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Mann KE, Panfilio KA. Tissue-Level Integration Overrides Gradations of Differentiating Cell Identity in Beetle Extraembryonic Tissue. Cells 2024; 13:1211. [PMID: 39056793 PMCID: PMC11274815 DOI: 10.3390/cells13141211] [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: 04/12/2024] [Revised: 07/10/2024] [Accepted: 07/10/2024] [Indexed: 07/28/2024] Open
Abstract
During animal embryogenesis, one of the earliest specification events distinguishes extraembryonic (EE) from embryonic tissue fates: the serosa in the case of the insects. While it is well established that the homeodomain transcription factor Zen1 is the critical determinant of the serosa, the subsequent realization of this tissue's identity has not been investigated. Here, we examine serosal differentiation in the beetle Tribolium castaneum based on the quantification of morphological and morphogenetic features, comparing embryos from a Tc-zen1 RNAi dilution series, where complete knockdown results in amnion-only EE tissue identity. We assess features including cell density, tissue boundary morphology, and nuclear size as dynamic readouts for progressive tissue maturation. While some features exhibit an all-or-nothing outcome, other key features show dose-dependent phenotypic responses with trait-specific thresholds. Collectively, these findings provide nuance beyond the known status of Tc-Zen1 as a selector gene for serosal tissue patterning. Overall, our approach illustrates how the analysis of tissue maturation dynamics from live imaging extends but also challenges interpretations based on gene expression data, refining our understanding of tissue identity and when it is achieved.
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Affiliation(s)
- Katie E. Mann
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Kristen A. Panfilio
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
- Department of Molecular Genetics, Institute of Biology, University of Hohenheim, Garbenstr. 30, 70599 Stuttgart, Germany
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2
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Kaufholz F, Ulrich J, Hakeemi MS, Bucher G. Temporal control of RNAi reveals both robust and labile feedback loops in the segmentation clock of the red flour beetle. Proc Natl Acad Sci U S A 2024; 121:e2318229121. [PMID: 38865277 PMCID: PMC11194489 DOI: 10.1073/pnas.2318229121] [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: 10/19/2023] [Accepted: 05/03/2024] [Indexed: 06/14/2024] Open
Abstract
Animals from all major clades have evolved a segmented trunk, reflected in the human spine or the insect segments. These units emerge during embryogenesis from a posterior segment addition zone (SAZ), where repetitive gene activity is regulated by a mechanism described by the clock and wavefront/speed gradient model. In the red flour beetle Tribolium castaneum, RNA interference (RNAi) has been used to continuously knock down the function of primary pair-rule genes (pPRGs), caudal or Wnt pathway components, which has led to the complete breakdown of segmentation. However, it has remained untested, if this breakdown was reversible by bringing the missing gene function back to the system. To fill this gap, we established a transgenic system in T. castaneum, which allows blocking an ongoing RNAi effect with temporal control by expressing a viral inhibitor of RNAi via heat shock. We show that the T. castaneum segmentation machinery was able to reestablish after RNAi targeting the pPRGs Tc-eve, Tc-odd, and Tc-runt was blocked. However, we observed no rescue after blocking RNAi targeting Wnt pathway components. We conclude that the insect segmentation system contains both robust feedback loops that can reestablish and labile feedback loops that break down irreversibly. This combination may reconcile conflicting needs of the system: Labile systems controlling initiation and maintenance of the SAZ ensure that only one SAZ is formed. Robust feedback loops confer developmental robustness toward external disturbances.
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Affiliation(s)
- Felix Kaufholz
- Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, Göttingen37077, Germany
- Department of Evolutionary Developmental Genetics, University of Göttingen, Johann-Friedrich-Blumenbach Institute, Göttingen Center for Molecular Biosciences, Göttingen37077, Germany
| | - Julia Ulrich
- Department of Evolutionary Developmental Genetics, University of Göttingen, Johann-Friedrich-Blumenbach Institute, Göttingen Center for Molecular Biosciences, Göttingen37077, Germany
| | - Muhammad Salim Hakeemi
- Department of Evolutionary Developmental Genetics, University of Göttingen, Johann-Friedrich-Blumenbach Institute, Göttingen Center for Molecular Biosciences, Göttingen37077, Germany
| | - Gregor Bucher
- Department of Evolutionary Developmental Genetics, University of Göttingen, Johann-Friedrich-Blumenbach Institute, Göttingen Center for Molecular Biosciences, Göttingen37077, Germany
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3
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Murugesan SN, Monteiro A. Butterfly eyespots exhibit unique patterns of open chromatin. F1000Res 2023; 12:1428. [PMID: 38778811 PMCID: PMC11109672 DOI: 10.12688/f1000research.133789.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/02/2023] [Indexed: 05/25/2024] Open
Abstract
Background: How the precise spatial regulation of genes is correlated with spatial variation in chromatin accessibilities is not yet clear. Previous studies that analysed chromatin from homogenates of whole-body parts of insects found little variation in chromatin accessibility across those parts, but single-cell studies of Drosophila brains showed extensive spatial variation in chromatin accessibility across that organ. In this work we studied the chromatin accessibility of butterfly wing tissue fated to differentiate distinct colors and patterns in pupal wings of Bicyclus anynana. Methods: We dissected small eyespot and adjacent control tissues from 3h pupae and performed ATAC-Seq to identify the chromatin accessibility differences between different sections of the wings. Results: We observed that three dissected wing regions showed unique chromatin accessibilities. Open chromatin regions specific to eyespot color patterns were highly enriched for binding motifs recognized by Suppressor of Hairless (Su(H)), Krüppel (Kr), Buttonhead (Btd) and Nubbin (Nub) transcription factors. Genes in the vicinity of the eyespot-specific open chromatin regions included those involved in wound healing and SMAD signal transduction pathways, previously proposed to be involved in eyespot development. Conclusions: We conclude that eyespot and non-eyespot tissue samples taken from the same wing have distinct patterns of chromatin accessibility, possibly driven by the eyespot-restricted expression of potential pioneer factors, such as Kr.
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Affiliation(s)
| | - Antónia Monteiro
- Biological Sciences, National University of Singapore, Singapore, 117558, Singapore
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4
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Klingler M, Bucher G. The red flour beetle T. castaneum: elaborate genetic toolkit and unbiased large scale RNAi screening to study insect biology and evolution. EvoDevo 2022; 13:14. [PMID: 35854352 PMCID: PMC9295526 DOI: 10.1186/s13227-022-00201-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 07/05/2022] [Indexed: 11/16/2022] Open
Abstract
The red flour beetle Tribolium castaneum has emerged as an important insect model system for a variety of topics. With respect to studying gene function, it is second only to the vinegar fly D. melanogaster. The RNAi response in T. castaneum is exceptionally strong and systemic, and it appears to target all cell types and processes. Uniquely for emerging model organisms, T. castaneum offers the opportunity of performing time- and cost-efficient large-scale RNAi screening, based on commercially available dsRNAs targeting all genes, which are simply injected into the body cavity. Well established transgenic and genome editing approaches are met by ease of husbandry and a relatively short generation time. Consequently, a number of transgenic tools like UAS/Gal4, Cre/Lox, imaging lines and enhancer trap lines are already available. T. castaneum has been a genetic experimental system for decades and now has become a workhorse for molecular and reverse genetics as well as in vivo imaging. Many aspects of development and general biology are more insect-typical in this beetle compared to D. melanogaster. Thus, studying beetle orthologs of well-described fly genes has allowed macro-evolutionary comparisons in developmental processes such as axis formation, body segmentation, and appendage, head and brain development. Transgenic approaches have opened new ways for in vivo imaging. Moreover, this emerging model system is the first choice for research on processes that are not represented in the fly, or are difficult to study there, e.g. extraembryonic tissues, cryptonephridial organs, stink gland function, or dsRNA-based pesticides.
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Affiliation(s)
- Martin Klingler
- Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Staudtstr. 5, 91058, Erlangen, Germany.
| | - Gregor Bucher
- Johann-Friedrich-Blumenbach-Institut, GZMB, University of Göttingen, Justus-von-Liebig-Weg 11, 37077, Göttingen, Germany.
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5
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Diaz-Cuadros M, Pourquié O, El-Sherif E. Patterning with clocks and genetic cascades: Segmentation and regionalization of vertebrate versus insect body plans. PLoS Genet 2021; 17:e1009812. [PMID: 34648490 PMCID: PMC8516289 DOI: 10.1371/journal.pgen.1009812] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Oscillatory and sequential processes have been implicated in the spatial patterning of many embryonic tissues. For example, molecular clocks delimit segmental boundaries in vertebrates and insects and mediate lateral root formation in plants, whereas sequential gene activities are involved in the specification of regional identities of insect neuroblasts, vertebrate neural tube, vertebrate limb, and insect and vertebrate body axes. These processes take place in various tissues and organisms, and, hence, raise the question of what common themes and strategies they share. In this article, we review 2 processes that rely on the spatial regulation of periodic and sequential gene activities: segmentation and regionalization of the anterior-posterior (AP) axis of animal body plans. We study these processes in species that belong to 2 different phyla: vertebrates and insects. By contrasting 2 different processes (segmentation and regionalization) in species that belong to 2 distantly related phyla (arthropods and vertebrates), we elucidate the deep logic of patterning by oscillatory and sequential gene activities. Furthermore, in some of these organisms (e.g., the fruit fly Drosophila), a mode of AP patterning has evolved that seems not to overtly rely on oscillations or sequential gene activities, providing an opportunity to study the evolution of pattern formation mechanisms.
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Affiliation(s)
- Margarete Diaz-Cuadros
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Pathology, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
| | - Olivier Pourquié
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Pathology, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
- Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts, United States of America
| | - Ezzat El-Sherif
- Division of Developmental Biology, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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6
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Chipman AD. The evolution of the gene regulatory networks patterning the Drosophila Blastoderm. Curr Top Dev Biol 2021; 139:297-324. [PMID: 32450964 DOI: 10.1016/bs.ctdb.2020.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The Drosophila blastoderm gene regulatory network is one of the best studied networks in biology. It is composed of a series of tiered sub-networks that act sequentially to generate a primary segmental pattern. Many of these sub-networks have been studied in other arthropods, allowing us to reconstruct how each of them evolved over the transition from the arthropod ancestor to the situation seen in Drosophila today. I trace the evolution of each of these networks, showing how some of them have been modified significantly in Drosophila relative to the ancestral state while others are largely conserved across evolutionary timescales. I compare the putative ancestral arthropod segmentation network with that found in Drosophila and discuss how and why it has been modified throughout evolution, and to what extent this modification is unusual.
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Affiliation(s)
- Ariel D Chipman
- The Department of Ecology, Evolution & Behavior, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, Israel.
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7
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Tidswell ORA, Benton MA, Akam M. The neuroblast timer gene nubbin exhibits functional redundancy with gap genes to regulate segment identity in Tribolium. Development 2021; 148:271199. [PMID: 34351412 PMCID: PMC8406537 DOI: 10.1242/dev.199719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 07/23/2021] [Indexed: 12/05/2022]
Abstract
The neuroblast timer genes hunchback, Krüppel, nubbin and castor are expressed in temporal sequence in neural stem cells, and in corresponding spatial sequence along the Drosophila blastoderm. As canonical gap genes, hunchback and Krüppel play a crucial role in insect segmentation, but the roles of nubbin and castor in this process remain ambiguous. We have investigated the expression and functions of nubbin and castor during segmentation in the beetle Tribolium. We show that Tc-hunchback, Tc-Krüppel, Tc-nubbin and Tc-castor are expressed sequentially in the segment addition zone, and that Tc-nubbin regulates segment identity redundantly with two previously described gap/gap-like genes, Tc-giant and Tc-knirps. Simultaneous knockdown of Tc-nubbin, Tc-giant and Tc-knirps results in the formation of ectopic legs on abdominal segments. This homeotic transformation is caused by loss of abdominal Hox gene expression, likely due to expanded Tc-Krüppel expression. Our findings support the theory that the neuroblast timer series was co-opted for use in insect segment patterning, and contribute to our growing understanding of the evolution and function of the gap gene network outside of Drosophila. Summary:nubbin and the gap genes knirps and giant redundantly repress Krüppel expression during segmentation. Simultaneous knockdown of all three genes causes ectopic Krüppel expression and loss of abdominal segment identity.
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Affiliation(s)
| | - Matthew A Benton
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
| | - Michael Akam
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
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8
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Nakao H. Early embryonic development of Bombyx. Dev Genes Evol 2021; 231:95-107. [PMID: 34296338 DOI: 10.1007/s00427-021-00679-8] [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: 12/03/2020] [Accepted: 07/09/2021] [Indexed: 11/25/2022]
Abstract
Decades have passed since the early molecular embryogenesis of Drosophila melanogaster was outlined. During this period, the molecular mechanisms underlying early embryonic development in other insects, particularly the flour beetle, Tribolium castaneum, have been described in more detail. The information clearly demonstrated that Drosophila embryogenesis is not representative of other insects and has highly distinctive characteristics. At the same time, this new data has been gradually clarifying ancestral operating mechanisms. The silk moth, Bombyx mori, is a lepidopteran insect and, as a representative of the order, has many unique characteristics found in early embryonic development that have not been identified in other insect groups. Herein, some of these characteristics are introduced and discussed in the context of recent information obtained from other insects.
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Affiliation(s)
- Hajime Nakao
- Insect Genome Research and Engineering Unit, Division of Applied Genetics, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), 1-2 Oowashi, Tsukuba, Ibaraki, 305-8634, Japan.
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9
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Klann M, Schacht MI, Benton MA, Stollewerk A. Functional analysis of sense organ specification in the Tribolium castaneum larva reveals divergent mechanisms in insects. BMC Biol 2021; 19:22. [PMID: 33546687 PMCID: PMC7866635 DOI: 10.1186/s12915-021-00948-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/04/2021] [Indexed: 12/27/2022] Open
Abstract
Abstract Insects and other arthropods utilise external sensory structures for mechanosensory, olfactory, and gustatory reception. These sense organs have characteristic shapes related to their function, and in many cases are distributed in a fixed pattern so that they are identifiable individually. In Drosophila melanogaster, the identity of sense organs is regulated by specific combinations of transcription factors. In other arthropods, however, sense organ subtypes cannot be linked to the same code of gene expression. This raises the questions of how sense organ diversity has evolved and whether the principles underlying subtype identity in D. melanogaster are representative of other insects. Here, we provide evidence that such principles cannot be generalised, and suggest that sensory organ diversification followed the recruitment of sensory genes to distinct sensory organ specification mechanism. Results We analysed sense organ development in a nondipteran insect, the flour beetle Tribolium castaneum, by gene expression and RNA interference studies. We show that in contrast to D. melanogaster, T. castaneum sense organs cannot be categorised based on the expression or their requirement for individual or combinations of conserved sense organ transcription factors such as cut and pox neuro, or members of the Achaete-Scute (Tc ASH, Tc asense), Atonal (Tc atonal, Tc cato, Tc amos), and neurogenin families (Tc tap). Rather, our observations support an evolutionary scenario whereby these sensory genes are required for the specification of sense organ precursors and the development and differentiation of sensory cell types in diverse external sensilla which do not fall into specific morphological and functional classes. Conclusions Based on our findings and past research, we present an evolutionary scenario suggesting that sense organ subtype identity has evolved by recruitment of a flexible sensory gene network to the different sense organ specification processes. A dominant role of these genes in subtype identity has evolved as a secondary effect of the function of these genes in individual or subsets of sense organs, probably modulated by positional cues. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-00948-y.
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Affiliation(s)
- Marleen Klann
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.,Marine Eco-Evo-Devo Unit, Okinawa Institute for Science and Technology (OIST), 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
| | - Magdalena Ines Schacht
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Matthew Alan Benton
- Department of Zoology, University of Cambridge, Downing St, Cambridge, CB2 3EJ, UK
| | - Angelika Stollewerk
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
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10
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Lim J, Choe CP. Functional analysis of engrailed in Tribolium segmentation. Mech Dev 2019; 161:103594. [PMID: 31778794 DOI: 10.1016/j.mod.2019.103594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 11/05/2019] [Accepted: 11/21/2019] [Indexed: 10/25/2022]
Abstract
The segment-polarity gene engrailed is required for segmentation in the early Drosophila embryo. Loss of Engrailed function results in segmentation defects that vary in severity from pair-rule phenotypes to a lawn phenotype lacking in obvious of segmentation. During segmentation, Engrailed is expressed in stripes with a single segmental periodicity in Drosophila, which is conserved in all arthropods examined so far. To define segments, the segmental stripes of Engrailed induce the segmental stripes of wingless at each parasegmental boundary. However, segmentation functions of orthologs of engrailed in non-Drosophila arthropods have yet to be reported. Here, we analyzed functions of the Tribolium ortholog of engrailed (Tc-engrailed) during embryonic segmentation. Larval cuticles with Tc-engrailed being knocked down had segmentation phenotypes including incomplete segment formation and loss of a group of segments. In agreement with the cuticle segmentation defects, segments developed incompletely and irregularly or did not form in Tribolium germbands where Tc-engrailed was knocked down. Furthermore, knock-down of Tc-engrailed did not properly express the segmental stripes of wingless in Tribolium germbands. Taken together with the conserved expression patterns of Engrailed in arthropod segmentation, our data suggest that Tc-engrailed is required for embryonic segmentation in Tribolium, and the genetic mechanism of Engrailed inducing wingless expression is conserved at least between Drosophila and Tribolium.
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Affiliation(s)
- Jinsung Lim
- Division of Applied Life Science (BK21 Plus Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Chong Pyo Choe
- Division of Applied Life Science (BK21 Plus Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 52828, Republic of Korea; Division of Life Science, Gyeongsang National University, Jinju 52828, Republic of Korea.
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11
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Rudolf H, Zellner C, El-Sherif E. Speeding up anterior-posterior patterning of insects by differential initialization of the gap gene cascade. Dev Biol 2019; 460:20-31. [PMID: 31075221 DOI: 10.1016/j.ydbio.2019.04.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 04/25/2019] [Accepted: 04/25/2019] [Indexed: 01/28/2023]
Abstract
Recently, it was shown that anterior-posterior patterning genes in the red flour beetle Tribolium castaneum are expressed sequentially in waves. However, in the fruit fly Drosophila melanogaster, an insect with a derived mode of embryogenesis compared to Tribolium, anterior-posterior patterning genes quickly and simultaneously arise as mature gene expression domains that, afterwards, undergo slight posterior-to-anterior shifts. This raises the question of how a fast and simultaneous mode of patterning, like that of Drosophila, could have evolved from a rather slow sequential mode of patterning, like that of Tribolium. In this paper, we propose a mechanism for this evolutionary transition based on a switch from a uniform to a gradient-mediated initialization of the gap gene cascade by maternal Hb. The model is supported by computational analyses and experiments.
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Affiliation(s)
- Heike Rudolf
- Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 5, Erlangen, 91058, Germany
| | - Christine Zellner
- Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 5, Erlangen, 91058, Germany
| | - Ezzat El-Sherif
- Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 5, Erlangen, 91058, Germany.
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12
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Ray S, Rosenberg MI, Chanut-Delalande H, Decaras A, Schwertner B, Toubiana W, Auman T, Schnellhammer I, Teuscher M, Valenti P, Khila A, Klingler M, Payre F. The mlpt/Ubr3/Svb module comprises an ancient developmental switch for embryonic patterning. eLife 2019; 8:e39748. [PMID: 30896406 PMCID: PMC6428570 DOI: 10.7554/elife.39748] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 03/07/2019] [Indexed: 12/30/2022] Open
Abstract
Small open reading frames (smORFs) encoding 'micropeptides' exhibit remarkable evolutionary complexity. Conserved peptides encoded by mille-pattes (mlpt)/polished rice (pri)/tarsal less (tal) are essential for embryo segmentation in Tribolium but, in Drosophila, function in terminal epidermal differentiation and patterning of adult legs. Here, we show that a molecular complex identified in Drosophila epidermal differentiation, comprising Mlpt peptides, ubiquitin-ligase Ubr3 and transcription factor Shavenbaby (Svb), represents an ancient developmental module required for early insect embryo patterning. We find that loss of segmentation function for this module in flies evolved concomitantly with restriction of Svb expression in early Drosophila embryos. Consistent with this observation, artificially restoring early Svb expression in flies causes segmentation defects that depend on mlpt function, demonstrating enduring potency of an ancestral developmental switch despite evolving embryonic patterning modes. These results highlight the evolutionary plasticity of conserved molecular complexes under the constraints of essential genetic networks. Editorial note This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).
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Affiliation(s)
- Suparna Ray
- Department of Biology, Developmental BiologyUniversity of Erlangen-NurembergErlangenGermany
| | - Miriam I Rosenberg
- Department of Ecology, Evolution and BehaviorHebrew University of JerusalemJerusalemIsrael
| | | | | | - Barbara Schwertner
- Department of Biology, Developmental BiologyUniversity of Erlangen-NurembergErlangenGermany
| | | | - Tzach Auman
- Department of Ecology, Evolution and BehaviorHebrew University of JerusalemJerusalemIsrael
| | - Irene Schnellhammer
- Department of Biology, Developmental BiologyUniversity of Erlangen-NurembergErlangenGermany
| | - Matthias Teuscher
- Department of Biology, Developmental BiologyUniversity of Erlangen-NurembergErlangenGermany
| | - Philippe Valenti
- Centre de Biologie du Développement, Université Paul Sabatier de ToulouseToulouseFrance
| | | | - Martin Klingler
- Department of Biology, Developmental BiologyUniversity of Erlangen-NurembergErlangenGermany
| | - François Payre
- Centre de Biologie du Développement, Université Paul Sabatier de ToulouseToulouseFrance
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13
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Boos A, Distler J, Rudolf H, Klingler M, El-Sherif E. A re-inducible gap gene cascade patterns the anterior-posterior axis of insects in a threshold-free fashion. eLife 2018; 7:41208. [PMID: 30570485 PMCID: PMC6329609 DOI: 10.7554/elife.41208] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 12/19/2018] [Indexed: 12/05/2022] Open
Abstract
Gap genes mediate the division of the anterior-posterior axis of insects into different fates through regulating downstream hox genes. Decades of tinkering the segmentation gene network of Drosophila melanogaster led to the conclusion that gap genes are regulated (at least initially) through a threshold-based mechanism, guided by both anteriorly- and posteriorly-localized morphogen gradients. In this paper, we show that the response of the gap gene network in the beetle Tribolium castaneum upon perturbation is consistent with a threshold-free ‘Speed Regulation’ mechanism, in which the speed of a genetic cascade of gap genes is regulated by a posterior morphogen gradient. We show this by re-inducing the leading gap gene (namely, hunchback) resulting in the re-induction of the gap gene cascade at arbitrary points in time. This demonstrates that the gap gene network is self-regulatory and is primarily under the control of a posterior regulator in Tribolium and possibly other short/intermediate-germ insects.
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Affiliation(s)
- Alena Boos
- Division of Developmental Biology, Department of Biology, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jutta Distler
- Division of Developmental Biology, Department of Biology, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Heike Rudolf
- Division of Developmental Biology, Department of Biology, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Martin Klingler
- Division of Developmental Biology, Department of Biology, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Ezzat El-Sherif
- Division of Developmental Biology, Department of Biology, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
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14
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Stahi R, Chipman AD. Blastoderm segmentation in Oncopeltus fasciatus and the evolution of insect segmentation mechanisms. Proc Biol Sci 2017; 283:rspb.2016.1745. [PMID: 27708151 PMCID: PMC5069518 DOI: 10.1098/rspb.2016.1745] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 09/07/2016] [Indexed: 01/21/2023] Open
Abstract
Segments are formed simultaneously in the blastoderm of the fly Drosophila melanogaster through a hierarchical cascade of interacting transcription factors. Conversely, in many insects and in all non-insect arthropods most segments are formed sequentially from the posterior. We have looked at segmentation in the milkweed bug Oncopeltus fasciatus. Posterior segments are formed sequentially, through what is probably the ancestral arthropod mechanism. Formation of anterior segments bears many similarities to the Drosophila segmentation mode. These segments appear nearly simultaneously in the blastoderm, via a segmentation cascade that involves orthologues of Drosophila gap genes working through a functionally similar mechanism. We suggest that simultaneous blastoderm segmentation evolved at or close to the origin of holometabolous insects, and formed the basis for the evolution of the segmentation mode seen in Drosophila. We discuss the changes in segmentation mechanisms throughout insect evolution, and suggest that the appearance of simultaneous segmentation as a novel feature of holometabolous insects may have contributed to the phenomenal success of this group.
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Affiliation(s)
- Reut Stahi
- The Department of Ecology, Evolution and Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram 91904, Jerusalem, Israel
| | - Ariel D Chipman
- The Department of Ecology, Evolution and Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram 91904, Jerusalem, Israel
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Speed regulation of genetic cascades allows for evolvability in the body plan specification of insects. Proc Natl Acad Sci U S A 2017; 114:E8646-E8655. [PMID: 28973882 DOI: 10.1073/pnas.1702478114] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
During the anterior-posterior fate specification of insects, anterior fates arise in a nonelongating tissue (called the "blastoderm"), and posterior fates arise in an elongating tissue (called the "germband"). However, insects differ widely in the extent to which anterior-posterior fates are specified in the blastoderm versus the germband. Here we present a model in which patterning in both the blastoderm and germband of the beetle Tribolium castaneum is based on the same flexible mechanism: a gradient that modulates the speed of a genetic cascade of gap genes, resulting in the induction of sequential kinematic waves of gap gene expression. The mechanism is flexible and capable of patterning both elongating and nonelongating tissues, and hence converting blastodermal to germband fates and vice versa. Using RNAi perturbations, we found that blastodermal fates could be shifted to the germband, and germband fates could be generated in a blastoderm-like morphology. We also suggest a molecular mechanism underlying our model, in which gradient levels regulate the switch between two enhancers: One enhancer is responsible for sequential gene activation, and the other is responsible for freezing temporal rhythms into spatial patterns. This model is consistent with findings in Drosophila melanogaster, where gap genes were found to be regulated by two nonredundant "shadow" enhancers.
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Strobl F, Ross JA, Stelzer EHK. Non-lethal genotyping of Tribolium castaneum adults using genomic DNA extracted from wing tissue. PLoS One 2017; 12:e0182564. [PMID: 28800588 PMCID: PMC5553768 DOI: 10.1371/journal.pone.0182564] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 07/20/2017] [Indexed: 01/11/2023] Open
Abstract
The red flour beetle Tribolium castaneum has become the second most important insect model organism and is frequently used in developmental biology, genetics and pest-associated research. Consequently, the methodological arsenal increases continuously, but many routinely applied techniques for Drosophila melanogaster and other insect species are still unavailable. For example, a protocol for non-lethal genotyping has not yet been adapted but is particularly useful when individuals with known genotypes are required for downstream experiments. In this study, we present a workflow for non-lethal genotyping of T. castaneum adults based on extracting genomic DNA from wing tissue. In detail, we describe a convenient procedure for wing dissection and a custom method for wing digestion that allows PCR-based genotyping of up to fifty adults in less than an afternoon with a success rate of about 86%. The amount of template is sufficient for up to ten reactions while viability and fertility of the beetles are preserved. We prove the applicability of our protocol by genotyping the white / scarlet gene pair alleles from the black-eyed San Bernadino wild-type and white-eyed Pearl recessive mutant strains spanning four generations. Non-lethal genotyping has the potential to improve and accelerate many workflows: Firstly, during the establishment process of homozygous cultures or during stock keeping of cultures that carry recessively lethal alleles, laborious test crossing is replaced by non-lethal genotyping. Secondly, in genome engineering assays, non-lethal genotyping allows the identification of appropriate founders before they are crossed against wild-types, narrowing the efforts down to only the relevant individuals. Thirdly, non-lethal genotyping simplifies experimental strategies, in which genotype and behavior should be correlated, since the genetic configuration of potential individuals can be determined before the actual behavior assays is performed.
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Affiliation(s)
- Frederic Strobl
- Physical Biology / Physikalische Biologie (IZN, FB 15), Buchmann Institute for Molecular Life Sciences (BMLS), Cluster of Excellence Frankfurt–Macromolecular Complexes (CEF–MC), Goethe Universität–Frankfurt am Main (Campus Riedberg), Max-von-Laue-Straße 15, Frankfurt am Main–Germany
| | - J. Alexander Ross
- Physical Biology / Physikalische Biologie (IZN, FB 15), Buchmann Institute for Molecular Life Sciences (BMLS), Cluster of Excellence Frankfurt–Macromolecular Complexes (CEF–MC), Goethe Universität–Frankfurt am Main (Campus Riedberg), Max-von-Laue-Straße 15, Frankfurt am Main–Germany
| | - Ernst H. K. Stelzer
- Physical Biology / Physikalische Biologie (IZN, FB 15), Buchmann Institute for Molecular Life Sciences (BMLS), Cluster of Excellence Frankfurt–Macromolecular Complexes (CEF–MC), Goethe Universität–Frankfurt am Main (Campus Riedberg), Max-von-Laue-Straße 15, Frankfurt am Main–Germany
- * E-mail:
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17
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Janssen R. A molecular view of onychophoran segmentation. ARTHROPOD STRUCTURE & DEVELOPMENT 2017; 46:341-353. [PMID: 27725255 DOI: 10.1016/j.asd.2016.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/22/2016] [Accepted: 10/03/2016] [Indexed: 06/06/2023]
Abstract
This paper summarizes our current knowledge on the expression and assumed function of Drosophila and (other) arthropod segmentation gene orthologs in Onychophora, a closely related outgroup to Arthropoda. This includes orthologs of the so-called Drosophila segmentation gene cascade including the Hox genes, as well as other genetic factors and pathways involved in non-drosophilid arthropods. Open questions about and around the topic are addressed, such as the definition of segments in onychophorans, the unclear regulation of conserved expression patterns downstream of non-conserved factors, and the potential role of mesodermal patterning in onychophoran segmentation.
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Affiliation(s)
- Ralf Janssen
- Uppsala University, Department of Earth Sciences, Palaeobiology, Villavägen 16, 75236 Uppsala, Sweden.
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18
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Strobl F, Klees S, Stelzer EHK. Light Sheet-based Fluorescence Microscopy of Living or Fixed and Stained Tribolium castaneum Embryos. J Vis Exp 2017. [PMID: 28518097 DOI: 10.3791/55629] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The red flour beetle Tribolium castaneum has become an important insect model organism in developmental genetics and evolutionary developmental biology. The observation of Tribolium embryos with light sheet-based fluorescence microscopy has multiple advantages over conventional widefield and confocal fluorescence microscopy. Due to the unique properties of a light sheet-based microscope, three dimensional images of living specimens can be recorded with high signal-to-noise ratios and significantly reduced photo-bleaching as well as photo-toxicity along multiple directions over periods that last several days. With more than four years of methodological development and a continuous increase of data, the time seems appropriate to establish standard operating procedures for the usage of light sheet technology in the Tribolium community as well as in the insect community at large. This protocol describes three mounting techniques suitable for different purposes, presents two novel custom-made transgenic Tribolium lines appropriate for long-term live imaging, suggests five fluorescent dyes to label intracellular structures of fixed embryos and provides information on data post-processing for the timely evaluation of the recorded data. Representative results concentrate on long-term live imaging, optical sectioning and the observation of the same embryo along multiple directions. The respective datasets are provided as a downloadable resource. Finally, the protocol discusses quality controls for live imaging assays, current limitations and the applicability of the outlined procedures to other insect species. This protocol is primarily intended for developmental biologists who seek imaging solutions that outperform standard laboratory equipment. It promotes the continuous attempt to close the gap between the technically orientated laboratories/communities, which develop and refine microscopy methodologically, and the life science laboratories/communities, which require 'plug-and-play' solutions to technical challenges. Furthermore, it supports an axiomatic approach that moves the biological questions into the center of attention.
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Affiliation(s)
- Frederic Strobl
- Physical Biology, Buchmann Institute for Molecular Life Sciences (BMLS); Cluster of Excellence Frankfurt, Macromolecular Complexes; Goethe-Universität Frankfurt am Main - Campus Riedberg
| | - Selina Klees
- Physical Biology, Buchmann Institute for Molecular Life Sciences (BMLS); Cluster of Excellence Frankfurt, Macromolecular Complexes; Goethe-Universität Frankfurt am Main - Campus Riedberg
| | - Ernst H K Stelzer
- Physical Biology, Buchmann Institute for Molecular Life Sciences (BMLS); Cluster of Excellence Frankfurt, Macromolecular Complexes; Goethe-Universität Frankfurt am Main - Campus Riedberg;
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Hunding A, Baumgartner S. Ancient role of ten-m/ odz in segmentation and the transition from sequential to syncytial segmentation. Hereditas 2017; 154:8. [PMID: 28461810 PMCID: PMC5408475 DOI: 10.1186/s41065-017-0029-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 04/11/2017] [Indexed: 02/07/2023] Open
Abstract
Background Until recently, mechanisms of segmentation established for Drosophila served as a paradigm for arthropod segmentation. However, with the discovery of gene expression waves in vertebrate segmentation, another paradigm based on oscillations linked to axial growth was established. The Notch pathway and hairy delay oscillator are basic components of this mechanism, as is the wnt pathway. With the establishment of oscillations during segmentation of the beetle Tribolium, a common segmentation mechanism may have been present in the last common ancestor of vertebrates and arthropods. However, the Notch pathway is not involved in segmentation of the initial Drosophila embryo. In arthropods, the engrailed, wingless pair has a much more conserved function in segmentation than most of the hierarchy established for Drosophila. Results Here, we work backwards from this conserved pair by discussing possible mechanisms which could have taken over the role of the Notch pathway. We propose a pivotal role for the large transmembrane protein Ten-m/Odz. Ten-m/Odz may have had an ancient role in cell-cell communication, parallel to the Notch and wnt pathways. The Ten-m protein binds to the membrane with properties which resemble other membrane-based biochemical oscillators. Conclusion We propose that such a simple transition could have formed the initial scaffold, on top of which the hierarchy, observed in the syncytium of dipterans, could have evolved.
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Affiliation(s)
- Axel Hunding
- Biophysical Chemistry, Department of Chemistry S01, H. C. 0rsted Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Stefan Baumgartner
- Department of Experimental Medical Sciences, Lund University, BMC D10, 22184 Lund, Sweden
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Pridöhl F, Weißkopf M, Koniszewski N, Sulzmaier A, Uebe S, Ekici AB, Schoppmeier M. Transcriptome sequencing reveals maelstrom as a novel target gene of the terminal-system in the red flour beetle Tribolium castaneum. Development 2017; 144:1339-1349. [DOI: 10.1242/dev.136853] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 02/07/2017] [Indexed: 12/30/2022]
Abstract
Terminal regions of the Drosophila embryo are patterned by the localized activation of the Torso-RTK pathway, which promotes the down-regulation of Capicua. In the short-germ beetle Tribolium, the function of the terminal system appears to be rather different, as the pathway promotes axis elongation and in addition, is required for patterning the extraembryonic serosa at the anterior. Here we show that Torso signalling induces gene expression by relieving CAPICUA-mediated repression also in Tribolium. Given that the majority of Torso target genes remain to be identified, we established a differential gene-expression screen. A subset of 50 putative terminal target genes was screened for functions in early embryonic patterning. Of those, 13 genes show early terminal expression domains and also phenotypes were related to terminal patterning. Among others, we found the PIWI-interacting RNA factor Maelstrom to be crucial for early embryonic polarization. Tc-mael is required for proper serosal size regulation and head morphogenesis. Moreover, Tc-mael promotes growth-zone formation and axis elongation. Our results suggest that posterior patterning by Torso may be realized through Maelstrom depended activation of posterior wnt-domains.
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Affiliation(s)
- Fabian Pridöhl
- Department Biology, Developmental Biology Unit, Friedrich-Alexander-University Erlangen-Nuremberg, Staudtstr. 5, 91058, Erlangen, Germany, phone: ++49-9131-8528097, fax: ++49-9131-8528040
| | - Matthias Weißkopf
- Department Biology, Developmental Biology Unit, Friedrich-Alexander-University Erlangen-Nuremberg, Staudtstr. 5, 91058, Erlangen, Germany, phone: ++49-9131-8528097, fax: ++49-9131-8528040
| | - Nikolaus Koniszewski
- Department Biology, Developmental Biology Unit, Friedrich-Alexander-University Erlangen-Nuremberg, Staudtstr. 5, 91058, Erlangen, Germany, phone: ++49-9131-8528097, fax: ++49-9131-8528040
- present address: Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Otto-von-Guericke-University, Leipziger Str. 44, 39120 Magdeburg, Germany, phone: ++49-391-6721834, fax: ++49-391-6713384
| | - Andreas Sulzmaier
- Department Biology, Developmental Biology Unit, Friedrich-Alexander-University Erlangen-Nuremberg, Staudtstr. 5, 91058, Erlangen, Germany, phone: ++49-9131-8528097, fax: ++49-9131-8528040
| | - Steffen Uebe
- Institute of Human Genetics, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 10, 91054 Erlangen, Germany, phone: ++49-9131 8522318, fax: ++49-9131 85-23232
| | - Arif B. Ekici
- Institute of Human Genetics, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 10, 91054 Erlangen, Germany, phone: ++49-9131 8522318, fax: ++49-9131 85-23232
| | - Michael Schoppmeier
- Department Biology, Developmental Biology Unit, Friedrich-Alexander-University Erlangen-Nuremberg, Staudtstr. 5, 91058, Erlangen, Germany, phone: ++49-9131-8528097, fax: ++49-9131-8528040
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21
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Nakao H. Hunchback knockdown induces supernumerary segment formation in Bombyx. Dev Biol 2016; 413:207-16. [DOI: 10.1016/j.ydbio.2016.03.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/17/2016] [Accepted: 03/20/2016] [Indexed: 12/13/2022]
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22
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Abstract
Genetic screens are powerful tools to identify the genes required for a given biological process. However, for technical reasons, comprehensive screens have been restricted to very few model organisms. Therefore, although deep sequencing is revealing the genes of ever more insect species, the functional studies predominantly focus on candidate genes previously identified in Drosophila, which is biasing research towards conserved gene functions. RNAi screens in other organisms promise to reduce this bias. Here we present the results of the iBeetle screen, a large-scale, unbiased RNAi screen in the red flour beetle, Tribolium castaneum, which identifies gene functions in embryonic and postembryonic development, physiology and cell biology. The utility of Tribolium as a screening platform is demonstrated by the identification of genes involved in insect epithelial adhesion. This work transcends the restrictions of the candidate gene approach and opens fields of research not accessible in Drosophila. Unbiased screening for insect gene function has been largely restricted to Drosophila. Here, Schmitt-Engel et al. perform an unbiased large-scale RNAi screen in the red flour beetle Tribolium castaneum to identify putative gene functions.
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23
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Kazemian M, Suryamohan K, Chen JY, Zhang Y, Samee MAH, Halfon MS, Sinha S. Evidence for deep regulatory similarities in early developmental programs across highly diverged insects. Genome Biol Evol 2015; 6:2301-20. [PMID: 25173756 PMCID: PMC4217690 DOI: 10.1093/gbe/evu184] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Many genes familiar from Drosophila development, such as the so-called gap, pair-rule, and segment polarity genes, play important roles in the development of other insects and in many cases appear to be deployed in a similar fashion, despite the fact that Drosophila-like "long germband" development is highly derived and confined to a subset of insect families. Whether or not these similarities extend to the regulatory level is unknown. Identification of regulatory regions beyond the well-studied Drosophila has been challenging as even within the Diptera (flies, including mosquitoes) regulatory sequences have diverged past the point of recognition by standard alignment methods. Here, we demonstrate that methods we previously developed for computational cis-regulatory module (CRM) discovery in Drosophila can be used effectively in highly diverged (250-350 Myr) insect species including Anopheles gambiae, Tribolium castaneum, Apis mellifera, and Nasonia vitripennis. In Drosophila, we have successfully used small sets of known CRMs as "training data" to guide the search for other CRMs with related function. We show here that although species-specific CRM training data do not exist, training sets from Drosophila can facilitate CRM discovery in diverged insects. We validate in vivo over a dozen new CRMs, roughly doubling the number of known CRMs in the four non-Drosophila species. Given the growing wealth of Drosophila CRM annotation, these results suggest that extensive regulatory sequence annotation will be possible in newly sequenced insects without recourse to costly and labor-intensive genome-scale experiments. We develop a new method, Regulus, which computes a probabilistic score of similarity based on binding site composition (despite the absence of nucleotide-level sequence alignment), and demonstrate similarity between functionally related CRMs from orthologous loci. Our work represents an important step toward being able to trace the evolutionary history of gene regulatory networks and defining the mechanisms underlying insect evolution.
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Affiliation(s)
- Majid Kazemian
- Department of Computer Science, University of Illinois at Urbana-Champaign Laboratory of Molecular Immunology, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Kushal Suryamohan
- Department of Biochemistry, University at Buffalo-State University of New York NY State Center of Excellence in Bioinformatics and Life Sciences, Buffalo, New York
| | - Jia-Yu Chen
- Department of Computer Science, University of Illinois at Urbana-Champaign
| | - Yinan Zhang
- Department of Computer Science, University of Illinois at Urbana-Champaign
| | | | - Marc S Halfon
- Department of Biochemistry, University at Buffalo-State University of New York NY State Center of Excellence in Bioinformatics and Life Sciences, Buffalo, New York Department of Biological Sciences, University at Buffalo-State University of New York Molecular and Cellular Biology Department and Program in Cancer Genetics, Roswell Park Cancer Institute, Buffalo, New York
| | - Saurabh Sinha
- Department of Computer Science, University of Illinois at Urbana-Champaign Institute of Genomic Biology, University of Illinois at Urbana-Champaign
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Dönitz J, Schmitt-Engel C, Grossmann D, Gerischer L, Tech M, Schoppmeier M, Klingler M, Bucher G. iBeetle-Base: a database for RNAi phenotypes in the red flour beetle Tribolium castaneum. Nucleic Acids Res 2014; 43:D720-5. [PMID: 25378303 PMCID: PMC4383896 DOI: 10.1093/nar/gku1054] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The iBeetle-Base (http://ibeetle-base.uni-goettingen.de) makes available annotations of RNAi phenotypes, which were gathered in a large scale RNAi screen in the red flour beetle Tribolium castaneum (iBeetle screen). In addition, it provides access to sequence information and links for all Tribolium castaneum genes. The iBeetle-Base contains the annotations of phenotypes of several thousands of genes knocked down during embryonic and metamorphic epidermis and muscle development in addition to phenotypes linked to oogenesis and stink gland biology. The phenotypes are described according to the EQM (entity, quality, modifier) system using controlled vocabularies and the Tribolium morphological ontology (TrOn). Furthermore, images linked to the respective annotations are provided. The data are searchable either for specific phenotypes using a complex ‘search for morphological defects’ or a ‘quick search’ for gene names and IDs. The red flour beetle Tribolium castaneum has become an important model system for insect functional genetics and is a representative of the most species rich taxon, the Coleoptera, which comprise several devastating pests. It is used for studying insect typical development, the evolution of development and for research on metabolism and pest control. Besides Drosophila, Tribolium is the first insect model organism where large scale unbiased screens have been performed.
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Affiliation(s)
- Jürgen Dönitz
- Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology, GZMB, Department of Evolutionary Developmental Genetics, Georg-August-University Göttingen, 37075 Göttingen, Germany
| | - Christian Schmitt-Engel
- Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology, GZMB, Department of Evolutionary Developmental Genetics, Georg-August-University Göttingen, 37075 Göttingen, Germany Department of Biology, Friedrich-Alexander University, 91058 Erlangen, Germany
| | - Daniela Grossmann
- Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology, GZMB, Department of Evolutionary Developmental Genetics, Georg-August-University Göttingen, 37075 Göttingen, Germany
| | - Lizzy Gerischer
- Institute for Mathematics and Computer Science, Ernst Moritz Arndt University, 17487 Greifswald, Germany
| | - Maike Tech
- Institute of Microbiology and Genetics, Department of Bioinformatics, Georg-August-University Göttingen, 37073 Göttingen, Germany
| | - Michael Schoppmeier
- Department of Biology, Friedrich-Alexander University, 91058 Erlangen, Germany
| | - Martin Klingler
- Department of Biology, Friedrich-Alexander University, 91058 Erlangen, Germany
| | - Gregor Bucher
- Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology, GZMB, Department of Evolutionary Developmental Genetics, Georg-August-University Göttingen, 37075 Göttingen, Germany
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25
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Sucena É, Vanderberghe K, Zhurov V, Grbić M. Reversion of developmental mode in insects: evolution from long germband to short germband in the polyembrionic wasp Macrocentrus cingulum Brischke. Evol Dev 2014; 16:233-46. [PMID: 24981069 DOI: 10.1111/ede.12086] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Germband size in insects has played a central role in our understanding of insect patterning mechanisms and their evolution. The polarity of evolutionary change in insect patterning has been viewed so far as the unidirectional shift from the ancestral short germband patterning of basal hemimetabolous insects to the long germband patterning observed in most modern Holometabola. However, some orders of holometabolic insects display both short and long germband development, though the absence of a clear phylogenetic context does not permit definite conclusions on the polarity of change. Derived hymenoptera, that is, bees and wasps, represent a classical textbook example of long germband development. Yet, in some wasps putative short germband development has been described correlating with lifestyle changes, namely with evolution of endoparasitism and polyembryony. To address the potential reversion from long to short germband, we focused on the family Braconidae, which displays ancestral long germband development, and examined the derived polyembryonic braconid Macrocentrus cingulum. Using SEM analysis of M. cingulum embryogenesis coupled with analyses of embryonic patterning markers, we show that this wasp evolved short germband embryogenesis secondarily, in a way that is reminiscent of embryogenesis in the beetle Tribolium castaneum. This work shows that the evolution of germband size in insects is a reversible process that may correlate with other life-history traits and suggests broader implications on the mechanisms and evolvability of insect development.
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Affiliation(s)
- Élio Sucena
- Instituto Gulbenkian de Ciência, Apartado 14, 2781-901, Oeiras, Portugal; Universidade de Lisboa, Faculdade de Ciências, Departamento de Biologia Animal, edifício C2, Campo Grande, 1749-016, Lisboa, Portugal
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Heffer A, Grubbs N, Mahaffey J, Pick L. The evolving role of the orphan nuclear receptor ftz-f1, a pair-rule segmentation gene. Evol Dev 2014; 15:406-17. [PMID: 24261442 DOI: 10.1111/ede.12050] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Segmentation is a critical developmental process that occurs by different mechanisms in diverse taxa. In insects, there are three common modes of embryogenesis-short-, intermediate-, and long-germ development-which differ in the number of segments specified at the blastoderm stage. While genes involved in segmentation have been extensively studied in the long-germ insect Drosophila melanogaster (Dm), it has been found that their expression and function in segmentation in short- and intermediate-germ insects often differ. Drosophila ftz-f1 encodes an orphan nuclear receptor that functions as a maternally expressed pair-rule segmentation gene, responsible for the formation of alternate body segments during Drosophila embryogenesis. Here we investigated the expression and function of ftz-f1 in the short-germ beetle, Tribolium castaneum (Tc). We found that Tc-ftz-f1 is expressed in stripes in Tribolium embryos. These stripes overlap alternate Tc-Engrailed (Tc-En) stripes, indicative of a pair-rule expression pattern. To test whether Tc-ftz-f1 has pair-rule function, we utilized embryonic RNAi, injecting double-stranded RNA corresponding to Tc-ftz-f1 coding or non-coding regions into early Tribolium embryos. Knockdown of Tc-ftz-f1 produced pair-rule segmentation defects, evidenced by loss of expression of alternate En stripes. In addition, a later role for Tc-ftz-f1 in cuticle formation was revealed. These results identify a new pair-rule gene in Tribolium and suggest that its role in segmentation may be shared among holometabolous insects. Interestingly, while Tc-ftz-f1 is expressed in pair-rule stripes, the gene is ubiquitously expressed in Drosophila embryos. Thus, the pair-rule function of ftz-f1 is conserved despite differences in expression patterns of ftz-f1 genes in different lineages. This suggests that ftz-f1 expression changed after the divergence of lineages leading to extant beetles and flies, likely due to differences in cis-regulatory sequences. We propose that the dependence of Dm-Ftz-F1 on interaction with the homeodomain protein Ftz which is expressed in stripes in Drosophila, loosened constraints on Dm-ftz-f1 expression, allowing for ubiquitous expression of this pair-rule gene in Drosophila.
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Affiliation(s)
- Alison Heffer
- Department of Entomology and Program in Molecular & Cell Biology, University of Maryland, College Park, MD, 20742, USA
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Milutinović B, Stolpe C, Peuβ R, Armitage SAO, Kurtz J. The red flour beetle as a model for bacterial oral infections. PLoS One 2013; 8:e64638. [PMID: 23737991 PMCID: PMC3667772 DOI: 10.1371/journal.pone.0064638] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 04/17/2013] [Indexed: 01/03/2023] Open
Abstract
Experimental infection systems are important for studying antagonistic interactions and coevolution between hosts and their pathogens. The red flour beetle Tribolium castaneum and the spore-forming bacterial insect pathogen Bacillus thuringiensis (Bt) are widely used and tractable model organisms. However, they have not been employed yet as an efficient experimental system to study host-pathogen interactions. We used a high throughput oral infection protocol to infect T. castaneum insects with coleopteran specific B. thuringiensis bv. tenebrionis (Btt) bacteria. We found that larval mortality depends on the dietary spore concentration and on the duration of exposure to the spores. Furthermore, differential susceptibility of larvae from different T. castaneum populations indicates that the host genetic background influences infection success. The recovery of high numbers of infectious spores from the cadavers indicates successful replication of bacteria in the host and suggests that Btt could establish infectious cycles in T. castaneum in nature. We were able to transfer plasmids from Btt to a non-pathogenic but genetically well-characterised Bt strain, which was thereafter able to successfully infect T. castaneum, suggesting that factors residing on the plasmids are important for the virulence of Btt. The availability of a genetically accessible strain will provide an ideal model for more in-depth analyses of pathogenicity factors during oral infections. Combined with the availability of the full genome sequence of T. castaneum, this system will enable analyses of host responses during infection, as well as addressing basic questions concerning host-parasite coevolution.
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Affiliation(s)
- Barbara Milutinović
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Clemens Stolpe
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Robert Peuβ
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | | | - Joachim Kurtz
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
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Duncan EJ, Leask MP, Dearden PK. The pea aphid (Acyrthosiphon pisum) genome encodes two divergent early developmental programs. Dev Biol 2013; 377:262-74. [PMID: 23416037 DOI: 10.1016/j.ydbio.2013.01.036] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 01/18/2013] [Accepted: 01/29/2013] [Indexed: 12/28/2022]
Abstract
The pea aphid (Acyrthosiphon pisum) can reproduce either sexually or asexually (parthenogenetically), giving rise, in each case, to almost identical adults. These two modes of reproduction are accompanied by differences in ovarian morphology and the developmental environment of the offspring, with sexual forms producing eggs that are laid, whereas asexual development occurs within the mother. Here we examine the effect each mode of reproduction has on the expression of key maternal and axis patterning genes; orthodenticle (otd), hunchback (hb), caudal (cad) and nanos (nos). We show that three of these genes (Ap-hb, Ap-otd and Ap-cad) are expressed differently between the sexually and asexually produced oocytes and embryos of the pea aphid. We also show, using immunohistochemistry and cytoskeletal inhibitors, that Ap-hb RNA is localized differently between sexually and asexually produced oocytes, and that this is likely due to differences in the 3' untranslated regions of the RNA. Furthermore, Ap-hb and Ap-otd have extensive expression domains in early sexually produced embryos, but are not expressed at equivalent stages in asexually produced embryos. These differences in expression likely correspond with substantial changes in the gene regulatory networks controlling early development in the pea aphid. These data imply that in the evolution of parthenogenesis a new program has evolved to control the development of asexually produced embryos, whilst retaining the existing, sexual, developmental program. The patterns of modification of these developmental processes mirror the changes that we see in developmental processes between species, in that early acting pathways in development are less constrained, and evolve faster, than later ones. We suggest that the evolution of the novel asexual development pathway in aphids is not a simple modification of an ancestral system, but the evolution of two very different developmental mechanisms occurring within a single species.
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Affiliation(s)
- Elizabeth J Duncan
- Laboratory for Evolution and Development, Genetics Otago & Gravida, National Centre for Growth and Development, Department of Biochemistry, University of Otago, 56, Dunedin 9054, Aotearoa, New Zealand.
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RNAi phenotypes are influenced by the genetic background of the injected strain. BMC Genomics 2013; 14:5. [PMID: 23324472 PMCID: PMC3574008 DOI: 10.1186/1471-2164-14-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 12/19/2012] [Indexed: 12/22/2022] Open
Abstract
Background RNA interference (RNAi) is a powerful tool to study gene function in organisms that are not amenable to classical forward genetics. Hence, together with the ease of comprehensively identifying genes by new generation sequencing, RNAi is expanding the scope of animal species and questions that can be addressed in terms of gene function. In the case of genetic mutants, the genetic background of the strains used is known to influence the phenotype while this has not been described for RNAi experiments. Results Here we show in the red flour beetle Tribolium castaneum that RNAi against Tc-importin α1 leads to different phenotypes depending on the injected strain. We rule out off target effects and show that sequence divergence does not account for this difference. By quantitatively comparing phenotypes elicited by RNAi knockdown of four different genes we show that there is no general difference in RNAi sensitivity between these strains. Finally, we show that in case of Tc-importin α1 the difference depends on the maternal genotype. Conclusions These results show that in RNAi experiments strain specific differences have to be considered and that a proper documentation of the injected strain is required. This is especially important for the increasing number of emerging model organisms that are being functionally investigated using RNAi. In addition, our work shows that RNAi is suitable to systematically identify the differences in the gene regulatory networks present in populations of the same species, which will allow novel insights into the evolution of animal diversity.
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30
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Schmitt-Engel C, Cerny AC, Schoppmeier M. A dual role for nanos and pumilio in anterior and posterior blastodermal patterning of the short-germ beetle Tribolium castaneum. Dev Biol 2012; 364:224-35. [DOI: 10.1016/j.ydbio.2012.01.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 01/09/2012] [Accepted: 01/20/2012] [Indexed: 11/15/2022]
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31
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El-Sherif E, Lynch JA, Brown SJ. Comparisons of the embryonic development of Drosophila, Nasonia, and Tribolium. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2012; 1:16-39. [PMID: 23801665 PMCID: PMC5323069 DOI: 10.1002/wdev.3] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Studying the embryogenesis of diverse insect species is crucial to understanding insect evolution. Here, we review current advances in understanding the development of two emerging model organisms: the wasp Nasonia vitripennis and the beetle Tribolium castaneum in comparison with the well-studied fruit fly Drosophila melanogaster. Although Nasonia represents the most basally branching order of holometabolous insects, it employs a derived long germband mode of embryogenesis, more like that of Drosophila, whereas Tribolium undergoes an intermediate germband mode of embryogenesis, which is more similar to the ancestral mechanism. Comparing the embryonic development and genetic regulation of early patterning events in these three insects has given invaluable insights into insect evolution. The similar mode of embryogenesis of Drosophila and Nasonia is reflected in their reliance on maternal morphogenetic gradients. However, they employ different genes as maternal factors, reflecting the evolutionary distance separating them. Tribolium, on the other hand, relies heavily on self-regulatory mechanisms other than maternal cues, reflecting its sequential nature of segmentation and the need for reiterated patterning.
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Affiliation(s)
- Ezzat El-Sherif
- Program of Genetics, Kansas State University, Manhattan, Kansas
| | - Jeremy A Lynch
- Institute for Developmental Biology, University of Cologne, Cologne, Germany
| | - Susan J Brown
- Division of Biology, Kansas State University, Manhattan, Kansas
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Lavore A, Pagola L, Esponda-Behrens N, Rivera-Pomar R. The gap gene giant of Rhodnius prolixus is maternally expressed and required for proper head and abdomen formation. Dev Biol 2011; 361:147-55. [PMID: 21763688 DOI: 10.1016/j.ydbio.2011.06.038] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Revised: 06/09/2011] [Accepted: 06/11/2011] [Indexed: 01/20/2023]
Abstract
The segmentation process in insects depends on a hierarchical cascade of gene activity. The first effectors downstream of the maternal activation are the gap genes, which divide the embryo in broad fields. We discovered a sequence corresponding to the leucine-zipper domain of the orthologue of the gene giant (Rp-gt) in traces from the genome of Rhodnius prolixus, a hemipteran with intermediate germ-band development. We cloned the Rp-gt gene from a normalized cDNA library and characterized its expression and function. Bioinformatic analysis of 12.5 kbp of genomic sequence containing the Rp-gt transcriptional unit shows a cluster of bona fide regulatory binding sites, which is similar in location and structure to the predicted posterior expression domain of the Drosophila orthologue. Rp-gt is expressed in ovaries and maternally supplied in the early embryo. The maternal contribution forms a gradient of scattered patches of mRNA in the preblastoderm embryo. Zygotic Rp-gt is expressed in two domains that after germ band extension are restricted to the head and the posterior growth zone. Parental RNAi shows that Rp-gt is required for proper head and abdomen formation. The head lacks mandibulary and maxillary appendages and shows reduced clypeus-labrum, while the abdomen lacks anterior segments. We conclude that Rp-gt is a gap gene on the head and abdomen and, in addition, has a function in patterning the anterior head capsule suggesting that the function of gt in hemipterans is more similar to dipterans than expected.
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Affiliation(s)
- Andrés Lavore
- Laboratorio de Genética y Genómica Funcional, Centro Regional de Estudios Genómicos, Universidad Nacional de La Plata, Florencio Varela, Argentina
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Blechert O, Douglas D, Baumgartner S. Conserved function of the Krüppel gap gene in the blowfly Lucilia sericata, despite anterior shift of expression. INSECT MOLECULAR BIOLOGY 2011; 20:257-265. [PMID: 21166911 DOI: 10.1111/j.1365-2583.2010.01063.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
To determine whether expression patterns of segmentation genes found in Drosophila melanogaster can be scaled to pattern larger insects, we studied the expression of the Krüppel (Kr) gene in the blowfly Lucilia sericata. Compared with Drosophila Kr, L. sericata Kr showed an unexpected 10% shift of expression towards the anterior pole. Furthermore, expression domains not found in D. melanogaster were present at the blastoderm stage of L. sericata. To compare Kr activity and function, we employed RNA interference-mediated gene silencing. We found Kr phenotypes in L. sericata comparable with those observed in D. melanogaster, demonstrating that L. sericata Kr functions as a gap gene as it does in Drosophila. Our results show that, despite an anterior shift in expression, Kr function has remained conserved during the evolution of the blowflies.
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Affiliation(s)
- O Blechert
- Lund University, Department of Experimental Medical Sciences, Lund, Sweden
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34
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Abstract
Gap genes are involved in segment determination during the early development of the fruit fly Drosophila melanogaster as well as in other insects. This review attempts to synthesize the current knowledge of the gap gene network through a comprehensive survey of the experimental literature. I focus on genetic and molecular evidence, which provides us with an almost-complete picture of the regulatory interactions responsible for trunk gap gene expression. I discuss the regulatory mechanisms involved, and highlight the remaining ambiguities and gaps in the evidence. This is followed by a brief discussion of molecular regulatory mechanisms for transcriptional regulation, as well as precision and size-regulation provided by the system. Finally, I discuss evidence on the evolution of gap gene expression from species other than Drosophila. My survey concludes that studies of the gap gene system continue to reveal interesting and important new insights into the role of gene regulatory networks in development and evolution.
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Affiliation(s)
- Johannes Jaeger
- Centre de Regulació Genòmica, Universtitat Pompeu Fabra, Barcelona, Spain.
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35
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JAK-STAT signalling is required throughout telotrophic oogenesis and short-germ embryogenesis of the beetle Tribolium. Dev Biol 2010; 350:169-82. [PMID: 20974121 DOI: 10.1016/j.ydbio.2010.10.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 10/04/2010] [Accepted: 10/15/2010] [Indexed: 12/16/2022]
Abstract
In Drosophila, the JAK-STAT signalling pathway regulates a broad array of developmental functions including segmentation and oogenesis. Here we analysed the functions of Tribolium JAK-STAT signalling factors and of Suppressor Of Cytokine Signalling (SOCS) orthologues, which are known to function as negative regulators of JAK-STAT signalling, during telotrophic oogenesis and short-germ embryogenesis. The beetle Tribolium features telotrophic ovaries, which differ fundamentally from the polytrophic ovary of Drosophila. While we found the requirement for JAK-STAT signalling in specifying the interfollicular stalk to be principally conserved, we demonstrate that these genes also have early and presumably telotrophic specific functions. Moreover, we show that the SOCS genes crucially contribute to telotrophic Tribolium oogenesis, as their inactivation by RNAi results in compound follicles. During short-germ embryogenesis, JAK-STAT signalling is required in the maintenance of segment primordia, indicating that this signalling cascade acts in the framework of the segment-polarity network. In addition, we demonstrate that JAK-STAT signalling crucially contributes to early anterior patterning. We posit that this signalling cascade is involved in achieving accurate levels of expression of individual pair-rule and gap gene domains in early embryonic patterning.
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36
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Mutual regulatory interactions of the trunk gap genes during blastoderm patterning in the hemipteran Oncopeltus fasciatus. Dev Biol 2010; 346:140-9. [DOI: 10.1016/j.ydbio.2010.07.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 07/01/2010] [Accepted: 07/07/2010] [Indexed: 02/07/2023]
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37
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García-Solache M, Jaeger J, Akam M. A systematic analysis of the gap gene system in the moth midge Clogmia albipunctata. Dev Biol 2010; 344:306-18. [DOI: 10.1016/j.ydbio.2010.04.019] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2009] [Revised: 04/19/2010] [Accepted: 04/21/2010] [Indexed: 02/04/2023]
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38
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Schinko JB, Weber M, Viktorinova I, Kiupakis A, Averof M, Klingler M, Wimmer EA, Bucher G. Functionality of the GAL4/UAS system in Tribolium requires the use of endogenous core promoters. BMC DEVELOPMENTAL BIOLOGY 2010; 10:53. [PMID: 20482875 PMCID: PMC2882914 DOI: 10.1186/1471-213x-10-53] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Accepted: 05/19/2010] [Indexed: 12/05/2022]
Abstract
Background The red flour beetle Tribolium castaneum has developed into an insect model system second only to Drosophila. Moreover, as a coleopteran it represents the most species-rich metazoan taxon which also includes many pest species. The genetic toolbox for Tribolium research has expanded in the past years but spatio-temporally controlled misexpression of genes has not been possible so far. Results Here we report the establishment of the GAL4/UAS binary expression system in Tribolium castaneum. Both GAL4Δ and GAL4VP16 driven by the endogenous heat shock inducible promoter of the Tribolium hsp68 gene are efficient in activating reporter gene expression under the control of the Upstream Activating Sequence (UAS). UAS driven ubiquitous tGFP fluorescence was observed in embryos within four hours after activation while in-situ hybridization against tGFP revealed expression already after two hours. The response is quick in relation to the duration of embryonic development in Tribolium - 72 hours with segmentation being completed after 24 hours - which makes the study of early embryonic processes possible using this system. By comparing the efficiency of constructs based on Tribolium, Drosophila, and artificial core promoters, respectively, we find that the use of endogenous core promoters is essential for high-level expression of transgenic constructs. Conclusions With the established GAL4/UAS binary expression system, ectopic misexpression approaches are now feasible in Tribolium. Our results support the contention that high-level transgene expression usually requires endogenous regulatory sequences, including endogenous core promoters in Tribolium and probably also other model systems.
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Affiliation(s)
- Johannes B Schinko
- Ernst Caspari Haus, Georg-August-University Göttingen, Justus-von-Liebig-Weg11, 37077 Göttingen, Germany
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Lemke S, Busch SE, Antonopoulos DA, Meyer F, Domanus MH, Schmidt-Ott U. Maternal activation of gap genes in the hover fly Episyrphus. Development 2010; 137:1709-19. [DOI: 10.1242/dev.046649] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The metameric organization of the insect body plan is initiated with the activation of gap genes, a set of transcription-factor-encoding genes that are zygotically expressed in broad and partially overlapping domains along the anteroposterior (AP) axis of the early embryo. The spatial pattern of gap gene expression domains along the AP axis is generally conserved, but the maternal genes that regulate their expression are not. Building on the comprehensive knowledge of maternal gap gene activation in Drosophila, we used loss- and gain-of-function experiments in the hover fly Episyrphus balteatus (Syrphidae) to address the question of how the maternal regulation of gap genes evolved. We find that, in Episyrphus, a highly diverged bicoid ortholog is solely responsible for the AP polarity of the embryo. Episyrphus bicoid represses anterior zygotic expression of caudal and activates the anterior and central gap genes orthodenticle, hunchback and Krüppel. In bicoid-deficient Episyrphus embryos, nanos is insufficient to generate morphological asymmetry along the AP axis. Furthermore, we find that torso transiently regulates anterior repression of caudal and is required for the activation of orthodenticle, whereas all posterior gap gene domains of knirps, giant, hunchback, tailless and huckebein depend on caudal. We conclude that all maternal coordinate genes have altered their specific functions during the radiation of higher flies (Cyclorrhapha).
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Affiliation(s)
- Steffen Lemke
- University of Chicago, Department of Organismal Biology and Anatomy, CLSC 921B, 920 E. 58th Street, Chicago, IL 60637, USA
| | - Stephanie E. Busch
- University of Chicago, Department of Organismal Biology and Anatomy, CLSC 921B, 920 E. 58th Street, Chicago, IL 60637, USA
| | - Dionysios A. Antonopoulos
- Argonne National Laboratory, Institute for Genomics & Systems Biology, 9700 S. Cass Avenue, Argonne, IL 60439, USA
| | - Folker Meyer
- Argonne National Laboratory, Institute for Genomics & Systems Biology, 9700 S. Cass Avenue, Argonne, IL 60439, USA
| | - Marc H. Domanus
- Argonne National Laboratory, Institute for Genomics & Systems Biology, 9700 S. Cass Avenue, Argonne, IL 60439, USA
| | - Urs Schmidt-Ott
- University of Chicago, Department of Organismal Biology and Anatomy, CLSC 921B, 920 E. 58th Street, Chicago, IL 60637, USA
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Kotkamp K, Klingler M, Schoppmeier M. Apparent role of Tribolium orthodenticle in anteroposterior blastoderm patterning largely reflects novel functions in dorsoventral axis formation and cell survival. Development 2010; 137:1853-62. [PMID: 20431120 DOI: 10.1242/dev.047043] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the short-germ beetle Tribolium castaneum, the head gap gene orthodenticle (Tc-otd) has been proposed to functionally substitute for bicoid, the anterior morphogen unique to higher dipterans. In this study we reanalyzed the function of Tc-otd. We obtained a similar range of cuticle phenotypes as in previously described RNAi experiments; however, we noticed unexpected effects on blastodermal cell fates. First, we found that Tc-otd is essential for dorsoventral patterning. RNAi depletion results in lateralized embryos, a fate map change that by itself can explain the observed loss of the anterior head, which is a ventral anlage in Tribolium. We find that this effect is due to diminished expression of short gastrulation (sog), a gene essential for establishment of the Decapentaplegic (Dpp) gradient in this species. Second, we found that gnathal segment primordia in Tc-otd RNAi embryos are shifted anteriorly but otherwise appear patterned normally. This anteroposterior (AP) fate map shift might largely be due to diminished zen-1 expression and is not responsible for the severe segmentation defects observed in some Tc-otd RNAi embryos. As neither Tc-sog nor Tc-zen-1 probably requires Otd gradient-mediated positional information, we posit that the blastoderm function of Tc-Otd depends on its initial homogeneous maternal expression and that this maternal factor does not provide significant positional information for Tribolium blastoderm embryos.
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Affiliation(s)
- Kay Kotkamp
- Department of Biology, Developmental Biology Unit, Erlangen University, 90158 Erlangen, Germany.
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41
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Liu PZ, Patel NH. giant is a bona fide gap gene in the intermediate germband insect, Oncopeltus fasciatus. Development 2010; 137:835-44. [PMID: 20147384 DOI: 10.1242/dev.045948] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Drosophila undergoes a form of development termed long germ segmentation, where all segments are specified nearly simultaneously so that by the blastoderm stage, the entire body plan has been determined. This mode of segmentation is evolutionarily derived. Most insects undergo short or intermediate germ segmentation, where only anterior segments are specified early, and posterior segments are sequentially specified during germband elongation. These embryological differences imply that anterior and posterior segments might rely upon different molecular mechanisms. In Drosophila, embryos mutant for giant show a gap in the anterior as well fusions of several abdominal segments. In Tribolium, a short germ beetle, giant is required for segmental identity, but not formation, in gnathal segments and also for segmentation of the entire abdomen. This raises the possibility that giant might not act as a gap gene in short and intermediate germ insects. Oncopeltus fasciatus is an intermediate germ insect that is an outgroup to the clade containing Drosophila and Tribolium. We cloned the Oncopeltus homolog of giant and determined its expression and function during segmentation. We find that Oncopeltus giant is a canonical gap gene in the maxillary and labial segments and also plays a gap-like role in the first four abdominal segments. Our results suggest that giant was a bona fide gap gene in the ancestor of these insects with this role being lost in the lineage leading towards Tribolium. This highlights the conservation of anterior patterning and evolutionary plasticity of the genetic regulation controlling posterior segmentation, even in short and intermediate germ insects.
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Affiliation(s)
- Paul Z Liu
- Howard Hughes Medical Institute, Department of Molecular and Cell Biology, and Department of Integrative Biology, University of California, Berkeley, CA 94702, USA.
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42
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Wilson MJ, Havler M, Dearden PK. Giant, Krüppel, and caudal act as gap genes with extensive roles in patterning the honeybee embryo. Dev Biol 2010; 339:200-11. [DOI: 10.1016/j.ydbio.2009.12.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Revised: 12/08/2009] [Accepted: 12/10/2009] [Indexed: 01/26/2023]
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Yang X, ZarinKamar N, Bao R, Friedrich M. Probing the Drosophila retinal determination gene network in Tribolium (I): The early retinal genes dachshund, eyes absent and sine oculis. Dev Biol 2009; 333:202-14. [DOI: 10.1016/j.ydbio.2009.02.040] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2008] [Revised: 02/18/2009] [Accepted: 02/19/2009] [Indexed: 12/24/2022]
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Evolution of axis formation: mRNA localization, regulatory circuits and posterior specification in non-model arthropods. Curr Opin Genet Dev 2009; 19:404-11. [DOI: 10.1016/j.gde.2009.04.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Accepted: 04/09/2009] [Indexed: 11/18/2022]
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45
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Rosenberg MI, Lynch JA, Desplan C. Heads and tails: evolution of antero-posterior patterning in insects. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2008; 1789:333-42. [PMID: 18976722 DOI: 10.1016/j.bbagrm.2008.09.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 09/23/2008] [Accepted: 09/30/2008] [Indexed: 01/30/2023]
Abstract
In spite of their varied appearances, insects share a common body plan whose layout is established by patterning genes during embryogenesis. We understand in great molecular detail how the Drosophila embryo patterns its segments. However, Drosophila has a type of embryogenesis that is highly derived and varies extensively as compared to most insects. Therefore, the study of other insects is invaluable for piecing together how the ancestor of all insects established its segmented body plan, and how this process can be plastic during evolution. In this review, we discuss the evolution of Antero-Posterior (A-P) patterning mechanisms in insects. We first describe two distinct modes of insect development - long and short germ development - and how these two modes of patterning are achieved. We then summarize how A-P patterning occurs in the long-germ Drosophila, where most of our knowledge comes from, and in the well-studied short-germ insect, Tribolium. Finally, using examples from other insects, we highlight differences in patterns of expression, which suggest foci of evolutionary change.
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The Drosophila gap gene giant has an anterior segment identity function mediated through disconnected and teashirt. Genetics 2008; 179:441-53. [PMID: 18493063 DOI: 10.1534/genetics.107.084988] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The C2H2 zinc-finger-containing transcription factors encoded by the disconnected (disco) and teashirt (tsh) genes contribute to the regionalization of the Drosophila embryo by establishing fields in which specific Homeotic complex (Hom-C) proteins can function. In Drosophila embryos, disco and the paralogous disco-related (disco-r) are expressed throughout most of the epidermis of the head segments, but only in small patches in the trunk segments. Conversely, tsh is expressed extensively in the trunk segments, with little or no accumulation in the head segments. Little is known about the regulation of these genes; for example, what limits their expression to these domains? Here, we report the regulatory effects of gap genes on the spatial expression of disco, disco-r, and tsh during Drosophila embryogenesis. The data shed new light on how mutations in giant (gt) affect patterning within the anterior gt domain, demonstrating homeotic function in this domain. However, the homeosis does not occur through altered expression of the Hom-C genes but through changes in the regulation of disco and tsh.
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Cerny AC, Grossmann D, Bucher G, Klingler M. The Tribolium ortholog of knirps and knirps-related is crucial for head segmentation but plays a minor role during abdominal patterning. Dev Biol 2008; 321:284-94. [DOI: 10.1016/j.ydbio.2008.05.527] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2007] [Revised: 05/08/2008] [Accepted: 05/09/2008] [Indexed: 12/01/2022]
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Peel AD. The evolution of developmental gene networks: lessons from comparative studies on holometabolous insects. Philos Trans R Soc Lond B Biol Sci 2008; 363:1539-47. [PMID: 18192180 DOI: 10.1098/rstb.2007.2244] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Recent comparative studies have revealed significant differences in the developmental gene networks operating in three holometabolous insects: the beetle Tribolium castaneum, the parasitic wasp Nasonia vitripennis and the fruitfly Drosophila melanogaster. I discuss these differences in relation to divergent and convergent changes in cellular embryology. I speculate on how segmentation gene networks have evolved to operate in divergent embryological contexts, and highlight the role that co-option might have played in this process. I argue that insects represent an important example of how diversification in life-history strategies between lineages can lead to divergence in the genetic and cellular mechanisms controlling the development of homologous adult structures.
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Affiliation(s)
- Andrew D Peel
- Institute for Molecular Biology and Biotechnology , Vassilika Vouton, 711 10 Iraklio, Crete, Greece.
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Abstract
One of the major goals in evolutionary developmental biology is to understand the relationship between gene regulatory networks and the diverse morphologies and their functionalities. Are the diversities solely triggered by random events, or are they inevitable outcomes of an interplay between evolving gene networks and natural selection? Segmentation in arthropod embryogenesis represents a well-known example of body plan diversity. Striped patterns of gene expression that lead to the future body segments appear simultaneously or sequentially in long and short germ-band development, respectively. Moreover, a combination of both is found in intermediate germ-band development. Regulatory genes relevant for stripe formation are evolutionarily conserved among arthropods, therefore the differences in the observed traits are thought to have originated from how the genes are wired. To reveal the basic differences in the network structure, we have numerically evolved hundreds of gene regulatory networks that produce striped patterns of gene expression. By analyzing the topologies of the generated networks, we show that the characteristics of stripe formation in long and short germ-band development are determined by Feed-Forward Loops (FFLs) and negative Feed-Back Loops (FBLs) respectively, and those of intermediate germ-band development are determined by the interconnections between FFL and negative FBL. Network architectures, gene expression patterns and knockout responses exhibited by the artificially evolved networks agree with those reported in the fly Drosophila melanogaster and the beetle Tribolium castaneum. For other arthropod species, principal network architectures that remain largely unknown are predicted. Our results suggest that the emergence of the three modes of body segmentation in arthropods is an inherent property of the evolving networks.
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Affiliation(s)
- Koichi Fujimoto
- ERATO Complex Systems Biology Project, Japan Science and Technology Agency, Tokyo, Japan.
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50
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Abstract
Beetles are reckoned to make up about one quarter of animal species. Now, the first genome of a beetle--the red flour beetle Tribolium castaneum, a pest and developmental model system alike--has been sequenced.
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