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Klementz BC, Brenneis G, Hinne IA, Laumer EM, Neu SM, Hareid GM, Gainett G, Setton EVW, Simian C, Vrech DE, Joyce I, Barnett AA, Patel NH, Harvey MS, Peretti AV, Gulia-Nuss M, Sharma PP. A novel expression domain of extradenticle underlies the evolutionary developmental origin of the chelicerate patella. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.16.594547. [PMID: 38826321 PMCID: PMC11142128 DOI: 10.1101/2024.05.16.594547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Neofunctionalization of duplicated gene copies is thought to be an important process underlying the origin of evolutionary novelty and provides an elegant mechanism for the origin of new phenotypic traits. One putative case where a new gene copy has been linked to a novel morphological trait is the origin of the arachnid patella, a taxonomically restricted leg segment. In spiders, the origin of this segment has been linked to the origin of the paralog dachshund-2 , suggesting that a new gene facilitated the expression of a new trait. However, various arachnid groups that possess patellae do not have a copy of dachshund-2 , disfavoring the direct link between gene origin and trait origin. We investigated the developmental genetic basis for patellar patterning in the harvestman Phalangium opilio , which lacks dachshund-2 . Here, we show that the harvestman patella is established by a novel expression domain of the transcription factor extradenticle . Leveraging this definition of patellar identity, we surveyed targeted groups across chelicerate phylogeny to assess when this trait evolved. We show that a patellar homolog is present in Pycnogonida (sea spiders) and various arachnid orders, suggesting a single origin of the patella in the ancestor of Chelicerata. A potential loss of the patella is observed in Ixodida. Our results suggest that the modification of an ancient gene, rather than the neofunctionalization of a new gene copy, underlies the origin of the patella. Broadly, this work underscores the value of comparative data and broad taxonomic sampling when testing hypotheses in evolutionary developmental biology.
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Medina-Jiménez BI, Budd GE, Janssen R. Single-cell RNA sequencing of mid-to-late stage spider embryos: new insights into spider development. BMC Genomics 2024; 25:150. [PMID: 38326752 PMCID: PMC10848406 DOI: 10.1186/s12864-023-09898-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 12/12/2023] [Indexed: 02/09/2024] Open
Abstract
BACKGROUND The common house spider Parasteatoda tepidariorum represents an emerging new model organism of arthropod evolutionary and developmental (EvoDevo) studies. Recent technical advances have resulted in the first single-cell sequencing (SCS) data on this species allowing deeper insights to be gained into its early development, but mid-to-late stage embryos were not included in these pioneering studies. RESULTS Therefore, we performed SCS on mid-to-late stage embryos of Parasteatoda and characterized resulting cell clusters by means of in-silico analysis (comparison of key markers of each cluster with previously published information on these genes). In-silico prediction of the nature of each cluster was then tested/verified by means of additional in-situ hybridization experiments with additional markers of each cluster. CONCLUSIONS Our data show that SCS data reliably group cells with similar genetic fingerprints into more or less distinct clusters, and thus allows identification of developing cell types on a broader level, such as the distinction of ectodermal, mesodermal and endodermal cell lineages, as well as the identification of distinct developing tissues such as subtypes of nervous tissue cells, the developing heart, or the ventral sulcus (VS). In comparison with recent other SCS studies on the same species, our data represent later developmental stages, and thus provide insights into different stages of developing cell types and tissues such as differentiating neurons and the VS that are only present at these later stages.
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Affiliation(s)
- Brenda I Medina-Jiménez
- Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, 75236, Uppsala, Sweden.
| | - Graham E Budd
- Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, 75236, Uppsala, Sweden
| | - Ralf Janssen
- Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, 75236, Uppsala, Sweden.
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Chen Y, Li H, Yi TC, Shen J, Zhang J. Notch Signaling in Insect Development: A Simple Pathway with Diverse Functions. Int J Mol Sci 2023; 24:14028. [PMID: 37762331 PMCID: PMC10530718 DOI: 10.3390/ijms241814028] [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: 07/31/2023] [Revised: 09/05/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
Notch signaling is an evolutionarily conserved pathway which functions between adjacent cells to establish their distinct identities. Despite operating in a simple mechanism, Notch signaling plays remarkably diverse roles in development to regulate cell fate determination, organ growth and tissue patterning. While initially discovered and characterized in the model insect Drosophila melanogaster, recent studies across various insect species have revealed the broad involvement of Notch signaling in shaping insect tissues. This review focuses on providing a comprehensive picture regarding the roles of the Notch pathway in insect development. The roles of Notch in the formation and patterning of the insect embryo, wing, leg, ovary and several specific structures, as well as in physiological responses, are summarized. These results are discussed within the developmental context, aiming to deepen our understanding of the diversified functions of the Notch signaling pathway in different insect species.
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Affiliation(s)
- Yao Chen
- Department of Plant Biosecurity and MOA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, College of Plant Protection, China Agricultural University, Beijing 100193, China; (Y.C.)
| | - Haomiao Li
- Department of Plant Biosecurity and MOA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, College of Plant Protection, China Agricultural University, Beijing 100193, China; (Y.C.)
| | - Tian-Ci Yi
- Guizhou Provincial Key Laboratory for Agricultural Pest Management of Mountainous Regions, Institute of Entomology, Guizhou University, Guiyang 550025, China
| | - Jie Shen
- Department of Plant Biosecurity and MOA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, College of Plant Protection, China Agricultural University, Beijing 100193, China; (Y.C.)
| | - Junzheng Zhang
- Department of Plant Biosecurity and MOA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, College of Plant Protection, China Agricultural University, Beijing 100193, China; (Y.C.)
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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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6
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Thümecke S, Schröder R. The odd-skipped related gene drumstick is required for leg development in the beetle Tribolium castaneum. Dev Dyn 2021; 251:1456-1471. [PMID: 33871128 DOI: 10.1002/dvdy.347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/07/2021] [Accepted: 04/07/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The evolutionarily conserved odd-skipped related genes odd-skipped (odd), drumstick (drm), sister of odd and bowel (sob), and brother-of-odd-with-entrails-limited (bwl) act downstream of the Notch pathway in various insect tissues including the appendages and the gut. While the function of some of these genes have been analyzed in the adult Tribolium beetle, the expression during and their requirement for embryonic development is not known. RESULTS We describe here the embryonic expression patterns of drm, sob, and bwl and analyze the RNAi knockdown phenotypes with emphasize on the appendages and the hindgut. We show that in Tribolium, drm acts independently of other odd-family members in the formation of legs, hindgut, and the dorsal epidermis. Moreover, we establish drm and sob as further markers for segment borders in the appendages that include the gnathobasic mandibles. CONCLUSIONS We conclude that the regulatory interrelationship among the odd genes differs between Tribolium and Drosophila, where odd and drm seem to act redundantly. In Tribolium, the genes drm and sob uncover the relict of a precoxal joint incorporated in the lateral body wall.
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Affiliation(s)
- Susanne Thümecke
- Institut für Insektenbiotechnologie, Universität Gießen, Gießen, Germany.,Institut für Biowissenschaften, Universität Rostock, Rostock, Germany
| | - Reinhard Schröder
- Institut für Biowissenschaften, Universität Rostock, Rostock, Germany
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Mariano-Martins P, Lo-Man-Hung N, Torres TT. Evolution of Spiders and Silk Spinning: Mini Review of the Morphology, Evolution, and Development of Spiders’ Spinnerets. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00109] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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Crabtree JR, Macagno ALM, Moczek AP, Rohner PT, Hu Y. Notch signaling patterns head horn shape in the bull-headed dung beetle Onthophagus taurus. Dev Genes Evol 2020; 230:213-225. [PMID: 31960122 DOI: 10.1007/s00427-020-00645-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 01/14/2020] [Indexed: 02/07/2023]
Abstract
Size and shape constitute fundamental aspects in the description of morphology. Yet while the developmental-genetic underpinnings of trait size, in particular with regard to scaling relationships, are increasingly well understood, those of shape remain largely elusive. Here we investigate the potential function of the Notch signaling pathway in instructing the shape of beetle horns, a highly diversified and evolutionarily novel morphological structure. We focused on the bull-headed dung beetle Onthophagus taurus due to the wide range of horn sizes and shapes present among males in this species, in order to assess the potential function of Notch signaling in the specification of horn shape alongside the regulation of shape changes with allometry. Using RNA interference-mediated transcript depletion of Notch and its ligands, we document a highly conserved role of Notch signaling in general appendage formation. By integrating our functional genetic approach with a geometric morphometric analysis, we find that Notch signaling moderately but consistently affects horn shape, and does so differently for the horns of minor, intermediate-sized, and major males. Our results suggest that the function of Notch signaling during head horn formation may vary in a complex manner across male morphs, and highlights the power of integrating functional genetic and geometric morphometric approaches in analyzing subtle but nevertheless biologically important phenotypes in the face of significant allometric variation.
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Affiliation(s)
- Jordan R Crabtree
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| | - Anna L M Macagno
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| | - Armin P Moczek
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| | - Patrick T Rohner
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| | - Yonggang Hu
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA.
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Heingård M, Turetzek N, Prpic NM, Janssen R. FoxB, a new and highly conserved key factor in arthropod dorsal-ventral (DV) limb patterning. EvoDevo 2019; 10:28. [PMID: 31728178 PMCID: PMC6842170 DOI: 10.1186/s13227-019-0141-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 10/16/2019] [Indexed: 12/25/2022] Open
Abstract
Forkhead box (Fox) transcription factors evolved early in animal evolution and represent important components of conserved gene regulatory networks (GRNs) during animal development. Most of the researches concerning Fox genes, however, are on vertebrates and only a relatively low number of studies investigate Fox gene function in invertebrates. In addition to this shortcoming, the focus of attention is often restricted to a few well-characterized Fox genes such as FoxA (forkhead), FoxC (crocodile) and FoxQ2. Although arthropods represent the largest and most diverse animal group, most other Fox genes have not been investigated in detail, not even in the arthropod model species Drosophila melanogaster. In a general gene expression pattern screen for panarthropod Fox genes including the red flour beetle Tribolium castaneum, the pill millipede Glomeris marginata, the common house spider Parasteatoda tepidariorum, and the velvet worm Euperipatoides kanangrensis, we identified a Fox gene with a highly conserved expression pattern along the ventral ectoderm of arthropod and onychophoran limbs. Functional investigation of FoxB in Parasteatoda reveals a hitherto unrecognized important function of FoxB upstream of wingless (wg) and decapentaplegic (dpp) in the GRN orchestrating dorsal–ventral limb patterning.
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Affiliation(s)
- Miriam Heingård
- 1Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, Uppsala, Sweden.,4Present Address: Department of Geology, Faculty of Science, Lund University, Sölvegatan 12, Lund, Sweden
| | - Natascha Turetzek
- 2Abteilung für Entwicklungsbiologie, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Georg-August-Universität, Göttingen, Germany.,Present Address: Göttingen Center for Molecular Biosciences (GZMB), Ernst-Caspari-Haus, Göttingen, Germany
| | - Nikola-Michael Prpic
- 2Abteilung für Entwicklungsbiologie, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Georg-August-Universität, Göttingen, Germany.,5Present Address: Bereich Allgemeine Zoologie und Entwicklungsbiologie, Institut für Allgemeine und Spezielle Zoologie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 38, 35392 Gießen, Germany
| | - Ralf Janssen
- 1Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, Uppsala, Sweden
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10
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Tweedt SM. Gene Regulatory Networks, Homology, and the Early Panarthropod Fossil Record. Integr Comp Biol 2017; 57:477-487. [PMID: 28957522 DOI: 10.1093/icb/icx095] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The arthropod body plan is widely believed to have derived from an ancestral form resembling Cambrian-aged fossil lobopodians, and interpretations of morphological and molecular data have long favored this hypothesis. It is possible, however, that appendages and other morphologies observed in extinct and living panarthropods evolved independently. The key to distinguishing between morphological homology and homoplasy lies in the study of developmental gene regulatory networks (GRNs), and specifically, in determining the unique genetic circuits that construct characters. In this study, I discuss character identity and panarthropod appendage evolution within a developmental GRN framework, with a specific focus on potential limb character identity networks ("ChINs"). I summarize recent molecular studies, and argue that current data do not rule out the possibility of independent panarthropod limb evolution. The link between character identity and GRN architecture has broad implications for homology assessment, and this genetic framework offers alternative approaches to fossil character coding, phylogenetic analyses, and future research into the origin of the arthropod body plan.
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Affiliation(s)
- Sarah M Tweedt
- Department of Geology & Geophysics, Yale University, New Haven, CT 06520-8109, USA
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11
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Jockusch EL. Developmental and Evolutionary Perspectives on the Origin and Diversification of Arthropod Appendages. Integr Comp Biol 2017; 57:533-545. [DOI: 10.1093/icb/icx063] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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12
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Sharma PP, Santiago MA, González-Santillán E, Monod L, Wheeler WC. Evidence of duplicated Hox genes in the most recent common ancestor of extant scorpions. Evol Dev 2016; 17:347-55. [PMID: 26492826 DOI: 10.1111/ede.12166] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Scorpions (order Scorpiones) are unusual among arthropods, both for the extreme heteronomy of their bauplan and for the high gene family turnover exhibited in their genomes. These phenomena appear to be correlated, as two scorpion species have been shown to possess nearly twice the number of Hox genes present in most arthropods. Segmentally offset anterior expression boundaries of a subset of Hox paralogs have been shown to correspond to transitions in segmental identities in the scorpion posterior tagmata, suggesting that posterior heteronomy in scorpions may have been achieved by neofunctionalization of Hox paralogs. However, both the first scorpion genome sequenced and the developmental genetic data are based on exemplars of Buthidae, one of 19 families of scorpions. It is therefore not known whether Hox paralogy is limited to Buthidae or widespread among scorpions. We surveyed 24 high throughput transcriptomes and the single whole genome available for scorpions, in order to test the prediction that Hox gene duplications are common to the order. We used gene tree parsimony to infer whether the paralogy was consistent with a duplication event in the scorpion common ancestor. Here we show that duplicated Hox genes in non-buthid scorpions occur in six of the ten Hox classes. Gene tree topologies and parsimony-based reconciliation of the gene trees are consistent with a duplication event in the most recent common ancestor of scorpions. These results suggest that a Hox paralogy, and by extension the model of posterior patterning established in a buthid, can be extended to non-Buthidae scorpions.
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Affiliation(s)
- Prashant P Sharma
- Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA.,Department of Zoology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Marc A Santiago
- Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA
| | - Edmundo González-Santillán
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigaciones y de Estudios Avanzados del Instituto Politecnico Nacional, and Laboratorio de Aracnología, Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, Coyoacán, C.P. 04510, México D.F., México
| | - Lionel Monod
- Département des Arthropodes et d'Entomologie I, Muséum d'histoire naturelle de la Ville de Genève, Route de Malagnou 1, CH-1208 Genève, Suisse
| | - Ward C Wheeler
- Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA
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Chipman AD. An embryological perspective on the early arthropod fossil record. BMC Evol Biol 2015; 15:285. [PMID: 26678148 PMCID: PMC4683962 DOI: 10.1186/s12862-015-0566-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 12/10/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Our understanding of the early evolution of the arthropod body plan has recently improved significantly through advances in phylogeny and developmental biology and through new interpretations of the fossil record. However, there has been limited effort to synthesize data from these different sources. Bringing an embryological perspective into the fossil record is a useful way to integrate knowledge from different disciplines into a single coherent view of arthropod evolution. RESULTS I have used current knowledge on the development of extant arthropods, together with published descriptions of fossils, to reconstruct the germband stages of a series of key taxa leading from the arthropod lower stem group to crown group taxa. These reconstruction highlight the main evolutionary transitions that have occurred during early arthropod evolution, provide new insights into the types of mechanisms that could have been active and suggest new questions and research directions. CONCLUSIONS The reconstructions suggest several novel homology hypotheses - e.g. the lower stem group head shield and head capsules in the crown group are all hypothesized to derive from the embryonic head lobes. The homology of anterior segments in different groups is resolved consistently. The transition between "lower-stem" and "upper-stem" arthropods is highlighted as a major transition with a concentration of novelties and innovations, suggesting a gap in the fossil record. A close relationship between chelicerates and megacheirans is supported by the embryonic reconstructions, and I suggest that the depth of the mandibulate-chelicerate split should be reexamined.
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Affiliation(s)
- Ariel D Chipman
- The Department of Ecology, Evolution and Behavior, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram 91904, Jerusalem, Israel. .,The Department of Paleobiology, The Smithsonian Museum of Natural History, Washington, DC, USA.
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14
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Notch signaling induces cell proliferation in the labrum in a regulatory network different from the thoracic legs. Dev Biol 2015; 408:164-77. [DOI: 10.1016/j.ydbio.2015.09.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 09/25/2015] [Accepted: 09/26/2015] [Indexed: 11/18/2022]
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Molecular developmental evidence for a subcoxal origin of pleurites in insects and identity of the subcoxa in the gnathal appendages. Sci Rep 2015; 5:15757. [PMID: 26507752 PMCID: PMC4623811 DOI: 10.1038/srep15757] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 09/29/2015] [Indexed: 11/11/2022] Open
Abstract
Pleurites are chitinous plates in the body wall of insects and myriapods. They are believed to be an adaptation to locomotion on land but their developmental and evolutionary origins are unclear. A widely endorsed explanation for their origin is through toughening pre-existing parts of the body wall; in contrast, the subcoxal theory suggests pleurites derive from a redeployment of the proximal-most section of the leg, the subcoxa. Here, by studying expression of appendage patterning genes in embryos and larvae of the beetle Tribolium castaneum, we provide the first molecular evidence for the existence of a cryptic subcoxal segment in developing legs. We follow this structure during development and show that the embryonic subcoxa later forms the pleurites of the larva as predicted by the subcoxal theory. Our data also demonstrate that subcoxal segments are present in all post-antennal appendages, including the first molecular evidence of a two-segmented mandible with a subcoxal segment in insects.
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Identification and embryonic expression of Wnt2, Wnt4, Wnt5 and Wnt9 in the millipede Glomeris marginata (Myriapoda: Diplopoda). Gene Expr Patterns 2014; 14:55-61. [DOI: 10.1016/j.gep.2013.12.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 12/26/2013] [Accepted: 12/29/2013] [Indexed: 11/23/2022]
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17
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Eriksson BJ, Ungerer P, Stollewerk A. The function of Notch signalling in segment formation in the crustacean Daphnia magna (Branchiopoda). Dev Biol 2013; 383:321-30. [DOI: 10.1016/j.ydbio.2013.09.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 09/11/2013] [Accepted: 09/15/2013] [Indexed: 01/14/2023]
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18
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Claverie T, Patek SN. MODULARITY AND RATES OF EVOLUTIONARY CHANGE IN A POWER-AMPLIFIED PREY CAPTURE SYSTEM. Evolution 2013; 67:3191-207. [DOI: 10.1111/evo.12185] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 05/23/2013] [Indexed: 01/18/2023]
Affiliation(s)
- Thomas Claverie
- Department of Biology; Organismic and Evolutionary Biology Graduate Program; University of Massachusetts; Amherst Massachusetts
| | - S. N. Patek
- Department of Biology; Organismic and Evolutionary Biology Graduate Program; University of Massachusetts; Amherst Massachusetts
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19
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Sharma PP, Schwager EE, Giribet G, Jockusch EL, Extavour CG. Distal-lessanddachshundpattern both plesiomorphic and apomorphic structures in chelicerates: RNA interference in the harvestmanPhalangium opilio(Opiliones). Evol Dev 2013; 15:228-42. [DOI: 10.1111/ede.12029] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Evelyn E. Schwager
- Department of Organismic and Evolutionary Biology; Harvard University; 26 Oxford Street, Cambridge, MA 02138; USA
| | | | - Elizabeth L. Jockusch
- Department of Ecology and Evolutionary Biology; University of Connecticut; 75 N. Eagleville Road, Storrs, CT 06269; USA
| | - Cassandra G. Extavour
- Department of Organismic and Evolutionary Biology; Harvard University; 26 Oxford Street, Cambridge, MA 02138; USA
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Liu W. Bmdelta phenotype implies involvement of Notch signaling in body segmentation and appendage development of silkworm, Bombyx mori. ARTHROPOD STRUCTURE & DEVELOPMENT 2013; 42:143-151. [PMID: 23142088 DOI: 10.1016/j.asd.2012.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 07/21/2012] [Accepted: 10/03/2012] [Indexed: 06/01/2023]
Abstract
The domesticated silkworm, Bombyx mori, belongs to the intermediate germband insects, in which the anterior segments are specified in the blastoderm, while the remaining posterior segments are sequentially generated from the cellularized growth zone. The pattern formation is distinct from Drosophila but somewhat resembles a vertebrate. Notch signaling is involved in the segmentation of vertebrates and spiders. Here, we studied the function of Notch signaling in silkworm embryogenesis via RNA interference (RNAi). Depletion of Bmdelta, the homolog of the Notch signaling ligand, led to severe defects in segment patterning, including a loss of posterior segments and irregular segment boundaries. The paired appendages on each segment were symmetrically fused along the ventral midline in Bmdelta RNAi embryos. An individual segment seemed to possess only one segmental appendage. Segmentation in prolegs could be observed. Our results show that Notch signaling is employed in not only appendage development but also body segmentation. Thus, conservation of Notch-mediated segmentation could also be extended to holometabolous insects. The involvement of Notch signaling seems to be the ancestral segmentation mechanism of arthropods.
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Affiliation(s)
- Wenbin Liu
- Department of Pharmaceutical and Biological Engineering, School of Chemical Engineering, Sichuan University, No. 24 South Section 1, Yihuan Road, Chengdu 610065, PR China.
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Liu W. Functional analyses in the silkworm, Bombyx mori, support a role for Notch signaling in appendage development but not the groucho-dependent pair-rule process. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2012; 318:651-62. [PMID: 22907748 DOI: 10.1002/jez.b.22470] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 04/26/2012] [Accepted: 07/23/2012] [Indexed: 11/12/2022]
Abstract
Pair-rule genes are crucial for generating dual segment periodicity for body plan patterning in Drosophila. Bombyx mori is an intermediate germband insect, in which the formation of posterior segments via sequential addition follows a different process from that in Drosophila, although it is somewhat comparable to the process that occurs in vertebrates. Notch signaling is involved in the segmentation of vertebrates, spiders, and basal insects. Groucho (Gro) participates in Notch signaling as a corepressor and plays an important role during segmentation by interacting with other pair-rule proteins. Here, we cloned a gro homolog in the silkworm and positioned it at chromosome 21 in the genetic linkage map. Functional analyses of Bmgro and Bmnotch during embryogenesis were conducted using RNA interference (RNAi). Depletion of Bmgro led to a loss of odd-numbered segments, a characteristic pair-rule phenotype. Bmnotch RNAi resulted in that paired appendages on each segment were symmetrically fused along the ventral midline. An individual segment seemed to possess only one segmental appendage when Notch signaling was compromised. Irregular segments were observed in the Bmnotch RNAi embryo. Our results show that the involvement of Bmgro during the pair-rule process is not mediated by Notch signaling in silkworm. Notch signaling remains in appendage segmentation and restriction of cell fate.
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Affiliation(s)
- Wenbin Liu
- Department of Pharmaceutical and Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, PR, China.
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Extent With Modification: Leg Patterning in the Beetle Tribolium castaneum and the Evolution of Serial Homologs. G3-GENES GENOMES GENETICS 2012; 2:235-48. [PMID: 22384402 PMCID: PMC3284331 DOI: 10.1534/g3.111.001537] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 12/01/2011] [Indexed: 01/17/2023]
Abstract
Serial homologs are similar structures that develop at different positions within a body plan. These structures share some, but not all, aspects of developmental patterning, and their evolution is thought to be constrained by shared, pleiotropic gene functions. Here we describe the functions of 17 developmental genes during metamorphic development of the legs in the red flour beetle, Tribolium castaneum. This study provides informative comparisons between appendage development in Drosophila melanogaster and T. castaneum, between embryonic and adult development in T. castaneum, and between the development of serially homologous appendages. The leg gap genes Distal-less and dachshund are conserved in function. Notch signaling, the zinc-finger transcription factors related to odd-skipped, and bric-à-brac have conserved functions in promoting joint development. homothorax knockdown alters the identity of proximal leg segments but does not reduce growth. Lim1 is required for intermediate leg development but not distal tarsus and pretarsus development as in D. melanogaster. Development of the tarsus requires decapentaplegic, rotund, spineless, abrupt, and bric-à-brac and the EGF ligand encoded by Keren. Metathoracic legs of T. castaneum have four tarsomeres, whereas other legs have five. Patterns of gene activity in the tarsus suggest that patterning in the middle of the tarsal region, not the proximal- or distal-most areas, is responsible for this difference in segment number. Through comparisons with other recent studies of T. castaneum appendage development, we test hypotheses for the modularity or interdependence of development during evolution of serial homologs.
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Brenneis G, Arango CP, Scholtz G. Morphogenesis of Pseudopallene sp. (Pycnogonida, Callipallenidae) II: postembryonic development. Dev Genes Evol 2011; 221:329-50. [DOI: 10.1007/s00427-011-0381-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 11/08/2011] [Indexed: 12/22/2022]
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Morphogenesis of Pseudopallene sp. (Pycnogonida, Callipallenidae) I: embryonic development. Dev Genes Evol 2011; 221:309-28. [DOI: 10.1007/s00427-011-0382-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 11/08/2011] [Indexed: 12/20/2022]
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Patterning of the adult mandibulate mouthparts in the red flour beetle, Tribolium castaneum. Genetics 2011; 190:639-54. [PMID: 22135350 DOI: 10.1534/genetics.111.134296] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Specialized insect mouthparts, such as those of Drosophila, are derived from an ancestral mandibulate state, but little is known about the developmental genetics of mandibulate mouthparts. Here, we study the metamorphic patterning of mandibulate mouthparts of the beetle Tribolium castaneum, using RNA interference to deplete the expression of 13 genes involved in mouthpart patterning. These data were used to test three hypotheses related to mouthpart development and evolution. First, we tested the prediction that maxillary and labial palps are patterned using conserved components of the leg-patterning network. This hypothesis was strongly supported: depletion of Distal-less and dachshund led to distal and intermediate deletions of these structures while depletion of homothorax led to homeotic transformation of the proximal maxilla and labium, joint formation required the action of Notch signaling components and odd-skipped paralogs, and distal growth and patterning required epidermal growth factor (EGF) signaling. Additionally, depletion of abrupt or pdm/nubbin caused fusions of palp segments. Second, we tested hypotheses for how adult endites, the inner branches of the maxillary and labial appendages, are formed at metamorphosis. Our data reveal that Distal-less, Notch signaling components, and odd-skipped paralogs, but not dachshund, are required for metamorphosis of the maxillary endites. Endite development thus requires components of the limb proximal-distal axis patterning and joint segmentation networks. Finally, adult mandible development is considered in light of the gnathobasic hypothesis. Interestingly, while EGF activity is required for distal, but not proximal, patterning of other appendages, it is required for normal metamorphic growth of the mandibles.
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Mito T, Shinmyo Y, Kurita K, Nakamura T, Ohuchi H, Noji S. Ancestral functions of Delta/Notch signaling in the formation of body and leg segments in the cricket Gryllus bimaculatus. Development 2011; 138:3823-33. [DOI: 10.1242/dev.060681] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Delta/Notch signaling controls a wide spectrum of developmental processes, including body and leg segmentation in arthropods. The various functions of Delta/Notch signaling vary among species. For instance, in Cupiennius spiders, Delta/Notch signaling is essential for body and leg segmentation, whereas in Drosophila fruit flies it is involved in leg segmentation but not body segmentation. Therefore, to gain further insight into the functional evolution of Delta/Notch signaling in arthropod body and leg segmentation, we analyzed the function of the Delta (Gb′Delta) and Notch (Gb′Notch) genes in the hemimetabolous, intermediate-germ cricket Gryllus bimaculatus. We found that Gb′Delta and Gb′Notch were expressed in developing legs, and that RNAi silencing of Gb′Notch resulted in a marked reduction in leg length with a loss of joints. Our results suggest that the role of Notch signaling in leg segmentation is conserved in hemimetabolous insects. Furthermore, we found that Gb′Delta was expressed transiently in the posterior growth zone of the germband and in segmental stripes earlier than the appearance of wingless segmental stripes, whereas Gb′Notch was uniformly expressed in early germbands. RNAi knockdown of Gb′Delta or Gb′Notch expression resulted in malformation in body segments and a loss of posterior segments, the latter probably due to a defect in posterior growth. Therefore, in the cricket, Delta/Notch signaling might be required for proper morphogenesis of body segments and posterior elongation, but not for specification of segment boundaries.
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Affiliation(s)
- Taro Mito
- Department of Life Systems, Institute of Technology and Science, The University of Tokushima, 2-1 Minami-Jyosanjima-cho, Tokushima City, 770-8506 Japan
| | - Yohei Shinmyo
- Department of Life Systems, Institute of Technology and Science, The University of Tokushima, 2-1 Minami-Jyosanjima-cho, Tokushima City, 770-8506 Japan
| | - Kazuki Kurita
- Department of Life Systems, Institute of Technology and Science, The University of Tokushima, 2-1 Minami-Jyosanjima-cho, Tokushima City, 770-8506 Japan
| | - Taro Nakamura
- Department of Life Systems, Institute of Technology and Science, The University of Tokushima, 2-1 Minami-Jyosanjima-cho, Tokushima City, 770-8506 Japan
| | - Hideyo Ohuchi
- Department of Life Systems, Institute of Technology and Science, The University of Tokushima, 2-1 Minami-Jyosanjima-cho, Tokushima City, 770-8506 Japan
| | - Sumihare Noji
- Department of Life Systems, Institute of Technology and Science, The University of Tokushima, 2-1 Minami-Jyosanjima-cho, Tokushima City, 770-8506 Japan
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Pueyo JI, Couso JP. Tarsal-less peptides control Notch signalling through the Shavenbaby transcription factor. Dev Biol 2011; 355:183-93. [PMID: 21527259 PMCID: PMC3940869 DOI: 10.1016/j.ydbio.2011.03.033] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 03/28/2011] [Accepted: 03/29/2011] [Indexed: 11/24/2022]
Abstract
The formation of signalling boundaries is one of the strategies employed by the Notch (N) pathway to give rise to two distinct signalling populations of cells. Unravelling the mechanisms involved in the regulation of these signalling boundaries is essential to understanding the role of N during development and diseases. The function of N in the segmentation of the Drosophila leg provides a good system to pursue these mechanisms at the molecular level. Transcriptional and post-transcriptional regulation of the N ligands, Serrate (Ser) and Delta (Dl) generates a signalling boundary that allows the directional activation of N in the distalmost part of the segment, the presumptive joint. A negative feedback loop between odd-skipped-related genes and the N pathway maintains this signalling boundary throughout development in the true joints. However, the mechanisms controlling N signalling boundaries in the tarsal joints are unknown. Here we show that the non-canonical tarsal-less (tal) gene (also known as pri), which encodes for four small related peptides, is expressed in the N-activated region and required for joint development in the tarsi during pupal development. This function of tal is both temporally and functionally separate from the tal-mediated tarsal intercalation during mid-third instar that we reported previously. In the pupal function described here, N signalling activates tal expression and reciprocally Tal peptides feedback on N by repressing the transcription of Dl in the tarsal joints. This Tal-induced repression of Dl is mediated by the post-transcriptional activation of the Shavenbaby transcription factor, in a similar manner as it has been recently described in the embryo. Thus, a negative feedback loop involving Tal regulates the formation and maintenance of a Dl+/Dl- boundary in the tarsal segments highlighting an ancient mechanism for the regulation of N signalling based on the action of small cell signalling peptides.
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Affiliation(s)
| | - Juan Pablo Couso
- Corresponding author: School of Life Sciences, University of Sussex, Falmer, Brighton, United Kingdom, BN1 9QG.
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Turchyn N, Chesebro J, Hrycaj S, Couso JP, Popadić A. Evolution of nubbin function in hemimetabolous and holometabolous insect appendages. Dev Biol 2011; 357:83-95. [PMID: 21708143 DOI: 10.1016/j.ydbio.2011.06.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 06/10/2011] [Accepted: 06/11/2011] [Indexed: 10/18/2022]
Abstract
Insects display a whole spectrum of morphological diversity, which is especially noticeable in the organization of their appendages. A recent study in a hemipteran, Oncopeltus fasciatus (milkweed bug), showed that nubbin (nub) affects antenna morphogenesis, labial patterning, the length of the femoral segment in legs, and the formation of a limbless abdomen. To further determine the role of this gene in the evolution of insect morphology, we analyzed its functions in two additional hemimetabolous species, Acheta domesticus (house cricket) and Periplaneta americana (cockroach), and re-examined its role in Drosophila melanogaster (fruit fly). While both Acheta and Periplaneta nub-RNAi first nymphs develop crooked antennae, no visible changes are observed in the morphologies of their mouthparts and abdomen. Instead, the main effect is seen in legs. The joint between the tibia and first tarsomere (Ta-1) is lost in Acheta, which in turn, causes a fusion of these two segments and creates a chimeric nub-RNAi tibia-tarsus that retains a tibial identity in its proximal half and acquires a Ta-1 identity in its distal half. Similarly, our re-analysis of nub function in Drosophila reveals that legs lack all true joints and the fly tibia also exhibits a fused tibia and tarsus. Finally, we observe a similar phenotype in Periplaneta except that it encompasses different joints (coxa-trochanter and femur-tibia), and in this species we also show that nub expression in the legs is regulated by Notch signaling, as had previously been reported in flies and spiders. Overall, we propose that nub acts downstream of Notch on the distal part of insect leg segments to promote their development and growth, which in turn is required for joint formation. Our data represent the first functional evidence defining a role for nub in leg segmentation and highlight the varying degrees of its involvement in this process across insects.
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Affiliation(s)
- Nataliya Turchyn
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
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Wolff C, Hilbrant M. The embryonic development of the central American wandering spider Cupiennius salei. Front Zool 2011; 8:15. [PMID: 21672209 PMCID: PMC3141654 DOI: 10.1186/1742-9994-8-15] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Accepted: 06/14/2011] [Indexed: 12/04/2022] Open
Abstract
Background The spider Cupiennius salei (Keyserling 1877) has become an important study organism in evolutionary and developmental biology. However, the available staging system for its embryonic development is difficult to apply to modern studies, with strong bias towards the earliest developmental stages. Furthermore, important embryonic events are poorly understood. We address these problems, providing a new description of the embryonic development of C. salei. The paper also discusses various observations that will improve our understanding of spider development. Results Conspicuous developmental events were used to define numbered stages 1 to 21. Stages 1 to 9 follow the existing staging system for the spider Achaearanea tepidariorum, and stages 10 to 21 provide a high-resolution description of later development. Live-embryo imaging shows cell movements during the earliest formation of embryonic tissue in C. salei. The imaging procedure also elucidates the encircling border between the cell-dense embryo hemisphere and the hemisphere with much lower cell density (a structure termed 'equator' in earlier studies). This border results from subsurface migration of primordial mesendodermal cells from their invagination site at the blastopore. Furthermore, our detailed successive sequence shows: 1) early differentiation of the precheliceral neuroectoderm; 2) the morphogenetic process of inversion and 3) initial invaginations of the opisthosomal epithelium for the respiratory system. Conclusions Our improved staging system of development in C. salei development should be of considerable value to future comparative studies of animal development. A dense germ disc is not evident during development in C. salei, but we show that the gastrulation process is similar to that in spider species that do have a dense germ disc. In the opisthosoma, the order of appearance of precursor epithelial invaginations provides evidence for the non-homology of the tracheal and book lung respiratory systems.
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Affiliation(s)
- Carsten Wolff
- Humboldt-Universität zu Berlin Institut für Biologie/Vergleichende Zoologie Philippstraße 13, 10115 Berlin, Germany
| | - Maarten Hilbrant
- Universität zu Köln Institut für Genetik, Zülpicher Straße 47a, 50674 Köln, Germany.,Oxford Brookes University Headington Campus Gipsy Lane, Oxford OX3 0BP, UK
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Maruzzo D, Minelli A. Post-embryonic development of amphipod crustacean pleopods and the patterning of arthropod limbs. ZOOL ANZ 2011. [DOI: 10.1016/j.jcz.2010.11.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Pechmann M, Khadjeh S, Sprenger F, Prpic NM. Patterning mechanisms and morphological diversity of spider appendages and their importance for spider evolution. ARTHROPOD STRUCTURE & DEVELOPMENT 2010; 39:453-467. [PMID: 20696272 DOI: 10.1016/j.asd.2010.07.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 07/07/2010] [Accepted: 07/27/2010] [Indexed: 05/29/2023]
Abstract
The prosoma of spiders bears different gnathal (labrum, chelicerae, pedipalps) and locomotory appendages (legs). In most species these appendages are also used for additional functions, e.g. sensing, mating, and courtship. The opisthosoma is equipped with four pairs of highly specialized appendages. Two pairs of spinnerets are used for silk production and manipulation. The other two pairs of appendages are internalized during development and give rise to a complex respiratory system of book lungs and tracheae. Thus spiders have a number of different appendage types with radically different adult morphologies. Furthermore, all these appendage types display significant additional species specific diversity correlating with a large spectrum of functions of the appendages. Despite this importance of appendage diversity for the evolution of the spiders we know relatively little about the genetic patterning mechanisms producing this diversity of morphology. We review recent advances concerning the developmental genetics of spider appendage diversification, mainly concentrating on open questions and future directions of research. We conclude that the deeper understanding of appendage development and diversity in spiders can contribute significantly not only to evolutionary developmental biology, but also to behavioral biology, speciation research and population genetics, and the study of sexually dimorphic traits.
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Affiliation(s)
- Matthias Pechmann
- Georg-August-Universität Göttingen, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Abteilung für Entwicklungsbiologie, GZMB Ernst-Caspari-Haus, Justus-von-Liebig-Weg 11, Göttingen, Germany
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Janssen R, Eriksson BJ, Budd GE, Akam M, Prpic NM. Gene expression patterns in an onychophoran reveal that regionalization predates limb segmentation in pan-arthropods. Evol Dev 2010; 12:363-72. [DOI: 10.1111/j.1525-142x.2010.00423.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Separable functions of wingless in distal and ventral patterning of the Tribolium leg. Dev Genes Evol 2009; 219:469-79. [PMID: 20024581 PMCID: PMC2811246 DOI: 10.1007/s00427-009-0310-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Accepted: 11/23/2009] [Indexed: 11/29/2022]
Abstract
The gene wingless (wg) in Drosophila is an important factor in leg development. During embryonic development wg is involved in the allocation of the limb primordia. During imaginal disk development wg is involved in distal development and it has a separate role in ventral development. The expression pattern of wg is highly conserved in all arthropods (comprising data from insects, myriapods, crustaceans, and chelicerates), suggesting that its function in leg development is also conserved. However, recent work in other insects (e.g. the milkweed bug Oncopeltus fasciatus) argued against a role of wg in leg development. We have studied the role of wg in leg development of the flour beetle Tribolium castaneum. Using stage-specific staggered embryonic RNAi in wild-type and transgenic EGFP expressing enhancer trap lines we are able to demonstrate separable functions of Tribolium wg in distal and in ventral leg development. The distal role affects all podomeres distal to the coxa, whereas the ventral role is restricted to cells along the ventral midline of the legs. In addition, severe leg defects after injection into early embryonic stages are evidence that wg is also involved in proximal development and limb allocation in Tribolium. Our data suggest that the roles of wg in leg development are highly conserved in the holometabolous insects. Further studies will reveal the degree of conservation in other arthropod groups.
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Insertional mutagenesis screening identifies the zinc finger homeodomain 2 (zfh2) gene as a novel factor required for embryonic leg development in Tribolium castaneum. Dev Genes Evol 2009; 219:399-407. [PMID: 19760181 PMCID: PMC2773040 DOI: 10.1007/s00427-009-0303-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Accepted: 08/30/2009] [Indexed: 11/18/2022]
Abstract
The genetic control of leg development is well characterized in the fly Drosophila melanogaster. These control mechanisms, however, must differ to some degree between different insect species to account for the morphological diversity of thoracic legs in the insects. The legs of the flour beetle Tribolium castaneum differ from the Drosophila legs in their developmental mode as well as in their specific morphology especially at the larval stage. In order to identify genes involved in the morphogenesis of the Tribolium larval legs, we have analyzed EGFP enhancer trap lines of Tribolium. We have identified the zfh2 gene as a novel factor required for normal leg development in Tribolium. RNA interference with zfh2 function leads to two alternative classes of leg phenotype. The loss of a leg segment boundary and the generation of ectopic outgrowths in one class of phenotype suggest a role in leg segmentation and segment growth. The malformation of the pretarsal claw in the second class of phenotype suggests a role in distal development and the morphogenesis of the claw-shaped morphology of the pretarsus. This suggests that zfh2 is involved in the regulation of an unidentified target gene in a concentration-dependent manner. Our results demonstrate that enhancer trap screens in T. castaneum have the potential to identify novel gene functions regulating specific developmental processes.
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Schaeper ND, Prpic NM, Wimmer EA. A conserved function of the zinc finger transcription factor Sp8/9 in allometric appendage growth in the milkweed bug Oncopeltus fasciatus. Dev Genes Evol 2009; 219:427-35. [PMID: 19760183 PMCID: PMC2773111 DOI: 10.1007/s00427-009-0301-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Accepted: 08/30/2009] [Indexed: 11/01/2022]
Abstract
The genes encoding the closely related zinc finger transcription factors Buttonhead (Btd) and D-Sp1 are expressed in the developing limb primordia of Drosophila melanogaster and are required for normal growth of the legs. The D-Sp1 homolog of the red flour beetle Tribolium castaneum, Sp8 (appropriately termed Sp8/9), is also required for the proper growth of the leg segments. Here we report on the isolation and functional study of the Sp8/9 gene from the milkweed bug Oncopeltus fasciatus. We show that Sp8/9 is expressed in the developing appendages throughout development and that the downregulation of Sp8/9 via RNAi leads to antennae, rostrum, and legs with shortened and fused segments. This supports a conserved role of Sp8/9 in allometric leg segment growth. However, all leg segments including the claws are present and the expression of the leg genes Distal-less, dachshund, and homothorax are proportionally normal, thus providing no evidence for a role of Sp8/9 in appendage specification.
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Affiliation(s)
- Nina D Schaeper
- Georg-August-Universität, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Abteilung Entwicklungsbiologie, GZMB, Ernst-Caspari-Haus, Justus-von-Liebig-Weg 11, Göttingen, Germany
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Appendage patterning in the South American bird spider Acanthoscurria geniculata (Araneae: Mygalomorphae). Dev Genes Evol 2009; 219:189-98. [DOI: 10.1007/s00427-009-0279-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Accepted: 02/19/2009] [Indexed: 01/08/2023]
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