1
|
Mongiardino Koch N, Tilic E, Miller AK, Stiller J, Rouse GW. Confusion will be my epitaph: genome-scale discordance stifles phylogenetic resolution of Holothuroidea. Proc Biol Sci 2023; 290:20230988. [PMID: 37434530 PMCID: PMC10336381 DOI: 10.1098/rspb.2023.0988] [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: 05/02/2023] [Accepted: 06/12/2023] [Indexed: 07/13/2023] Open
Abstract
Sea cucumbers (Holothuroidea) are a diverse clade of echinoderms found from intertidal waters to the bottom of the deepest oceanic trenches. Their reduced skeletons and limited number of phylogenetically informative traits have long obfuscated morphological classifications. Sanger-sequenced molecular datasets have also failed to constrain the position of major lineages. Noteworthy, topological uncertainty has hindered a resolution for Neoholothuriida, a highly diverse clade of Permo-Triassic age. We perform the first phylogenomic analysis of Holothuroidea, combining existing datasets with 13 novel transcriptomes. Using a highly curated dataset of 1100 orthologues, our efforts recapitulate previous results, struggling to resolve interrelationships among neoholothuriid clades. Three approaches to phylogenetic reconstruction (concatenation under both site-homogeneous and site-heterogeneous models, and coalescent-aware inference) result in alternative resolutions, all of which are recovered with strong support and across a range of datasets filtered for phylogenetic usefulness. We explore this intriguing result using gene-wise log-likelihood scores and attempt to correlate these with a large set of gene properties. While presenting novel ways of exploring and visualizing support for alternative trees, we are unable to discover significant predictors of topological preference, and our efforts fail to favour one topology. Neoholothuriid genomes seem to retain an amalgam of signals derived from multiple phylogenetic histories.
Collapse
Affiliation(s)
| | - Ekin Tilic
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
- Department of Marine Zoology, Senckenberg Research Institute and Museum, Frankfurt, Germany
| | - Allison K. Miller
- Anatomy Department, University of Otago, Dunedin, Otago, New Zealand
| | - Josefin Stiller
- Centre for Biodiversity Genomics, Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Greg W. Rouse
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| |
Collapse
|
2
|
Mongiardino Koch N, Thompson JR, Hiley AS, McCowin MF, Armstrong AF, Coppard SE, Aguilera F, Bronstein O, Kroh A, Mooi R, Rouse GW. Phylogenomic analyses of echinoid diversification prompt a re-evaluation of their fossil record. eLife 2022; 11:72460. [PMID: 35315317 PMCID: PMC8940180 DOI: 10.7554/elife.72460] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 03/03/2022] [Indexed: 12/25/2022] Open
Abstract
Echinoids are key components of modern marine ecosystems. Despite a remarkable fossil record, the emergence of their crown group is documented by few specimens of unclear affinities, rendering their early history uncertain. The origin of sand dollars, one of its most distinctive clades, is also unclear due to an unstable phylogenetic context. We employ 18 novel genomes and transcriptomes to build a phylogenomic dataset with a near-complete sampling of major lineages. With it, we revise the phylogeny and divergence times of echinoids, and place their history within the broader context of echinoderm evolution. We also introduce the concept of a chronospace - a multidimensional representation of node ages - and use it to explore methodological decisions involved in time calibrating phylogenies. We find the choice of clock model to have the strongest impact on divergence times, while the use of site-heterogeneous models and alternative node prior distributions show minimal effects. The choice of loci has an intermediate impact, affecting mostly deep Paleozoic nodes, for which clock-like genes recover dates more congruent with fossil evidence. Our results reveal that crown group echinoids originated in the Permian and diversified rapidly in the Triassic, despite the relative lack of fossil evidence for this early diversification. We also clarify the relationships between sand dollars and their close relatives and confidently date their origins to the Cretaceous, implying ghost ranges spanning approximately 50 million years, a remarkable discrepancy with their rich fossil record.
Collapse
Affiliation(s)
- Nicolás Mongiardino Koch
- Department of Earth & Planetary Sciences, Yale University, New Haven, United States.,Scripps Institution of Oceanography, University of California San Diego, La Jolla, United States
| | - Jeffrey R Thompson
- Department of Earth Sciences, Natural History Museum, London, United Kingdom.,University College London Center for Life's Origins and Evolution, London, United Kingdom
| | - Avery S Hiley
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, United States
| | - Marina F McCowin
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, United States
| | - A Frances Armstrong
- Department of Invertebrate Zoology and Geology, California Academy of Sciences, San Francisco, United States
| | - Simon E Coppard
- Bader International Study Centre, Queen's University, Herstmonceux Castle, East Sussex, United Kingdom
| | - Felipe Aguilera
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Omri Bronstein
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.,Steinhardt Museum of Natural History, Tel-Aviv, Israel
| | - Andreas Kroh
- Department of Geology and Palaeontology, Natural History Museum Vienna, Vienna, Austria
| | - Rich Mooi
- Department of Invertebrate Zoology and Geology, California Academy of Sciences, San Francisco, United States
| | - Greg W Rouse
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, United States
| |
Collapse
|
3
|
Pucker B. Automatic identification and annotation of MYB gene family members in plants. BMC Genomics 2022; 23:220. [PMID: 35305581 PMCID: PMC8933966 DOI: 10.1186/s12864-022-08452-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 03/07/2022] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND MYBs are among the largest transcription factor families in plants. Consequently, members of this family are involved in a plethora of processes including development and specialized metabolism. The MYB families of many plant species were investigated in the last two decades since the first investigation looked at Arabidopsis thaliana. This body of knowledge and characterized sequences provide the basis for the identification, classification, and functional annotation of candidate sequences in new genome and transcriptome assemblies. RESULTS A pipeline for the automatic identification and functional annotation of MYBs in a given sequence data set was implemented in Python. MYB candidates are identified, screened for the presence of a MYB domain and other motifs, and finally placed in a phylogenetic context with well characterized sequences. In addition to technical benchmarking based on existing annotation, the transcriptome assembly of Croton tiglium and the annotated genome sequence of Castanea crenata were screened for MYBs. Results of both analyses are presented in this study to illustrate the potential of this application. The analysis of one species takes only a few minutes depending on the number of predicted sequences and the size of the MYB gene family. This pipeline, the required bait sequences, and reference sequences for a classification are freely available on github: https://github.com/bpucker/MYB_annotator . CONCLUSIONS This automatic annotation of the MYB gene family in novel assemblies makes genome-wide investigations consistent and paves the way for comparative studies in the future. Candidate genes for in-depth analyses are presented based on their orthology to previously characterized sequences which allows the functional annotation of the newly identified MYBs with high confidence. The identification of orthologs can also be harnessed to detect duplication and deletion events.
Collapse
Affiliation(s)
- Boas Pucker
- Institute of Plant Biology & Braunschweig Integrated Centre of Systems Biology (BRICS), Braunschweig, Braunschweig, TU, Germany.
| |
Collapse
|
4
|
Munro C, Zapata F, Howison M, Siebert S, Dunn CW. Evolution of gene expression across species and specialized zooids in Siphonophora. Mol Biol Evol 2022; 39:6521037. [PMID: 35134205 PMCID: PMC8844502 DOI: 10.1093/molbev/msac027] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Siphonophores are complex colonial animals, consisting of asexually produced bodies (zooids) that are functionally specialized for specific tasks, including feeding, swimming, and sexual reproduction. Though this extreme functional specialization has captivated biologists for generations, its genomic underpinnings remain unknown. We use RNA-seq to investigate gene expression patterns in five zooids and one specialized tissue across seven siphonophore species. Analyses of gene expression across species present several challenges, including identification of comparable expression changes on gene trees with complex histories of speciation, duplication, and loss. We examine gene expression within species, conduct classical analyses examining expression patterns between species, and introduce species branch filtering, which allows us to examine the evolution of expression across species in a phylogenetic framework. Within and across species, we identified hundreds of zooid-specific and species-specific genes, as well as a number of putative transcription factors showing differential expression in particular zooids and developmental stages. We found that gene expression patterns tended to be largely consistent in zooids with the same function across species, but also some large lineage-specific shifts in gene expression. Our findings show that patterns of gene expression have the potential to define zooids in colonial organisms. Traditional analyses of the evolution of gene expression focus on the tips of gene phylogenies, identifying large-scale expression patterns that are zooid or species variable. The new explicit phylogenetic approach we propose here focuses on branches (not tips) offering a deeper evolutionary perspective into specific changes in gene expression within zooids along all branches of the gene (and species) trees.
Collapse
Affiliation(s)
- Catriona Munro
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI, 02912, USA
| | - Felipe Zapata
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Mark Howison
- Research Improving People’s Lives (RIPL), Providence, RI, USA
| | - Stefan Siebert
- Department of Molecular and Cellular Biology, University of California, Davis, California, 95616, USA
| | - Casey W Dunn
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA
| |
Collapse
|
5
|
Church SH, Extavour CG. Phylotranscriptomics reveals discordance in the phylogeny of Hawaiian Drosophila and Scaptomyza (Diptera: Drosophilidae). Mol Biol Evol 2022; 39:6512066. [PMID: 35048974 PMCID: PMC8892949 DOI: 10.1093/molbev/msac012] [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] [Indexed: 11/17/2022] Open
Abstract
Island radiations present natural laboratories for studying the evolutionary process. The Hawaiian Drosophilidae are one such radiation, with nearly 600 described species and substantial morphological and ecological diversification. These species are largely divided into a few major clades, but the relationship between clades remains uncertain. Here, we present new assembled transcriptomes from 12 species across these clades, and use these transcriptomes to resolve the base of the evolutionary radiation. We recover a new hypothesis for the relationship between clades, and demonstrate its support over previously published hypotheses. We then use the evolutionary radiation to explore dynamics of concordance in phylogenetic support, by analyzing the gene and site concordance factors for every possible topological combination of major groups. We show that high bootstrap values mask low evolutionary concordance, and we demonstrate that the most likely topology is distinct from the topology with the highest support across gene trees and from the topology with highest support across sites. We then combine all previously published genetic data for the group to estimate a time-calibrated tree for over 300 species of drosophilids. Finally, we digitize dozens of published Hawaiian Drosophilidae descriptions, and use this to pinpoint probable evolutionary shifts in reproductive ecology as well as body, wing, and egg size. We show that by examining the entire landscape of tree and trait space, we can gain a more complete understanding of how evolutionary dynamics play out across an island radiation.
Collapse
Affiliation(s)
- Samuel H Church
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA.,Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06511, USA
| | - Cassandra G Extavour
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA.,Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, 20815
| |
Collapse
|