1
|
Weiner AKM, Sehein T, Cote-L’Heureux A, Sleith RS, Greco M, Malekshahi C, Ryan-Embry C, Ostriker N, Katz LA. Single-cell transcriptomics supports presence of cryptic species and reveals low levels of population genetic diversity in two testate amoebae morphospecies with large population sizes. Evolution 2023; 77:2472-2483. [PMID: 37672006 PMCID: PMC10629589 DOI: 10.1093/evolut/qpad158] [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: 08/03/2022] [Revised: 08/13/2023] [Accepted: 09/05/2023] [Indexed: 09/07/2023]
Abstract
The enormous population sizes and wide biogeographical distribution of many microbial eukaryotes set the expectation of high levels of intraspecific genetic variation. However, studies investigating protist populations remain scarce, mostly due to limited 'omics data. Instead, most genetics studies of microeukaryotes have thus far relied on single loci, which can be misleading and do not easily allow for detection of recombination, a hallmark of sexual reproduction. Here, we analyze >40 genes from 72 single-cell transcriptomes from two morphospecies-Hyalosphenia papilio and Hyalosphenia elegans-of testate amoebae (Arcellinida, Amoebozoa) to assess genetic diversity in samples collected over four years from New England bogs. We confirm the existence of cryptic species based on our multilocus dataset, which provides evidence of recombination within and high levels of divergence between the cryptic species. At the same time, total levels of genetic diversity within cryptic species are low, suggesting that these abundant organisms have small effective population sizes, perhaps due to extinction and repopulation events coupled with efficient modes of dispersal. This study is one of the first to investigate population genetics in uncultivable heterotrophic protists using transcriptomics data and contributes towards understanding cryptic species of nonmodel microeukaryotes.
Collapse
Affiliation(s)
- Agnes K M Weiner
- Department of Biological Sciences, Smith College, Northampton, MA, United States
- NORCE Climate and Environment, NORCE Norwegian Research Centre AS, Bergen, Norway
| | - Taylor Sehein
- Department of Biological Sciences, Smith College, Northampton, MA, United States
| | - Auden Cote-L’Heureux
- Department of Biological Sciences, Smith College, Northampton, MA, United States
| | - Robin S Sleith
- Department of Biological Sciences, Smith College, Northampton, MA, United States
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States
| | - Mattia Greco
- Department of Biological Sciences, Smith College, Northampton, MA, United States
| | - Clara Malekshahi
- Department of Biological Sciences, Smith College, Northampton, MA, United States
| | - Chase Ryan-Embry
- Department of Biological Sciences, Smith College, Northampton, MA, United States
| | - Naomi Ostriker
- Department of Biological Sciences, Smith College, Northampton, MA, United States
| | - Laura A Katz
- Department of Biological Sciences, Smith College, Northampton, MA, United States
- University of Massachusetts Amherst, Program in Organismic and Evolutionary Biology, Amherst, MA, United States
| |
Collapse
|
2
|
Hazra S, Kalyan Dinda S, Kumar Mondal N, Hossain SR, Datta P, Yasmin Mondal A, Malakar P, Manna D. Giant cells: multiple cells unite to survive. Front Cell Infect Microbiol 2023; 13:1220589. [PMID: 37790914 PMCID: PMC10543420 DOI: 10.3389/fcimb.2023.1220589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 07/26/2023] [Indexed: 10/05/2023] Open
Abstract
Multinucleated Giant Cells (MGCs) are specialized cells that develop from the fusion of multiple cells, and their presence is commonly observed in human cells during various infections. However, MGC formation is not restricted to infections alone but can also occur through different mechanisms, such as endoreplication and abortive cell cycle. These processes lead to the formation of polyploid cells, eventually resulting in the formation of MGCs. In Entamoeba, a protozoan parasite that causes amoebic dysentery and liver abscesses in humans, the formation of MGCs is a unique phenomenon and not been reported in any other protozoa. This organism is exposed to various hostile environmental conditions, including changes in temperature, pH, and nutrient availability, which can lead to stress and damage to its cells. The formation of MGCs in Entamoeba is thought to be a survival strategy to cope with these adverse conditions. This organism forms MGCs through cell aggregation and fusion in response to osmotic and heat stress. The MGCs in Entamoeba are thought to have increased resistance to various stresses and can survive longer than normal cells under adverse conditions. This increased survival could be due to the presence of multiple nuclei, which could provide redundancy in case of DNA damage or mutations. Additionally, MGCs may play a role in the virulence of Entamoeba as they are found in the inflammatory foci of amoebic liver abscesses and other infections caused by Entamoeba. The presence of MGCs in these infections suggests that they may contribute to the pathogenesis of the disease. Overall, this article offers valuable insights into the intriguing phenomenon of MGC formation in Entamoeba. By unraveling the mechanisms behind this process and examining its implications, researchers can gain a deeper understanding of the complex biology of Entamoeba and potentially identify new targets for therapeutic interventions. The study of MGCs in Entamoeba serves as a gateway to exploring the broader field of cell fusion in various organisms, providing a foundation for future investigations into related cellular processes and their significance in health and disease.
Collapse
Affiliation(s)
- Shreyasee Hazra
- Department of Biomedical Science and Technology, School of Biological Sciences, Ramakrishna Mission Vivekananda Educational and Research Institute (RKMVERI), Kolkata, India
| | - Suman Kalyan Dinda
- Department of Biomedical Science and Technology, School of Biological Sciences, Ramakrishna Mission Vivekananda Educational and Research Institute (RKMVERI), Kolkata, India
| | - Naba Kumar Mondal
- Department of Biomedical Science and Technology, School of Biological Sciences, Ramakrishna Mission Vivekananda Educational and Research Institute (RKMVERI), Kolkata, India
| | - Sk Rajjack Hossain
- Department of Biomedical Science and Technology, School of Biological Sciences, Ramakrishna Mission Vivekananda Educational and Research Institute (RKMVERI), Kolkata, India
| | - Pratyay Datta
- Department of Biomedical Science and Technology, School of Biological Sciences, Ramakrishna Mission Vivekananda Educational and Research Institute (RKMVERI), Kolkata, India
| | - Afsana Yasmin Mondal
- Institute of Health Sciences, Presidency University, Kolkata, West Bengal, India
| | - Pushkar Malakar
- Department of Biomedical Science and Technology, School of Biological Sciences, Ramakrishna Mission Vivekananda Educational and Research Institute (RKMVERI), Kolkata, India
| | - Dipak Manna
- Department of Biomedical Science and Technology, School of Biological Sciences, Ramakrishna Mission Vivekananda Educational and Research Institute (RKMVERI), Kolkata, India
| |
Collapse
|
3
|
Zurita-Artaloitia JM, Rivera J, Vinuesa P. Extensive Cryptic Diversity and Ecological Associations Uncovered among Mexican and Global Collections of Naegleria and Vermamoeba Species by 18S Ribosomal DNA, Internal Transcribed Spacer, and Cytochrome Oxidase Subunit I Sequence Analysis. Microbiol Spectr 2023; 11:e0379522. [PMID: 36943092 PMCID: PMC10100766 DOI: 10.1128/spectrum.03795-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 02/26/2023] [Indexed: 03/23/2023] Open
Abstract
Free-living amoebae (FLA) are phagocytic protists that play crucial roles in microbial communities as significant microbial grazers. However, our current knowledge of their diversity, ecology, and population genetic structures is marginal due to the shallow and biased sampling of ecosystems and the use of few, poorly resolving molecular markers. Thirty-two FLA were isolated from soil and water samples collected across representative ecosystems of the State of Morelos in Central Mexico, including the drinking water distribution system (DWDS) from the state capital. We classified our isolates as members of Acanthamoeba, Vermamoeba, Naegleria, and Tetramitus by 18S ribosomal DNA (rDNA) sequencing. Vermamoeba isolates were recovered exclusively from the DWDS samples. In contrast, Naegleria strains displayed a broad distribution in soil and water samples across the natural ecosystems. We used a combination of phylogenetic and population genetic analyses of internal transcribed spacer (ITS) and cytochrome oxidase subunit I (COI) sequences from our isolates and a comprehensive set of reference sequences to analyze the currently known diversity of Naegleria spp. Significant associations were uncovered between the most prevalent lineages of Naegleria and Vermamoeba and broad ecological and geographical variables at regional and global levels. The population structure and cryptic diversity within the Naegleria galeacystis-Naegleria americana and Vermamoeba vermiformis species complexes were thoroughly analyzed. Our results prove that the genus Vermamoeba, which was previously thought to consist of only one species, actually encompasses at least seven widely distributed species, as indicated by consistent evidence from Bayesian phylogenetics, two species-delimitation programs, and population genetics analyses. IMPORTANCE Our study sheds new light on the population genetic structure of V. vermiformis and diverse Naegleria species. Using improved molecular markers and advanced analytical approaches, we discovered that N. americana, previously considered a single species, actually contains multiple distinct lineages, as revealed by COI sequencing. These lineages are highly differentiated, with little gene flow between them. Our findings demonstrate that the genus Vermamoeba holds multiple cryptic species, requiring a significant taxonomic revision in light of multilocus sequence analyses. These results advance our understanding of the ecology, molecular systematics, and biogeography of these genera and species complexes at both regional and global scales. This study has significant implications for diagnosing amoebal infections and evaluating health risks associated with FLA in domestic and recreational waters.
Collapse
Affiliation(s)
| | - Javier Rivera
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Pablo Vinuesa
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| |
Collapse
|
4
|
Dereeper A, Allouch N, Guerlais V, Garnier M, Ma L, De Jonckheere JF, Joseph SJ, Ali IKM, Talarmin A, Marcelino I. Naegleria genus pangenome reveals new structural and functional insights into the versatility of these free-living amoebae. Front Microbiol 2023; 13:1056418. [PMID: 36817109 PMCID: PMC9928731 DOI: 10.3389/fmicb.2022.1056418] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/21/2022] [Indexed: 02/04/2023] Open
Abstract
Introduction Free-living amoebae of the Naegleria genus belong to the major protist clade Heterolobosea and are ubiquitously distributed in soil and freshwater habitats. Of the 47 Naegleria species described, N. fowleri is the only one being pathogenic to humans, causing a rare but fulminant primary amoebic meningoencephalitis. Some Naegleria genome sequences are publicly available, but the genetic basis for Naegleria diversity and ability to thrive in diverse environments (including human brain) remains unclear. Methods Herein, we constructed a high-quality Naegleria genus pangenome to obtain a comprehensive catalog of genes encoded by these amoebae. For this, we first sequenced, assembled, and annotated six new Naegleria genomes. Results and Discussion Genome architecture analyses revealed that Naegleria may use genome plasticity features such as ploidy/aneuploidy to modulate their behavior in different environments. When comparing 14 near-to-complete genome sequences, our results estimated the theoretical Naegleria pangenome as a closed genome, with 13,943 genes, including 3,563 core and 10,380 accessory genes. The functional annotations revealed that a large fraction of Naegleria genes show significant sequence similarity with those already described in other kingdoms, namely Animalia and Plantae. Comparative analyses highlighted a remarkable genomic heterogeneity, even for closely related strains and demonstrate that Naegleria harbors extensive genome variability, reflected in different metabolic repertoires. If Naegleria core genome was enriched in conserved genes essential for metabolic, regulatory and survival processes, the accessory genome revealed the presence of genes involved in stress response, macromolecule modifications, cell signaling and immune response. Commonly reported N. fowleri virulence-associated genes were present in both core and accessory genomes, suggesting that N. fowleri's ability to infect human brain could be related to its unique species-specific genes (mostly of unknown function) and/or to differential gene expression. The construction of Naegleria first pangenome allowed us to move away from a single reference genome (that does not necessarily represent each species as a whole) and to identify essential and dispensable genes in Naegleria evolution, diversity and biology, paving the way for further genomic and post-genomic studies.
Collapse
Affiliation(s)
- Alexis Dereeper
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Nina Allouch
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Vincent Guerlais
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Maëlle Garnier
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Laurence Ma
- Institut Pasteur de Paris, Biomics, Paris, France
| | | | - Sandeep J. Joseph
- Centers for Disease Control and Prevention (CDC), Atlanta, GA, United States
| | - Ibne Karim M. Ali
- Centers for Disease Control and Prevention (CDC), Atlanta, GA, United States
| | - Antoine Talarmin
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France
| | - Isabel Marcelino
- Institut Pasteur de la Guadeloupe, Unité TReD-Path, Les Abymes, Guadeloupe, France,*Correspondence: Isabel Marcelino,
| |
Collapse
|
5
|
Tekle YI, Wang F, Tran H, Hayes TD, Ryan JF. The draft genome of Cochliopodium minus reveals a complete meiosis toolkit and provides insight into the evolution of sexual mechanisms in Amoebozoa. Sci Rep 2022; 12:9841. [PMID: 35701521 PMCID: PMC9198077 DOI: 10.1038/s41598-022-14131-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 05/06/2022] [Indexed: 11/23/2022] Open
Abstract
To date, genomic analyses in amoebozoans have been mostly limited to model organisms or medically important lineages. Consequently, the vast diversity of Amoebozoa genomes remain unexplored. A draft genome of Cochliopodium minus, an amoeba characterized by extensive cellular and nuclear fusions, is presented. C. minus has been a subject of recent investigation for its unusual sexual behavior. Cochliopodium's sexual activity occurs during vegetative stage making it an ideal model for studying sexual development, which is sorely lacking in the group. Here we generate a C. minus draft genome assembly. From this genome, we detect a substantial number of lateral gene transfer (LGT) instances from bacteria (15%), archaea (0.9%) and viruses (0.7%) the majority of which are detected in our transcriptome data. We identify the complete meiosis toolkit genes in the C. minus genome, as well as the absence of several key genes involved in plasmogamy and karyogamy. Comparative genomics of amoebozoans reveals variation in sexual mechanism exist in the group. Similar to complex eukaryotes, C. minus (some amoebae) possesses Tyrosine kinases and duplicate copies of SPO11. We report a first example of alternative splicing in a key meiosis gene and draw important insights on molecular mechanism of sex in C. minus using genomic and transcriptomic data.
Collapse
Affiliation(s)
- Yonas I Tekle
- Department of Biology, Spelman College, 350 Spelman Lane Southwest, Atlanta, GA, 30314, USA.
| | - Fang Wang
- Department of Biology, Spelman College, 350 Spelman Lane Southwest, Atlanta, GA, 30314, USA
| | - Hanh Tran
- Department of Biology, Spelman College, 350 Spelman Lane Southwest, Atlanta, GA, 30314, USA
| | - T Danielle Hayes
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL, USA
- Iowa State University, Ames, IA, USA
| | - Joseph F Ryan
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL, USA
- Department of Biology, University of Florida, Gainesville, FL, USA
| |
Collapse
|
6
|
Wang F, Tekle YI. Variation of natural selection in the Amoebozoa reveals heterogeneity across the phylogeny and adaptive evolution in diverse lineages. Front Ecol Evol 2022; 10:851816. [PMID: 36874909 PMCID: PMC9980437 DOI: 10.3389/fevo.2022.851816] [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] [Indexed: 11/13/2022] Open
Abstract
The evolution and diversity of the supergroup Amoebozoa is complex and poorly understood. The supergroup encompasses predominantly amoeboid lineages characterized by extreme diversity in phenotype, behavior and genetics. The study of natural selection, a driving force of diversification, within and among species of Amoebozoa will play a crucial role in understanding the evolution of the supergroup. In this study, we searched for traces of natural selection based on a set of highly conserved protein-coding genes in a phylogenetic framework from a broad sampling of amoebozoans. Using these genes, we estimated substitution rates and inferred patterns of selective pressure in lineages and sites with various models. We also examined the effect of selective pressure on codon usage bias and potential correlations with observed biological traits and habitat. Results showed large heterogeneity of selection across lineages of Amoebozoa, indicating potential species-specific optimization of adaptation to their diverse ecological environment. Overall, lineages in Tubulinea had undergone stronger purifying selection with higher average substitution rates compared to Discosea and Evosea. Evidence of adaptive evolution was observed in some representative lineages and in a gene (Rpl7a) within Evosea, suggesting potential innovation and beneficial mutations in these lineages. Our results revealed that members of the fast-evolving lineages, Entamoeba and Cutosea, all underwent strong purifying selection but had distinct patterns of codon usage bias. For the first time, this study revealed an overall pattern of natural selection across the phylogeny of Amoebozoa and provided significant implications on their distinctive evolutionary processes.
Collapse
Affiliation(s)
- Fang Wang
- Department of Biology, Spelman College, Atlanta, GA, United States
| | - Yonas I Tekle
- Department of Biology, Spelman College, Atlanta, GA, United States
| |
Collapse
|
7
|
Tromer EC, Wemyss TA, Ludzia P, Waller RF, Akiyoshi B. Repurposing of synaptonemal complex proteins for kinetochores in Kinetoplastida. Open Biol 2021; 11:210049. [PMID: 34006126 PMCID: PMC8131943 DOI: 10.1098/rsob.210049] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 04/16/2021] [Indexed: 12/25/2022] Open
Abstract
Chromosome segregation in eukaryotes is driven by the kinetochore, a macromolecular complex that connects centromeric DNA to microtubules of the spindle apparatus. Kinetochores in well-studied model eukaryotes consist of a core set of proteins that are broadly conserved among distant eukaryotic phyla. By contrast, unicellular flagellates of the class Kinetoplastida have a unique set of 36 kinetochore components. The evolutionary origin and history of these kinetochores remain unknown. Here, we report evidence of homology between axial element components of the synaptonemal complex and three kinetoplastid kinetochore proteins KKT16-18. The synaptonemal complex is a zipper-like structure that assembles between homologous chromosomes during meiosis to promote recombination. By using sensitive homology detection protocols, we identify divergent orthologues of KKT16-18 in most eukaryotic supergroups, including experimentally established chromosomal axis components, such as Red1 and Rec10 in budding and fission yeast, ASY3-4 in plants and SYCP2-3 in vertebrates. Furthermore, we found 12 recurrent duplications within this ancient eukaryotic SYCP2-3 gene family, providing opportunities for new functional complexes to arise, including KKT16-18 in the kinetoplastid parasite Trypanosoma brucei. We propose the kinetoplastid kinetochore system evolved by repurposing meiotic components of the chromosome synapsis and homologous recombination machinery that were already present in early eukaryotes.
Collapse
Affiliation(s)
- Eelco C. Tromer
- Department of Biochemistry, University of Cambridge, Cambridge, UK
- Cell Biochemistry, Groningen Institute of Biomolecular Sciences & Biotechnology, University of Groningen, Groningen, The Netherlands
| | - Thomas A. Wemyss
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Patryk Ludzia
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Ross F. Waller
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Bungo Akiyoshi
- Department of Biochemistry, University of Oxford, Oxford, UK
| |
Collapse
|
8
|
Kin K, Schaap P. Evolution of Multicellular Complexity in The Dictyostelid Social Amoebas. Genes (Basel) 2021; 12:487. [PMID: 33801615 PMCID: PMC8067170 DOI: 10.3390/genes12040487] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/17/2021] [Accepted: 03/20/2021] [Indexed: 12/14/2022] Open
Abstract
Multicellularity evolved repeatedly in the history of life, but how it unfolded varies greatly between different lineages. Dictyostelid social amoebas offer a good system to study the evolution of multicellular complexity, with a well-resolved phylogeny and molecular genetic tools being available. We compare the life cycles of the Dictyostelids with closely related amoebozoans to show that complex life cycles were already present in the unicellular common ancestor of Dictyostelids. We propose frost resistance as an early driver of multicellular evolution in Dictyostelids and show that the cell signalling pathways for differentiating spore and stalk cells evolved from that for encystation. The stalk cell differentiation program was further modified, possibly through gene duplication, to evolve a new cell type, cup cells, in Group 4 Dictyostelids. Studies in various multicellular organisms, including Dictyostelids, volvocine algae, and metazoans, suggest as a common principle in the evolution of multicellular complexity that unicellular regulatory programs for adapting to environmental change serve as "proto-cell types" for subsequent evolution of multicellular organisms. Later, new cell types could further evolve by duplicating and diversifying the "proto-cell type" gene regulatory networks.
Collapse
Affiliation(s)
- Koryu Kin
- School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK;
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37–49, 08003 Barcelona, Spain
| | - Pauline Schaap
- School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK;
| |
Collapse
|
9
|
Collens AB, Katz LA. Opinion: Genetic Conflict With Mobile Elements Drives Eukaryotic Genome Evolution, and Perhaps Also Eukaryogenesis. J Hered 2021; 112:140-144. [PMID: 33538295 PMCID: PMC7953837 DOI: 10.1093/jhered/esaa060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 12/17/2020] [Indexed: 12/13/2022] Open
Abstract
Through analyses of diverse microeukaryotes, we have previously argued that eukaryotic genomes are dynamic systems that rely on epigenetic mechanisms to distinguish germline (i.e., DNA to be inherited) from soma (i.e., DNA that undergoes polyploidization, genome rearrangement, etc.), even in the context of a single nucleus. Here, we extend these arguments by including two well-documented observations: (1) eukaryotic genomes interact frequently with mobile genetic elements (MGEs) like viruses and transposable elements (TEs), creating genetic conflict, and (2) epigenetic mechanisms regulate MGEs. Synthesis of these ideas leads to the hypothesis that genetic conflict with MGEs contributed to the evolution of a dynamic eukaryotic genome in the last eukaryotic common ancestor (LECA), and may have contributed to eukaryogenesis (i.e., may have been a driver in the evolution of FECA, the first eukaryotic common ancestor). Sex (i.e., meiosis) may have evolved within the context of the development of germline-soma distinctions in LECA, as this process resets the germline genome by regulating/eliminating somatic (i.e., polyploid, rearranged) genetic material. Our synthesis of these ideas expands on hypotheses of the origin of eukaryotes by integrating the roles of MGEs and epigenetics.
Collapse
Affiliation(s)
- Adena B Collens
- Department of Biological Sciences, Smith College, Northampton, MA
| | - Laura A Katz
- Department of Biological Sciences, Smith College, Northampton, MA
- Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA
| |
Collapse
|
10
|
Tekle YI, Wang F, Heidari A, Stewart AJ. Differential gene expression analysis and cytological evidence reveal a sexual stage of an amoeba with multiparental cellular and nuclear fusion. PLoS One 2020; 15:e0235725. [PMID: 33147262 PMCID: PMC7641356 DOI: 10.1371/journal.pone.0235725] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 10/06/2020] [Indexed: 12/20/2022] Open
Abstract
Sex is a hallmark of eukaryotes but its evolution in microbial eukaryotes is poorly elucidated. Recent genomic studies revealed microbial eukaryotes possess a genetic toolkit necessary for sexual reproduction. However, the mechanism of sexual development in a majority of microbial eukaryotes including amoebozoans is poorly characterized. The major hurdle in studying sex in microbial eukaryotes is a lack of observational evidence, primarily due to its cryptic nature. In this study, we used a tractable fusing amoeba, Cochliopodium, to investigate sexual development using stage-specific Differential Gene Expression (DGE) and cytological analyses. Both DGE and cytological results showed that most of the meiosis and sex-related genes are upregulated in Cochliopodium undergoing fusion in laboratory culture. Relative gene ontology (GO) category representations in unfused and fused cells revealed a functional skew of the fused transcriptome toward DNA metabolism, nucleus and ligases that are suggestive of a commitment to sexual development. However, the GO categories of unfused cells were dominated by metabolic pathways and other processes indicative of a vegetative phase. Our study provides strong evidence that the fused cells represent a sexual stage in Cochliopodium. Our findings have further implications in understanding the evolution and mechanism of inheritance involving multiparents in other eukaryotes with a similar reproductive strategy.
Collapse
Affiliation(s)
- Yonas I. Tekle
- Department of Biology, Spelman College, Atlanta, Georgia, United States of America
- * E-mail:
| | - Fang Wang
- Department of Biology, Spelman College, Atlanta, Georgia, United States of America
| | - Alireza Heidari
- Department of Biology, Spelman College, Atlanta, Georgia, United States of America
| | | |
Collapse
|
11
|
Wang S, Li L, Li H, Sahu SK, Wang H, Xu Y, Xian W, Song B, Liang H, Cheng S, Chang Y, Song Y, Çebi Z, Wittek S, Reder T, Peterson M, Yang H, Wang J, Melkonian B, Van de Peer Y, Xu X, Wong GKS, Melkonian M, Liu H, Liu X. Genomes of early-diverging streptophyte algae shed light on plant terrestrialization. NATURE PLANTS 2020; 6:95-106. [PMID: 31844283 PMCID: PMC7027972 DOI: 10.1038/s41477-019-0560-3] [Citation(s) in RCA: 124] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 10/28/2019] [Indexed: 05/18/2023]
Abstract
Mounting evidence suggests that terrestrialization of plants started in streptophyte green algae, favoured by their dual existence in freshwater and subaerial/terrestrial environments. Here, we present the genomes of Mesostigma viride and Chlorokybus atmophyticus, two sister taxa in the earliest-diverging clade of streptophyte algae dwelling in freshwater and subaerial/terrestrial environments, respectively. We provide evidence that the common ancestor of M. viride and C. atmophyticus (and thus of streptophytes) had already developed traits associated with a subaerial/terrestrial environment, such as embryophyte-type photorespiration, canonical plant phytochrome, several phytohormones and transcription factors involved in responses to environmental stresses, and evolution of cellulose synthase and cellulose synthase-like genes characteristic of embryophytes. Both genomes differed markedly in genome size and structure, and in gene family composition, revealing their dynamic nature, presumably in response to adaptations to their contrasting environments. The ancestor of M. viride possibly lost several genomic traits associated with a subaerial/terrestrial environment following transition to a freshwater habitat.
Collapse
Affiliation(s)
- Sibo Wang
- BGI-Shenzhen, Shenzhen, China
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Linzhou Li
- BGI-Shenzhen, Shenzhen, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, China
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Haoyuan Li
- BGI-Shenzhen, Shenzhen, China
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Sunil Kumar Sahu
- BGI-Shenzhen, Shenzhen, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, China
| | - Hongli Wang
- BGI-Shenzhen, Shenzhen, China
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Yan Xu
- BGI-Shenzhen, Shenzhen, China
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China
| | - Wenfei Xian
- BGI-Shenzhen, Shenzhen, China
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Bo Song
- BGI-Shenzhen, Shenzhen, China
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Hongping Liang
- BGI-Shenzhen, Shenzhen, China
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China
| | - Shifeng Cheng
- BGI-Shenzhen, Shenzhen, China
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Yue Chang
- BGI-Shenzhen, Shenzhen, China
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Yue Song
- BGI-Shenzhen, Shenzhen, China
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Zehra Çebi
- Botanical Institute, Cologne Biocenter, University of Cologne, Cologne, Germany
| | - Sebastian Wittek
- Botanical Institute, Cologne Biocenter, University of Cologne, Cologne, Germany
| | - Tanja Reder
- Botanical Institute, Cologne Biocenter, University of Cologne, Cologne, Germany
| | - Morten Peterson
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Huanming Yang
- BGI-Shenzhen, Shenzhen, China
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Jian Wang
- BGI-Shenzhen, Shenzhen, China
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Barbara Melkonian
- Botanical Institute, Cologne Biocenter, University of Cologne, Cologne, Germany
- University of Duisburg-Essen, Campus Essen, Faculty of Biology, Essen, Germany
| | - Yves Van de Peer
- Department of Plant Biotechnology and Bioinformatics, Ghent University and VIB/UGent Center for Plant Systems Biology, Ghent, Belgium
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Xun Xu
- BGI-Shenzhen, Shenzhen, China
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Gane Ka-Shu Wong
- BGI-Shenzhen, Shenzhen, China.
- Department of Biological Sciences and Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
| | - Michael Melkonian
- Botanical Institute, Cologne Biocenter, University of Cologne, Cologne, Germany.
- University of Duisburg-Essen, Campus Essen, Faculty of Biology, Essen, Germany.
| | - Huan Liu
- BGI-Shenzhen, Shenzhen, China.
- Department of Biology, University of Copenhagen, Copenhagen, Denmark.
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, China.
| | - Xin Liu
- BGI-Shenzhen, Shenzhen, China.
- China National GeneBank, BGI-Shenzhen, Shenzhen, China.
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, China.
| |
Collapse
|
12
|
Lotonin K, Smirnov A. Stygamoeba cauta n. sp. (Amoebozoa, Discosea) - a new brackish-water species from Nivå Bay (Baltic Sea, The Sound). Eur J Protistol 2019; 72:125660. [PMID: 31835237 DOI: 10.1016/j.ejop.2019.125660] [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: 10/03/2019] [Revised: 11/21/2019] [Accepted: 11/26/2019] [Indexed: 11/18/2022]
Abstract
Several evolutionary lineages of Amoebozoa are characterized by unusual morphological and ultrastructural features that impede resolving of their position in the phylogenetic tree. Among them is the genus Stygamoeba, not yet reliably placed on the phylogenetic tree even by a phylogenomic analysis. Only two species of Stygamoeba are known at present, and molecular data exists on one species only. Here, we present a description of the mesohaline species Stygamoeba cauta n. sp. isolated from the bottom sediments of Nivå Bay (Baltic Sea, The Sound). This stick-like, flattened amoeba morphologically resembles the previously described species Stygamoeba regulataSmirnov, 1996. However, the molecular analysis based on the 18S rRNA gene sequences and differences in cell behavior and pattern of locomotion provide strong support for establishing a new species.
Collapse
Affiliation(s)
- Kirill Lotonin
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, 199034 Universitetskaya nab. 7/9, Saint Petersburg, Russia.
| | - Alexey Smirnov
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, 199034 Universitetskaya nab. 7/9, Saint Petersburg, Russia
| |
Collapse
|
13
|
Hofstatter PG, Brown MW, Lahr DJG. Comparative Genomics Supports Sex and Meiosis in Diverse Amoebozoa. Genome Biol Evol 2018; 10:3118-3128. [PMID: 30380054 PMCID: PMC6263441 DOI: 10.1093/gbe/evy241] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2018] [Indexed: 12/30/2022] Open
Abstract
Sex and reproduction are often treated as a single phenomenon in animals and plants, as in these organisms reproduction implies mixis and meiosis. In contrast, sex and reproduction are independent biological phenomena that may or may not be linked in the majority of other eukaryotes. Current evidence supports a eukaryotic ancestor bearing a mating type system and meiosis, which is a process exclusive to eukaryotes. Even though sex is ancestral, the literature regarding life cycles of amoeboid lineages depicts them as asexual organisms. Why would loss of sex be common in amoebae, if it is rarely lost, if ever, in plants and animals, as well as in fungi? One way to approach the question of meiosis in the "asexuals" is to evaluate the patterns of occurrence of genes for the proteins involved in syngamy and meiosis. We have applied a comparative genomic approach to study the occurrence of the machinery for plasmogamy, karyogamy, and meiosis in Amoebozoa, a major amoeboid supergroup. Our results support a putative occurrence of syngamy and meiotic processes in all major amoebozoan lineages. We conclude that most amoebozoans may perform mixis, recombination, and ploidy reduction through canonical meiotic processes. The present evidence indicates the possibility of sexual cycles in many lineages traditionally held as asexual.
Collapse
Affiliation(s)
- Paulo G Hofstatter
- Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, Brazil
| | - Matthew W Brown
- Department of Biological Sciences, Mississippi State University
| | - Daniel J G Lahr
- Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, Brazil
| |
Collapse
|
14
|
Wood FC, Heidari A, Tekle YI. Genetic Evidence for Sexuality in Cochliopodium (Amoebozoa). J Hered 2018; 108:769-779. [PMID: 29036297 PMCID: PMC5892394 DOI: 10.1093/jhered/esx078] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Accepted: 09/18/2017] [Indexed: 12/18/2022] Open
Abstract
Microbial eukaryotes, including amoeboids, display diverse and complex life cycles that may or may not involve sexual reproduction. A recent comprehensive gene inventory study concluded that the Amoebozoa are ancestrally sexual. However, the detection of sex genes in some lineages known for their potentially sexual life cycle was very low. Particularly, the genus Cochliopodium, known to undergo a process of cell fusion, karyogamy, and subsequent fission previously described as parasexual, had no meiosis genes detected. This is likely due to low data representation, given the extensive nuclear fusion observed in the genus. In this study, we generate large amounts of transcriptome data for 2 species of Cochliopodium, known for their high frequency of cellular and nuclear fusion, in order to study the genetic basis of the complex life cycle observed in the genus. We inventory 60 sex-related genes, including 11 meiosis-specific genes, and 31 genes involved in fusion and karyogamy. We find a much higher detection of sex-related genes, including 5 meiosis-specific genes not previously detected in Cochliopodium, in this large transcriptome data. The expressed genes form a near-complete recombination machinery, indicating that Cochliopodium is an actively recombining sexual lineage. We also find 9 fusion-related genes in Cochliopodium, although no conserved fusion-specific genes were detected in the transcriptomes. Cochliopodium thus likely uses lineage specific genes for the fusion and depolyploidization processes. Our results demonstrate that Cochliopodium possess the genetic toolkit for recombination, while the mechanism involving fusion and genome reduction remains to be elucidated.
Collapse
Affiliation(s)
- Fiona C Wood
- Department of Biology, Spelman College, 350 Spelman Lane Southwest, Atlanta, GA 30314
| | - Alireza Heidari
- Department of Biology, Spelman College, 350 Spelman Lane Southwest, Atlanta, GA 30314
| | - Yonas I Tekle
- Department of Biology, Spelman College, 350 Spelman Lane Southwest, Atlanta, GA 30314
| |
Collapse
|
15
|
Nowell RW, Almeida P, Wilson CG, Smith TP, Fontaneto D, Crisp A, Micklem G, Tunnacliffe A, Boschetti C, Barraclough TG. Comparative genomics of bdelloid rotifers: Insights from desiccating and nondesiccating species. PLoS Biol 2018; 16:e2004830. [PMID: 29689044 PMCID: PMC5916493 DOI: 10.1371/journal.pbio.2004830] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 03/19/2018] [Indexed: 12/22/2022] Open
Abstract
Bdelloid rotifers are a class of microscopic invertebrates that have existed for millions of years apparently without sex or meiosis. They inhabit a variety of temporary and permanent freshwater habitats globally, and many species are remarkably tolerant of desiccation. Bdelloids offer an opportunity to better understand the evolution of sex and recombination, but previous work has emphasised desiccation as the cause of several unusual genomic features in this group. Here, we present high-quality whole-genome sequences of 3 bdelloid species: Rotaria macrura and R. magnacalcarata, which are both desiccation intolerant, and Adineta ricciae, which is desiccation tolerant. In combination with the published assembly of A. vaga, which is also desiccation tolerant, we apply a comparative genomics approach to evaluate the potential effects of desiccation tolerance and asexuality on genome evolution in bdelloids. We find that ancestral tetraploidy is conserved among all 4 bdelloid species, but homologous divergence in obligately aquatic Rotaria genomes is unexpectedly low. This finding is contrary to current models regarding the role of desiccation in shaping bdelloid genomes. In addition, we find that homologous regions in A. ricciae are largely collinear and do not form palindromic repeats as observed in the published A. vaga assembly. Consequently, several features interpreted as genomic evidence for long-term ameiotic evolution are not general to all bdelloid species, even within the same genus. Finally, we substantiate previous findings of high levels of horizontally transferred nonmetazoan genes in both desiccating and nondesiccating bdelloid species and show that this unusual feature is not shared by other animal phyla, even those with desiccation-tolerant representatives. These comparisons call into question the proposed role of desiccation in mediating horizontal genetic transfer.
Collapse
Affiliation(s)
- Reuben W. Nowell
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, United Kingdom
| | - Pedro Almeida
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, United Kingdom
| | - Christopher G. Wilson
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, United Kingdom
| | - Thomas P. Smith
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, United Kingdom
| | - Diego Fontaneto
- National Research Council of Italy, Institute of Ecosystem Study, Verbania Pallanza, Italy
| | - Alastair Crisp
- Department of Chemical Engineering and Biotechnology, West Cambridge Site, University of Cambridge, Cambridge, United Kingdom
| | - Gos Micklem
- Department of Genetics, Cambridge Systems Biology Centre, Downing Site, University of Cambridge, Cambridge, United Kingdom
| | - Alan Tunnacliffe
- Department of Chemical Engineering and Biotechnology, West Cambridge Site, University of Cambridge, Cambridge, United Kingdom
| | - Chiara Boschetti
- Department of Chemical Engineering and Biotechnology, West Cambridge Site, University of Cambridge, Cambridge, United Kingdom
- School of Biological and Marine Sciences, Plymouth University, Portland Square Building, Plymouth, United Kingdom
| | - Timothy G. Barraclough
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, United Kingdom
| |
Collapse
|
16
|
Nalepa CA. What Kills the Hindgut Flagellates of Lower Termites during the Host Molting Cycle? Microorganisms 2017; 5:E82. [PMID: 29258251 PMCID: PMC5748591 DOI: 10.3390/microorganisms5040082] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 12/07/2017] [Accepted: 12/09/2017] [Indexed: 11/17/2022] Open
Abstract
Subsocial wood feeding cockroaches in the genus Cryptocercus, the sister group of termites, retain their symbiotic gut flagellates during the host molting cycle, but in lower termites, closely related flagellates die prior to host ecdysis. Although the prevalent view is that termite flagellates die because of conditions of starvation and desiccation in the gut during the host molting cycle, the work of L.R. Cleveland in the 1930s through the 1960s provides a strong alternate hypothesis: it was the changed hormonal environment associated with the origin of eusociality and its concomitant shift in termite developmental ontogeny that instigates the death of the flagellates in termites. Although the research on termite gut microbial communities has exploded since the advent of modern molecular techniques, the role of the host hormonal environment on the life cycle of its gut flagellates has been neglected. Here Cleveland's studies are revisited to provide a basis for re-examination of the problem, and the results framed in the context of two alternate hypotheses: the flagellate symbionts are victims of the change in host social status, or the flagellates have become incorporated into the life cycle of the eusocial termite colony. Recent work on parasitic protists suggests clear paths for exploring these hypotheses and for resolving long standing issues regarding sexual-encystment cycles in flagellates of the Cryptocercus-termite lineage using molecular methodologies, bringing the problem into the modern era.
Collapse
Affiliation(s)
- Christine A Nalepa
- Department of Entomology, North Carolina State University, Raleigh, NC 27695-7613, USA.
| |
Collapse
|
17
|
Kang S, Tice AK, Spiegel FW, Silberman JD, Pánek T, Cepicka I, Kostka M, Kosakyan A, Alcântara DMC, Roger AJ, Shadwick LL, Smirnov A, Kudryavtsev A, Lahr DJG, Brown MW. Between a Pod and a Hard Test: The Deep Evolution of Amoebae. Mol Biol Evol 2017; 34:2258-2270. [PMID: 28505375 PMCID: PMC5850466 DOI: 10.1093/molbev/msx162] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Amoebozoa is the eukaryotic supergroup sister to Obazoa, the lineage that contains the animals and Fungi, as well as their protistan relatives, and the breviate and apusomonad flagellates. Amoebozoa is extraordinarily diverse, encompassing important model organisms and significant pathogens. Although amoebozoans are integral to global nutrient cycles and present in nearly all environments, they remain vastly understudied. We present a robust phylogeny of Amoebozoa based on broad representative set of taxa in a phylogenomic framework (325 genes). By sampling 61 taxa using culture-based and single-cell transcriptomics, our analyses show two major clades of Amoebozoa, Discosea, and Tevosa. This phylogeny refutes previous studies in major respects. Our results support the hypothesis that the last common ancestor of Amoebozoa was sexual and flagellated, it also may have had the ability to disperse propagules from a sporocarp-type fruiting body. Overall, the main macroevolutionary patterns in Amoebozoa appear to result from the parallel losses of homologous characters of a multiphase life cycle that included flagella, sex, and sporocarps rather than independent acquisition of convergent features.
Collapse
Affiliation(s)
- Seungho Kang
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS.,Institute for Genomics, Biocomputing & Biotechnology, Mississippi State University, Mississippi State, MS
| | - Alexander K Tice
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS.,Institute for Genomics, Biocomputing & Biotechnology, Mississippi State University, Mississippi State, MS
| | | | | | - Tomáš Pánek
- Department of Biology and Ecology, University of Ostrava, Ostrava, Czech Republic
| | - Ivan Cepicka
- Department of Zoology, Charles University, Prague, Czech Republic
| | - Martin Kostka
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Českě Budějovice, Czech Republic.,Department of Parasitology, University of South Bohemia, Českě Budějovice, Czech Republic
| | - Anush Kosakyan
- Department of Zoology, University of São Paulo, São Paulo, Brazil
| | | | - Andrew J Roger
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Lora L Shadwick
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR
| | - Alexey Smirnov
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Alexander Kudryavtsev
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Daniel J G Lahr
- Department of Zoology, University of São Paulo, São Paulo, Brazil
| | - Matthew W Brown
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS.,Institute for Genomics, Biocomputing & Biotechnology, Mississippi State University, Mississippi State, MS
| |
Collapse
|