain, CBS 14171. We demonstrate that this yeast is diploid and describe the high contiguity nuclear genome assembly consisting of eight chromosome-sized contigs with a total size of about 15.1 Mbp. We find that the genome sequence contains multiple copies of the mating type loci and codes for essential components of the mating pheromone response pathway, however, the missing orthologs of several genes involved in the meiotic program raise questions about the mode of sexual reproduction. We also show that L. beijingensis genome codes for the 3-oxoadipate pathway enzymes, which allow the assimilation of protocatechuate. In contrast, the GAL gene cluster underwent a decay resulting in an inability of L. beijingensis to utilize galactose. Moreover, we find that the 56.5 kbp long mitochondrial DNA is structurally similar to known linear mitochondrial genomes terminating on both sides with covalently closed single-stranded hairpins. Finally, we discovered a new double-stranded RNA mycovirus from the Totiviridae family and characterized its genome sequence.
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Affiliation(s)
- Broňa Brejová
- Department of Computer Science, Faculty of Mathematics, Physics and Informatics, Comenius University Bratislava, 842 48 Bratislava, Slovak Republic
| | - Viktória Hodorová
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University Bratislava, 842 15 Bratislava, Slovak Republic
| | - Sofia Mutalová
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University Bratislava, 842 15 Bratislava, Slovak Republic
| | - Andrea Cillingová
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University Bratislava, 842 15 Bratislava, Slovak Republic
| | - Ľubomír Tomáška
- Department of Genetics, Faculty of Natural Sciences, Comenius University Bratislava, 842 15 Bratislava, Slovak Republic
| | - Tomáš Vinař
- Department of Applied Informatics, Faculty of Mathematics, Physics and Informatics, Comenius University Bratislava, 842 48 Bratislava, Slovak Republic
| | - Jozef Nosek
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University Bratislava, 842 15 Bratislava, Slovak Republic
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3
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Jacques F, Tichopád T, Demko M, Bystrý V, Křížová KC, Seifertová M, Voříšková K, Fuad MMH, Vetešník L, Šimková A. Reproduction-associated pathways in females of gibel carp (Carassius gibelio) shed light on the molecular mechanisms of the coexistence of asexual and sexual reproduction. BMC Genomics 2024; 25:548. [PMID: 38824502 PMCID: PMC11144346 DOI: 10.1186/s12864-024-10462-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 05/28/2024] [Indexed: 06/03/2024] Open
Abstract
Gibel carp (Carassius gibelio) is a cyprinid fish that originated in eastern Eurasia and is considered as invasive in European freshwater ecosystems. The populations of gibel carp in Europe are mostly composed of asexually reproducing triploid females (i.e., reproducing by gynogenesis) and sexually reproducing diploid females and males. Although some cases of coexisting sexual and asexual reproductive forms are known in vertebrates, the molecular mechanisms maintaining such coexistence are still in question. Both reproduction modes are supposed to exhibit evolutionary and ecological advantages and disadvantages. To better understand the coexistence of these two reproduction strategies, we performed transcriptome profile analysis of gonad tissues (ovaries) and studied the differentially expressed reproduction-associated genes in sexual and asexual females. We used high-throughput RNA sequencing to generate transcriptomic profiles of gonadal tissues of triploid asexual females and males, diploid sexual males and females of gibel carp, as well as diploid individuals from two closely-related species, C. auratus and Cyprinus carpio. Using SNP clustering, we showed the close similarity of C. gibelio and C. auratus with a basal position of C. carpio to both Carassius species. Using transcriptome profile analyses, we showed that many genes and pathways are involved in both gynogenetic and sexual reproduction in C. gibelio; however, we also found that 1500 genes, including 100 genes involved in cell cycle control, meiosis, oogenesis, embryogenesis, fertilization, steroid hormone signaling, and biosynthesis were differently expressed in the ovaries of asexual and sexual females. We suggest that the overall downregulation of reproduction-associated pathways in asexual females, and their maintenance in sexual ones, allows the populations of C. gibelio to combine the evolutionary and ecological advantages of the two reproductive strategies. However, we showed that many sexual-reproduction-related genes are maintained and expressed in asexual females, suggesting that gynogenetic gibel carp retains the genetic toolkits for meiosis and sexual reproduction. These findings shed new light on the evolution of this asexual and sexual complex.
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Affiliation(s)
- Florian Jacques
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, Brno, 611 37, Czech Republic.
| | - Tomáš Tichopád
- Laboratory of Non-Mendelian Evolution, Institute of Animal Physiology and Genetics of the CAS, Liběchov, 277 21, Czech Republic
- Faculty of Fisheries and Protection of Waters, University of South Bohemia in České Budějovice, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, Vodňany, 389 25, Czech Republic
| | - Martin Demko
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, Brno, 611 37, Czech Republic
- Central European Institute of Technology, Masaryk University, Brno, 625 00, Czech Republic
| | - Vojtěch Bystrý
- Central European Institute of Technology, Masaryk University, Brno, 625 00, Czech Republic
| | - Kristína Civáňová Křížová
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, Brno, 611 37, Czech Republic
| | - Mária Seifertová
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, Brno, 611 37, Czech Republic
| | - Kristýna Voříšková
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, Brno, 611 37, Czech Republic
| | - Md Mehedi Hasan Fuad
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, Brno, 611 37, Czech Republic
| | - Lukáš Vetešník
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, Brno, 611 37, Czech Republic
- Institute of Vertebrate Biology, Czech Academy of Science, Květná 8, Brno, 603 65, Czech Republic
| | - Andrea Šimková
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, Brno, 611 37, Czech Republic
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4
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Fields PD, Jalinsky JR, Bankers L, McElroy KE, Sharbrough J, Higgins C, Morgan-Richards M, Boore JL, Neiman M, Logsdon JM. Genome Evolution and Introgression in the New Zealand mud Snails Potamopyrgus estuarinus and Potamopyrgus kaitunuparaoa. Genome Biol Evol 2024; 16:evae091. [PMID: 38776329 PMCID: PMC11110935 DOI: 10.1093/gbe/evae091] [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] [Accepted: 04/22/2024] [Indexed: 05/24/2024] Open
Abstract
We have sequenced, assembled, and analyzed the nuclear and mitochondrial genomes and transcriptomes of Potamopyrgus estuarinus and Potamopyrgus kaitunuparaoa, two prosobranch snail species native to New Zealand that together span the continuum from estuary to freshwater. These two species are the closest known relatives of the freshwater species Potamopyrgus antipodarum-a model for studying the evolution of sex, host-parasite coevolution, and biological invasiveness-and thus provide key evolutionary context for understanding its unusual biology. The P. estuarinus and P. kaitunuparaoa genomes are very similar in size and overall gene content. Comparative analyses of genome content indicate that these two species harbor a near-identical set of genes involved in meiosis and sperm functions, including seven genes with meiosis-specific functions. These results are consistent with obligate sexual reproduction in these two species and provide a framework for future analyses of P. antipodarum-a species comprising both obligately sexual and obligately asexual lineages, each separately derived from a sexual ancestor. Genome-wide multigene phylogenetic analyses indicate that P. kaitunuparaoa is likely the closest relative to P. antipodarum. We nevertheless show that there has been considerable introgression between P. estuarinus and P. kaitunuparaoa. That introgression does not extend to the mitochondrial genome, which appears to serve as a barrier to hybridization between P. estuarinus and P. kaitunuparaoa. Nuclear-encoded genes whose products function in joint mitochondrial-nuclear enzyme complexes exhibit similar patterns of nonintrogression, indicating that incompatibilities between the mitochondrial and the nuclear genome may have prevented more extensive gene flow between these two species.
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Affiliation(s)
- Peter D Fields
- Department of Environmental Sciences, Zoology, University of Basel, Basel 4051, Switzerland
| | | | - Laura Bankers
- Department of Biology, University of Iowa, Iowa City, IA, USA
| | - Kyle E McElroy
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Joel Sharbrough
- Department of Biology, New Mexico Institute of Mining and Technology, Socorro, NM, USA
| | - Chelsea Higgins
- Department of Biology, University of Iowa, Iowa City, IA, USA
| | - Mary Morgan-Richards
- School of Natural Sciences, Massey University Manawatū, Palmerston North, New Zealand
| | - Jeffrey L Boore
- Phenome Health, Seattle, WA, USA
- Institute for Systems Biology, Seattle, WA, USA
| | - Maurine Neiman
- Department of Biology, University of Iowa, Iowa City, IA, USA
- Department of Gender, Women's, and Sexuality Studies, University of Iowa, Iowa City, IA, USA
| | - John M Logsdon
- Department of Biology, University of Iowa, Iowa City, IA, USA
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5
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da Roza PA, Muller H, Sullivan GJ, Walker RSK, Goold HD, Willows RD, Palenik B, Paulsen IT. Chromosome-scale assembly of the streamlined picoeukaryote Picochlorum sp. SENEW3 genome reveals Rabl-like chromatin structure and potential for C 4 photosynthesis. Microb Genom 2024; 10. [PMID: 38625719 DOI: 10.1099/mgen.0.001223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024] Open
Abstract
Genome sequencing and assembly of the photosynthetic picoeukaryotic Picochlorum sp. SENEW3 revealed a compact genome with a reduced gene set, few repetitive sequences, and an organized Rabl-like chromatin structure. Hi-C chromosome conformation capture revealed evidence of possible chromosomal translocations, as well as putative centromere locations. Maintenance of a relatively few selenoproteins, as compared to similarly sized marine picoprasinophytes Mamiellales, and broad halotolerance compared to others in Trebouxiophyceae, suggests evolutionary adaptation to variable salinity environments. Such adaptation may have driven size and genome minimization and have been enabled by the retention of a high number of membrane transporters. Identification of required pathway genes for both CAM and C4 photosynthetic carbon fixation, known to exist in the marine mamiellale pico-prasinophytes and seaweed Ulva, but few other chlorophyte species, further highlights the unique adaptations of this robust alga. This high-quality assembly provides a significant advance in the resources available for genomic investigations of this and other photosynthetic picoeukaryotes.
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Affiliation(s)
- Patrick A da Roza
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, NSW 2109, Australia
- School of Natural Sciences, Macquarie University, Sydney, Australia
| | - Héloïse Muller
- Institut Curie, PSL University, Sorbonne Université, CNRS, Nuclear Dynamics, 75005 Paris, France
| | - Geraldine J Sullivan
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, NSW 2109, Australia
- School of Natural Sciences, Macquarie University, Sydney, Australia
| | - Roy S K Walker
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, NSW 2109, Australia
- School of Natural Sciences, Macquarie University, Sydney, Australia
| | - Hugh D Goold
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, NSW 2109, Australia
- New South Wales Department of Primary Industries, Orange, NSW 2800, Australia
| | - Robert D Willows
- School of Natural Sciences, Macquarie University, Sydney, Australia
| | - Brian Palenik
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093-0202, USA
| | - Ian T Paulsen
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, NSW 2109, Australia
- School of Natural Sciences, Macquarie University, Sydney, Australia
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6
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Catta-Preta CMC, Ferreira TR, Ghosh K, Paun A, Sacks D. HOP1 and HAP2 are conserved components of the meiosis-related machinery required for successful mating in Leishmania. Nat Commun 2023; 14:7159. [PMID: 37935664 PMCID: PMC10630298 DOI: 10.1038/s41467-023-42789-z] [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: 06/22/2023] [Accepted: 10/21/2023] [Indexed: 11/09/2023] Open
Abstract
Whole genome analysis of Leishmania hybrids generated experimentally in sand flies supports a meiotic mechanism of genetic exchange, with Mendelian segregation of the nuclear genome. Here, we perform functional analyses through the generation of double drug-resistant hybrids in vitro and in vivo (during sand fly infections) to assess the importance of conserved meiosis-related genes in recombination and plasmogamy. We report that HOP1 and a HAP2-paralog (HAP2-2) are essential components of the Leishmania meiosis machinery and cell-to-cell fusion mechanism, respectively, since deletion of either gene in one or both parents significantly reduces or completely abrogates mating competence. These findings significantly advance our understanding of sexual reproduction in Leishmania, with likely relevance to other trypanosomatids, by formally demonstrating the involvement of a meiotic protein homolog and a distinct fusogen that mediates non-canonical, bilateral fusion in the hybridizing cells.
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Affiliation(s)
- Carolina Moura Costa Catta-Preta
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Tiago Rodrigues Ferreira
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Kashinath Ghosh
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Andrea Paun
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - David Sacks
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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7
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Molinier C, Lenormand T, Haag CR. No recombination suppression in asexually produced males of Daphnia pulex. Evolution 2023; 77:1987-1999. [PMID: 37345677 DOI: 10.1093/evolut/qpad114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 05/26/2023] [Accepted: 06/20/2023] [Indexed: 06/23/2023]
Abstract
Obligate parthenogenesis (OP) is often thought to evolve by disruption of reductional meiosis and suppression of crossover recombination. In the crustacean Daphnia pulex, OP lineages, which have evolved from cyclical parthenogenetic (CP) ancestors, occasionally produce males that are capable of reductional meiosis. Here, by constructing high-density linkage maps, we find that these males show only slightly and nonsignificantly reduced recombination rates compared to CP males and females. Both meiosis disruption and recombination suppression are therefore sex-limited (or partly so), which speaks against the evolution of OP by disruption of a gene that is essential for meiosis or recombination in both sexes. The findings may be explained by female-limited action of genes that suppress recombination, but previously identified candidate genes are known to be expressed in both sexes. Alternatively, and equally consistent with the data, OP might have evolved through a reuse of the parthenogenesis pathways already present in CP and through their extension to all events of oogenesis. The causal mutations for the CP to OP transition may therefore include mutations in genes involved in oogenesis regulation and may not necessarily be restricted to genes of the "meiosis toolkit." More generally, our study emphasizes that there are many ways to achieve asexuality, and elucidating the possible mechanisms is key to ultimately identify the genes and traits involved.
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Affiliation(s)
- Cécile Molinier
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France
- Department of Algal Development and Evolution, Max Planck Institute for Biology, Tuebingen, Germany
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8
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Gollo G. On the emergence of eukaryotes and other enigmas. Biosystems 2023; 231:104958. [PMID: 37442362 DOI: 10.1016/j.biosystems.2023.104958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 05/20/2023] [Accepted: 06/15/2023] [Indexed: 07/15/2023]
Abstract
The origin of eukaryotes is one of the most fundamental problems in the entire history of life. How did eukaryotes arise? Previous attempts to solve the problem are very far from an answer, at best they propose a solution to one of the various innovations that ended up culminating in eukaryotes. Based on a hypothetical-deductive methodology, as usual in evolutionary issues, I propose that eukaryotes emerged from the endosymbiotic association between a flagellate parasite and its host, of which the sperm is the main vestige. The hypothesis unifies the solution to the vast array of acquisitions shared by eukaryotes that differentiate them from other beings, remarkably cell nucleus, mitosis, meiosis and sexual reproduction. The solution has a deep impact on understanding the origin and functioning of all complex life forms.
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Affiliation(s)
- Gustavo Gollo
- Universidade de Brasília, Eecologia, Brasilia, DF, Brazil.
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Inwood SN, Skelly J, Guhlin JG, Harrop TWR, Goldson SL, Dearden PK. Chromosome-level genome assemblies of two parasitoid biocontrol wasps reveal the parthenogenesis mechanism and an associated novel virus. BMC Genomics 2023; 24:440. [PMID: 37543591 PMCID: PMC10403939 DOI: 10.1186/s12864-023-09538-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 07/27/2023] [Indexed: 08/07/2023] Open
Abstract
BACKGROUND Biocontrol is a key technology for the control of pest species. Microctonus parasitoid wasps (Hymenoptera: Braconidae) have been released in Aotearoa New Zealand as biocontrol agents, targeting three different pest weevil species. Despite their value as biocontrol agents, no genome assemblies are currently available for these Microctonus wasps, limiting investigations into key biological differences between the different species and strains. METHODS AND FINDINGS Here we present high-quality genomes for Microctonus hyperodae and Microctonus aethiopoides, assembled with short read sequencing and Hi-C scaffolding. These assemblies have total lengths of 106.7 Mb for M. hyperodae and 129.2 Mb for M. aethiopoides, with scaffold N50 values of 9 Mb and 23 Mb respectively. With these assemblies we investigated differences in reproductive mechanisms, and association with viruses between Microctonus wasps. Meiosis-specific genes are conserved in asexual Microctonus, with in-situ hybridisation validating expression of one of these genes in the ovaries of asexual Microctonus aethiopoides. This implies asexual reproduction in these Microctonus wasps involves meiosis, with the potential for sexual reproduction maintained. Investigation of viral gene content revealed candidate genes that may be involved in virus-like particle production in M. aethiopoides, as well as a novel virus infecting M. hyperodae, for which a complete genome was assembled. CONCLUSION AND SIGNIFICANCE These are the first published genomes for Microctonus wasps which have been deployed as biocontrol agents, in Aotearoa New Zealand. These assemblies will be valuable resources for continued investigation and monitoring of these biocontrol systems. Understanding the biology underpinning Microctonus biocontrol is crucial if we are to maintain its efficacy, or in the case of M. hyperodae to understand what may have influenced the significant decline of biocontrol efficacy. The potential for sexual reproduction in asexual Microctonus is significant given that empirical modelling suggests this asexual reproduction is likely to have contributed to biocontrol decline. Furthermore the identification of a novel virus in M. hyperodae highlights a previously unknown aspect of this biocontrol system, which may contribute to premature mortality of the host pest. These findings have potential to be exploited in future in attempt to increase the effectiveness of M. hyperodae biocontrol.
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Affiliation(s)
- Sarah N Inwood
- Bioprotection Aotearoa and Biochemistry Department, University of Otago, Dunedin, Aotearoa, New Zealand
| | - John Skelly
- Bioprotection Aotearoa and Biochemistry Department, University of Otago, Dunedin, Aotearoa, New Zealand
- Humble Bee Bio, Wellington, Aotearoa, New Zealand
| | - Joseph G Guhlin
- Genomics Aotearoa, University of Otago, Dunedin, Aotearoa, New Zealand
| | - Thomas W R Harrop
- Melbourne Bioinformatics, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Stephen L Goldson
- Biocontrol and Biosecurity Group, AgResearch Limited, Lincoln, Aotearoa, New Zealand
| | - Peter K Dearden
- Bioprotection Aotearoa and Biochemistry Department, University of Otago, Dunedin, Aotearoa, New Zealand.
- Genomics Aotearoa, University of Otago, Dunedin, Aotearoa, New Zealand.
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10
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Steins L, Guerreiro MA, Duhamel M, Liu F, Wang QM, Boekhout T, Begerow D. Comparative genomics of smut fungi suggest the ability of meiosis and mating in asexual species of the genus Pseudozyma (Ustilaginales). BMC Genomics 2023; 24:321. [PMID: 37312063 DOI: 10.1186/s12864-023-09387-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 05/18/2023] [Indexed: 06/15/2023] Open
Abstract
BACKGROUND The Ustilaginales comprise hundreds of plant-parasitic fungi with a characteristic life cycle that directly links sexual reproduction and parasitism: One of the two mating-type loci codes for a transcription factor that not only facilitates mating, but also initiates the infection process. However, several species within the Ustilaginales have no described parasitic stage and were historically assigned to the genus Pseudozyma. Molecular studies have shown that the group is polyphyletic, with members being scattered in various lineages of the Ustilaginales. Together with recent findings of conserved fungal effectors in these non-parasitic species, this raises the question if parasitism has been lost recently and in multiple independent events or if there are hitherto undescribed parasitic stages of these fungi. RESULTS In this study, we sequenced genomes of five Pseudozyma species together with six parasitic species from the Ustilaginales to compare their genomic capability to perform two central functions in sexual reproduction: mating and meiosis. While the loss of sexual capability is assumed in certain lineages and asexual species are common in Asco- and Basidiomycota, we were able to successfully annotate potentially functional mating and meiosis genes that are conserved throughout the whole group. CONCLUSION Our data suggest that at least the key functions of a sexual lifestyle are maintained in the analyzed genomes, challenging the current understanding of the so-called asexual species with respect to their evolution and ecological role.
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Affiliation(s)
- Lena Steins
- Evolution of Plants and Fungi, Ruhr-University Bochum, Bochum, Germany
| | - Marco Alexandre Guerreiro
- Evolution of Plants and Fungi, Ruhr-University Bochum, Bochum, Germany
- Environmental Genomics, Germany and Max Planck Institute for Evolutionary Biology, Botanical Institute, Christian-Albrechts University of Kiel, Plön, Germany
| | - Marine Duhamel
- Evolution of Plants and Fungi, Ruhr-University Bochum, Bochum, Germany
- Ecologie Systématique Evolution, IDEEV, CNRS, Université Paris-Saclay, AgroParisTech, Gif-Sur-Yvette, Paris, France
| | - Fei Liu
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, 071002, Hebei, China
| | - Qi-Ming Wang
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding, 071002, Hebei, China
| | - Teun Boekhout
- College of Science, King Saud University, Riyadh, Saudi Arabia
- Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands
| | - Dominik Begerow
- Evolution of Plants and Fungi, Ruhr-University Bochum, Bochum, Germany.
- Organismic Botany and Mycology, University of Hamburg, IPM, Hamburg, Germany.
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11
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Inwood SN, Harrop TWR, Dearden PK. The venom composition and parthenogenesis mechanism of the parasitoid wasp Microctonus hyperodae, a declining biocontrol agent. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 153:103897. [PMID: 36584929 DOI: 10.1016/j.ibmb.2022.103897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 06/17/2023]
Abstract
A biocontrol system in New Zealand using the endoparasitoid Microctonus hyperodae is failing, despite once being one of the most successful examples of classical biocontrol worldwide. Though it is of significant economic importance as a control agent, little is known about the genetics of M. hyperodae. In this study, RNA-seq was used to characterise two key traits of M. hyperodae in this system, the venom, critical for the initial success of biocontrol, and the asexual reproduction mode, which influenced biocontrol decline. Expanded characterisation of M. hyperodae venom revealed candidates involved in manipulating the host environment to source nutrition for the parasitoid egg, preventing a host immune response against the egg, as well as two components that may stimulate the host's innate immune system. Notably lacking from the venom-specific expression list was calreticulin, as it also had high expression in the ovaries. In-situ hybridisation revealed this ovarian expression was localised to the follicle cells, which may result in the deposition of calreticulin into the egg exochorion. Investigating the asexual reproduction of M. hyperodae revealed core meiosis-specific genes had conserved expression patterns with the highest expression in the ovaries, suggesting M. hyperodae parthenogenesis involves meiosis and that the potential for sexual reproduction may have been retained. Upregulation of genes involved in endoreduplication provides a potential mechanism for the restoration of diploidy in eggs after meiosis.
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Affiliation(s)
- Sarah N Inwood
- Bioprotection Aotearoa, Genomics Aotearoa, and the Biochemistry Department, University of Otago, Dunedin, Aotearoa, New Zealand
| | - Thomas W R Harrop
- Bioprotection Aotearoa, Genomics Aotearoa, and the Biochemistry Department, University of Otago, Dunedin, Aotearoa, New Zealand; Melbourne Bioinformatics, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Peter K Dearden
- Bioprotection Aotearoa, Genomics Aotearoa, and the Biochemistry Department, University of Otago, Dunedin, Aotearoa, New Zealand.
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12
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Every refuge has its price: Ostreobium as a model for understanding how algae can live in rock and stay in business. Semin Cell Dev Biol 2023; 134:27-36. [PMID: 35341677 DOI: 10.1016/j.semcdb.2022.03.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 02/20/2022] [Accepted: 03/08/2022] [Indexed: 11/23/2022]
Abstract
Ostreobium is a siphonous green alga in the Bryopsidales (Chlorophyta) that burrows into calcium carbonate (CaCO3) substrates. In this habitat, it lives under environmental conditions unusual for an alga (i.e., low light and low oxygen) and it is a major agent of carbonate reef bioerosion. In coral skeletons, Ostreobium can form conspicuous green bands recognizable by the naked eye and it is thought to contribute to the coral's nutritional needs. With coral reefs in global decline, there is a renewed focus on understanding Ostreobium biology and its roles in the coral holobiont. This review summarizes knowledge on Ostreobium's morphological structure, biodiversity and evolution, photosynthesis, mechanism of bioerosion and its role as a member of the coral holobiont. We discuss the resources available to study Ostreobium biology, lay out some of the uncharted territories in Ostreobium biology and offer perspectives for future research.
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Population Genomic Analyses Suggest a Hybrid Origin, Cryptic Sexuality, and Decay of Genes Regulating Seed Development for the Putatively Strictly Asexual Kingdonia uniflora (Circaeasteraceae, Ranunculales). Int J Mol Sci 2023; 24:ijms24021451. [PMID: 36674965 PMCID: PMC9866071 DOI: 10.3390/ijms24021451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/20/2022] [Accepted: 12/28/2022] [Indexed: 01/15/2023] Open
Abstract
Asexual lineages are perceived to be short-lived on evolutionary timescales. Hence, reports for exceptional cases of putative 'ancient asexuals' usually raise questions about the persistence of such species. So far, there have been few studies to solve the mystery in plants. The monotypic Kingdonia dating to the early Eocene, contains only K. uniflora that has no known definitive evidence for sexual reproduction nor records for having congeneric sexual species, raising the possibility that the species has persisted under strict asexuality for a long period of time. Here, we analyze whole genome polymorphism and divergence in K. uniflora. Our results show that K. uniflora is characterized by high allelic heterozygosity and elevated πN/πS ratio, in line with theoretical expectations under asexual evolution. Allele frequency spectrum analysis reveals the origin of asexuality in K. uniflora occurred prior to lineage differentiation of the species. Although divergence within K. uniflora individuals exceeds that between populations, the topologies of the two haplotype trees, however, fail to match each other, indicating long-term asexuality is unlikely to account for the high allele divergence and K. uniflora may have a recent hybrid origin. Phi-test shows a statistical probability of recombination for the conflicting phylogenetic signals revealed by the split network, suggesting K. uniflora engages in undetected sexual reproduction. Detection of elevated genetic differentiation and premature stop codons (in some populations) in genes regulating seed development indicates mutational degradation of sexuality-specific genes in K. uniflora. This study unfolds the origin and persistence mechanism of a plant lineage that has been known to reproduce asexually and presents the genomic consequences of lack of sexuality.
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14
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Cofre J, Saalfeld K. The first embryo, the origin of cancer and animal phylogeny. I. A presentation of the neoplastic process and its connection with cell fusion and germline formation. Front Cell Dev Biol 2023; 10:1067248. [PMID: 36684435 PMCID: PMC9846517 DOI: 10.3389/fcell.2022.1067248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 11/16/2022] [Indexed: 01/05/2023] Open
Abstract
The decisive role of Embryology in understanding the evolution of animal forms is founded and deeply rooted in the history of science. It is recognized that the emergence of multicellularity would not have been possible without the formation of the first embryo. We speculate that biophysical phenomena and the surrounding environment of the Ediacaran ocean were instrumental in co-opting a neoplastic functional module (NFM) within the nucleus of the first zygote. Thus, the neoplastic process, understood here as a biological phenomenon with profound embryologic implications, served as the evolutionary engine that favored the formation of the first embryo and cancerous diseases and allowed to coherently create and recreate body shapes in different animal groups during evolution. In this article, we provide a deep reflection on the Physics of the first embryogenesis and its contribution to the exaptation of additional NFM components, such as the extracellular matrix. Knowledge of NFM components, structure, dynamics, and origin advances our understanding of the numerous possibilities and different innovations that embryos have undergone to create animal forms via Neoplasia during evolutionary radiation. The developmental pathways of Neoplasia have their origins in ctenophores and were consolidated in mammals and other apical groups.
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Affiliation(s)
- Jaime Cofre
- Laboratório de Embriologia Molecular e Câncer, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil,*Correspondence: Jaime Cofre,
| | - Kay Saalfeld
- Laboratório de Filogenia Animal, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
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15
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Luo H, Wang J, Goes JI, Gomes HDR, Al-Hashmi K, Tobias C, Koerting C, Lin S. A grazing-driven positive nutrient feedback loop and active sexual reproduction underpin widespread Noctiluca green tides. ISME COMMUNICATIONS 2022; 2:103. [PMID: 37938758 PMCID: PMC9723592 DOI: 10.1038/s43705-022-00187-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 09/29/2022] [Accepted: 10/06/2022] [Indexed: 11/09/2023]
Abstract
The mixoplankton green Noctiluca scintillans (gNoctiluca) is known to form extensive green tides in tropical coastal ecosystems prone to eutrophication. In the Arabian Sea, their recent appearance and annual recurrence have upended an ecosystem that was once exclusively dominated by diatoms. Despite evidence of strong links to eutrophication, hypoxia and warming, the mechanisms underlying outbreaks of this mixoplanktonic dinoflagellate remain uncertain. Here we have used eco-physiological measurements and transcriptomic profiling to ascribe gNoctiluca's explosive growth during bloom formation to the form of sexual reproduction that produces numerous gametes. Rapid growth of gNoctiluca coincided with active ammonium and phosphate release from gNoctiluca cells, which exhibited high transcriptional activity of phagocytosis and metabolism generating ammonium. This grazing-driven nutrient flow ostensibly promotes the growth of phytoplankton as prey and offers positive support successively for bloom formation and maintenance. We also provide the first evidence that the host gNoctiluca cell could be manipulating growth of its endosymbiont population in order to exploit their photosynthetic products and meet critical energy needs. These findings illuminate gNoctiluca's little known nutritional and reproductive strategies that facilitate its ability to form intense and expansive gNoctiluca blooms to the detriment of regional water, food and the socio-economic security in several tropical countries.
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Affiliation(s)
- Hao Luo
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, and College of Ocean and Earth Sciences, Xiamen University, 361102, Xiamen, China
| | - Jingtian Wang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, and College of Ocean and Earth Sciences, Xiamen University, 361102, Xiamen, China
| | - Joaquim I Goes
- Lamont-Doherty Earth Observatory at Columbia University, Palisades, NY, 10964, USA.
| | - Helga do R Gomes
- Lamont-Doherty Earth Observatory at Columbia University, Palisades, NY, 10964, USA
| | - Khalid Al-Hashmi
- Department of Marine Sciences and Fisheries, Sultan Qaboos University, Muscat, Oman
| | - Craig Tobias
- Department of Marine Sciences, University of Connecticut, Groton, CT, 06340, USA
| | - Claudia Koerting
- Department of Marine Sciences, University of Connecticut, Groton, CT, 06340, USA
| | - Senjie Lin
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, and College of Ocean and Earth Sciences, Xiamen University, 361102, Xiamen, China.
- Department of Marine Sciences, University of Connecticut, Groton, CT, 06340, USA.
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16
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da Silva VS, Machado CR. Sex in protists: A new perspective on the reproduction mechanisms of trypanosomatids. Genet Mol Biol 2022; 45:e20220065. [PMID: 36218381 PMCID: PMC9552303 DOI: 10.1590/1678-4685-gmb-2022-0065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 08/07/2022] [Indexed: 11/04/2022] Open
Abstract
The Protist kingdom individuals are the most ancestral representatives of
eukaryotes. They have inhabited Earth since ancient times and are currently
found in the most diverse environments presenting a great heterogeneity of life
forms. The unicellular and multicellular algae, photosynthetic and heterotrophic
organisms, as well as free-living and pathogenic protozoa represents the protist
group. The evolution of sex is directly associated with the origin of eukaryotes
being protists the earliest protagonists of sexual reproduction on earth. In
eukaryotes, the recombination through genetic exchange is a ubiquitous mechanism
that can be stimulated by DNA damage. Scientific evidences support the
hypothesis that reactive oxygen species (ROS) induced DNA damage can promote
sexual recombination in eukaryotes which might have been a decisive factor for
the origin of sex. The fact that some recombination enzymes also participate in
meiotic sex in modern eukaryotes reinforces the idea that sexual reproduction
emerged as consequence of specific mechanisms to cope with mutations and
alterations in genetic material. In this review we will discuss about origin of
sex and different strategies of evolve sexual reproduction in some protists such
that cause human diseases like malaria, toxoplasmosis, sleeping sickness, Chagas
disease, and leishmaniasis.
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Affiliation(s)
- Verônica Santana da Silva
- Universidade Federal de Minas Gerais, Departamento de Genética,
Ecologia e Evolução, Belo Horizonte, MG, Brazil
| | - Carlos Renato Machado
- Universidade Federal de Minas Gerais, Departamento de Bioquímica e
Imunologia, Belo Horizonte, MG, Brazil
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17
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Lin S, Yu L, Wu X, Li M, Zhang Y, Luo H, Li H, Li T, Li L. Active meiosis during dinoflagellate blooms: A 'sex for proliferation' hypothesis. HARMFUL ALGAE 2022; 118:102307. [PMID: 36195414 DOI: 10.1016/j.hal.2022.102307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/05/2022] [Accepted: 08/05/2022] [Indexed: 06/16/2023]
Abstract
In dinoflagellates, sexual reproduction is best known to be induced by adverse environmental conditions and culminate in encystment for survival ('sex for encystment'). Although increasing laboratory observations indicate that sex can lead to production of vegetative cells bypassing encystment, the occurrence of this alternative pathway in natural populations and its ecological roles remain poorly understood. Here we report evidence that sex in dinoflagellates can potentially be an instrument for bloom proliferation or extension. By bloom metatranscriptome profiling, we documented elevated expression of meiosis genes in two evolutionarily distinct species (Prorocentrum shikokuense and Karenia mikimotoi) during bloom, a timing unexpected of the 'sex for encystment' scenario. To link these genes to meiosis, we induced encystment and cyst germination in the cyst-forming species Scrippsiella acuminata, and found that five of these genes were upregulated during cyst germination, when meiosis occurs. Integrating data from all three species revealed that SPO11, MND1, and DMC1 were likely common between cyst-forming and non-encysting sex in dinoflagellates. Furthermore, flow cytometric analyses revealed consecutive rounds of DNA halving during blooms of P. shikokuense and K. mikimotoi, evidencing meiosis. These data provided novel evidence that sexual reproduction in dinoflagellates might serve to promote cell proliferation, and along with the consequent enhancement of genetic diversity facilitating resistance against pathogens and environmental stress, to boost or extend a bloom ('sex for proliferation'). The putative meiosis-specific genes and insights reported here will prove to be helpful for rigorously testing the hypothesis and addressing whether the two modes of sex are genetically predisposed (i.e. species-specific) or environmentally induced (switchable within species), and if the latter what triggers the switch.
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Affiliation(s)
- Senjie Lin
- Department of Marine Sciences, University of Connecticut, Groton, CT 06340, USA.
| | - Liying Yu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Xiaomei Wu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Meizhen Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Yaqun Zhang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Hao Luo
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Hongfei Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Tangcheng Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Ling Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian 361102, China
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Genomic adaptation of the picoeukaryote Pelagomonas calceolata to iron-poor oceans revealed by a chromosome-scale genome sequence. Commun Biol 2022; 5:983. [PMID: 36114260 PMCID: PMC9481584 DOI: 10.1038/s42003-022-03939-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 09/02/2022] [Indexed: 11/13/2022] Open
Abstract
The smallest phytoplankton species are key actors in oceans biogeochemical cycling and their abundance and distribution are affected with global environmental changes. Among them, algae of the Pelagophyceae class encompass coastal species causative of harmful algal blooms while others are cosmopolitan and abundant. The lack of genomic reference in this lineage is a main limitation to study its ecological importance. Here, we analysed Pelagomonas calceolata relative abundance, ecological niche and potential for the adaptation in all oceans using a complete chromosome-scale assembled genome sequence. Our results show that P. calceolata is one of the most abundant eukaryotic species in the oceans with a relative abundance favoured by high temperature, low-light and iron-poor conditions. Climate change projections based on its relative abundance suggest an extension of the P. calceolata habitat toward the poles at the end of this century. Finally, we observed a specific gene repertoire and expression level variations potentially explaining its ecological success in low-iron and low-nitrate environments. Collectively, these findings reveal the ecological importance of P. calceolata and lay the foundation for a global scale analysis of the adaptation and acclimation strategies of this small phytoplankton in a changing environment. Genomic inference reveals potential climate change-driven range expansion of the phytoplankton species Pelagomonas calceolata.
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19
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Repeat sequences limit the effectiveness of lateral gene transfer and favored the evolution of meiotic sex in early eukaryotes. Proc Natl Acad Sci U S A 2022; 119:e2205041119. [PMID: 35994648 PMCID: PMC9436333 DOI: 10.1073/pnas.2205041119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The transition from prokaryotic lateral gene transfer to eukaryotic meiotic sex is poorly understood. Phylogenetic evidence suggests that it was tightly linked to eukaryogenesis, which involved an unprecedented rise in both genome size and the density of genetic repeats. Expansion of genome size raised the severity of Muller's ratchet, while limiting the effectiveness of lateral gene transfer (LGT) at purging deleterious mutations. In principle, an increase in recombination length combined with higher rates of LGT could solve this problem. Here, we show using a computational model that this solution fails in the presence of genetic repeats prevalent in early eukaryotes. The model demonstrates that dispersed repeat sequences allow ectopic recombination, which leads to the loss of genetic information and curtails the capacity of LGT to prevent mutation accumulation. Increasing recombination length in the presence of repeat sequences exacerbates the problem. Mutational decay can only be resisted with homology along extended sequences of DNA. We conclude that the transition to homologous pairing along linear chromosomes was a key innovation in meiotic sex, which was instrumental in the expansion of eukaryotic genomes and morphological complexity.
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20
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Passer AR, Clancey SA, Shea T, David-Palma M, Averette AF, Boekhout T, Porcel BM, Nowrousian M, Cuomo CA, Sun S, Heitman J, Coelho MA. Obligate sexual reproduction of a homothallic fungus closely related to the Cryptococcus pathogenic species complex. eLife 2022; 11:79114. [PMID: 35713948 PMCID: PMC9296135 DOI: 10.7554/elife.79114] [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: 03/31/2022] [Accepted: 06/15/2022] [Indexed: 12/03/2022] Open
Abstract
<title>eLife digest</title>. Fungi are enigmatic organisms that flourish in soil, on decaying plants, or during infection of animals or plants. Growing in myriad forms, from single-celled yeast to multicellular molds and mushrooms, fungi have also evolved a variety of strategies to reproduce. Normally, fungi reproduce in one of two ways: either they reproduce asexually, with one individual producing a new individual identical to itself, or they reproduce sexually, with two individuals of different 'mating types' contributing to produce a new individual. However, individuals of some species exhibit 'homothallism' or self-fertility: these individuals can produce reproductive cells that are universally compatible, and therefore can reproduce sexually with themselves or with any other cell in the population. Homothallism has evolved multiple times throughout the fungal kingdom, suggesting it confers advantage when population numbers are low or mates are hard to find. Yet some homothallic fungi been overlooked compared to heterothallic species, whose mating types have been well characterised. Understanding the genetic basis of homothallism and how it evolved in different species can provide insights into pathogenic species that cause fungal disease. With that in mind, Passer, Clancey et al. explored the genetic basis of homothallism in Cryptococcus depauperatus, a close relative of C. neoformans, a species that causes fungal infections in humans. A combination of genetic sequencing techniques and experiments were applied to analyse, compare, and manipulate C. depauperatus' genome to see how this species evolved self-fertility. Passer, Clancey et al. showed that C. depauperatus evolved the ability to reproduce sexually by itself via a unique evolutionary pathway. The result is a form of homothallism never reported in fungi before. C. depauperatus lost some of the genes that control mating in other species of fungi, and acquired genes from the opposing mating types of a heterothallic ancestor to become self-fertile. Passer, Clancey et al. also found that, unlike other Cryptococcus species that switch between asexual and sexual reproduction, C. depauperatus grows only as long, branching filaments called hyphae, a sexual form. The species reproduces sexually with itself throughout its life cycle and is unable to produce a yeast (asexual) form, in contrast to other closely related species. This work offers new insights into how different modes of sexual reproduction have evolved in fungi. It also provides another interesting case of how genome plasticity and evolutionary pressures can produce similar outcomes, homothallism, via different evolutionary paths. Lastly, assembling the complete genome of C. depauperatus will foster comparative studies between pathogenic and non-pathogenic Cryptococcus species.
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Affiliation(s)
- Andrew Ryan Passer
- Department of Molecular Genetics and Microbiology, Duke University Medical CenterDurhamUnited States
| | - Shelly Applen Clancey
- Department of Molecular Genetics and Microbiology, Duke University Medical CenterDurhamUnited States
| | - Terrance Shea
- Broad Institute of MIT and HarvardCambridgeUnited States
| | - Márcia David-Palma
- Department of Molecular Genetics and Microbiology, Duke University Medical CenterDurhamUnited States
| | - Anna Floyd Averette
- Department of Molecular Genetics and Microbiology, Duke University Medical CenterDurhamUnited States
| | - Teun Boekhout
- Westerdijk Fungal Biodiversity InstituteUtrechtNetherlands,Institute of Biodiversity and Ecosystem Dynamics (IBED), University of AmsterdamAmsterdamNetherlands
| | - Betina M Porcel
- Génomique Métabolique, CNRS, University Evry, Université Paris-SaclayEvryFrance
| | - Minou Nowrousian
- Lehrstuhl für Molekulare und Zelluläre Botanik, Ruhr-Universität BochumBochumGermany
| | | | - Sheng Sun
- Department of Molecular Genetics and Microbiology, Duke University Medical CenterDurhamUnited States
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical CenterDurhamUnited States
| | - Marco A Coelho
- Department of Molecular Genetics and Microbiology, Duke University Medical CenterDurhamUnited States
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21
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Cruz-Bustos T, Feix AS, Ruttkowski B, Joachim A. Sexual Development in Non-Human Parasitic Apicomplexa: Just Biology or Targets for Control? Animals (Basel) 2021; 11:ani11102891. [PMID: 34679913 PMCID: PMC8532714 DOI: 10.3390/ani11102891] [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: 09/06/2021] [Revised: 09/30/2021] [Accepted: 10/01/2021] [Indexed: 12/17/2022] Open
Abstract
Simple Summary Cellular reproduction is a key part of the apicomplexan life cycle, and both mitotic (asexual) and meiotic (sexual) cell divisions produce new individual cells. Sexual reproduction in most eukaryotic taxa indicates that it has had considerable success during evolution, and it must confer profound benefits, considering its significant costs. The phylum Apicomplexa consists of almost exclusively parasitic single-celled eukaryotic organisms that can affect a wide host range of animals from invertebrates to mammals. Their development is characterized by complex steps in which asexual and sexual replication alternate and the fertilization of a macrogamete by a microgamete results in the formation of a zygote that undergoes meiosis, thus forming a new generation of asexual stages. In apicomplexans, sex is assumed to be induced by the (stressful) condition of having to leave the host, and either gametes or zygotes (or stages arising from it) are transmitted to a new host. Therefore, sex and meiosis are linked to parasite transmission, and consequently dissemination, which are key to the parasitic lifestyle. We hypothesize that improved knowledge of the sexual biology of the Apicomplexa will be essential to design and implement effective transmission-blocking strategies for the control of the major parasites of this group. Abstract The phylum Apicomplexa is a major group of protozoan parasites including gregarines, coccidia, haemogregarines, haemosporidia and piroplasms, with more than 6000 named species. Three of these subgroups, the coccidia, hemosporidia, and piroplasms, contain parasites that cause important diseases of humans and animals worldwide. All of them have complex life cycles involving a switch between asexual and sexual reproduction, which is key to their development. Fertilization (i.e., fusion of female and male cells) results in the formation of a zygote that undergoes meiosis, forming a new generation of asexual stages. In eukaryotes, sexual reproduction is the predominant mode of recombination and segregation of DNA. Sex is well documented in many protist groups, and together with meiosis, is frequently linked with transmission to new hosts. Apicomplexan sexual stages constitute a bottleneck in the life cycle of these parasites, as they are obligatory for the development of new transmissible stages. Consequently, the sexual stages represent attractive targets for vaccination. Detailed understanding of apicomplexan sexual biology will pave the way for the design and implementation of effective transmission-blocking strategies for parasite control. This article reviews the current knowledge on the sexual development of Apicomplexa and the progress in transmission-blocking vaccines for their control, their advantages and limitations and outstanding questions for the future.
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22
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Peixoto JF, dos Santos DG, Ribeiro L, de Oliveira VSC, Nunes-da-Fonseca R, Nepomuceno-Silva JL. Establishment of suitable reference genes for studying relative gene expression during the transition from trophozoites to cyst-like stages and first evidences of stress-induced expression of meiotic genes in Trichomonas vaginalis. Parasitology 2021; 148:934-946. [PMID: 33827719 PMCID: PMC11010144 DOI: 10.1017/s0031182021000585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 11/07/2022]
Abstract
Trichomonas vaginalis is a parasite of the human urogenital tract and the causative agent of trichomoniasis, a sexually transmitted disease of worldwide importance. This parasite is usually found as a motile flagellated trophozoite. However, when subjected to stressful microenvironmental conditions, T. vaginalis trophozoites can differentiate into peculiar cyst-like stages, which exhibit notable physiological resistance to unfavourable conditions. Although well documented in morphological and proteomic terms, patterns of gene expression changes involved in the cellular differentiation into cyst-like stages are mostly unknown. The real-time reverse transcription polymerase chain reaction (RT-qPCR) is recognized as a sensitive and accurate method for quantification of gene expression, providing fluorescence-based data that are proportional to the amount of a target RNA. However, the reliability of relative expression studies depends on the validation of suitable reference genes, which RNAs exhibit a minimum of variation between tested conditions. Here, we attempt to determine suitable reference genes to be used as controls of invariant expression during cold-induced in vitro differentiation of T. vaginalis trophozoites into cyst-like forms. Furthermore, we reveal that the mRNA from the meiotic recombinase Dmc1 is upregulated during this process, indicating that cryptic sexual events may take place in cyst-like stages of T. vaginalis.
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Affiliation(s)
- Juliana Figueiredo Peixoto
- Laboratório Integrado de Bioquímica Hatisaburo Masuda (LIBHM), Instituto de Biodiversidade e Sustentabilidade (NUPEM/UFRJ), Universidade Federal do Rio de Janeiro, Macaé/RJ, Brazil
| | - Daniele Graças dos Santos
- Laboratório Integrado de Bioquímica Hatisaburo Masuda (LIBHM), Instituto de Biodiversidade e Sustentabilidade (NUPEM/UFRJ), Universidade Federal do Rio de Janeiro, Macaé/RJ, Brazil
| | - Lupis Ribeiro
- Laboratório Integrado de Ciências Morfofuncionais (LICM), Instituto de Biodiversidade e Sustentabilidade (NUPEM/UFRJ), Universidade Federal do Rio de Janeiro, Macaé/RJ, Brazil
| | - Vitor Silva Cândido de Oliveira
- Laboratório Integrado de Bioquímica Hatisaburo Masuda (LIBHM), Instituto de Biodiversidade e Sustentabilidade (NUPEM/UFRJ), Universidade Federal do Rio de Janeiro, Macaé/RJ, Brazil
| | - Rodrigo Nunes-da-Fonseca
- Laboratório Integrado de Ciências Morfofuncionais (LICM), Instituto de Biodiversidade e Sustentabilidade (NUPEM/UFRJ), Universidade Federal do Rio de Janeiro, Macaé/RJ, Brazil
| | - José Luciano Nepomuceno-Silva
- Laboratório Integrado de Bioquímica Hatisaburo Masuda (LIBHM), Instituto de Biodiversidade e Sustentabilidade (NUPEM/UFRJ), Universidade Federal do Rio de Janeiro, Macaé/RJ, Brazil
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A functional bacteria-derived restriction modification system in the mitochondrion of a heterotrophic protist. PLoS Biol 2021; 19:e3001126. [PMID: 33891594 PMCID: PMC8099122 DOI: 10.1371/journal.pbio.3001126] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 05/05/2021] [Accepted: 03/23/2021] [Indexed: 01/04/2023] Open
Abstract
The overarching trend in mitochondrial genome evolution is functional streamlining coupled with gene loss. Therefore, gene acquisition by mitochondria is considered to be exceedingly rare. Selfish elements in the form of self-splicing introns occur in many organellar genomes, but the wider diversity of selfish elements, and how they persist in the DNA of organelles, has not been explored. In the mitochondrial genome of a marine heterotrophic katablepharid protist, we identify a functional type II restriction modification (RM) system originating from a horizontal gene transfer (HGT) event involving bacteria related to flavobacteria. This RM system consists of an HpaII-like endonuclease and a cognate cytosine methyltransferase (CM). We demonstrate that these proteins are functional by heterologous expression in both bacterial and eukaryotic cells. These results suggest that a mitochondrion-encoded RM system can function as a toxin-antitoxin selfish element, and that such elements could be co-opted by eukaryotic genomes to drive biased organellar inheritance.
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Berdieva MA, Pozdnyakov IA, Kalinina VO, Skarlato SO. Putative Meiotic Toolkit in the Dinoflagellate Prorocentrum cordatum: Additional Evidence for Sexual Process from Transcriptome. J Eukaryot Microbiol 2021; 68:e12845. [PMID: 33624379 DOI: 10.1111/jeu.12845] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 01/25/2021] [Accepted: 02/13/2021] [Indexed: 01/16/2023]
Abstract
Prorocentrum cordatum (Ostenfeld) Dodge-is a planktonic armored dinoflagellate that is a bloom-forming, potentially toxic cosmopolitan species. The transition from vegetative reproduction to the sexual process has been recently shown for this organism. Here, we present the results of transcriptomic data analysis that uncovered one syngamy-associated and 16 meiosis-associated proteins in P. cordatum. We also detected an amino acid sequence homologous to bacterial MutS2 protein. The MutS2 presence and origin in dinoflagellates are discussed for the first time.
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Affiliation(s)
- Mariia A Berdieva
- Institute of Cytology of the Russian Academy of Science, Tikhoretsky Avenue 4, St. Petersburg, 194064, Russia
| | - Ilya A Pozdnyakov
- Institute of Cytology of the Russian Academy of Science, Tikhoretsky Avenue 4, St. Petersburg, 194064, Russia
| | - Vera O Kalinina
- Institute of Cytology of the Russian Academy of Science, Tikhoretsky Avenue 4, St. Petersburg, 194064, Russia
| | - Sergei O Skarlato
- Institute of Cytology of the Russian Academy of Science, Tikhoretsky Avenue 4, St. Petersburg, 194064, Russia
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25
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Jaron KS, Bast J, Nowell RW, Ranallo-Benavidez TR, Robinson-Rechavi M, Schwander T. Genomic Features of Parthenogenetic Animals. J Hered 2021; 112:19-33. [PMID: 32985658 PMCID: PMC7953838 DOI: 10.1093/jhered/esaa031] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 08/17/2020] [Indexed: 12/21/2022] Open
Abstract
Evolution without sex is predicted to impact genomes in numerous ways. Case studies of individual parthenogenetic animals have reported peculiar genomic features that were suggested to be caused by their mode of reproduction, including high heterozygosity, a high abundance of horizontally acquired genes, a low transposable element load, or the presence of palindromes. We systematically characterized these genomic features in published genomes of 26 parthenogenetic animals representing at least 18 independent transitions to asexuality. Surprisingly, not a single feature was systematically replicated across a majority of these transitions, suggesting that previously reported patterns were lineage-specific rather than illustrating the general consequences of parthenogenesis. We found that only parthenogens of hybrid origin were characterized by high heterozygosity levels. Parthenogens that were not of hybrid origin appeared to be largely homozygous, independent of the cellular mechanism underlying parthenogenesis. Overall, despite the importance of recombination rate variation for the evolution of sexual animal genomes, the genome-wide absence of recombination does not appear to have had the dramatic effects which are expected from classical theoretical models. The reasons for this are probably a combination of lineage-specific patterns, the impact of the origin of parthenogenesis, and a survivorship bias of parthenogenetic lineages.
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Affiliation(s)
- Kamil S Jaron
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Jens Bast
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Reuben W Nowell
- Department of Life Sciences, Imperial College London, Ascot, Berkshire, UK
- Reuben W. Nowell is now at the Department of Zoology, University of Oxford, Oxford, UK
| | | | - Marc Robinson-Rechavi
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Tanja Schwander
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
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Hofstatter PG, Thangavel G, Castellani M, Marques A. Meiosis Progression and Recombination in Holocentric Plants: What Is Known? FRONTIERS IN PLANT SCIENCE 2021; 12:658296. [PMID: 33968114 PMCID: PMC8100227 DOI: 10.3389/fpls.2021.658296] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 03/22/2021] [Indexed: 05/02/2023]
Abstract
Differently from the common monocentric organization of eukaryotic chromosomes, the so-called holocentric chromosomes present many centromeric regions along their length. This chromosomal organization can be found in animal and plant lineages, whose distribution suggests that it has evolved independently several times. Holocentric chromosomes present an advantage: even broken chromosome parts can be correctly segregated upon cell division. However, the evolution of holocentricity brought about consequences to nuclear processes and several adaptations are necessary to cope with this new organization. Centromeres of monocentric chromosomes are involved in a two-step cohesion release during meiosis. To deal with that holocentric lineages developed different adaptations, like the chromosome remodeling strategy in Caenorhabditis elegans or the inverted meiosis in plants. Furthermore, the frequency of recombination at or around centromeres is normally very low and the presence of centromeric regions throughout the entire length of the chromosomes could potentially pose a problem for recombination in holocentric organisms. However, meiotic recombination happens, with exceptions, in those lineages in spite of their holocentric organization suggesting that the role of centromere as recombination suppressor might be altered in these lineages. Most of the available information about adaptations to meiosis in holocentric organisms is derived from the animal model C. elegans. As holocentricity evolved independently in different lineages, adaptations observed in C. elegans probably do not apply to other lineages and very limited research is available for holocentric plants. Currently, we still lack a holocentric model for plants, but good candidates may be found among Cyperaceae, a large angiosperm family. Besides holocentricity, chiasmatic and achiasmatic inverted meiosis are found in the family. Here, we introduce the main concepts of meiotic constraints and adaptations with special focus in meiosis progression and recombination in holocentric plants. Finally, we present the main challenges and perspectives for future research in the field of chromosome biology and meiosis in holocentric plants.
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Affiliation(s)
- Zoe K. Ross
- Institute of Medical Sciences (IMS), University of Aberdeen, Aberdeen, United Kingdom
- MRC Centre for Medical Mycology, Department of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Alexander Lorenz
- Institute of Medical Sciences (IMS), University of Aberdeen, Aberdeen, United Kingdom
- * E-mail:
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28
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Koutsouveli V, Cárdenas P, Santodomingo N, Marina A, Morato E, Rapp HT, Riesgo A. The Molecular Machinery of Gametogenesis in Geodia Demosponges (Porifera): Evolutionary Origins of a Conserved Toolkit across Animals. Mol Biol Evol 2020; 37:3485-3506. [PMID: 32929503 PMCID: PMC7743902 DOI: 10.1093/molbev/msaa183] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
All animals are capable of undergoing gametogenesis. The ability of forming haploid cells from diploid cells through meiosis and recombination appeared early in eukaryotes, whereas further gamete differentiation is mostly a metazoan signature. Morphologically, the gametogenic process presents many similarities across animal taxa, but little is known about its conservation at the molecular level. Porifera are the earliest divergent animals and therefore are an ideal phylum to understand evolution of the gametogenic toolkits. Although sponge gametogenesis is well known at the histological level, the molecular toolkits for gamete production are largely unknown. Our goal was to identify the genes and their expression levels which regulate oogenesis and spermatogenesis in five gonochoristic and oviparous species of the genus Geodia, using both RNAseq and proteomic analyses. In the early stages of both female and male gametogenesis, genes involved in germ cell fate and cell-renewal were upregulated. Then, molecular signals involved in retinoic acid pathway could trigger the meiotic processes. During later stages of oogenesis, female sponges expressed genes involved in cell growth, vitellogenesis, and extracellular matrix reassembly, which are conserved elements of oocyte maturation in Metazoa. Likewise, in spermatogenesis, genes regulating the whole meiotic cycle, chromatin compaction, and flagellum axoneme formation, that are common across Metazoa were overexpressed in the sponges. Finally, molecular signals possibly related to sperm capacitation were identified during late stages of spermatogenesis for the first time in Porifera. In conclusion, the activated molecular toolkit during gametogenesis in sponges was remarkably similar to that deployed during gametogenesis in vertebrates.
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Affiliation(s)
- Vasiliki Koutsouveli
- Department of Life Sciences, The Natural History Museum of London, London, United Kingdom
- Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, BMC, Uppsala, Sweden
| | - Paco Cárdenas
- Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, BMC, Uppsala, Sweden
| | - Nadiezhda Santodomingo
- Department of Life Sciences, The Natural History Museum of London, London, United Kingdom
| | - Anabel Marina
- Servicio de Proteómica, Centro de Biología Molecular Severo Ochoa (CBMSO), Universidad Autónoma de Madrid (UAM) and Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Esperanza Morato
- Servicio de Proteómica, Centro de Biología Molecular Severo Ochoa (CBMSO), Universidad Autónoma de Madrid (UAM) and Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Hans Tore Rapp
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Ana Riesgo
- Department of Life Sciences, The Natural History Museum of London, London, United Kingdom
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29
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Bogema DR, Yam J, Micallef ML, Gholipourkanani H, Go J, Jenkins C, Dang C. Draft genomes of Perkinsus olseni and Perkinsus chesapeaki reveal polyploidy and regional differences in heterozygosity. Genomics 2020; 113:677-688. [PMID: 33017625 DOI: 10.1016/j.ygeno.2020.09.064] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 09/28/2020] [Accepted: 09/30/2020] [Indexed: 12/13/2022]
Abstract
Perkinsus spp. parasites have significant impact on aquaculture and wild mollusc populations. We sequenced the genomes of five monoclonal isolates of Perkinsus olseni and one Perkinsus chesapeaki from international sources. Sequence analysis revealed similar levels of repetitive sequence within species, a polyploid genome structure, and substantially higher heterozygosity in Oceanian-sourced isolates. We also identified tandem replication of the rRNA transcriptional unit, with high strain variation. Characterized gene content was broadly similar amongst all Perkinsus spp. but P. olseni Oceanian isolates contained an elevated number of genes compared to other P. olseni isolates and cox3 could not be identified in any Perkinsus spp. sequence. Phylogenetics and average nucleotide identity scans were consistent with all P. olseni isolates being within one species. These are the first genome sequences generated for both P. olseni and P. chesapeaki and will allow future advances in diagnostic design and population genomics of these important aquatic parasites.
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Affiliation(s)
- Daniel R Bogema
- Elizabeth Macarthur Agricultural Institute, NSW Department of Primary Industries, Menangle, NSW 2568, Australia.
| | - Jerald Yam
- Elizabeth Macarthur Agricultural Institute, NSW Department of Primary Industries, Menangle, NSW 2568, Australia; The Ithree Institute, University of Technology Sydney, NSW 2007, Australia
| | - Melinda L Micallef
- Elizabeth Macarthur Agricultural Institute, NSW Department of Primary Industries, Menangle, NSW 2568, Australia
| | - Hosna Gholipourkanani
- Department of Primary Industries and Regional Development, Government of Western Australia, Perth, WA, Australia
| | - Jeffrey Go
- Elizabeth Macarthur Agricultural Institute, NSW Department of Primary Industries, Menangle, NSW 2568, Australia
| | - Cheryl Jenkins
- Elizabeth Macarthur Agricultural Institute, NSW Department of Primary Industries, Menangle, NSW 2568, Australia
| | - Cecile Dang
- Department of Primary Industries and Regional Development, Government of Western Australia, Perth, WA, Australia
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30
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Colnaghi M, Lane N, Pomiankowski A. Genome expansion in early eukaryotes drove the transition from lateral gene transfer to meiotic sex. eLife 2020; 9:58873. [PMID: 32990598 PMCID: PMC7524546 DOI: 10.7554/elife.58873] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 09/03/2020] [Indexed: 12/17/2022] Open
Abstract
Prokaryotes acquire genes from the environment via lateral gene transfer (LGT). Recombination of environmental DNA can prevent the accumulation of deleterious mutations, but LGT was abandoned by the first eukaryotes in favour of sexual reproduction. Here we develop a theoretical model of a haploid population undergoing LGT which includes two new parameters, genome size and recombination length, neglected by previous theoretical models. The greater complexity of eukaryotes is linked with larger genomes and we demonstrate that the benefit of LGT declines rapidly with genome size. The degeneration of larger genomes can only be resisted by increases in recombination length, to the same order as genome size - as occurs in meiosis. Our results can explain the strong selective pressure towards the evolution of sexual cell fusion and reciprocal recombination during early eukaryotic evolution - the origin of meiotic sex.
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Affiliation(s)
- Marco Colnaghi
- CoMPLEX, University College London, London, United Kingdom.,Department of Genetics, Evolution and Environment University College London, London, United Kingdom
| | - Nick Lane
- CoMPLEX, University College London, London, United Kingdom.,Department of Genetics, Evolution and Environment University College London, London, United Kingdom
| | - Andrew Pomiankowski
- CoMPLEX, University College London, London, United Kingdom.,Department of Genetics, Evolution and Environment University College London, London, United Kingdom
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31
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Polyphyletic origin, intracellular invasion, and meiotic genes in the putatively asexual agamococcidians (Apicomplexa incertae sedis). Sci Rep 2020; 10:15847. [PMID: 32985520 PMCID: PMC7522995 DOI: 10.1038/s41598-020-72287-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/28/2020] [Indexed: 12/30/2022] Open
Abstract
Agamococcidians are enigmatic and poorly studied parasites of marine invertebrates with unexplored diversity and unclear relationships to other sporozoans such as the human pathogens Plasmodium and Toxoplasma. It is believed that agamococcidians are not capable of sexual reproduction, which is essential for life cycle completion in all well studied parasitic apicomplexans. Here, we describe three new species of agamococcidians belonging to the genus Rhytidocystis. We examined their cell morphology and ultrastructure, resolved their phylogenetic position by using near-complete rRNA operon sequences, and searched for genes associated with meiosis and oocyst wall formation in two rhytidocystid transcriptomes. Phylogenetic analyses consistently recovered rhytidocystids as basal coccidiomorphs and away from the corallicolids, demonstrating that the order Agamococcidiorida Levine, 1979 is polyphyletic. Light and transmission electron microscopy revealed that the development of rhytidocystids begins inside the gut epithelial cells, a characteristic which links them specifically with other coccidiomorphs to the exclusion of gregarines and suggests that intracellular invasion evolved early in the coccidiomorphs. We propose a new superorder Eococcidia for early coccidiomorphs. Transcriptomic analysis demonstrated that both the meiotic machinery and oocyst wall proteins are preserved in rhytidocystids. The conservation of meiotic genes and ultrastructural similarity of rhytidocystid trophozoites to macrogamonts of true coccidians point to an undescribed, cryptic sexual process in the group.
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32
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Jalinsky J, Logsdon JM, Neiman M. Male phenotypes in a female framework: Evidence for degeneration in sperm produced by male snails from asexual lineages. J Evol Biol 2020; 33:1050-1059. [PMID: 32304112 DOI: 10.1111/jeb.13632] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 03/21/2020] [Accepted: 04/02/2020] [Indexed: 01/14/2023]
Abstract
How changes in selective regimes affect trait evolution is an important open biological question. We take advantage of naturally occurring and repeated transitions from sexual to asexual reproduction in a New Zealand freshwater snail species, Potamopyrgus antipodarum, to address how evolution in an asexual context-including the potential for relaxed selection on male-specific traits-influences sperm morphology. The occasional production of male offspring by the otherwise all-female asexual P. antipodarum lineages affords a unique and powerful opportunity to assess the fate of sperm traits in a context where males are exceedingly rare. These comparisons revealed that the sperm produced by 'asexual' males are markedly distinct from sexual counterparts. We also found that the asexual male sperm harboured markedly higher phenotypic variation and was much more likely to be morphologically abnormal. Together, these data suggest that transitions to asexual reproduction might be irreversible, at least in part because male function is likely to be compromised. These results are also consistent with a scenario where relaxed selection and/or mutation accumulation in the absence of sex translates into rapid trait degeneration.
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Affiliation(s)
- Joseph Jalinsky
- Department of Biology, University of Iowa, Iowa City, IA, USA
| | - John M Logsdon
- Department of Biology, University of Iowa, Iowa City, IA, USA
| | - Maurine Neiman
- Department of Biology, University of Iowa, Iowa City, IA, USA
- Department of Gender, Women's, and Sexuality Studies, University of Iowa, Iowa City, IA, USA
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33
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Barcaccia G, Palumbo F, Sgorbati S, Albertini E, Pupilli F. A Reappraisal of the Evolutionary and Developmental Pathway of Apomixis and Its Genetic Control in Angiosperms. Genes (Basel) 2020; 11:E859. [PMID: 32731368 PMCID: PMC7466056 DOI: 10.3390/genes11080859] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 07/24/2020] [Accepted: 07/27/2020] [Indexed: 12/16/2022] Open
Abstract
Apomixis sensu stricto (agamospermy) is asexual reproduction by seed. In angiosperms it represents an easy byway of life cycle renewal through gamete-like cells that give rise to maternal embryos without ploidy reduction (meiosis) and ploidy restitution (syngamy). The origin of apomixis still represents an unsolved problem, as it may be either evolved from sex or the other way around. This review deals with a reappraisal of the origin of apomixis in order to deepen knowledge on such asexual mode of reproduction which seems mainly lacking in the most basal angiosperm orders (i.e., Amborellales, Nymphaeales and Austrobaileyales, also known as ANA-grade), while it clearly occurs in different forms and variants in many unrelated families of monocots and eudicots. Overall findings strengthen the hypothesis that apomixis as a whole may have evolved multiple times in angiosperm evolution following different developmental pathways deviating to different extents from sexuality. Recent developments on the genetic control of apomixis in model species are also presented and adequately discussed in order to shed additional light on the antagonist theories of gain- and loss-of-function over sexuality.
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Affiliation(s)
- Gianni Barcaccia
- Department of Agronomy Food Natural Resources Animals Environment, University of Padova, Campus of Agripolis, Viale dell’Università 16, Legnaro, 35020 Padova, Italy;
| | - Fabio Palumbo
- Department of Agronomy Food Natural Resources Animals Environment, University of Padova, Campus of Agripolis, Viale dell’Università 16, Legnaro, 35020 Padova, Italy;
| | - Sergio Sgorbati
- Department of Environmental and Territory Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milano, Italy;
| | - Emidio Albertini
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy;
| | - Fulvio Pupilli
- Research Division of Perugia, Institute of Biosciences and Bioresources, National Research Council (CNR), Via Madonna Alta 130, 06128 Perugia, Italy;
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Öztoprak H, Walden S, Heger T, Bonkowski M, Dumack K. What Drives the Diversity of the Most Abundant Terrestrial Cercozoan Family (Rhogostomidae, Cercozoa, Rhizaria)? Microorganisms 2020; 8:E1123. [PMID: 32722603 PMCID: PMC7463998 DOI: 10.3390/microorganisms8081123] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/22/2020] [Accepted: 07/23/2020] [Indexed: 12/25/2022] Open
Abstract
Environmental sequencing surveys of soils and freshwaters revealed high abundance and diversity of the Rhogostomidae, a group of omnivorous thecate amoebae. This is puzzling since only a few Rhogostomidae species have yet been described and only a handful of reports mention them in field surveys. We investigated the putative cryptic diversity of the Rhogostomidae by a critical re-evaluation of published environmental sequencing data and in-depth ecological and morphological trait analyses. The Rhogostomidae exhibit an amazing diversity of genetically distinct clades that occur in a variety of different environments. We further broadly sampled for Rhogostomidae species; based on these isolates, we describe eleven new species and highlight important morphological traits for species delimitation. The most important environmental drivers that shape the Rhogostomidae community were soil moisture, soil pH, and total plant biomass. The length/width ratio of the theca was a morphological trait related to the colonized habitats, but not the shape and size of the aperture that is often linked to moisture adaption in testate and thecate amoebae.
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Affiliation(s)
- Hüsna Öztoprak
- Institute of Zoology, Terrestrial Ecology, University of Cologne, Zülpicher Str. 47b, 50674 Köln, Germany; (H.Ö.); (S.W.); (M.B.)
| | - Susanne Walden
- Institute of Zoology, Terrestrial Ecology, University of Cologne, Zülpicher Str. 47b, 50674 Köln, Germany; (H.Ö.); (S.W.); (M.B.)
| | - Thierry Heger
- Soil Science and Environment Group, CHANGINS, University of Applied Sciences and Arts Western Switzerland, Route de Duillier 50, 1260 Nyon, Switzerland;
| | - Michael Bonkowski
- Institute of Zoology, Terrestrial Ecology, University of Cologne, Zülpicher Str. 47b, 50674 Köln, Germany; (H.Ö.); (S.W.); (M.B.)
| | - Kenneth Dumack
- Institute of Zoology, Terrestrial Ecology, University of Cologne, Zülpicher Str. 47b, 50674 Köln, Germany; (H.Ö.); (S.W.); (M.B.)
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Moi D, Kilchoer L, Aguilar PS, Dessimoz C. Scalable phylogenetic profiling using MinHash uncovers likely eukaryotic sexual reproduction genes. PLoS Comput Biol 2020; 16:e1007553. [PMID: 32697802 PMCID: PMC7423146 DOI: 10.1371/journal.pcbi.1007553] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 08/12/2020] [Accepted: 05/18/2020] [Indexed: 01/09/2023] Open
Abstract
Phylogenetic profiling is a computational method to predict genes involved in the same biological process by identifying protein families which tend to be jointly lost or retained across the tree of life. Phylogenetic profiling has customarily been more widely used with prokaryotes than eukaryotes, because the method is thought to require many diverse genomes. There are now many eukaryotic genomes available, but these are considerably larger, and typical phylogenetic profiling methods require at least quadratic time as a function of the number of genes. We introduce a fast, scalable phylogenetic profiling approach entitled HogProf, which leverages hierarchical orthologous groups for the construction of large profiles and locality-sensitive hashing for efficient retrieval of similar profiles. We show that the approach outperforms Enhanced Phylogenetic Tree, a phylogeny-based method, and use the tool to reconstruct networks and query for interactors of the kinetochore complex as well as conserved proteins involved in sexual reproduction: Hap2, Spo11 and Gex1. HogProf enables large-scale phylogenetic profiling across the three domains of life, and will be useful to predict biological pathways among the hundreds of thousands of eukaryotic species that will become available in the coming few years. HogProf is available at https://github.com/DessimozLab/HogProf. Genes that are involved in the same biological process tend to co-evolve. This property is exploited by the technique of phylogenetic profiling, which identifies co-evolving (and therefore likely functionally related) genes through patterns of correlated gene retention and loss in evolution and across species. However, conventional methods to computing and clustering these correlated genes do not scale with increasing numbers of genomes. HogProf is a novel phylogenetic profiling tool built on probabilistic data structures. It allows the user to construct searchable databases containing the evolutionary history of hundreds of thousands of protein families. Such fast detection of coevolution takes advantage of the rapidly increasing amount of genomic data publicly available, and can uncover unknown biological networks and guide in-vivo research and experimentation. We have applied our tool to describe the biological networks underpinning sexual reproduction in eukaryotes.
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Affiliation(s)
- David Moi
- Department of Computational Biology, University of Lausanne, Lausanne, Switzerland
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
- SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
- * E-mail: (DM); (CD)
| | - Laurent Kilchoer
- Department of Computational Biology, University of Lausanne, Lausanne, Switzerland
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
- SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Pablo S. Aguilar
- Instituto de Investigaciones Biotecnologicas (IIBIO), Universidad Nacional de San Martín, Buenos Aires, Argentina
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-CONICET), Buenos Aires, Argentina
| | - Christophe Dessimoz
- Department of Computational Biology, University of Lausanne, Lausanne, Switzerland
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
- SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
- Department of Genetics, Evolution, and Environment, University College London, London, United Kingdom
- Department of Computer Science, University College London, London, United Kingdom
- * E-mail: (DM); (CD)
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Hofstatter PG, Ribeiro GM, Porfírio‐Sousa AL, Lahr DJG. The Sexual Ancestor of all Eukaryotes: A Defense of the “Meiosis Toolkit”. Bioessays 2020; 42:e2000037. [DOI: 10.1002/bies.202000037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/08/2020] [Indexed: 12/16/2022]
Affiliation(s)
- Paulo G. Hofstatter
- Universidade de São Paulo Instituto de Biociencias, Rua do Matão, travessa 14, A101. São Paulo, CEP.: 05508‐090, Brazil
| | - Giulia M. Ribeiro
- Universidade de São Paulo Instituto de Biociencias, Rua do Matão, travessa 14, A101. São Paulo, CEP.: 05508‐090, Brazil
| | - Alfredo L. Porfírio‐Sousa
- Universidade de São Paulo Instituto de Biociencias, Rua do Matão, travessa 14, A101. São Paulo, CEP.: 05508‐090, Brazil
| | - Daniel J. G. Lahr
- Universidade de São Paulo Instituto de Biociencias, Rua do Matão, travessa 14, A101. São Paulo, CEP.: 05508‐090, Brazil
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Tvedte ES, Walden KKO, McElroy KE, Werren JH, Forbes AA, Hood GR, Logsdon JM, Feder JL, Robertson HM. Genome of the Parasitoid Wasp Diachasma alloeum, an Emerging Model for Ecological Speciation and Transitions to Asexual Reproduction. Genome Biol Evol 2020; 11:2767-2773. [PMID: 31553440 PMCID: PMC6781843 DOI: 10.1093/gbe/evz205] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2019] [Indexed: 12/24/2022] Open
Abstract
Parasitoid wasps are among the most speciose animals, yet have relatively few available genomic resources. We report a draft genome assembly of the wasp Diachasma alloeum (Hymenoptera: Braconidae), a host-specific parasitoid of the apple maggot fly Rhagoletis pomonella (Diptera: Tephritidae), and a developing model for understanding how ecological speciation can “cascade” across trophic levels. Identification of gene content confirmed the overall quality of the draft genome, and we manually annotated ∼400 genes as part of this study, including those involved in oxidative phosphorylation, chemosensation, and reproduction. Through comparisons to model hymenopterans such as the European honeybee Apis mellifera and parasitoid wasp Nasonia vitripennis, as well as a more closely related braconid parasitoid Microplitis demolitor, we identified a proliferation of transposable elements in the genome, an expansion of chemosensory genes in parasitoid wasps, and the maintenance of several key genes with known roles in sexual reproduction and sex determination. The D. alloeum genome will provide a valuable resource for comparative genomics studies in Hymenoptera as well as specific investigations into the genomic changes associated with ecological speciation and transitions to asexuality.
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Affiliation(s)
- Eric S Tvedte
- Department of Biology, University of Iowa, IA.,Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD
| | | | | | | | | | - Glen R Hood
- Department of Biological Sciences, Wayne State University, Detroit, MI
| | | | - Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, IN
| | - Hugh M Robertson
- Department of Entomology, University of Illinois at Urbana-Champaign, IL
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The genome of the sea anemone Actinia equina (L.): Meiotic toolkit genes and the question of sexual reproduction. Mar Genomics 2020; 53:100753. [PMID: 32057717 DOI: 10.1016/j.margen.2020.100753] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/05/2020] [Accepted: 02/05/2020] [Indexed: 12/15/2022]
Abstract
The beadlet anemone Actinia equina (L.) (Cnidaria: Anthozoa: Actiniaria: Actiniidae) is one of the most familiar organisms of the North European intertidal zone. Once considered a single, morphologically variable species across northern Europe, it is now recognised as one member of a variable species complex. Previous studies of distribution, aggression, allozymes and mitochondrial DNA suggest that the diversity in form and colour within A. equina may hide still unrecognised species diversity. To empower further study of A. equina population genetics and systematics, we sequenced (PacBio Sequel) the genome of a single A. equina individual to produce a high-quality genome assembly (contig N50 = 492,607 bp, 1485 contigs, number of protein coding genes = 47,671, 97% BUSCO completeness). There is debate as to whether A. equina reproduces solely asexually, since no reliable, consistent evidence of sexual reproduction has been found. To gain further insight, we examined the genome for evidence of a 'meiotic toolkit' - genes believed to be found consistently in sexually reproducing organisms - and demonstrate that the A. equina genome appears not to have this full complement. Additionally, Smudgeplot analysis, coupled with high haplotype diversity, indicates this genome assembly to be of ambiguous ploidy, suggesting that A. equina may not be diploid. The suggested polyploid nature of this species coupled with the deficiency in meiotic toolkit genes, indicates that further field and laboratory studies of this species is warranted to understand how this species reproduces and what role ploidy may play in speciation within this speciose genus.
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Ji N, Huang J, Zhang Z, Zhou L, Shen X, Lin S. Identification and expression analysis of meiosis-related genes in the harmful alga Heterosigma akashiwo (Raphidophyceae). HARMFUL ALGAE 2020; 92:101736. [PMID: 32113592 DOI: 10.1016/j.hal.2019.101736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 12/20/2019] [Accepted: 12/20/2019] [Indexed: 06/10/2023]
Abstract
Sexual reproduction (SR), hallmarked by meiosis, is widespread in eukaryotes. In phytoplankton, SR has been observed in many lineages, but molecular information on SR or meiosis of harmful algal bloom (HAB) species is scarce. The raphidophyte Heterosigma akashiwo is a globally distributed and devastating HAB species, but molecular evidence of its SR or meiosis is lacking. Here, to address the gap of knowledge, the presence of meiotic genes in H. akashiwo were examined. Interestingly, seven meiosis-specific or related genes (SPO11, MND, RAD21, RAD51, MSH2, MSH6 and MEI2) were identified from H. akashiwo transcriptomes. Furthermore, expression patterns of these genes except MSH6 (excluded due to primer failure) were investigated using quantitative reverse-transcription PCR. Results showed that the examined genes exhibited similar diel rhythms, typically, highest in early dark period and then gradually decreasing until mid-day. In addition, the expression of these six genes was not higher in the stationary growth stage than in the exponential stage, as would be expected if meiosis was to form cysts, and their elevated expression in response to colchicine treatment (arresting cells in the G2/M transition) indicated a potential role of these genes in cell division and population growth in H. akashiwo. Consistent with this, we also found a morning to afternoon shift in the expression of these genes during the bloom of H. akashiwo. This study documents a part of the typical SR gene repertoire and its potential role in regulating cell division in H. akashiwo, offering candidates for population growth markers for bloom monitoring although its linkage to meiosis and SR remain to be studied further in the future.
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Affiliation(s)
- Nanjing Ji
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, 361005, China; Department of Marine Sciences, University of Connecticut, Groton, CT, 06340, USA
| | - Jinwang Huang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China
| | - Zhenzhen Zhang
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China
| | - Lingjie Zhou
- Department of Marine Sciences, University of Connecticut, Groton, CT, 06340, USA
| | - Xin Shen
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, China
| | - Senjie Lin
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, 361005, China; Department of Marine Sciences, University of Connecticut, Groton, CT, 06340, USA.
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40
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Archetti M. Inverted meiosis and the evolution of sex by loss of complementation. J Evol Biol 2020; 33:460-467. [PMID: 31872486 DOI: 10.1111/jeb.13580] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 11/19/2019] [Accepted: 12/06/2019] [Indexed: 11/29/2022]
Abstract
Inverted meiosis, in which sister chromatids segregate before homologous chromosomes, is a common aberration of conventional meiosis (in which sister chromatids segregate after homologous chromosomes) and is routinely observed in certain species. This raises an evolutionary mystery: what is the adaptive advantage of the more common, conventional order of segregation in meiosis? I use a population genetic model to show that asexual mutants arising from inverted meiosis are relatively immune from the deleterious effects of loss of complementation (heterozygosity), unlike the asexual mutants arising from conventional meiosis, in which loss of complementation can outweigh the two-fold cost of meiosis. Hence, asexual reproduction can replace sexual reproduction with inverted meiosis, but not with conventional meiosis. The results are in line with analogous considerations on other alternative types of reproduction and support the idea that amphimixis is stable in spite of the two-fold cost of meiosis because loss of complementation in mutant asexuals outweigh the two-fold cost.
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Affiliation(s)
- Marco Archetti
- Department of Biology, Pennsylvania State University, University Park, PA, USA
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41
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Liang Z, Geng Y, Ji C, Du H, Wong CE, Zhang Q, Zhang Y, Zhang P, Riaz A, Chachar S, Ding Y, Wen J, Wu Y, Wang M, Zheng H, Wu Y, Demko V, Shen L, Han X, Zhang P, Gu X, Yu H. Mesostigma viride Genome and Transcriptome Provide Insights into the Origin and Evolution of Streptophyta. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:1901850. [PMID: 31921561 PMCID: PMC6947507 DOI: 10.1002/advs.201901850] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/10/2019] [Indexed: 05/02/2023]
Abstract
The Streptophyta include unicellular and multicellular charophyte green algae and land plants. Colonization of the terrestrial habitat by land plants is a major evolutionary event that has transformed the planet. So far, lack of genome information on unicellular charophyte algae hinders the understanding of the origin and the evolution from unicellular to multicellular life in Streptophyta. This work reports the high-quality reference genome and transcriptome of Mesostigma viride, a single-celled charophyte alga with a position at the base of Streptophyta. There are abundant segmental duplications and transposable elements in M. viride, which contribute to a relatively large genome with high gene content compared to other algae and early diverging land plants. This work identifies the origin of genetic tools that multicellular Streptophyta have inherited and key genetic innovations required for the evolution of land plants from unicellular aquatic ancestors. The findings shed light on the age-old questions of the evolution of multicellularity and the origin of land plants.
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Affiliation(s)
- Zhe Liang
- Department of Biological SciencesNational University of SingaporeSingapore117543Singapore
| | - Yuke Geng
- Biotechnology Research InstituteChinese Academy of Agricultural SciencesBeijing100081China
| | - Changmian Ji
- Biomarker TechnologiesBeijing101300China
- Institute of Tropical Bioscience and BiotechnologyChinese Academy of Tropical Agricultural SciencesHaikou571101China
| | - Hai Du
- College of Agronomy and BiotechnologySouthwest UniversityChongqing400715China
| | - Chui Eng Wong
- Department of Biological SciencesNational University of SingaporeSingapore117543Singapore
| | - Qian Zhang
- Biotechnology Research InstituteChinese Academy of Agricultural SciencesBeijing100081China
| | - Ye Zhang
- Biotechnology Research InstituteChinese Academy of Agricultural SciencesBeijing100081China
| | - Pingxian Zhang
- Biotechnology Research InstituteChinese Academy of Agricultural SciencesBeijing100081China
| | - Adeel Riaz
- Biotechnology Research InstituteChinese Academy of Agricultural SciencesBeijing100081China
| | - Sadaruddin Chachar
- Biotechnology Research InstituteChinese Academy of Agricultural SciencesBeijing100081China
| | - Yike Ding
- Department of EntomologyUniversity of California RiversideRiversideCA92521USA
| | - Jing Wen
- College of Agronomy and BiotechnologySouthwest UniversityChongqing400715China
| | - Yunwen Wu
- Biotechnology Research InstituteChinese Academy of Agricultural SciencesBeijing100081China
- College of Agronomy and BiotechnologySouthwest UniversityChongqing400715China
| | | | | | - Yanmin Wu
- College of Agronomy and BiotechnologySouthwest UniversityChongqing400715China
| | - Viktor Demko
- Department of Plant PhysiologyFaculty of Natural SciencesComenius University in BratislavaBratislava84215Slovakia
| | - Lisha Shen
- Temasek Life Sciences LaboratoryNational University of SingaporeSingapore117604Singapore
| | - Xiao Han
- College of Biological Science and EngineeringFuzhou UniversityFuzhou350108China
| | - Pengpeng Zhang
- Biotechnology Research InstituteChinese Academy of Agricultural SciencesBeijing100081China
| | - Xiaofeng Gu
- Biotechnology Research InstituteChinese Academy of Agricultural SciencesBeijing100081China
| | - Hao Yu
- Department of Biological SciencesNational University of SingaporeSingapore117543Singapore
- Temasek Life Sciences LaboratoryNational University of SingaporeSingapore117604Singapore
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Ota S, Oshima K, Yamazaki T, Takeshita T, Bišová K, Zachleder V, Hattori M, Kawano S. The Parachlorella Genome and Transcriptome Endorse Active RWP-RK, Meiosis and Flagellar Genes in Trebouxiophycean Algae. CYTOLOGIA 2019. [DOI: 10.1508/cytologia.84.323] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Shuhei Ota
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo
- Japan Science and Technology Agency, CREST/START
| | - Kenshiro Oshima
- Laboratory of Metagenomics, Graduate School of Frontier Sciences, The University of Tokyo
- Center for Omics and Bioinformatics, Graduate School of Frontier Sciences, The University of Tokyo
| | - Tomokazu Yamazaki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo
- Japan Science and Technology Agency, CREST/START
| | - Tsuyoshi Takeshita
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo
- Japan Science and Technology Agency, CREST/START
- Future Center Initiative, The University of Tokyo
| | - Kateřina Bišová
- Institute of Microbiology, Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae
| | - Vilém Zachleder
- Institute of Microbiology, Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae
| | - Masahira Hattori
- Center for Omics and Bioinformatics, Graduate School of Frontier Sciences, The University of Tokyo
- Graduate School of Advanced Science and Engineering, Waseda University
| | - Shigeyuki Kawano
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo
- Japan Science and Technology Agency, CREST/START
- Future Center Initiative, The University of Tokyo
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43
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Maciver SK, Koutsogiannis Z, de Obeso Fernández Del Valle A. 'Meiotic genes' are constitutively expressed in an asexual amoeba and are not necessarily involved in sexual reproduction. Biol Lett 2019; 15:20180871. [PMID: 30836881 DOI: 10.1098/rsbl.2018.0871] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The amoebae (and many other protists) have traditionally been considered as asexual organisms, but suspicion has been growing that these organisms are cryptically sexual or are at least related to sexual lineages. This contention is mainly based on genome studies in which the presence of 'meiotic genes' has been discovered. Using RNA-seq (next-generation shotgun sequencing, identifying and quantifying the RNA species in a sample), we have found that the entire repertoire of meiotic genes is expressed in exponentially growing Acanthamoeba and we argue that these so-called meiotic genes are involved in the related process of homologous recombination in this amoeba. We contend that they are only involved in meiosis in other organisms that indulge in sexual reproduction and that homologous recombination is important in asexual protists as a guard against the accumulation of mutations. We also suggest that asexual reproduction is the ancestral state.
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Affiliation(s)
- Sutherland K Maciver
- Centre for Discovery Brain Sciences, Edinburgh Medical School, Biomedical Sciences, University of Edinburgh , Hugh Robson Building, George Square, Edinburgh EH8 9XD , UK
| | - Zisis Koutsogiannis
- Centre for Discovery Brain Sciences, Edinburgh Medical School, Biomedical Sciences, University of Edinburgh , Hugh Robson Building, George Square, Edinburgh EH8 9XD , UK
| | - Alvaro de Obeso Fernández Del Valle
- Centre for Discovery Brain Sciences, Edinburgh Medical School, Biomedical Sciences, University of Edinburgh , Hugh Robson Building, George Square, Edinburgh EH8 9XD , UK
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44
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Maciver SK. Ancestral Eukaryotes Reproduced Asexually, Facilitated by Polyploidy: A Hypothesis. Bioessays 2019; 41:e1900152. [DOI: 10.1002/bies.201900152] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/10/2019] [Indexed: 12/29/2022]
Affiliation(s)
- Sutherland K. Maciver
- Centre for Discovery Brain Sciences, Edinburgh Medical SchoolBiomedical SciencesUniversity of Edinburgh Hugh Robson Building, George Square Edinburgh EH8 9XD Scotland UK
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45
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A 'parameiosis' drives depolyploidization and homologous recombination in Candida albicans. Nat Commun 2019; 10:4388. [PMID: 31558727 PMCID: PMC6763455 DOI: 10.1038/s41467-019-12376-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 08/28/2019] [Indexed: 12/14/2022] Open
Abstract
Meiosis is a conserved tenet of sexual reproduction in eukaryotes, yet this program is seemingly absent from many extant species. In the human fungal pathogen Candida albicans, mating of diploid cells generates tetraploid products that return to the diploid state via a non-meiotic process of depolyploidization known as concerted chromosome loss (CCL). Here, we report that recombination rates are more than three orders of magnitude higher during CCL than during normal mitotic growth. Furthermore, two conserved ‘meiosis-specific’ factors play central roles in CCL as SPO11 mediates DNA double-strand break formation while both SPO11 and REC8 regulate chromosome stability and promote inter-homolog recombination. Unexpectedly, SPO11 also promotes DNA repair and recombination during normal mitotic divisions. These results indicate that C. albicans CCL represents a ‘parameiosis’ that blurs the conventional boundaries between mitosis and meiosis. They also reveal parallels with depolyploidization in mammalian cells and provide potential insights into the evolution of meiosis. Mating of Candida albicans produces tetraploid products that return to the diploid state via a non-meiotic process known as concerted chromosome loss (CCL). Here, Anderson et al. show high recombination rates during CCL and identify factors that are essential for chromosome stability and recombination during CCL.
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Genetic and genomic evolution of sexual reproduction: echoes from LECA to the fungal kingdom. Curr Opin Genet Dev 2019; 58-59:70-75. [PMID: 31473482 DOI: 10.1016/j.gde.2019.07.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/28/2019] [Accepted: 07/16/2019] [Indexed: 12/30/2022]
Abstract
Sexual reproduction is vastly diverse and yet highly conserved across the eukaryotic domain. This ubiquity suggests that the last eukaryotic common ancestor (LECA) was sexual. It is hypothesized that several critical processes in sexual reproduction, including cell fusion and meiosis, were acquired during the evolution from the first eukaryotic common ancestor (FECA) to the sexual LECA. However, it is challenging to delineate the exact origin and evolution of sexual reproduction given that both FECA and LECA are extinct. Studies of diverse eukaryotes have helped to shed light on this sexual evolutionary trajectory, revealing that a primordial sexual ploidy cycle likely involved endoreplication followed by concerted chromosome loss and that cell-cell fusion, meiosis, and sex determination later arose to shape modern sexual reproduction. Despite the general conservation of sexual reproduction processes throughout eukaryotes, modern sexual cycles are immensely diverse and complex. This diversity and complexity has become readily apparent in the fungal kingdom with the recent rapid expansion of whole-genome sequencing. This abundance of data, the variety of genetic tools available to manipulate and characterize fungi, and the thorough characterization of many fungal sexual cycles make the fungal kingdom an excellent forum, in which to study the conservation and diversification of sexual reproduction.
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47
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Morse D. A Transcriptome-based Perspective of Meiosis in Dinoflagellates. Protist 2019; 170:397-403. [DOI: 10.1016/j.protis.2019.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/19/2019] [Accepted: 06/21/2019] [Indexed: 01/31/2023]
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Armaleo D, Müller O, Lutzoni F, Andrésson ÓS, Blanc G, Bode HB, Collart FR, Dal Grande F, Dietrich F, Grigoriev IV, Joneson S, Kuo A, Larsen PE, Logsdon JM, Lopez D, Martin F, May SP, McDonald TR, Merchant SS, Miao V, Morin E, Oono R, Pellegrini M, Rubinstein N, Sanchez-Puerta MV, Savelkoul E, Schmitt I, Slot JC, Soanes D, Szövényi P, Talbot NJ, Veneault-Fourrey C, Xavier BB. The lichen symbiosis re-viewed through the genomes of Cladonia grayi and its algal partner Asterochloris glomerata. BMC Genomics 2019; 20:605. [PMID: 31337355 PMCID: PMC6652019 DOI: 10.1186/s12864-019-5629-x] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 03/20/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Lichens, encompassing 20,000 known species, are symbioses between specialized fungi (mycobionts), mostly ascomycetes, and unicellular green algae or cyanobacteria (photobionts). Here we describe the first parallel genomic analysis of the mycobiont Cladonia grayi and of its green algal photobiont Asterochloris glomerata. We focus on genes/predicted proteins of potential symbiotic significance, sought by surveying proteins differentially activated during early stages of mycobiont and photobiont interaction in coculture, expanded or contracted protein families, and proteins with differential rates of evolution. RESULTS A) In coculture, the fungus upregulated small secreted proteins, membrane transport proteins, signal transduction components, extracellular hydrolases and, notably, a ribitol transporter and an ammonium transporter, and the alga activated DNA metabolism, signal transduction, and expression of flagellar components. B) Expanded fungal protein families include heterokaryon incompatibility proteins, polyketide synthases, and a unique set of G-protein α subunit paralogs. Expanded algal protein families include carbohydrate active enzymes and a specific subclass of cytoplasmic carbonic anhydrases. The alga also appears to have acquired by horizontal gene transfer from prokaryotes novel archaeal ATPases and Desiccation-Related Proteins. Expanded in both symbionts are signal transduction components, ankyrin domain proteins and transcription factors involved in chromatin remodeling and stress responses. The fungal transportome is contracted, as are algal nitrate assimilation genes. C) In the mycobiont, slow-evolving proteins were enriched for components involved in protein translation, translocation and sorting. CONCLUSIONS The surveyed genes affect stress resistance, signaling, genome reprogramming, nutritional and structural interactions. The alga carries many genes likely transferred horizontally through viruses, yet we found no evidence of inter-symbiont gene transfer. The presence in the photobiont of meiosis-specific genes supports the notion that sexual reproduction occurs in Asterochloris while they are free-living, a phenomenon with implications for the adaptability of lichens and the persistent autonomy of the symbionts. The diversity of the genes affecting the symbiosis suggests that lichens evolved by accretion of many scattered regulatory and structural changes rather than through introduction of a few key innovations. This predicts that paths to lichenization were variable in different phyla, which is consistent with the emerging consensus that ascolichens could have had a few independent origins.
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Affiliation(s)
| | - Olaf Müller
- Department of Biology, Duke University, Durham, USA
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, USA
| | | | - Ólafur S. Andrésson
- Faculty of Life and Environmental Sciences, University of Iceland, Reykjavík, Iceland
| | - Guillaume Blanc
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France
| | - Helge B. Bode
- Molekulare Biotechnologie, Fachbereich Biowissenschaften & Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Frank R. Collart
- Argonne National Laboratory, Biosciences Division, Argonne, & Department of Bioengineering, University of Illinois at Chicago, Chicago, USA
| | - Francesco Dal Grande
- Senckenberg Biodiversity and Climate Research Center (SBiK-F), Frankfurt am Main, Germany
| | - Fred Dietrich
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, USA
| | - Igor V. Grigoriev
- US Department of Energy Joint Genome Institute, Walnut Creek, USA
- Department of Plant and Microbial Biology, University of California – Berkeley, Berkeley, USA
| | - Suzanne Joneson
- Department of Biology, Duke University, Durham, USA
- College of General Studies, University of Wisconsin - Milwaukee at Waukesha, Waukesha, USA
| | - Alan Kuo
- US Department of Energy Joint Genome Institute, Walnut Creek, USA
| | - Peter E. Larsen
- Argonne National Laboratory, Biosciences Division, Argonne, & Department of Bioengineering, University of Illinois at Chicago, Chicago, USA
| | | | | | - Francis Martin
- INRA, Université de Lorraine, Interactions Arbres-Microorganismes, INRA-Nancy, Champenoux, France
| | - Susan P. May
- Department of Biology, Duke University, Durham, USA
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, USA
| | - Tami R. McDonald
- Department of Biology, Duke University, Durham, USA
- Department of Biology, St. Catherine University, St. Paul, USA
| | - Sabeeha S. Merchant
- Department of Plant and Microbial Biology, University of California – Berkeley, Berkeley, USA
- Department of Molecular and Cell Biology, University of California – Berkeley, Berkeley, USA
| | - Vivian Miao
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Emmanuelle Morin
- INRA, Université de Lorraine, Interactions Arbres-Microorganismes, INRA-Nancy, Champenoux, France
| | - Ryoko Oono
- Department of Ecology, Evolution, and Marine Biology, University of California - Santa Barbara, Santa Barbara, USA
| | - Matteo Pellegrini
- Department of Molecular, Cell, and Developmental Biology, and DOE Institute for Genomics and Proteomics, University of California, Los Angeles, USA
| | - Nimrod Rubinstein
- National Evolutionary Synthesis Center, Durham, USA
- Calico Life Sciences LLC, South San Francisco, USA
| | | | | | - Imke Schmitt
- Senckenberg Biodiversity and Climate Research Center (SBiK-F), Frankfurt am Main, Germany
- Institute of Ecology, Evolution and Diversity, Fachbereich Biowissenschaften, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jason C. Slot
- College of Food, Agricultural, and Environmental Sciences, Department of Plant Pathology, The Ohio State University, Columbus, USA
| | - Darren Soanes
- College of Life & Environmental Sciences, University of Exeter, Exeter, UK
| | - Péter Szövényi
- Department of Systematic and Evolutionary Botany, University of Zurich, Zurich, Switzerland
| | | | - Claire Veneault-Fourrey
- INRA, Université de Lorraine, Interactions Arbres-Microorganismes, INRA-Nancy, Champenoux, France
- Université de Lorraine, INRA, Interactions Arbres-Microorganismes, Faculté des Sciences et Technologies, Vandoeuvre les Nancy Cedex, France
| | - Basil B. Xavier
- Faculty of Life and Environmental Sciences, University of Iceland, Reykjavík, Iceland
- Laboratory of Medical Microbiology, Vaccine & Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
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49
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Guo L, Liang S, Zhang Z, Liu H, Wang S, Pan K, Xu J, Ren X, Pei S, Yang G. Genome assembly of Nannochloropsis oceanica provides evidence of host nucleus overthrow by the symbiont nucleus during speciation. Commun Biol 2019; 2:249. [PMID: 31286066 PMCID: PMC6610115 DOI: 10.1038/s42003-019-0500-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 05/29/2019] [Indexed: 11/08/2022] Open
Abstract
The species of the genus Nannochloropsis are unique in their maintenance of a nucleus-plastid continuum throughout their cell cycle, non-motility and asexual reproduction. These characteristics should have been endorsed in their gene assemblages (genomes). Here we show that N. oceanica has a genome of 29.3 Mb consisting of 32 pseudochromosomes and containing 7,330 protein-coding genes; and the host nucleus may have been overthrown by an ancient red alga symbiont nucleus during speciation through secondary endosymbiosis. In addition, N. oceanica has lost its flagella and abilities to undergo meiosis and sexual reproduction, and adopted a genome reduction strategy during speciation. We propose that N. oceanica emerged through the active fusion of a host protist and a photosynthesizing ancient red alga and the symbiont nucleus became dominant over the host nucleus while the chloroplast was wrapped by two layers of endoplasmic reticulum. Our findings evidenced an alternative speciation pathway of eukaryotes.
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Affiliation(s)
- Li Guo
- College of Marine Life Sciences, Ocean University of China (OUC), Qingdao, 266003 P. R. China
| | - Sijie Liang
- College of Marine Life Sciences, Ocean University of China (OUC), Qingdao, 266003 P. R. China
| | - Zhongyi Zhang
- College of Marine Life Sciences, Ocean University of China (OUC), Qingdao, 266003 P. R. China
| | - Hang Liu
- College of Marine Life Sciences, Ocean University of China (OUC), Qingdao, 266003 P. R. China
| | - Songwen Wang
- College of Agriculture and Resources and Environment, Tianjin Agricultural University, Tianjin, 300384 P. R. China
| | - Kehou Pan
- Laboratory of Applied Microalgae, College of Fisheries, OUC, Qingdao, 266003 P. R. China
| | - Jian Xu
- Functional Genomics Group, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 P. R. China
| | - Xue Ren
- Annoroad Gene Technology (Beijing) Co., Ltd, Beijing, 100176 P. R. China
| | - Surui Pei
- Annoroad Gene Technology (Beijing) Co., Ltd, Beijing, 100176 P. R. China
| | - Guanpin Yang
- College of Marine Life Sciences, Ocean University of China (OUC), Qingdao, 266003 P. R. China
- Institutes of Evolution and Marine Biodiversity, OUC, Qingdao, 266003 P. R. China
- Key Laboratory of Marine Genetics and Breeding of Ministry of Education, OUC, Qingdao, 266003 P. R. China
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50
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Exploring Molecular Signs of Sex in the Marine Diatom Skeletonema marinoi. Genes (Basel) 2019; 10:genes10070494. [PMID: 31261777 PMCID: PMC6678668 DOI: 10.3390/genes10070494] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 06/14/2019] [Accepted: 06/24/2019] [Indexed: 11/17/2022] Open
Abstract
Sexual reproduction plays a fundamental role in diatom life cycles. It contributes to increasing genetic diversity through meiotic recombination and also represents the phase where large-sized cells are produced to counteract the cell size reduction process that characterizes these microalgae. With the aim to identify genes linked to the sexual phase of the centric planktonic diatom Skeletonema marinoi, we carried out an RNA-seq experiment comparing the expression level of transcripts in sexualized cells with that of large cells not competent for sex. A set of genes involved in meiosis were found upregulated. Despite the fact that flagellate gametes were observed in the sample, we did not detect the expression of genes involved in the synthesis of flagella that were upregulated during sexual reproduction in another centric diatom. A comparison with the set of genes changing during the first phases of sexual reproduction of the pennate diatom Pseudo-nitzschia multistriata revealed the existence of commonalities, including the strong upregulation of genes with an unknown function that we named Sex Induced Genes (SIG). Our results further broadened the panel of genes that can be used as a marker for sexual reproduction of diatoms, crucial for the interpretation of metatranscriptomic datasets.
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