1
|
Finet C, Marlétaz F. Old hypotheses and theories at the heart of current evo-devo research. Evol Dev 2024:e12487. [PMID: 38924664 DOI: 10.1111/ede.12487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024]
Affiliation(s)
- Cédric Finet
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Ferdinand Marlétaz
- Department of Genetics, Evolution & Environment, Centre for Life's Origins and Evolution, University College London, London, UK
| |
Collapse
|
2
|
Posnien N, Hunnekuhl VS, Bucher G. Gene expression mapping of the neuroectoderm across phyla - conservation and divergence of early brain anlagen between insects and vertebrates. eLife 2023; 12:e92242. [PMID: 37750868 PMCID: PMC10522337 DOI: 10.7554/elife.92242] [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: 09/07/2023] [Accepted: 09/18/2023] [Indexed: 09/27/2023] Open
Abstract
Gene expression has been employed for homologizing body regions across bilateria. The molecular comparison of vertebrate and fly brains has led to a number of disputed homology hypotheses. Data from the fly Drosophila melanogaster have recently been complemented by extensive data from the red flour beetle Tribolium castaneum with its more insect-typical development. In this review, we revisit the molecular mapping of the neuroectoderm of insects and vertebrates to reconsider homology hypotheses. We claim that the protocerebrum is non-segmental and homologous to the vertebrate fore- and midbrain. The boundary between antennal and ocular regions correspond to the vertebrate mid-hindbrain boundary while the deutocerebrum represents the anterior-most ganglion with serial homology to the trunk. The insect head placode is shares common embryonic origin with the vertebrate adenohypophyseal placode. Intriguingly, vertebrate eyes develop from a different region compared to the insect compound eyes calling organ homology into question. Finally, we suggest a molecular re-definition of the classic concepts of archi- and prosocerebrum.
Collapse
Affiliation(s)
- Nico Posnien
- Department of Developmental Biology, Johann-Friedrich-Blumenbach Institute, University GoettingenGöttingenGermany
| | - Vera S Hunnekuhl
- Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, University of GöttingenGöttingenGermany
| | - Gregor Bucher
- Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, University of GöttingenGöttingenGermany
| |
Collapse
|
3
|
Smith FW, Game M, Mapalo MA, Chavarria RA, Harrison TR, Janssen R. Developmental and genomic insight into the origin of the tardigrade body plan. Evol Dev 2023. [PMID: 37721221 DOI: 10.1111/ede.12457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 08/11/2023] [Accepted: 08/29/2023] [Indexed: 09/19/2023]
Abstract
Tardigrada is an ancient lineage of miniaturized animals. As an outgroup of the well-studied Arthropoda and Onychophora, studies of tardigrades hold the potential to reveal important insights into body plan evolution in Panarthropoda. Previous studies have revealed interesting facets of tardigrade development and genomics that suggest that a highly compact body plan is a derived condition of this lineage, rather than it representing an ancestral state of Panarthropoda. This conclusion was based on studies of several species from Eutardigrada. We review these studies and expand on them by analyzing the publicly available genome and transcriptome assemblies of Echiniscus testudo, a representative of Heterotardigrada. These new analyses allow us to phylogenetically reconstruct important features of genome evolution in Tardigrada. We use available data from tardigrades to interrogate several recent models of body plan evolution in Panarthropoda. Although anterior segments of panarthropods are highly diverse in terms of anatomy and development, both within individuals and between species, we conclude that a simple one-to-one alignment of anterior segments across Panarthropoda is the best available model of segmental homology. In addition to providing important insight into body plan diversification within Panarthropoda, we speculate that studies of tardigrades may reveal generalizable pathways to miniaturization.
Collapse
Affiliation(s)
- Frank W Smith
- Biology Department, University of North Florida, Jacksonville, Florida, USA
| | - Mandy Game
- Biology Department, University of North Florida, Jacksonville, Florida, USA
| | - Marc A Mapalo
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Raul A Chavarria
- Biology Department, University of North Florida, Jacksonville, Florida, USA
| | - Taylor R Harrison
- Biology Department, University of North Florida, Jacksonville, Florida, USA
| | - Ralf Janssen
- Department of Earth Sciences, Palaeobiology, Uppsala University, Uppsala, Sweden
| |
Collapse
|
4
|
Blunk S, Garcia-Verdugo H, O’Sullivan S, Camp J, Haines M, Coalter T, Williams TA, Nagy LM. Functional Divergence of the Tribolium castaneum engrailed and invected Paralogs. INSECTS 2023; 14:691. [PMID: 37623401 PMCID: PMC10455198 DOI: 10.3390/insects14080691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/25/2023] [Accepted: 07/28/2023] [Indexed: 08/26/2023]
Abstract
Engrailed (en) and invected (inv) encode paralogous transcription factors found as a closely linked tandem duplication within holometabolous insects. Drosophila en mutants segment normally, then fail to maintain their segments. Loss of Drosophila inv is viable, while loss of both genes results in asegmental larvae. Surprisingly, the knockdown of Oncopeltus inv can result in the loss or fusion of the entire abdomen and en knockdowns in Tribolium show variable degrees of segmental loss. The consequence of losing or knocking down both paralogs on embryogenesis has not been studied beyond Drosophila. To further investigate the relative functions of each paralog and the mechanism behind the segmental loss, Tribolium double and single knockdowns of en and inv were analyzed. The most common cuticular phenotype of the double knockdowns was small, limbless, and open dorsally, with all but a single, segmentally iterated row of bristles. Less severe knockdowns had fused segments and reduced appendages. The Tribolium paralogs appear to act synergistically: the knockdown of either Tribolium gene alone was typically less severe, with all limbs present, whereas the most extreme single knockdowns mimic the most severe double knockdown phenotype. Morphological abnormalities unique to either single gene knockdown were not found. inv expression was not affected in the Tribolium en knockdowns, but hh expression was unexpectedly increased midway through development. Thus, while the segmental expression of en/inv is broadly conserved within insects, the functions of en and inv are evolving independently in different lineages.
Collapse
Affiliation(s)
- Summer Blunk
- Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA (H.G.-V.); (S.O.)
| | - Hector Garcia-Verdugo
- Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA (H.G.-V.); (S.O.)
| | - Sierra O’Sullivan
- Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA (H.G.-V.); (S.O.)
| | - James Camp
- Biology Department, Trinity College, Hartford, CT 06106, USA (T.A.W.)
| | - Michael Haines
- Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA (H.G.-V.); (S.O.)
| | - Tara Coalter
- Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA (H.G.-V.); (S.O.)
| | - Terri A. Williams
- Biology Department, Trinity College, Hartford, CT 06106, USA (T.A.W.)
| | - Lisa M. Nagy
- Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA (H.G.-V.); (S.O.)
| |
Collapse
|
5
|
Aria C, Vannier J, Park TYS, Gaines RR. Interpreting fossilized nervous tissues. Bioessays 2023; 45:e2200167. [PMID: 36693795 DOI: 10.1002/bies.202200167] [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: 08/25/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/26/2023]
Abstract
Paleoneuranatomy is an emerging subfield of paleontological research with great potential for the study of evolution. However, the interpretation of fossilized nervous tissues is a difficult task and presently lacks a rigorous methodology. We critically review here cases of neural tissue preservation reported in Cambrian arthropods, following a set of fundamental paleontological criteria for their recognition. These criteria are based on a variety of taphonomic parameters and account for morphoanatomical complexity. Application of these criteria shows that firm evidence for fossilized nervous tissues is less abundant and detailed than previously reported, and we synthesize here evidence that has stronger support. We argue that the vascular system, and in particular its lacunae, may be central to the understanding of many of the fossilized peri-intestinal features known across Cambrian arthropods. In conclusion, our results suggest the need for caution in the interpretation of evidence for fossilized neural tissue, which will increase the accuracy of evolutionary scenarios. Also see the video abstract here: https://youtu.be/2_JlQepRTb0.
Collapse
Affiliation(s)
- Cédric Aria
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.,Department of Natural History, Royal Ontario Museum, Toronto, Ontario, Canada.,Shaanxi Key Laboratory of Early Life and Environments, State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an, P. R. China
| | - Jean Vannier
- Université de Lyon, Université Lyon 1, ENS de Lyon, CNRS, UMR 5276 LGL-TPE, Bâtiment Géode, Villeurbanne, France
| | - Tae-Yoon S Park
- Division of Earth Sciences, Korea Polar Research Institute, Incheon, Republic of Korea
| | - Robert R Gaines
- Geology Department, Pomona College, Claremont, California, USA
| |
Collapse
|
6
|
DiFrisco J, Love AC, Wagner GP. The hierarchical basis of serial homology and evolutionary novelty. J Morphol 2023; 284:e21531. [PMID: 36317664 DOI: 10.1002/jmor.21531] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 10/26/2022] [Accepted: 10/29/2022] [Indexed: 11/05/2022]
Abstract
Given the pervasiveness of gene sharing in evolution and the extent of homology across the tree of life, why is everything not homologous with everything else? The continuity and overlapping genetic contributions to diverse traits across lineages seem to imply that no discrete determination of homology is possible. Although some argue that the widespread overlap in parts and processes should be acknowledged as "partial" homology, this threatens a broad base of presumed comparative morphological knowledge accepted by most biologists. Following a long scientific tradition, we advocate a strategy of "theoretical articulation" that introduces further distinctions to existing concepts to produce increased contrastive resolution among the labels used to represent biological phenomena. We pursue this strategy by drawing on successful patterns of reasoning from serial homology at the level of gene sequences to generate an enriched characterization of serial homology as a hierarchical, phylogenetic concept. Specifically, we propose that the concept of serial homology should be applied primarily to repeated but developmentally individualized body parts, such as cell types, differentiated body segments, or epidermal appendages. For these characters, a phylogenetic history can be reconstructed, similar to families of paralogous genes, endowing the notion of serial homology with a hierarchical, phylogenetic interpretation. On this basis, we propose a five-fold theoretical classification that permits a more fine-grained mapping of diverse trait-types. This facilitates answering the question of why everything is not homologous with everything else, as well as how novelty is possible given that any new character possesses evolutionary precursors. We illustrate the fecundity of our account by reference to debates over insect wing serial homologs and vertebrate paired appendages.
Collapse
Affiliation(s)
| | - Alan C Love
- Department of Philosophy, University of Minnesota, Minneapolis, Minnesota, USA.,Minnesota Center for Philosophy of Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Günter P Wagner
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA.,Yale Systems Biology Institute, Yale University, New Haven, Connecticut, USA.,Department of Obstetrics, Gynecology and Reproductive Sciences, Yale Medical School, New Haven, Connecticut, USA.,Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan, USA
| |
Collapse
|
7
|
Briggs DEG, Parry LA. Putting heads together. Science 2022; 378:831-832. [DOI: 10.1126/science.add7372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Cambrian fossils reveal ancestry of the segmented brain in arthropods
Collapse
Affiliation(s)
- Derek E. G. Briggs
- Department of Earth and Planetary Sciences, Yale University, New Haven, CT, USA
- Yale Peabody Museum of Natural History, Yale University, New Haven, CT, USA
| | - Luke A. Parry
- Department of Earth Sciences, University of Oxford, Oxford, UK
| |
Collapse
|
8
|
Strausfeld NJ, Hou X, Sayre ME, Hirth F. The lower Cambrian lobopodian Cardiodictyon resolves the origin of euarthropod brains. Science 2022; 378:905-909. [PMID: 36423269 DOI: 10.1126/science.abn6264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
For more than a century, the origin and evolution of the arthropod head and brain have eluded a unifying rationale reconciling divergent morphologies and phylogenetic relationships. Here, clarification is provided by the fossilized nervous system of the lower Cambrian lobopodian Cardiodictyon catenulum, which reveals an unsegmented head and brain comprising three cephalic domains, distinct from the metameric ventral nervous system serving its appendicular trunk. Each domain aligns with one of three components of the foregut and with a pair of head appendages. Morphological correspondences with stem group arthropods and alignments of homologous gene expression patterns with those of extant panarthropods demonstrate that cephalic domains of C. catenulum predate the evolution of the euarthropod head yet correspond to neuromeres defining brains of living chelicerates and mandibulates.
Collapse
Affiliation(s)
| | - Xianguang Hou
- Yunnan Key Laboratory for Palaeobiology, Institute of Palaeontology, Yunnan University, Kunming, China
| | - Marcel E Sayre
- Lund Vision Group, Department of Biology, Lund University, Lund, Sweden
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Frank Hirth
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| |
Collapse
|
9
|
Pates S, Botting JP, Muir LA, Wolfe JM. Ordovician opabiniid-like animals and the role of the proboscis in euarthropod head evolution. Nat Commun 2022; 13:6969. [PMID: 36379946 PMCID: PMC9666559 DOI: 10.1038/s41467-022-34204-w] [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: 01/04/2022] [Accepted: 10/18/2022] [Indexed: 11/16/2022] Open
Abstract
A crucial step in the evolution of Euarthropoda (chelicerates, myriapods, pancrustaceans) was the transition between fossil groups that possessed frontal appendages innervated by the first segment of the brain (protocerebrum), and living groups with a protocerebral labrum and paired appendages innervated by the second brain segment (deutocerebrum). Appendage homologies between the groups are controversial. Here we describe two specimens of opabiniid-like euarthropods, each bearing an anterior proboscis (a fused protocerebral appendage), from the Middle Ordovician Castle Bank Biota, Wales, UK. Phylogenetic analyses support a paraphyletic grade of stem-group euarthropods with fused protocerebral appendages and a posterior-facing mouth, as in the iconic Cambrian panarthropod Opabinia. These results suggest that the labrum may have reduced from an already-fused proboscis, rather than a pair of arthropodized appendages. If some shared features between the Castle Bank specimens and radiodonts are considered convergent rather than homologous, phylogenetic analyses retrieve them as opabiniids, substantially extending the geographic and temporal range of Opabiniidae.
Collapse
Affiliation(s)
- Stephen Pates
- grid.5335.00000000121885934Department of Zoology, University of Cambridge, Cambridge, UK
| | - Joseph P. Botting
- grid.9227.e0000000119573309Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, China ,grid.422296.90000 0001 2293 9551Department of Natural Sciences, Amgueddfa Cymru—National Museum Wales, Cardiff, UK
| | - Lucy A. Muir
- grid.422296.90000 0001 2293 9551Department of Natural Sciences, Amgueddfa Cymru—National Museum Wales, Cardiff, UK
| | - Joanna M. Wolfe
- grid.38142.3c000000041936754XMuseum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA USA
| |
Collapse
|
10
|
Vargas‐Parra EE, Hopkins MJ. Modularity in the trilobite head consistent with the hypothesized segmental origin of the eyes. Evol Dev 2022; 24:177-188. [PMID: 36111749 PMCID: PMC9786538 DOI: 10.1111/ede.12418] [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: 02/25/2022] [Revised: 07/06/2022] [Accepted: 08/18/2022] [Indexed: 12/30/2022]
Abstract
The trilobite head served multiple functions and was composed of several fused segments. Yet, the underlying organization of the trilobite head, and whether patterns are conserved across trilobites, remains unclear. Modeling the head as being composed of modules, or subunits that vary and thus have the potential to evolve semi-independently can reveal underlying patterns of organization. Hypotheses of modular organization based on the comparative developmental biology of arthropods were evaluated using geometric morphometrics. Two-dimensional (semi)landmark datasets collected from the cranidia of two Ordovician trilobite species, Calyptaulax annulata (Phacopida) and Cloacaspis senilis (Olenida sensu Adrain, 2011) were analyzed. The degree and pattern of modularity were assessed using the covariance ratio (CR), which compares the covariation within putative modules to the covariation between them, and the fit of different models was compared using an effect size measure derived from the CR. When treating the eyes as a distinct module, the best modular hypothesis identified for C. annulata shows the eyes and anteriormost region of the head integrated as a single module. The best modular hypotheses for C. senilis are more complex but the eyes still covary mostly strongly with the anterior part of the head. The latter is also the case for all other well-supported models for both species. These results can be interpreted as a developmental signal corresponding to the anteriormost ocular segment of early arthropods that is retained throughout development, despite any likely selective pressures related to functional needs.
Collapse
Affiliation(s)
| | - Melanie J. Hopkins
- Division of PaleontologyAmerican Museum of Natural HistoryNew YorkNew YorkUSA
| |
Collapse
|
11
|
Vinther J. Evolution: The arthropod brain - a saga in three parts. Curr Biol 2022; 32:R833-R836. [PMID: 35944482 DOI: 10.1016/j.cub.2022.06.091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
The arthropod brain comprises three segments and innervates three appendages. How it evolved has been a matter of intense debate. New Burgess Shale fossils preserving nervous tissue bring us closer to solving this mystery but evaluating the many hypotheses they could fit is not easy.
Collapse
Affiliation(s)
- Jakob Vinther
- Schools of Earth Sciences and Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK. Jakob.Vinther,@,bristol.ac.uk
| |
Collapse
|