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Palli SR. RNAi turns 25:contributions and challenges in insect science. FRONTIERS IN INSECT SCIENCE 2023; 3:1209478. [PMID: 38469536 PMCID: PMC10926446 DOI: 10.3389/finsc.2023.1209478] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 05/26/2023] [Indexed: 03/13/2024]
Abstract
Since its discovery in 1998, RNA interference (RNAi), a Nobel prize-winning technology, made significant contributions to advances in biology because of its ability to mediate the knockdown of specific target genes. RNAi applications in medicine and agriculture have been explored with mixed success. The past 25 years of research on RNAi resulted in advances in our understanding of the mechanisms of its action, target specificity, and differential efficiency among animals and plants. RNAi played a major role in advances in insect biology. Did RNAi technology fully meet insect pest and disease vector management expectations? This review will discuss recent advances in the mechanisms of RNAi and its contributions to insect science. The remaining challenges, including delivery to the target site, differential efficiency, potential resistance development and possible solutions for the widespread use of this technology in insect management.
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Affiliation(s)
- Subba Reddy Palli
- Department of Entomology, Martin-Gatton College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, United States
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2
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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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3
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Lu K, Cheng YB, Li YM, Li WR, Song YY, Zeng RS, Sun ZX. The KNRL nuclear receptor controls hydrolase-mediated vitellin breakdown during embryogenesis in the brown planthopper, Nilaparvata lugens. INSECT SCIENCE 2021; 28:1633-1650. [PMID: 33191602 DOI: 10.1111/1744-7917.12885] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/19/2020] [Accepted: 11/02/2020] [Indexed: 06/11/2023]
Abstract
Vitellin (Vn) homeostasis is central to the fecundity of oviparous insects. Most studies have focused on the synthesis and transportation of Vn as a building block for developing eggs during vitellogenesis; however, less is known about how the utilization of this nutrient reserve affects embryonic development. Here, we show that the single ortholog of the knirps and knirps-like nuclear receptors, KNRL, negatively regulates Vn breakdown by suppressing the expression of hydrolase genes in the brown planthopper, Nilaparvata lugens. KNRL was highly expressed in the ovary of adult females, and knockdown of KNRL by RNA interference resulted in the acceleration of Vn breakdown and the inhibition of embryonic development. Transcriptome sequencing analysis revealed that numerous hydrolase genes, including cathepsins and trypsins were up-regulated after KNRL knockdown. At least eight of the nine significantly enriched Gene Ontology terms for the up-regulated genes were in proteolysis-related categories. The expression levels of five selected trypsin genes and the enzymatic activities of trypsin in the embryos were significantly increased after KNRL knockdown. Moreover, trypsin injection prolonged egg duration, delayed embryonic development, accelerated Vn breakdown and severely reduced egg hatchability, a pattern similar to that observed in KNRL-silenced N. lugens. These observations suggest that KNRL controls Vn breakdown in embryos via the transcriptional inhibition of hydrolases. Generally, this study provides a foundation for understanding how embryo nutrient reserves are mobilized during embryogenesis and identifies several genes and pathways that may prove valuable targets for pest control.
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Affiliation(s)
- Kai Lu
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yi-Bei Cheng
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yi-Min Li
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Wen-Ru Li
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yuan-Yuan Song
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Ren-Sen Zeng
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zhong-Xiang Sun
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
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4
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Chafino S, Martín D, Franch-Marro X. Activation of EGFR signaling by Tc-Vein and Tc-Spitz regulates the metamorphic transition in the red flour beetle Tribolium castaneum. Sci Rep 2021; 11:18807. [PMID: 34552169 PMCID: PMC8458297 DOI: 10.1038/s41598-021-98334-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 08/25/2021] [Indexed: 02/08/2023] Open
Abstract
Animal development relies on a sequence of specific stages that allow the formation of adult structures with a determined size. In general, juvenile stages are dedicated mainly to growth, whereas last stages are devoted predominantly to the maturation of adult structures. In holometabolous insects, metamorphosis marks the end of the growth period as the animals stops feeding and initiate the final differentiation of the tissues. This transition is controlled by the steroid hormone ecdysone produced in the prothoracic gland. In Drosophila melanogaster different signals have been shown to regulate the production of ecdysone, such as PTTH/Torso, TGFß and Egfr signaling. However, to which extent the roles of these signals are conserved remains unknown. Here, we study the role of Egfr signaling in post-embryonic development of the basal holometabolous beetle Tribolium castaneum. We show that Tc-Egfr and Tc-pointed are required to induced a proper larval-pupal transition through the control of the expression of ecdysone biosynthetic genes. Furthermore, we identified an additional Tc-Egfr ligand in the Tribolium genome, the neuregulin-like protein Tc-Vein (Tc-Vn), which contributes to induce larval-pupal transition together with Tc-Spitz (Tc-Spi). Interestingly, we found that in addition to the redundant role in the control of pupa formation, each ligand possesses different functions in organ morphogenesis. Whereas Tc-Spi acts as the main ligand in urogomphi and gin traps, Tc-Vn is required in wings and elytra. Altogether, our findings show that in Tribolium, post-embryonic Tc-Egfr signaling activation depends on the presence of two ligands and that its role in metamorphic transition is conserved in holometabolous insects.
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Affiliation(s)
- Sílvia Chafino
- grid.507636.10000 0004 0424 5398Institute of Evolutionary Biology (IBE, CSIC-Universitat Pompeu Fabra), Passeig de la Barceloneta 37, 08003 Barcelona, Catalonia Spain
| | - David Martín
- grid.507636.10000 0004 0424 5398Institute of Evolutionary Biology (IBE, CSIC-Universitat Pompeu Fabra), Passeig de la Barceloneta 37, 08003 Barcelona, Catalonia Spain
| | - Xavier Franch-Marro
- grid.507636.10000 0004 0424 5398Institute of Evolutionary Biology (IBE, CSIC-Universitat Pompeu Fabra), Passeig de la Barceloneta 37, 08003 Barcelona, Catalonia Spain
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5
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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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6
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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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7
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Nascimento PVP, Almeida-Oliveira F, Macedo-Silva A, Ausina P, Motinha C, Sola-Penna M, Majerowicz D. Gene annotation of nuclear receptor superfamily genes in the kissing bug Rhodnius prolixus and the effects of 20-hydroxyecdysone on lipid metabolism. INSECT MOLECULAR BIOLOGY 2021; 30:297-314. [PMID: 33455040 DOI: 10.1111/imb.12696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 11/29/2020] [Accepted: 01/11/2021] [Indexed: 06/12/2023]
Abstract
The hormone 20-hydroxyecdysone is fundamental for regulating moulting and metamorphosis in immature insects, and it plays a role in physiological regulation in adult insects. This hormone acts by binding and activating a receptor, the ecdysone receptor, which is part of the nuclear receptor gene superfamily. Here, we analyse the genome of the kissing bug Rhodnius prolixus to annotate the nuclear receptor superfamily genes. The R. prolixus genome displays a possible duplication of the HNF4 gene. All the analysed insect organs express most nuclear receptor genes as shown by RT-PCR. The quantitative PCR analysis showed that the RpEcR and RpUSP genes are highly expressed in the testis, while the RpHNF4-1 and RpHNF4-2 genes are more active in the fat body and ovaries and in the anterior midgut, respectively. Feeding does not induce detectable changes in the expression of these genes in the fat body. However, the expression of the RpHNF4-2 gene is always higher than that of RpHNF4-1. Treating adult females with 20-hydroxyecdysone increased the amount of triacylglycerol stored in the fat bodies by increasing their lipogenic capacity. These results indicate that 20-hydroxyecdysone acts on the lipid metabolism of adult insects, although the underlying mechanism is not clear.
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Affiliation(s)
- P V P Nascimento
- Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - F Almeida-Oliveira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - A Macedo-Silva
- Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - P Ausina
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - C Motinha
- Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Sola-Penna
- Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - D Majerowicz
- Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
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8
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Hu B, Huang H, Hu S, Ren M, Wei Q, Tian X, Esmail Abdalla Elzaki M, Bass C, Su J, Reddy Palli S. Changes in both trans- and cis-regulatory elements mediate insecticide resistance in a lepidopteron pest, Spodoptera exigua. PLoS Genet 2021; 17:e1009403. [PMID: 33690635 PMCID: PMC7978377 DOI: 10.1371/journal.pgen.1009403] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 03/19/2021] [Accepted: 02/09/2021] [Indexed: 02/07/2023] Open
Abstract
The evolution of insect resistance to insecticides is frequently associated with overexpression of one or more cytochrome P450 enzyme genes. Although overexpression of CYP450 genes is a well-known mechanism of insecticide resistance, the underlying regulatory mechanisms are poorly understood. Here we uncovered the mechanisms of overexpression of the P450 gene, CYP321A8 in a major pest insect, Spodoptera exigua that is resistant to multiple insecticides. CYP321A8 confers resistance to organophosphate (chlorpyrifos) and pyrethroid (cypermethrin and deltamethrin) insecticides in this insect. Constitutive upregulation of transcription factors CncC/Maf are partially responsible for upregulated expression of CYP321A8 in the resistant strain. Reporter gene assays and site-directed mutagenesis analyses demonstrated that CncC/Maf enhanced the expression of CYP321A8 by binding to specific sites in the promoter. Additional cis-regulatory elements resulting from a mutation in the CYP321A8 promoter in the resistant strain facilitates the binding of the orphan nuclear receptor, Knirps, and enhances the promoter activity. These results demonstrate that two independent mechanisms; overexpression of transcription factors and mutations in the promoter region resulting in a new cis-regulatory element that facilitates binding of the orphan nuclear receptor are involved in overexpression of CYP321A8 in insecticide-resistant S. exigua. Insect pests developing resistance to insecticides used for their control is a major problem in agriculture. Many pests including the beet armyworm, Spodoptera exigua have developed resistance to insecticides used for their control. Information on the mechanisms of resistance would help in resistance management programs. Overexpression of detoxifying enzymes were associated with insecticide resistance, but their functions and regulatory mechanisms are still unidentified. The expression levels of P450 genes between susceptible and resistant strains of S. exigua were compared and CYP321A8 was identified as the major contributor to resistance to organophosphate and pyrethroid insecticides. Further studies uncovered two independent but synergistic mechanisms; constitutive upregulation of b-Zip transcription factors and mutations in the promoter that facilitates the binding of an orphan nuclear receptor, Knirps contributing to increase in the expression of CYP321A8 and resistance to multiple insecticides in S. exigua.
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Affiliation(s)
- Bo Hu
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - He Huang
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Songzhu Hu
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Miaomiao Ren
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Qi Wei
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Xiangrui Tian
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | | | - Chris Bass
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Penryn Campus, Penryn, United Kingdom
| | - Jianya Su
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- * E-mail: (JS); (SRP)
| | - Subba Reddy Palli
- Department of Entomology, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail: (JS); (SRP)
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9
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Dönitz J, Gerischer L, Hahnke S, Pfeiffer S, Bucher G. Expanded and updated data and a query pipeline for iBeetle-Base. Nucleic Acids Res 2019; 46:D831-D835. [PMID: 29069517 PMCID: PMC5753255 DOI: 10.1093/nar/gkx984] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 10/16/2017] [Indexed: 12/11/2022] Open
Abstract
The iBeetle-Base provides access to sequence and phenotype information for genes of the beetle Tribolium castaneum. It has been updated including more and updated data and new functions. RNAi phenotypes are now available for >50% of the genes, which represents an expansion of 60% compared to the previous version. Gene sequence information has been updated based on the new official gene set OGS3 and covers all genes. Interoperability with FlyBase has been enhanced: First, gene information pages of homologous genes are interlinked between both databases. Second, some steps of a new query pipeline allow transforming gene lists from either species into lists with related gene IDs, names or GO terms. This facilitates the comparative analysis of gene functions between fly and beetle. The backend of the pipeline is implemented as endpoints of a RESTful interface, such that it can be reused by other projects or tools. A novel online interface allows the community to propose GO terms for their gene of interest expanding the range of animals where GO terms are defined. iBeetle-Base is available at http://ibeetle-base.uni-goettingen.de/.
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Affiliation(s)
- Jürgen Dönitz
- Dpt. of Evolutionary Developmental Genetics, Georg August University of Göttingen, 37077 Göttingen, Germany.,Institute of Bioinformatics, University Medical Center Göttingen (UMG) Georg August University, 37077 Göttingen, Germany
| | - Lizzy Gerischer
- Institute for Mathematics and Computer Science, Ernst Moritz Arndt University, 17487 Greifswald, Germany
| | - Stefan Hahnke
- Dpt. of Evolutionary Developmental Genetics, Georg August University of Göttingen, 37077 Göttingen, Germany
| | - Stefan Pfeiffer
- Dpt. of Evolutionary Developmental Genetics, Georg August University of Göttingen, 37077 Göttingen, Germany
| | - Gregor Bucher
- Dpt. of Evolutionary Developmental Genetics, Georg August University of Göttingen, 37077 Göttingen, Germany
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10
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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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11
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The Function and Evolution of Nuclear Receptors in Insect Embryonic Development. Curr Top Dev Biol 2017; 125:39-70. [DOI: 10.1016/bs.ctdb.2017.01.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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12
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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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13
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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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14
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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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Peel AD, Schanda J, Grossmann D, Ruge F, Oberhofer G, Gilles AF, Schinko JB, Klingler M, Bucher G. Tc-knirps plays different roles in the specification of antennal and mandibular parasegment boundaries and is regulated by a pair-rule gene in the beetle Tribolium castaneum. BMC DEVELOPMENTAL BIOLOGY 2013; 13:25. [PMID: 23777260 PMCID: PMC3698154 DOI: 10.1186/1471-213x-13-25] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 06/12/2013] [Indexed: 01/03/2023]
Abstract
Background The Drosophila larval head is evolutionarily derived at the genetic and morphological level. In the beetle Tribolium castaneum, development of the larval head more closely resembles the ancestral arthropod condition. Unlike in Drosophila, a knirps homologue (Tc-kni) is required for development of the antennae and mandibles. However, published Tc-kni data are restricted to cuticle phenotypes and Tc-even-skipped and Tc-wingless stainings in knockdown embryos. Hence, it has remained unclear whether the entire antennal and mandibular segments depend on Tc-kni function, and whether the intervening intercalary segment is formed completely. We address these questions with a detailed examination of Tc-kni function. Results By examining the expression of marker genes in RNAi embryos, we show that Tc-kni is required only for the formation of the posterior parts of the antennal and mandibular segments (i.e. the parasegmental boundaries). Moreover, we find that the role of Tc-kni is distinct in these segments: Tc-kni is required for the initiation of the antennal parasegment boundary, but only for the maintenance of the mandibular parasegmental boundary. Surprisingly, Tc-kni controls the timing of expression of the Hox gene Tc-labial in the intercalary segment, although this segment does form in the absence of Tc-kni function. Unexpectedly, we find that the pair-rule gene Tc-even-skipped helps set the posterior boundary of Tc-kni expression in the mandible. Using the mutant antennaless, a likely regulatory Null mutation at the Tc-kni locus, we provide evidence that our RNAi studies represent a Null situation. Conclusions Tc-kni is required for the initiation of the antennal and the maintenance of the mandibular parasegmental boundaries. Tc-kni is not required for specification of the anterior regions of these segments, nor the intervening intercalary segment, confirming that Tc-kni is not a canonical ‘gap-gene’. Our finding that a gap gene orthologue is regulated by a pair rule gene adds to the view that the segmentation gene hierarchies differ between Tribolium and Drosophila upstream of the pair rule gene level. In Tribolium, as in Drosophila, head and trunk segmentation gene networks cooperate to pattern the mandibular segment, albeit involving Tc-kni as novel component.
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Affiliation(s)
- Andrew D Peel
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology - Hellas (FoRTH), Nikolaou Plastira 100, GR-70013, Heraklion, Crete, Greece
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Naggan Perl T, Schmid BG, Schwirz J, Chipman AD. The Evolution of the knirps Family of Transcription Factors in Arthropods. Mol Biol Evol 2013; 30:1348-57. [DOI: 10.1093/molbev/mst046] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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17
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Heat shock-mediated misexpression of genes in the beetle Tribolium castaneum. Dev Genes Evol 2012; 222:287-98. [DOI: 10.1007/s00427-012-0412-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 06/29/2012] [Indexed: 12/18/2022]
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18
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The evolution of novelty in conserved gene families. INTERNATIONAL JOURNAL OF EVOLUTIONARY BIOLOGY 2012; 2012:490894. [PMID: 22779028 PMCID: PMC3388334 DOI: 10.1155/2012/490894] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 04/23/2012] [Indexed: 12/05/2022]
Abstract
One of the major aims of contemporary evolutionary biology is the understanding of the current pattern of biological diversity. This involves, first, the description of character distribution at various nodes of the phylogenetic tree of life and, second, the functional explanation of such changes. The analysis of character distribution is a powerful tool at both the morphological and molecular levels. Recent high-throughput sequencing approaches provide new opportunities to study the genetic architecture of organisms at the genome-wide level. In eukaryotes, one overarching finding is the absence of simple correlations of gene count and biological complexity. Instead, the domain architecture of proteins is becoming a central focus for large-scale evolutionary innovations. Here, we review examples of the evolution of novelty in conserved gene families in insects and nematodes. We highlight how in the absence of whole-genome duplications molecular novelty can arise, how members of gene families have diversified at distinct mechanistic levels, and how gene expression can be maintained in the context of multiple innovations in regulatory mechanisms.
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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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Andrioli LP. Toward new Drosophila paradigms. Genesis 2012; 50:585-98. [DOI: 10.1002/dvg.22019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 02/07/2012] [Accepted: 02/08/2012] [Indexed: 11/07/2022]
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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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Posnien N, Koniszewski NDB, Hein HJ, Bucher G. Candidate gene screen in the red flour beetle Tribolium reveals six3 as ancient regulator of anterior median head and central complex development. PLoS Genet 2011; 7:e1002416. [PMID: 22216011 PMCID: PMC3245309 DOI: 10.1371/journal.pgen.1002416] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 10/13/2011] [Indexed: 11/19/2022] Open
Abstract
Several highly conserved genes play a role in anterior neural plate patterning of vertebrates and in head and brain patterning of insects. However, head involution in Drosophila has impeded a systematic identification of genes required for insect head formation. Therefore, we use the red flour beetle Tribolium castaneum in order to comprehensively test the function of orthologs of vertebrate neural plate patterning genes for a function in insect head development. RNAi analysis reveals that most of these genes are indeed required for insect head capsule patterning, and we also identified several genes that had not been implicated in this process before. Furthermore, we show that Tc-six3/optix acts upstream of Tc-wingless, Tc-orthodenticle1, and Tc-eyeless to control anterior median development. Finally, we demonstrate that Tc-six3/optix is the first gene known to be required for the embryonic formation of the central complex, a midline-spanning brain part connected to the neuroendocrine pars intercerebralis. These functions are very likely conserved among bilaterians since vertebrate six3 is required for neuroendocrine and median brain development with certain mutations leading to holoprosencephaly.
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Affiliation(s)
- Nico Posnien
- Center for Molecular Physiology of the Brain (CMPB), Göttingen Center of Molecular Biology, Caspari-Haus, Georg-August-University Göttingen, Göttingen, Germany
- School of Life Sciences, Oxford Brookes University, Oxford, United Kingdom
| | - Nikolaus Dieter Bernhard Koniszewski
- Center for Molecular Physiology of the Brain (CMPB), Göttingen Center of Molecular Biology, Caspari-Haus, Georg-August-University Göttingen, Göttingen, Germany
| | | | - Gregor Bucher
- Center for Molecular Physiology of the Brain (CMPB), Göttingen Center of Molecular Biology, Caspari-Haus, Georg-August-University Göttingen, Göttingen, Germany
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Abstract
The nuclear receptors (NRs) of metazoans are an ancient family of transcription factors defined by conserved DNA- and ligand-binding domains (DBDs and LBDs, respectively). The Drosophila melanogaster genome project revealed 18 canonical NRs (with DBDs and LBDs both present) and 3 receptors with the DBD only. Annotation of subsequently sequenced insect genomes revealed only minor deviations from this pattern. A renewed focus on functional analysis of the isoforms of insect NRs is therefore required to understand the diverse roles of these transcription factors in embryogenesis, metamorphosis, reproduction, and homeostasis. One insect NR, ecdysone receptor (EcR), functions as a receptor for the ecdysteroid molting hormones of insects. Researchers have developed nonsteroidal ecdysteroid agonists for EcR that disrupt molting and can be used as safe pesticides. An exciting new technology allows EcR to be used in chimeric, ligand-inducible gene-switch systems with applications in pest management and medicine.
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Affiliation(s)
- Susan E Fahrbach
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina 27109, USA.
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Birkan M, Schaeper ND, Chipman AD. Early patterning and blastodermal fate map of the head in the milkweed bug Oncopeltus fasciatus. Evol Dev 2011; 13:436-47. [DOI: 10.1111/j.1525-142x.2011.00497.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Michael Birkan
- Department of Ecology, Evolution and Behavior; The Hebrew University of Jerusalem; Edmond J. Safra Campus, Givat Ram; Jerusalem; 91904; Israel
| | - Nina D. Schaeper
- Johann-Friedrich-Blumenbach-Institute of Zoology and Anthropology; Georg-August-Universität Göttingen; GZMB, Ernst-Caspari-Haus, Justus-von-Liebig-Weg 11; Göttingen; 37077; Germany
| | - Ariel D. Chipman
- Department of Ecology, Evolution and Behavior; The Hebrew University of Jerusalem; Edmond J. Safra Campus, Givat Ram; Jerusalem; 91904; Israel
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25
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Schroeder MD, Greer C, Gaul U. How to make stripes: deciphering the transition from non-periodic to periodic patterns in Drosophila segmentation. Development 2011; 138:3067-78. [PMID: 21693522 DOI: 10.1242/dev.062141] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The generation of metameric body plans is a key process in development. In Drosophila segmentation, periodicity is established rapidly through the complex transcriptional regulation of the pair-rule genes. The 'primary' pair-rule genes generate their 7-stripe expression through stripe-specific cis-regulatory elements controlled by the preceding non-periodic maternal and gap gene patterns, whereas 'secondary' pair-rule genes are thought to rely on 7-stripe elements that read off the already periodic primary pair-rule patterns. Using a combination of computational and experimental approaches, we have conducted a comprehensive systems-level examination of the regulatory architecture underlying pair-rule stripe formation. We find that runt (run), fushi tarazu (ftz) and odd skipped (odd) establish most of their pattern through stripe-specific elements, arguing for a reclassification of ftz and odd as primary pair-rule genes. In the case of run, we observe long-range cis-regulation across multiple intervening genes. The 7-stripe elements of run, ftz and odd are active concurrently with the stripe-specific elements, indicating that maternal/gap-mediated control and pair-rule gene cross-regulation are closely integrated. Stripe-specific elements fall into three distinct classes based on their principal repressive gap factor input; stripe positions along the gap gradients correlate with the strength of predicted input. The prevalence of cis-elements that generate two stripes and their genomic organization suggest that single-stripe elements arose by splitting and subfunctionalization of ancestral dual-stripe elements. Overall, our study provides a greatly improved understanding of how periodic patterns are established in the Drosophila embryo.
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Affiliation(s)
- Mark D Schroeder
- Laboratory of Developmental Neurogenetics, Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
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26
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Ntini E, Wimmer EA. Unique establishment of procephalic head segments is supported by the identification of cis-regulatory elements driving segment-specific segment polarity gene expression in Drosophila. Dev Genes Evol 2011; 221:1-16. [PMID: 21399984 PMCID: PMC3089733 DOI: 10.1007/s00427-011-0354-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 02/10/2011] [Indexed: 12/20/2022]
Abstract
Anterior head segmentation is governed by different regulatory mechanisms than those that control trunk segmentation in Drosophila. For segment polarity genes, both initial mode of activation as well as cross-regulatory interactions among them differ from the typical genetic circuitry in the trunk and are unique for each of the procephalic segments. In order to better understand the segment-specific gene network responsible for the procephalic expression of the earliest active segment polarity genes wingless and hedgehog, we started to identify and analyze cis-regulatory DNA elements of these genes. For hedgehog, we could identify a cis-regulatory element, ic-CRE, that mediates expression specifically in the posterior part of the intercalary segment and requires promoter-specific interaction for its function. The intercalary stripe is the last part of the metameric hedgehog expression pattern that appears during embryonic development, which probably reflects the late and distinct establishment of this segment. The identification of a cis-regulatory element that is specific for one head segment supports the mutant-based observation that the expression of segment polarity genes is governed by a unique gene network in each of the procephalic segments. This provides further indication that the anterior-most head segments represent primary segments, which are set up independently, in contrast to the secondary segments of the trunk, which resemble true repetitive units.
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Affiliation(s)
- Evgenia Ntini
- Department of Developmental Biology, Johann-Friedrich-Blumenbach-Institute of Zoology und Anthropology, Georg-August-University Göttingen, GZMB, Ernst-Caspari-Haus, Justus-von-Liebig-Weg 11, 37077, Göttingen, Germany
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27
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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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28
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Posnien N, Schinko JB, Kittelmann S, Bucher G. Genetics, development and composition of the insect head--a beetle's view. ARTHROPOD STRUCTURE & DEVELOPMENT 2010; 39:399-410. [PMID: 20800703 DOI: 10.1016/j.asd.2010.08.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 08/08/2010] [Accepted: 08/15/2010] [Indexed: 05/29/2023]
Abstract
Many questions regarding evolution and ontogeny of the insect head remain open. Likewise, the genetic basis of insect head development is poorly understood. Recently, the investigation of gene expression data and the analysis of patterning gene function have revived interest in insect head development. Here, we argue that the red flour beetle Tribolium castaneum is a well suited model organism to spearhead research with respect to the genetic control of insect head development. We review recent molecular data and discuss its bearing on early development and morphogenesis of the head. We present a novel hypothesis on the ontogenetic origin of insect head sutures and review recent insights into the question on the origin of the labrum. Further, we argue that the study of developmental genes may identify the elusive anterior non-segmental region and present some evidence in favor of its existence. With respect to the question of evolution of patterning we show that the head Anlagen of the fruit fly Drosophila melanogaster and Tribolium differ considerably and we review profound differences of their genetic regulation. Finally, we discuss which insect model species might help us to answer the open questions concerning the genetic regulation of head development and its evolution.
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Affiliation(s)
- Nico Posnien
- Institute for Population Genetics, University of Veterinary Medicine Vienna, Veterinärplatz 1, Vienna, Austria
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29
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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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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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Xu J, Tan A, Palli SR. The function of nuclear receptors in regulation of female reproduction and embryogenesis in the red flour beetle, Tribolium castaneum. JOURNAL OF INSECT PHYSIOLOGY 2010; 56:1471-80. [PMID: 20416316 PMCID: PMC2918696 DOI: 10.1016/j.jinsphys.2010.04.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 04/05/2010] [Accepted: 04/06/2010] [Indexed: 05/09/2023]
Abstract
Nineteen canonical and two Knirps-like family nuclear receptors (NRs) were identified in the genome of Tribolium castaneum. The current study was conducted to determine the function of these NRs in regulation of female reproduction and embryogenesis. RNA interference (RNAi)-aided knock-down in the expression of genes coding for 21 NRs showed that seven NRs E75, hormone receptor 3 (HR3), ecdysone receptor (EcR), ultraspiracle (USP), seven-up (SVP), FTZ transcription factor 1 (FTZ-F1) and hormone receptor 4 (HR4) are required for successful vitellogenesis and oogenesis. Knocking down the expression of genes coding for these seven NRs affected egg production by reducing the levels of vitellogenin mRNAs as well as by affecting the oocyte maturation. Expression of seven additional NRs hormone receptor 96 (HR96), hormone receptor 51 (HR51), hormone receptor 38 (HR38), hormone receptor 39 (HR39), Tailless (Tll), Dissatisfaction (Dsf) and Knirps-like is required for successful embryogenesis. The knock-down in the expression of genes coding for three other NRs (E78, hepatocyte nuclear factor 4, HNF4 and Eagle) partially blocked embryogenesis. This study showed that at least 17 out of the 21 NRs identified in T. castaneum play key roles in female reproduction and embryogenesis.
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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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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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Christiaens O, Iga M, Velarde RA, Rougé P, Smagghe G. Halloween genes and nuclear receptors in ecdysteroid biosynthesis and signalling in the pea aphid. INSECT MOLECULAR BIOLOGY 2010; 19 Suppl 2:187-200. [PMID: 20482650 DOI: 10.1111/j.1365-2583.2009.00957.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The pea aphid (Acyrthosiphon pisum) is the first whole genome sequenced insect with a hemimetabolic development and an emerging model organism for studies in ecology, evolution and development. The insect steroid moulting hormone 20-hydroxyecdysone (20E) controls and coordinates development in insects, especially the moulting/metamorphosis process. We, therefore present here a comprehensive characterization of the Halloween genes phantom, disembodied, shadow, shade, spook and spookiest, coding for the P450 enzymes that control the biosynthesis of 20E. Regarding the presence of nuclear receptors in the pea aphid genome, we found 19 genes, representing all of the seven known subfamilies. The annotation and phylogenetic analysis revealed a strong conservation in the class of Insecta. But compared with other sequenced insect genomes, three orthologues are missing in the Acyrthosiphon genome, namely HR96, PNR-like and Knirps. We also cloned the EcR, Usp, E75 and HR3. Finally, 3D-modelling of the ligand-binding domain of Ap-EcR exhibited the typical canonical structural scaffold with 12 alpha-helices associated with a short hairpin of two antiparallel beta-strands. Upon docking, 20E was located in the hormone-binding groove, supporting the hypothesis that EcR has a role in 20E signalling.
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MESH Headings
- Animals
- Aphids/genetics
- Aphids/growth & development
- Aphids/metabolism
- Binding Sites
- Cloning, Molecular
- Ecdysteroids/biosynthesis
- Ecdysterone/biosynthesis
- Genes, Insect
- Genome, Insect
- Insect Proteins/chemistry
- Insect Proteins/genetics
- Insect Proteins/metabolism
- Insecta/genetics
- Insecta/metabolism
- Ligands
- Models, Molecular
- Pisum sativum/parasitology
- Phylogeny
- Protein Conformation
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Cytoplasmic and Nuclear/chemistry
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Steroid/chemistry
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Signal Transduction/genetics
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Affiliation(s)
- O Christiaens
- Department of Crop Protection, Ghent University, Belgium
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