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Hox genes in spiders: Their significance for development and evolution. Semin Cell Dev Biol 2022:S1084-9521(22)00355-X. [PMID: 36522242 DOI: 10.1016/j.semcdb.2022.11.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/13/2022] [Accepted: 11/30/2022] [Indexed: 12/15/2022]
Abstract
Hox genes are known for their role in the specification of typical body plan features in animals. Evolutionary changes in Hox gene function are believed to be involved in the emergence of the diverse body plans we observe in animals today. Spiders share many body plan features with other arthropods, but also have numerous unique traits of their own. Studies of spider Hox genes have already provided insights into evolutionarily conserved and derived features of the spider body plan and their genetic basis. However, many aspects of Hox gene biology have been insufficiently studied in spiders so far. In this review, we highlight previous comparative studies of Hox genes in spiders and their significance for our understanding of the evolution of the spider body plan. We also identify aspects of Hox gene biology that need to be studied in greater detail. Many spider Hox genes have not been investigated beyond their mRNA expression patterns, and the role of Hox genes with apparently plesiomorphic or dual functions, like ftz and Hox3 is still unclear. Spiders have a duplicated Hox gene cluster, but possible sub- or neofunctionalisation of duplicates have not yet been studied systematically. Future research should therefore focus on these issues, in addition to the role of Polycomb and trithorax-mediated regulation, the identification of regulatory regions, cofactors or spider-specific target genes, and the significance of non-coding RNAs transcribed from within the Hox cluster and even from the antisense strand of particular Hox genes.
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Janssen R, Schomburg C, Prpic NM, Budd GE. A comprehensive study of arthropod and onychophoran Fox gene expression patterns. PLoS One 2022; 17:e0270790. [PMID: 35802758 PMCID: PMC9269926 DOI: 10.1371/journal.pone.0270790] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 06/20/2022] [Indexed: 11/19/2022] Open
Abstract
Fox genes represent an evolutionary old class of transcription factor encoding genes that evolved in the last common ancestor of fungi and animals. They represent key-components of multiple gene regulatory networks (GRNs) that are essential for embryonic development. Most of our knowledge about the function of Fox genes comes from vertebrate research, and for arthropods the only comprehensive gene expression analysis is that of the fly Drosophila melanogaster. For other arthropods, only selected Fox genes have been investigated. In this study, we provide the first comprehensive gene expression analysis of arthropod Fox genes including representative species of all main groups of arthropods, Pancrustacea, Myriapoda and Chelicerata. We also provide the first comprehensive analysis of Fox gene expression in an onychophoran species. Our data show that many of the Fox genes likely retained their function during panarthropod evolution highlighting their importance in development. Comparison with published data from other groups of animals shows that this high degree of evolutionary conservation often dates back beyond the last common ancestor of Panarthropoda.
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Affiliation(s)
- Ralf Janssen
- Department of Earth Sciences, Palaeobiology, Uppsala University, Uppsala, Sweden
- * E-mail:
| | - Christoph Schomburg
- AG Zoologie mit dem Schwerpunkt Molekulare Entwicklungsbiologie, Institut für Allgemeine Zoologie und Entwicklungsbiologie, Justus-Liebig-Universität Gießen, Gießen, Germany
- Fachgebiet Botanik, Institut für Biologie, Universität Kassel, Kassel, Germany
| | - Nikola-Michael Prpic
- AG Zoologie mit dem Schwerpunkt Molekulare Entwicklungsbiologie, Institut für Allgemeine Zoologie und Entwicklungsbiologie, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Graham E. Budd
- Department of Earth Sciences, Palaeobiology, Uppsala University, Uppsala, Sweden
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Mariano-Martins P, Monfardini RD, Lo-Man-Hung N, Torres TT. Evidence of positive selection on six spider developmental genes. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART B, MOLECULAR AND DEVELOPMENTAL EVOLUTION 2022; 338:314-322. [PMID: 34985811 DOI: 10.1002/jez.b.23119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 11/16/2021] [Accepted: 12/04/2021] [Indexed: 06/14/2023]
Abstract
Spiders constitute more than 49,000 described species distributed all over the world, and all ecological environments. Their order, Araneae, is defined by a set of characteristics with no parallel among their arachnid counterparts (e.g., spinnerets, silk glands, chelicerae that inoculate venom, among others). Changes in developmental pathways often underlie the evolution of morphological synapomorphies, and as such spiders are a promising model to study the role of developmental genes in the origin of evolutionary novelties. With that in mind, we investigated changes in the evolutionary regime of a set of six developmental genes, using spiders as our model. The genes were mainly chosen for their roles in spinneret ontogeny, yet they are pleiotropic, and it is likely that the origins of other unique morphological phenotypes are also linked to changes in their sequences. Our results indicate no great differences in the selective pressures on those genes when comparing spiders to other arachnids, but a few site-specific positive selection evidence were found in the Araneae lineage. These findings lead us to new insights on spider evolution that are to be further tested.
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Affiliation(s)
- Pedro Mariano-Martins
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, São Paulo - SP, Brazil
| | - Raquel Dietsche Monfardini
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, São Paulo - SP, Brazil
| | - Nancy Lo-Man-Hung
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, São Paulo - SP, Brazil
| | - Tatiana Teixeira Torres
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, São Paulo - SP, Brazil
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Harper A, Baudouin Gonzalez L, Schönauer A, Janssen R, Seiter M, Holzem M, Arif S, McGregor AP, Sumner-Rooney L. Widespread retention of ohnologs in key developmental gene families following whole-genome duplication in arachnopulmonates. G3 (BETHESDA, MD.) 2021; 11:jkab299. [PMID: 34849767 PMCID: PMC8664421 DOI: 10.1093/g3journal/jkab299] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Revised: 07/19/2021] [Accepted: 08/03/2021] [Indexed: 01/12/2023]
Abstract
Whole-genome duplications (WGDs) have occurred multiple times during animal evolution, including in lineages leading to vertebrates, teleosts, horseshoe crabs, and arachnopulmonates. These dramatic events initially produce a wealth of new genetic material, generally followed by extensive gene loss. It appears, however, that developmental genes such as homeobox genes, signaling pathway components and microRNAs are frequently retained as duplicates (so-called ohnologs) following WGD. These not only provide the best evidence for WGD, but an opportunity to study its evolutionary consequences. Although these genes are well studied in the context of vertebrate WGD, similar comparisons across the extant arachnopulmonate orders are patchy. We sequenced embryonic transcriptomes from two spider species and two amblypygid species and surveyed three important gene families, Hox, Wnt, and frizzled, across these and 12 existing transcriptomic and genomic resources for chelicerates. We report extensive retention of putative ohnologs, further supporting the ancestral arachnopulmonate WGD. We also found evidence of consistent evolutionary trajectories in Hox and Wnt gene repertoires across three of the six arachnopulmonate orders, with interorder variation in the retention of specific paralogs. We identified variation between major clades in spiders and are better able to reconstruct the chronology of gene duplications and losses in spiders, amblypygids, and scorpions. These insights shed light on the evolution of the developmental toolkit in arachnopulmonates, highlight the importance of the comparative approach within lineages, and provide substantial new transcriptomic data for future study.
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Affiliation(s)
- Amber Harper
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Luis Baudouin Gonzalez
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Anna Schönauer
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Ralf Janssen
- Department of Earth Sciences, Uppsala University, Geocentrum, 752 36 Uppsala, Sweden
| | - Michael Seiter
- Department of Evolutionary Biology, Unit Integrative Zoology, University of Vienna, 1090 Vienna, Austria
| | - Michaela Holzem
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
- Division of Signalling and Functional Genomics, German Cancer Research Centre (DKFZ), Heidelberg, Germany and Department of Cell and Molecular Biology, Medical Faculty Mannheim, Heidelberg University, 69120 Heidelberg, Germany
| | - Saad Arif
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
- Centre for Functional Genomics, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Alistair P McGregor
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
- Centre for Functional Genomics, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Lauren Sumner-Rooney
- Oxford University Museum of Natural History, University of Oxford, Oxford OX1 3PW, UK
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Gainett G, Sharma PP. Genomic resources and toolkits for developmental study of whip spiders (Amblypygi) provide insights into arachnid genome evolution and antenniform leg patterning. EvoDevo 2020; 11:18. [PMID: 32874529 PMCID: PMC7455915 DOI: 10.1186/s13227-020-00163-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 08/11/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND The resurgence of interest in the comparative developmental study of chelicerates has led to important insights, such as the discovery of a genome duplication shared by spiders and scorpions, inferred to have occurred in the most recent common ancestor of Arachnopulmonata (a clade comprising the five arachnid orders that bear book lungs). Nonetheless, several arachnid groups remain understudied in the context of development and genomics, such as the order Amblypygi (whip spiders). The phylogenetic position of Amblypygi in Arachnopulmonata posits them as an interesting group to test the incidence of the proposed genome duplication in the common ancestor of Arachnopulmonata, as well as the degree of retention of duplicates over 450 Myr. Moreover, whip spiders have their first pair of walking legs elongated and modified into sensory appendages (a convergence with the antennae of mandibulates), but the genetic patterning of these antenniform legs has never been investigated. RESULTS We established genomic resources and protocols for cultivation of embryos and gene expression assays by in situ hybridization to study the development of the whip spider Phrynus marginemaculatus. Using embryonic transcriptomes from three species of Amblypygi, we show that the ancestral whip spider exhibited duplications of all ten Hox genes. We deploy these resources to show that paralogs of the leg gap genes dachshund and homothorax retain arachnopulmonate-specific expression patterns in P. marginemaculatus. We characterize the expression of leg gap genes Distal-less, dachshund-1/2 and homothorax-1/2 in the embryonic antenniform leg and other appendages, and provide evidence that allometry, and by extension the antenniform leg fate, is specified early in embryogenesis. CONCLUSION This study is the first step in establishing P. marginemaculatus as a chelicerate model for modern evolutionary developmental study, and provides the first resources sampling whip spiders for comparative genomics. Our results suggest that Amblypygi share a genome duplication with spiders and scorpions, and set up a framework to study the genetic specification of antenniform legs. Future efforts to study whip spider development must emphasize the development of tools for functional experiments in P. marginemaculatus.
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Affiliation(s)
- Guilherme Gainett
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706 USA
| | - Prashant P. Sharma
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706 USA
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