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Clark E, Battistara M, Benton MA. A timer gene network is spatially regulated by the terminal system in the Drosophila embryo. eLife 2022; 11:e78902. [PMID: 36524728 PMCID: PMC10065802 DOI: 10.7554/elife.78902] [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: 03/23/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
In insect embryos, anteroposterior patterning is coordinated by the sequential expression of the 'timer' genes caudal, Dichaete, and odd-paired, whose expression dynamics correlate with the mode of segmentation. In Drosophila, the timer genes are expressed broadly across much of the blastoderm, which segments simultaneously, but their expression is delayed in a small 'tail' region, just anterior to the hindgut, which segments during germband extension. Specification of the tail and the hindgut depends on the terminal gap gene tailless, but beyond this the regulation of the timer genes is poorly understood. We used a combination of multiplexed imaging, mutant analysis, and gene network modelling to resolve the regulation of the timer genes, identifying 11 new regulatory interactions and clarifying the mechanism of posterior terminal patterning. We propose that a dynamic Tailless expression gradient modulates the intrinsic dynamics of a timer gene cross-regulatory module, delineating the tail region and delaying its developmental maturation.
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Affiliation(s)
- Erik Clark
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Department of Systems Biology, Harvard Medical SchoolBostonUnited States
- Department of Genetics, University of CambridgeCambridgeUnited Kingdom
| | - Margherita Battistara
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Department of Physiology, Development and Neuroscience, University of CambridgeCambridgeUnited Kingdom
| | - Matthew A Benton
- Department of Zoology, University of CambridgeCambridgeUnited Kingdom
- Developmental Biology Unit, EMBLHeidelbergGermany
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2
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Zheng L, Byadgi O, Rakhshaninejad M, Nauwynck H. Upregulation of torso-like protein (perforin) and granzymes B and G in non-adherent, lymphocyte-like haemocytes during a WSSV infection in shrimp. FISH & SHELLFISH IMMUNOLOGY 2022; 128:676-683. [PMID: 35985630 DOI: 10.1016/j.fsi.2022.08.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 08/09/2022] [Accepted: 08/11/2022] [Indexed: 06/15/2023]
Abstract
Invertebrates only have an innate immunity in which haemocytes play an important role. In our lab, 5 subpopulations of haemocytes were identified in the past by an iodixanol density gradient: hyalinocytes, granulocytes, semi-granulocytes and two subpopulations of non-phagocytic cells. For the two latter subpopulations, the haemocytes have small cytoplasm rims, do not adhere to the bottom of plastic cell-culture grade wells and present folds in the nucleus. These characteristics are similar to those of mammalian lymphocytes. Therefore, they were designated lymphocyte-like haemocytes. Although little is known about their function, we hypothesize, based on their morphology, that they may have a cytotoxic activity. First, a fast isolation technique was developed to separate the non-adherent haemocytes from the adherent haemocytes. After 60 min incubation on cell culture plates, the non-adherent haemocytes were collected. The purity reached 93% as demonstrated by flow cytometry and light microscopy upon a Hematoxylin and Eosin (H&E) staining. Cytotoxicity by lymphocytes is mediated by molecules such as perforin and granzymes and therefore, we searched for their genes in the shrimp genome. Genes coding for a torso-like protein, granzyme B and granzyme G were identified. Primers were designed and RT-PCR/RT-qPCR assays were developed. The results demonstrated that torso-like protein, granzyme B and granzyme G were mainly expressed in non-adherent haemocytes. The shrimp torso-like protein gene was most related to that of the crab torso-like protein; granzyme B gene was most related to that of mouse granzyme B and granzyme G gene was most related to that of zebrafish granzyme G. In a 72-hour in vivo WSSV infection challenge, the mRNA expression of shrimp torso-like protein, granzyme B and granzyme G in haemocytes was increasing over time, which indicated that torso-like protein, granzyme B and granzyme G of shrimp haemocytes are involved in the immune response during a viral infection. In the future, antibodies will be raised against these proteins for more in-depth functional analyses.
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Affiliation(s)
- Liping Zheng
- Laboratory of Virology, Department of Translational Physiology, Infectiology and Public Health, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium.
| | - Omkar Byadgi
- International Program in Ornamental Fish Technology and Aquatic Animal Health, National Pingtung University of Science and Technology, 91201, Pingtung, Taiwan
| | - Mostafa Rakhshaninejad
- Laboratory of Virology, Department of Translational Physiology, Infectiology and Public Health, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium
| | - Hans Nauwynck
- Laboratory of Virology, Department of Translational Physiology, Infectiology and Public Health, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium
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3
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Li Z, Zhang J, Yin S, Xi G. Toxicity effect of the edible pigment carmoisine on Polyrhachis vicina Roger (Hymenoptera: Formicidae). ECOTOXICOLOGY (LONDON, ENGLAND) 2022; 31:1009-1022. [PMID: 35792963 DOI: 10.1007/s10646-022-02563-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/25/2022] [Indexed: 06/15/2023]
Abstract
Carmoisine belongs to a water-soluble synthetic dye and is often used as a food additive. Previous research has shown that carmoisine is toxic to rats and zebrafish, but there have been few reports on the effect of carmoisine on soil-dwelling social insects. The present study evaluated carmoisine toxicity in Polyrhachis vicina Roger. We found that the effects of different concentrations of carmoisine on the mortality of workers were dose-dependent. The 10% lethal dose (LD10), 50% lethal dose (LD50) and 90% lethal dose (LD90) of carmoisine to workers at 96 h was calculated to be 0.504, 5.491 and 10.478 g/L, respectivily. LD10 of workers were selected to treat the fourth instar larvae, pupae and adults for 10 days. The results showed that the survival rate of all ants, except for females, was significantly reduced, especially larvae and workers. The body weight of larvae, pupae and males decreased significantly, while weight gain was observed in the females and workers. The appearance of larvae, pupae and workers changed after carmoisine treatment, such as body darkening and epidermis shrinking of larvae and pupae, as well as body segment expansion of workers. Furthermore, carmoisine altered the expression of the estrogen-related receptor, tailless and homothorax of P. vicina (Pv-ERR, Pv-tll and Pv-hth) to varying degrees in larvae and adults. We believe that variations in body weight can lead to a decrease in survival rate and appearance changes in the ants, which may be related to abnormal gene expressions caused by carmoisine treatment. Therefore, we confirm that carmoisine has negative effects on the growth and development of P. vicina.
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Affiliation(s)
- Ziyu Li
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, Shaanxi Province, China
| | - Jing Zhang
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, Shaanxi Province, China
| | - Shaoting Yin
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, Shaanxi Province, China
| | - Gengsi Xi
- College of Life Science, Shaanxi Normal University, Xi'an, 710119, Shaanxi Province, China.
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4
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Li Z, Yin S, Zhang J, Xi G. Effect of aspartame on survival, morphological and molecular levels of Polyrhachis vicina Roger (Hymenoptera, Formicidae). Comp Biochem Physiol C Toxicol Pharmacol 2022; 254:109273. [PMID: 35038594 DOI: 10.1016/j.cbpc.2022.109273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 11/30/2021] [Accepted: 01/08/2022] [Indexed: 11/03/2022]
Abstract
Aspartame is a food additive that is widely used in the food industry. Previous data have shown that aspartame is toxic to humans and animals. However, there are few reports on the effect of aspartame on social insects living in the soil. The present study was designed to evaluate aspartame toxicity for Polyrhachis vicina Roger. Five dosages of aspartame were fed to the workers and 40 mg/kg (acceptable daily intake, ADI) aspartame was chosen to feed the 4th instar larvae, pupae, females and males in P. vicina. The results showed that the effect of aspartame on the survival rate of workers was in a time and dose dependent manner. The survival rate of 4th instar larvae, pupae and males decreased at 40 mg/kg aspartame. Meanwhile, we found that aspartame toxicity can cause weight and morphological changes. These changes may be related to the abnormal gene expression of Ecdysone receptor, Tailless and Extradenticle of P. vicina (PvEcR, PvTll and PvExd) resulting from aspartame treatment. The present study confirms the effect of aspartame toxicity on P. vicina even at the ADI dosage.
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Affiliation(s)
- Ziyu Li
- College of Life Science, Shaanxi Normal University, Xi'an, Shaanxi Province 710119, PR China
| | - Shaoting Yin
- College of Life Science, Shaanxi Normal University, Xi'an, Shaanxi Province 710119, PR China
| | - Jing Zhang
- College of Life Science, Shaanxi Normal University, Xi'an, Shaanxi Province 710119, PR China
| | - Gengsi Xi
- College of Life Science, Shaanxi Normal University, Xi'an, Shaanxi Province 710119, PR China.
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5
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Taylor SE, Tuffery J, Bakopoulos D, Lequeux S, Warr CG, Johnson TK, Dearden PK. The torso-like gene functions to maintain the structure of the vitelline membrane in Nasonia vitripennis, implying its co-option into Drosophila axis formation. Biol Open 2019; 8:bio.046284. [PMID: 31488408 PMCID: PMC6777369 DOI: 10.1242/bio.046284] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Axis specification is a fundamental developmental process. Despite this, the mechanisms by which it is controlled across insect taxa are strikingly different. An excellent example of this is terminal patterning, which in Diptera such as Drosophila melanogaster occurs via the localized activation of the receptor tyrosine kinase Torso. In Hymenoptera, however, the same process appears to be achieved via localized mRNA. How these mechanisms evolved and what they evolved from remains largely unexplored. Here, we show that torso-like, known for its role in Drosophila terminal patterning, is instead required for the integrity of the vitelline membrane in the hymenopteran wasp Nasonia vitripennis. We find that other genes known to be involved in Drosophila terminal patterning, such as torso and Ptth, also do not function in Nasonia embryonic development. These findings extended to orthologues of Drosophila vitelline membrane proteins known to play a role in localizing Torso-like in Drosophila; in Nasonia these are instead required for dorso–ventral patterning, gastrulation and potentially terminal patterning. Our data underscore the importance of the vitelline membrane in insect development, and implies phenotypes caused by knockdown of torso-like must be interpreted in light of its function in the vitelline membrane. In addition, our data imply that the signalling components of the Drosophila terminal patterning systems were co-opted from roles in regulating moulting, and co-option into terminal patterning involved the evolution of a novel interaction with the vitelline membrane protein Torso-like. This article has an associated First Person interview with the first author of the paper. Summary: In the parasitic wasp Nasonia, Tsl, a key component of the process that defines the termini of the embryo of Drosophila, has a function in the structure of the vitelline membrane.
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Affiliation(s)
- Shannon E Taylor
- Genomics Aotearoa and Biochemistry Department, University of Otago, P.O. Box 56, Dunedin, Aotearoa-New Zealand
| | - Jack Tuffery
- Genomics Aotearoa and Biochemistry Department, University of Otago, P.O. Box 56, Dunedin, Aotearoa-New Zealand
| | - Daniel Bakopoulos
- School of Biological Sciences, Monash University, 18 Innovation Walk, Clayton VIC 3800, Australia
| | - Sharon Lequeux
- Otago Micro- and Nano- scale Imaging, University of Otago, PO Box 913, Dunedin, New Zealand, Aotearoa-New Zealand
| | - Coral G Warr
- School of Medicine, University of Tasmania, 17 Liverpool St Hobart, TAS 7000, Australia
| | - Travis K Johnson
- School of Biological Sciences, Monash University, 18 Innovation Walk, Clayton VIC 3800, Australia
| | - Peter K Dearden
- Genomics Aotearoa and Biochemistry Department, University of Otago, P.O. Box 56, Dunedin, Aotearoa-New Zealand
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6
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Skelly J, Pushparajan C, Duncan EJ, Dearden PK. Evolution of the Torso activation cassette, a pathway required for terminal patterning and moulting. INSECT MOLECULAR BIOLOGY 2019; 28:392-408. [PMID: 30548465 DOI: 10.1111/imb.12560] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Embryonic terminal patterning and moulting are critical developmental processes in insects. In Drosophila and Tribolium both of these processes are regulated by the Torso-activation cassette (TAC). The TAC consists of a common receptor, Torso, ligands Trunk and prothoracicotropic hormone (PTTH), and the spatially restricted protein Torso-like, with combinations of these elements acting mechanistically to activate the receptor in different developmental contexts. In order to trace the evolutionary history of the TAC we determined the presence or absence of TAC components in the genomes of arthropods. Our analyses reveal that Torso, Trunk and PTTH are evolutionarily labile components of the TAC with multiple individual or combined losses occurring in the arthropod lineages leading to and within the insects. These losses are often correlated, with both ligands and receptor missing from the genome of the same species. We determine that the PTTH gene evolved in the common ancestor of Hemiptera and Holometabola, and is missing from the genomes of a number of species with experimentally demonstrated PTTH activity, implying another molecule may be involved in ecdysis in these species. In contrast, the torso-like gene is a common component of pancrustacean genomes.
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Affiliation(s)
- J Skelly
- Laboratory for Evolution and Development, Genomics Aotearoa, Biochemistry Department, University of Otago, Dunedin, Aotearoa-New Zealand
| | - C Pushparajan
- Laboratory for Evolution and Development, Genomics Aotearoa, Biochemistry Department, University of Otago, Dunedin, Aotearoa-New Zealand
| | - E J Duncan
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - P K Dearden
- Laboratory for Evolution and Development, Genomics Aotearoa, Biochemistry Department, University of Otago, Dunedin, Aotearoa-New Zealand
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Hu X, Ke L, Wang Z, Zeng Z. Dynamic transcriptome landscape of Asian domestic honeybee (Apis cerana) embryonic development revealed by high-quality RNA sequencing. BMC DEVELOPMENTAL BIOLOGY 2018; 18:11. [PMID: 29653508 PMCID: PMC5899340 DOI: 10.1186/s12861-018-0169-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 04/03/2018] [Indexed: 12/18/2022]
Abstract
Background Honeybee development consists of four stages: embryo, larva, pupa and adult. Embryogenesis, a key process of cell division and differentiation, takes 3 days in honeybees. However, the embryonic transcriptome and the dynamic regulation of embryonic transcription are still largely uncharacterized in honeybees, especially in the Asian honeybee (Apis cerana). Here, we employed high-quality RNA-seq to explore the transcriptome of Asian honeybee embryos at three ages, approximately 24, 48 and 72 h (referred to as Day1, Day2 and Day3, respectively). Results Nine embryo samples, three from each age, were collected for RNA-seq. According to the staging scheme of honeybee embryos and the morphological features we observed, our Day1, Day2 and Day3 embryos likely corresponded to the late stage four, stage eight and stage ten development stages, respectively. Hierarchical clustering and principal component analysis showed that same-age samples were grouped together, and the Day2 samples had a closer relationship with the Day3 samples than the Day1 samples. Finally, a total of 18,284 genes harboring 55,646 transcripts were detected in the A. cerana embryos, of which 44.5% consisted of the core transcriptome shared by all three ages of embryos. A total of 4088 upregulated and 3046 downregulated genes were identified among the three embryo ages, of which 2010, 3177 and 1528 genes were upregulated and 2088, 2294 and 303 genes were downregulated from Day1 to Day2, from Day1 to Day3 and from Day2 to Day3, respectively. The downregulated genes were mostly involved in cellular, biosynthetic and metabolic processes, gene expression and protein localization, and macromolecule modification; the upregulated genes mainly participated in cell development and differentiation, tissue, organ and system development, and morphogenesis. Interestingly, several biological processes related to the response to and detection of light stimuli were enriched in the first-day A. cerana embryogenesis but not in the Apis mellifera embryogenesis, which was valuable for further investigations. Conclusions Our transcriptomic data substantially expand the number of known transcribed elements in the A. cerana genome and provide a high-quality view of the transcriptome dynamics of A. cerana embryonic development. Electronic supplementary material The online version of this article (10.1186/s12861-018-0169-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiaofen Hu
- Honeybee Research Institute, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China
| | - Li Ke
- Honeybee Research Institute, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China
| | - Zilong Wang
- Honeybee Research Institute, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China
| | - Zhijiang Zeng
- Honeybee Research Institute, Jiangxi Agricultural University, Nanchang, 330045, Jiangxi, China.
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8
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Cridge AG, Lovegrove MR, Skelly JG, Taylor SE, Petersen GEL, Cameron RC, Dearden PK. The honeybee as a model insect for developmental genetics. Genesis 2017; 55. [PMID: 28432809 DOI: 10.1002/dvg.23019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Revised: 01/08/2017] [Accepted: 01/15/2017] [Indexed: 11/11/2022]
Abstract
Honeybees are an important component of modern agricultural systems, and a fascinating and scientifically engrossing insect. Honeybees are not commonly used as model systems for understanding development in insects despite their importance in agriculture. Honeybee embryogenesis, while being superficially similar to Drosophila, is molecularly very different, especially in axis formation and sex determination. In later development, much of honeybee biology is modified by caste development, an as yet poorly understood, but excellent, system to study developmental plasticity. In adult stages, developmental plasticity of the ovaries, related to reproductive constraint exhibits another aspect of plasticity. Here they review the tools, current knowledge and opportunities in honeybee developmental biology, and provide an updated embryonic staging scheme to support future studies.
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Affiliation(s)
- A G Cridge
- Laboratory for Evolution and Development, Genetics Otago, Biochemistry Department, University of Otago, Dunedin, 9054, P.O. Box 56, Aotearoa-New Zealand
| | - M R Lovegrove
- Laboratory for Evolution and Development, Genetics Otago, Biochemistry Department, University of Otago, Dunedin, 9054, P.O. Box 56, Aotearoa-New Zealand
| | - J G Skelly
- Laboratory for Evolution and Development, Genetics Otago, Biochemistry Department, University of Otago, Dunedin, 9054, P.O. Box 56, Aotearoa-New Zealand
| | - S E Taylor
- Laboratory for Evolution and Development, Genetics Otago, Biochemistry Department, University of Otago, Dunedin, 9054, P.O. Box 56, Aotearoa-New Zealand
| | - G E L Petersen
- Laboratory for Evolution and Development, Genetics Otago, Biochemistry Department, University of Otago, Dunedin, 9054, P.O. Box 56, Aotearoa-New Zealand.,AbacusBio Ltd, Public Trust Building, 442 Moray Place, Dunedin 9016, Aotearoa-New Zealand
| | - R C Cameron
- Department of Developmental and Molecular Biology and Gottesman Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, New York
| | - P K Dearden
- Laboratory for Evolution and Development, Genetics Otago, Biochemistry Department, University of Otago, Dunedin, 9054, P.O. Box 56, Aotearoa-New Zealand
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Feitosa NM, Pechmann M, Schwager EE, Tobias-Santos V, McGregor AP, Damen WGM, Nunes da Fonseca R. Molecular control of gut formation in the spider Parasteatoda tepidariorum. Genesis 2017; 55. [PMID: 28432834 DOI: 10.1002/dvg.23033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 02/23/2017] [Accepted: 03/16/2017] [Indexed: 12/16/2022]
Abstract
The development of a digestive system is an essential feature of bilaterians. Studies of the molecular control of gut formation in arthropods have been studied in detail in the fruit fly Drosophila melanogaster. However, little is known in other arthropods, especially in noninsect arthropods. To better understand the evolution of arthropod alimentary system, we investigate the molecular control of gut development in the spider Parasteatoda tepidariorum (Pt), the primary chelicerate model species for developmental studies. Orthologs of the ectodermal genes Pt-wingless (Pt-wg) and Pt-hedgehog (Pt-hh), of the endodermal genes, Pt-serpent (Pt-srp) and Pt-hepatocyte-nuclear factor-4 (Pt-hnf4) and of the mesodermal gene Pt-twist (Pt-twi) are expressed in the same germ layers during spider gut development as in D. melanogaster. Thus, our expression data suggest that the downstream molecular components involved in gut development in arthropods are conserved. However, Pt-forkhead (Pt-fkh) expression and function in spiders is considerably different from its D. melanogaster ortholog. Pt-fkh is expressed before gastrulation in a cell population that gives rise to endodermal and mesodermal precursors, suggesting a possible role for this factor in specification of both germ layers. To test this hypothesis, we knocked down Pt-fkh via RNA interference. Pt-fkh RNAi embryos not only fail to develop a proper gut, but also lack the mesodermal Pt-twi expressing cells. Thus, in spiders Pt-fkh specifies endodermal and mesodermal germ layers. We discuss the implications of these findings for the evolution and development of gut formation in Ecdysozoans.
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Affiliation(s)
- Natália Martins Feitosa
- Laboratório Integrado de Ciências Morfofuncionais, Núcleo em Ecologia e Desenvolvimento Socio-Ambiental de Macaé (NUPEM), Campus Macaé, Universidade Federal do Rio de Janeiro (UFRJ), Macaé, Rio de Janeiro, 27920-560, Brazil
| | - Matthias Pechmann
- Institute for Developmental Biology, University of Cologne, Cologne, North-Rhine Westphalia, 50674, Germany
| | - Evelyn E Schwager
- Department of Biological Sciences, University of Massachusetts Lowell, 198 Riverside Street, Lowell, Massachusetts, 01854
| | - Vitória Tobias-Santos
- Laboratório Integrado de Ciências Morfofuncionais, Núcleo em Ecologia e Desenvolvimento Socio-Ambiental de Macaé (NUPEM), Campus Macaé, Universidade Federal do Rio de Janeiro (UFRJ), Macaé, Rio de Janeiro, 27920-560, Brazil
| | - Alistair P McGregor
- Department of Biological and Medical Sciences, Oxford Brookes University, Gipsy Lane, Oxford, OX3 0BP, United Kingdom
| | - Wim G M Damen
- Department of Genetics, Friedrich-Schiller-Universität Jena, Philosophenweg 12, Jena, 07743, Germany
| | - Rodrigo Nunes da Fonseca
- Laboratório Integrado de Ciências Morfofuncionais, Núcleo em Ecologia e Desenvolvimento Socio-Ambiental de Macaé (NUPEM), Campus Macaé, Universidade Federal do Rio de Janeiro (UFRJ), Macaé, Rio de Janeiro, 27920-560, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Universidade Federal do Rio de Janeiro (UFRJ), 21941-599 Rio de Janeiro, Rio de Janeiro, Brazil
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10
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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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11
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Benton MA, Kenny NJ, Conrads KH, Roth S, Lynch JA. Deep, Staged Transcriptomic Resources for the Novel Coleopteran Models Atrachya menetriesi and Callosobruchus maculatus. PLoS One 2016; 11:e0167431. [PMID: 27907180 PMCID: PMC5132259 DOI: 10.1371/journal.pone.0167431] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 11/14/2016] [Indexed: 11/18/2022] Open
Abstract
Despite recent efforts to sample broadly across metazoan and insect diversity, current sequence resources in the Coleoptera do not adequately describe the diversity of the clade. Here we present deep, staged transcriptomic data for two coleopteran species, Atrachya menetriesi (Faldermann 1835) and Callosobruchus maculatus (Fabricius 1775). Our sampling covered key stages in ovary and early embryonic development in each species. We utilized this data to build combined assemblies for each species which were then analysed in detail. The combined A. menetriesi assembly consists of 228,096 contigs with an N50 of 1,598 bp, while the combined C. maculatus assembly consists of 128,837 contigs with an N50 of 2,263 bp. For these assemblies, 34.6% and 32.4% of contigs were identified using Blast2GO, and 97% and 98.3% of the BUSCO set of metazoan orthologs were present, respectively. We also carried out manual annotation of developmental signalling pathways and found that nearly all expected genes were present in each transcriptome. Our analyses show that both transcriptomes are of high quality. Lastly, we performed read mapping utilising our timed, stage specific RNA samples to identify differentially expressed contigs. The resources presented here will provide a firm basis for a variety of experimentation, both in developmental biology and in comparative genomic studies.
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Affiliation(s)
- Matthew A. Benton
- Institute for Developmental Biology, University of Cologne, Cologne, Germany
| | - Nathan J. Kenny
- Simon F.S. Li School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Kai H. Conrads
- Institute for Developmental Biology, University of Cologne, Cologne, Germany
| | - Siegfried Roth
- Institute for Developmental Biology, University of Cologne, Cologne, Germany
- * E-mail: (SR); (JAL)
| | - Jeremy A. Lynch
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail: (SR); (JAL)
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12
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Cridge AG, Dearden PK, Brownfield LR. Convergent occurrence of the developmental hourglass in plant and animal embryogenesis? ANNALS OF BOTANY 2016; 117:833-843. [PMID: 27013176 PMCID: PMC4845807 DOI: 10.1093/aob/mcw024] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 01/08/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND The remarkable similarity of animal embryos at particular stages of development led to the proposal of a developmental hourglass. In this model, early events in development are less conserved across species but lead to a highly conserved 'phylotypic period'. Beyond this stage, the model suggests that development once again becomes less conserved, leading to the diversity of forms. Recent comparative studies of gene expression in animal groups have provided strong support for the hourglass model. How and why might such an hourglass pattern be generated? More importantly, how might early acting events in development evolve while still maintaining a later conserved stage? SCOPE The discovery that an hourglass pattern may also exist in the embryogenesis of plants provides comparative data that may help us explain this phenomenon. Whether the developmental hourglass occurs in plants, and what this means for our understanding of embryogenesis in plants and animals is discussed. Models by which conserved early-acting genes might change their functional role in the evolution of gene networks, how networks buffer these changes, and how that might constrain, or confer diversity, of the body plan are also discused. CONCLUSIONS Evidence of a morphological and molecular hourglass in plant and animal embryogenesis suggests convergent evolution. This convergence is likely due to developmental constraints imposed upon embryogenesis by the need to produce a viable embryo with an established body plan, controlled by the architecture of the underlying gene regulatory networks. As the body plan is largely laid down during the middle phases of embryo development in plants and animals, then it is perhaps not surprising this stage represents the narrow waist of the hourglass where the gene regulatory networks are the oldest and most robust and integrated, limiting species diversity and constraining morphological space.
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Affiliation(s)
- Andrew G Cridge
- Laboratory for Evolution and Development, Genetics Otago and Department of Biochemistry, University of Otago, Dunedin, 9054, New Zealand and
| | - Peter K Dearden
- Laboratory for Evolution and Development, Genetics Otago and Department of Biochemistry, University of Otago, Dunedin, 9054, New Zealand and
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Pires CV, Freitas FCDP, Cristino AS, Dearden PK, Simões ZLP. Transcriptome Analysis of Honeybee (Apis Mellifera) Haploid and Diploid Embryos Reveals Early Zygotic Transcription during Cleavage. PLoS One 2016; 11:e0146447. [PMID: 26751956 PMCID: PMC4713447 DOI: 10.1371/journal.pone.0146447] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 12/17/2015] [Indexed: 12/19/2022] Open
Abstract
In honeybees, the haplodiploid sex determination system promotes a unique embryogenesis process wherein females develop from fertilized eggs and males develop from unfertilized eggs. However, the developmental strategies of honeybees during early embryogenesis are virtually unknown. Similar to most animals, the honeybee oocytes are supplied with proteins and regulatory elements that support early embryogenesis. As the embryo develops, the zygotic genome is activated and zygotic products gradually replace the preloaded maternal material. The analysis of small RNA and mRNA libraries of mature oocytes and embryos originated from fertilized and unfertilized eggs has allowed us to explore the gene expression dynamics in the first steps of development and during the maternal-to-zygotic transition (MZT). We localized a short sequence motif identified as TAGteam motif and hypothesized to play a similar role in honeybees as in fruit flies, which includes the timing of early zygotic expression (MZT), a function sustained by the presence of the zelda ortholog, which is the main regulator of genome activation. Predicted microRNA (miRNA)-target interactions indicated that there were specific regulators of haploid and diploid embryonic development and an overlap of maternal and zygotic gene expression during the early steps of embryogenesis. Although a number of functions are highly conserved during the early steps of honeybee embryogenesis, the results showed that zygotic genome activation occurs earlier in honeybees than in Drosophila based on the presence of three primary miRNAs (pri-miRNAs) (ame-mir-375, ame-mir-34 and ame-mir-263b) during the cleavage stage in haploid and diploid embryonic development.
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Affiliation(s)
- Camilla Valente Pires
- Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - Alexandre S. Cristino
- The University of Queensland, Diamantina Institute, Translational Research Institute, Brisbane, Australia
| | - Peter K. Dearden
- Genetics Otago and Gravida, the National Centre for Growth and Development, Biochemistry Department, University of Otago, Dunedin, New Zealand
| | - Zilá Luz Paulino Simões
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
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Brutscher LM, Flenniken ML. RNAi and Antiviral Defense in the Honey Bee. J Immunol Res 2015; 2015:941897. [PMID: 26798663 PMCID: PMC4698999 DOI: 10.1155/2015/941897] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 11/25/2015] [Accepted: 11/29/2015] [Indexed: 01/08/2023] Open
Abstract
Honey bees play an important agricultural and ecological role as pollinators of numerous agricultural crops and other plant species. Therefore, investigating the factors associated with high annual losses of honey bee colonies in the US is an important and active area of research. Pathogen incidence and abundance correlate with Colony Collapse Disorder- (CCD-) affected colonies in the US and colony losses in the US and in some European countries. Honey bees are readily infected by single-stranded positive sense RNA viruses. Largely dependent on the host immune response, virus infections can either remain asymptomatic or result in deformities, paralysis, or death of adults or larvae. RNA interference (RNAi) is an important antiviral defense mechanism in insects, including honey bees. Herein, we review the role of RNAi in honey bee antiviral defense and highlight some parallels between insect and mammalian immune systems. A more thorough understanding of the role of pathogens on honey bee health and the immune mechanisms bees utilize to combat infectious agents may lead to the development of strategies that enhance honey bee health and result in the discovery of additional mechanisms of immunity in metazoans.
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Affiliation(s)
- Laura M. Brutscher
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
- Institute on Ecosystems, Montana State University, Bozeman, MT 59717-3490, USA
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717-3460, USA
| | - Michelle L. Flenniken
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717-3150, USA
- Institute on Ecosystems, Montana State University, Bozeman, MT 59717-3490, USA
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15
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Duncan EJ, Johnson TK, Whisstock JC, Warr CG, Dearden PK. Capturing embryonic development from metamorphosis: how did the terminal patterning signalling pathway of Drosophila evolve? CURRENT OPINION IN INSECT SCIENCE 2014; 1:45-51. [PMID: 32846729 DOI: 10.1016/j.cois.2014.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 04/29/2014] [Accepted: 04/29/2014] [Indexed: 06/11/2023]
Abstract
The Torso receptor tyrosine kinase has two crucial roles in Drosophila melanogaster development. One is in the control of insect moulting, which is regulated by the neuropeptide hormone PTTH (prothoracicotropic hormone). PTTH activates ERK signalling via Torso in the prothoracic gland to stimulate ecdysone secretion. Torso also has a role in control of one of the earliest events in embryogenesis in Drosophila; patterning of the embryonic termini. Here Torso is activated by a different, but related, peptide called Trunk. During terminal patterning another protein, Torso-like, has a key role in mediating activation of Torso by Trunk. Torso-like is also expressed in the prothoracic gland and null-mutants have defective developmental timing in Drosophila. This function, however, has been recently shown to be independent of Torso and PTTH. We refer to these proteins, Trunk, PTTH, Torso and Torso-like, as the Torso-activation module. Outside Drosophila we see that the genes encoding the Torso-activation module have a complex phylogenetic history, with different origins and multiple losses of components of this signalling pathway during arthropod evolution. This, together with expression and functional data in a range of insects, leads us to propose that the terminal patterning pathway in Drosophila and Tribolium arose through co-option of PTTH/Trunk and Torso, which has a role in developmental timing, into a new context, and that Torso-like was recruited specifically in the ovary to modulate the specificity of this pathway.
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Affiliation(s)
- Elizabeth J Duncan
- Genetics Otago, University of Otago, P.O. Box 56, Dunedin, Aotearoa, New Zealand; Gravida; The National Centre for Growth and Development, University of Otago, P.O. Box 56, Dunedin, Aotearoa, New Zealand
| | - Travis K Johnson
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia; Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - James C Whisstock
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia; Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, VIC 3800, Australia
| | - Coral G Warr
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Peter K Dearden
- Genetics Otago, University of Otago, P.O. Box 56, Dunedin, Aotearoa, New Zealand; Gravida; The National Centre for Growth and Development, University of Otago, P.O. Box 56, Dunedin, Aotearoa, New Zealand.
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16
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Expression pattern of empty-spiracles, a conserved head-patterning gene, in honeybee (Apis mellifera) embryos. Gene Expr Patterns 2014; 15:142-8. [PMID: 24999162 DOI: 10.1016/j.gep.2014.06.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 06/19/2014] [Accepted: 06/20/2014] [Indexed: 11/21/2022]
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17
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Fang Y, Feng M, Han B, Lu X, Ramadan H, Li J. In-depth proteomics characterization of embryogenesis of the honey bee worker (Apis mellifera ligustica). Mol Cell Proteomics 2014; 13:2306-20. [PMID: 24895377 DOI: 10.1074/mcp.m114.037846] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Identifying proteome changes of honey bee embryogenesis is of prime importance for unraveling the molecular mechanisms that they underlie. However, many proteomic changes during the embryonic period are not well characterized. We analyzed the proteomic alterations over the complete time course of honey bee worker embryogenesis at 24, 48, and 72 h of age, using mass spectrometry-based proteomics, label-free quantitation, and bioinformatics. Of the 1460 proteins identified the embryo of all three ages, the core proteome (proteins shared by the embryos of all three ages, accounting for 40%) was mainly involved in protein synthesis, metabolic energy, development, and molecular transporter, which indicates their centrality in driving embryogenesis. However, embryos at different developmental stages have their own specific proteome and pathway signatures to coordinate and modulate developmental events. The young embryos (<24 h) stronger expression of proteins related to nutrition storage and nucleic acid metabolism may correlate with the cell proliferation occurring at this stage. The middle aged embryos (24-48 h) enhanced expression of proteins associated with cell cycle control, transporters, antioxidant activity, and the cytoskeleton suggest their roles to support rudimentary organogenesis. Among these proteins, the biological pathways of aminoacyl-tRNA biosynthesis, β-alanine metabolism, and protein export are intensively activated in the embryos of middle age. The old embryos (48-72 h) elevated expression of proteins implicated in fatty acid metabolism and morphogenesis indicate their functionality for the formation and development of organs and dorsal closure, in which the biological pathways of fatty acid metabolism and RNA transport are highly activated. These findings add novel understanding to the molecular details of honey bee embryogenesis, in which the programmed activation of the proteome matches with the physiological transition observed during embryogenesis. The identified biological pathways and key node proteins allow for further functional analysis and genetic manipulation for both the honey bee embryos and other eusocial insects.
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Affiliation(s)
- Yu Fang
- From the ‡Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Mao Feng
- From the ‡Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Bin Han
- From the ‡Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaoshan Lu
- From the ‡Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Haitham Ramadan
- From the ‡Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jianke Li
- From the ‡Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences, Beijing, China
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Wilson MJ, Kenny NJ, Dearden PK. Components of the dorsal-ventral pathway also contribute to anterior-posterior patterning in honeybee embryos (Apis mellifera). EvoDevo 2014; 5:11. [PMID: 24620747 PMCID: PMC3995682 DOI: 10.1186/2041-9139-5-11] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 01/20/2014] [Indexed: 01/27/2023] Open
Abstract
Background A key early step in embryogenesis is the establishment of the major body axes; the dorsal-ventral (DV) and anterior-posterior (AP) axes. Determination of these axes in some insects requires the function of different sets of signalling pathways for each axis. Patterning across the DV axis requires interaction between the Toll and Dpp/TGF-β pathways, whereas patterning across the AP axis requires gradients of bicoid/orthodenticle proteins and the actions of a hierarchy of gene transcription factors. We examined the expression and function of Toll and Dpp signalling during honeybee embryogenesis to assess to the role of these genes in DV patterning. Results Pathway components that are required for dorsal specification in Drosophila are expressed in an AP-restricted pattern in the honeybee embryo, including Dpp and its receptor Tkv. Components of the Toll pathway are expressed in a more conserved pattern along the ventral axis of the embryo. Late-stage embryos from RNA interference (RNAi) knockdown of Toll and Dpp pathways had both DV and AP patterning defects, confirmed by staining with Am-sna, Am-zen, Am-eve, and Am-twi at earlier stages. We also identified two orthologues of dorsal in the honeybee genome, with one being expressed during embryogenesis and having a minor role in axis patterning, as determined by RNAi and the other expressed during oogenesis. Conclusions We found that early acting pathways (Toll and Dpp) are involved not only in DV patterning but also AP patterning in honeybee embryogenesis. Changes to the expression patterns and function of these genes may reflect evolutionary changes in the placement of the extra-embryonic membranes during embryogenesis with respect to the AP and DV axes.
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Affiliation(s)
- Megan J Wilson
- Developmental Biology Laboratory, Department of Anatomy, University of Otago, P,O, Box 56, Dunedin 9054, New Zealand.
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19
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Weisbrod A, Cohen M, Chipman AD. Evolution of the insect terminal patterning system--insights from the milkweed bug, Oncopeltus fasciatus. Dev Biol 2013; 380:125-31. [PMID: 23665175 DOI: 10.1016/j.ydbio.2013.04.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Revised: 03/27/2013] [Accepted: 04/23/2013] [Indexed: 10/26/2022]
Abstract
The anterior and posterior ends of the insect embryo are patterned through the terminal patterning system, which is best known from the fruitfly Drosophila melanogaster. In Drosophila, the RTK receptor Torso and its presumed co-activator Torso-like initiate a signaling cascade, which activates two terminal gap genes, tailless and huckebein. These in turn interact with various patterning genes to define terminal structures. Work on other insect species has shown that this system is poorly conserved, and not all of its components have been found in all cases studied. We place the variability of the system within a broader phylogenetic framework. We describe the expression and knock-down phenotypes of the homologues of terminal patterning genes in the hemimetabolous Oncopeltus fasciatus. We have examined the interactions among these genes and between them and other patterning genes. We demonstrate that all of these genes have different roles in Oncopeltus relative to Drosophila; torso-like is expressed in follicle cells during oogenesis and is involved in the invagination of the blastoderm to form the germ band, and possibly also in defining the growth zone; tailless is regulated by orthodenticle and has a role only in anterior determination; huckebein is expressed only in the middle of the blastoderm; finally, torso was not found in Oncopeltus and its role in terminal patterning seems novel within holometabolous insects. We then use our data, together with published data on other insects, to reconstruct the evolution of the terminal patterning gene network in insects. We suggest that the Drosophila terminal patterning network evolved recently in the lineage leading to the Diptera, and represents an example of evolutionary "tinkering", where pre-existing pathways are co-opted for a new function.
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Affiliation(s)
- Anat Weisbrod
- The Deparment of Ecology, Evolution and Behavior, Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
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20
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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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21
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Carter JM, Baker SC, Pink R, Carter DRF, Collins A, Tomlin J, Gibbs M, Breuker CJ. Unscrambling butterfly oogenesis. BMC Genomics 2013; 14:283. [PMID: 23622113 PMCID: PMC3654919 DOI: 10.1186/1471-2164-14-283] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 04/05/2013] [Indexed: 12/16/2022] Open
Abstract
Background Butterflies are popular model organisms to study physiological mechanisms
underlying variability in oogenesis and egg provisioning in response to
environmental conditions. Nothing is known, however, about; the
developmental mechanisms governing butterfly oogenesis, how polarity in the
oocyte is established, or which particular maternal effect genes regulate
early embryogenesis. To gain insights into these developmental mechanisms
and to identify the conserved and divergent aspects of butterfly oogenesis,
we analysed a de novo ovarian transcriptome of the Speckled Wood
butterfly Pararge aegeria (L.), and compared the results with known
model organisms such as Drosophila melanogaster and Bombyx
mori. Results A total of 17306 contigs were annotated, with 30% possibly novel or highly
divergent sequences observed. Pararge aegeria females expressed
74.5% of the genes that are known to be essential for D.
melanogaster oogenesis. We discuss the genes involved in all
aspects of oogenesis, including vitellogenesis and choriogenesis, plus those
implicated in hormonal control of oogenesis and transgenerational hormonal
effects in great detail. Compared to other insects, a number of significant
differences were observed in; the genes involved in stem cell maintenance
and differentiation in the germarium, establishment of oocyte polarity, and
in several aspects of maternal regulation of zygotic development. Conclusions This study provides valuable resources to investigate a number of divergent
aspects of butterfly oogenesis requiring further research. In order to fully
unscramble butterfly oogenesis, we also now also have the resources to
investigate expression patterns of oogenesis genes under a range of
environmental conditions, and to establish their function.
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Affiliation(s)
- Jean-Michel Carter
- Evolutionary Developmental Biology Research Group, Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford, OX3 0BP, UK
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Bickel RD, Cleveland HC, Barkas J, Jeschke CC, Raz AA, Stern DL, Davis GK. The pea aphid uses a version of the terminal system during oviparous, but not viviparous, development. EvoDevo 2013; 4:10. [PMID: 23552511 PMCID: PMC3639227 DOI: 10.1186/2041-9139-4-10] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 02/18/2013] [Indexed: 01/03/2023] Open
Abstract
Background In most species of aphid, female nymphs develop into either sexual or asexual adults depending on the length of the photoperiod to which their mothers were exposed. The progeny of these sexual and asexual females, in turn, develop in dramatically different ways. The fertilized oocytes of sexual females begin embryogenesis after being deposited on leaves (oviparous development) while the oocytes of asexual females complete embryogenesis within the mother (viviparous development). Compared with oviparous development, viviparous development involves a smaller transient oocyte surrounded by fewer somatic epithelial cells and a smaller early embryo that comprises fewer cells. To investigate whether patterning mechanisms differ between the earliest stages of the oviparous and viviparous modes of pea aphid development, we examined the expression of pea aphid orthologs of genes known to specify embryonic termini in other insects. Results Here we show that pea aphid oviparous ovaries express torso-like in somatic posterior follicle cells and activate ERK MAP kinase at the posterior of the oocyte. In addition to suggesting that some posterior features of the terminal system are evolutionarily conserved, our detection of activated ERK in the oocyte, rather than in the embryo, suggests that pea aphids may transduce the terminal signal using a mechanism distinct from the one used in Drosophila. In contrast with oviparous development, the pea aphid version of the terminal system does not appear to be used during viviparous development, since we did not detect expression of torso-like in the somatic epithelial cells that surround either the oocyte or the blastoderm embryo and we did not observe restricted activated ERK in the oocyte. Conclusions We suggest that while oviparous oocytes and embryos may specify posterior fate through an aphid terminal system, viviparous oocytes and embryos employ a different mechanism, perhaps one that does not rely on an interaction between the oocyte and surrounding somatic cells. Together, these observations provide a striking example of a difference in the fundamental events of early development that is both environmentally induced and encoded by the same genome.
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Affiliation(s)
- Ryan D Bickel
- Department of Biology, Bryn Mawr College, Bryn Mawr, PA 19010, USA.
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Duncan EJ, Benton MA, Dearden PK. Canonical terminal patterning is an evolutionary novelty. Dev Biol 2013; 377:245-61. [PMID: 23438815 DOI: 10.1016/j.ydbio.2013.02.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 02/08/2013] [Accepted: 02/14/2013] [Indexed: 10/27/2022]
Abstract
Patterning of the terminal regions of the Drosophila embryo is achieved by an exquisitely regulated signal that passes between the follicle cells of the ovary, and the developing embryo. This pathway, however, is missing or modified in other insects. Here we trace the evolution of this pathway by examining the origins and expression of its components. The three core components of this pathway: trunk, torso and torso-like have different evolutionary histories and have been assembled step-wise to form the canonical terminal patterning pathway of Drosophila and Tribolium. Trunk, torso and a gene unrelated to terminal patterning, prothoraciotrophic hormone (PTTH), show an intimately linked evolutionary history, with every holometabolous insect, except the honeybee, possessing both PTTH and torso genes. Trunk is more restricted in its phylogenetic distribution, present only in the Diptera and Tribolium and, surprisingly, in the chelicerate Ixodes scapularis, raising the possibility that trunk and torso evolved earlier than previously thought. In Drosophila torso-like restricts the activation of the terminal patterning pathway to the poles of the embryo. Torso-like evolved in the pan-crustacean lineage, but based on expression of components of the canonical terminal patterning system in the hemimetabolous insect Acyrthosiphon pisum and the holometabolous insect Apis mellifera, we find that the canonical terminal-patterning system is not active in these insects. We therefore propose that the ancestral function of torso-like is unrelated to terminal patterning and that torso-like has become co-opted into terminal patterning in the lineage leading to Coleoptera and Diptera. We also show that this co-option has not resulted in changes to the molecular function of this protein. Torso-like from the pea aphid, honeybee and Drosophila, despite being expressed in different patterns, are functionally equivalent. We propose that co-option of torso-like into restricting the activity of trunk and torso facilitated the final step in the evolution of this pathway; the capture of transcriptional control of target genes such as tailless and huckebein by this complex and novel patterning pathway.
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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, P.O. Box 56, Dunedin, Aotearoa, New Zealand.
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Wilson MJ, Dearden PK. RNA localization in the honeybee (Apis mellifera) oocyte reveals insights about the evolution of RNA localization mechanisms. Dev Biol 2013; 375:193-201. [PMID: 23313731 DOI: 10.1016/j.ydbio.2013.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 12/21/2012] [Accepted: 01/02/2013] [Indexed: 11/28/2022]
Abstract
Subcellular localization of RNAs is a critical biological process for generation of cellular asymmetries for many cell types and a critical step in axis determination during the early development of animals. We have identified transcripts localized to the anterior and posterior of honeybee oocyte using laser capture microscopy and microarray analysis. Analysis of orthologous transcripts in Drosophila indicates that many do not show a conserved pattern of localization. By microinjecting fluorescently labeled honeybee transcripts into Drosophila egg chambers we show that these RNAs become localized in a similar manner to their localization in honeybee oocytes, indicating conservation of the localization machinery. Thus while the mechanisms for localizing RNA are conserved, the complement of localized RNAs are not. We propose that this complement of localized RNAs may change relatively rapidly through the loss or evolution of signal sequences detected by the conserved localization machinery, and show this has occurred in one transcript that is localized in a novel way in the honeybee. Our proposal, that the acquisition of novel RNA localization is relatively easy to evolve, has implications for the evolution of symmetry breaking mechanisms that trigger axis formation and development in animal embryos.
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Affiliation(s)
- Megan J Wilson
- Laboratory for Evolution and Development, Genetics Otago and Gravida, The National Centre for Growth and Development, Department of Biochemistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
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25
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Kittelmann S, Ulrich J, Posnien N, Bucher G. Changes in anterior head patterning underlie the evolution of long germ embryogenesis. Dev Biol 2012. [PMID: 23201022 DOI: 10.1016/j.ydbio.2012.11.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Early embryonic stages differ significantly among related animal taxa while subsequent development converges at the conserved phylotypic stage before again diverging. Although this phenomenon has long been observed, its underlying genetic mechanisms remain enigmatic. The dipteran Drosophila melanogaster develops as a long germ embryo where the head anlagen form a cap at the anterior pole of the blastoderm. Consequently, the anterior and terminal maternal systems give crucial input for head patterning. However, in the short germ beetle Tribolium castaneum, as in most insects, the head anlagen is located at a ventral position distant from the anterior pole of the blastoderm. In line with these divergent embryonic anlagen, several differences in the axis formation between the insects have been discovered. We now ask to what extent patterning and morphogenesis of the anterior median region (AMR) of the head, including clypeolabral and stomodeal anlagen, differ among these insects. Unexpectedly, we find that Tc-huckebein is not a terminal gap gene and, unlike its Drosophila ortholog, is not involved in Tribolium head development. Instead, Tc-six3 acts upstream of Tc-crocodile and Tc-cap'n'collar to pattern posterior and anterior parts of the AMR, respectively. We further find that instead of huckebein, Tc-crocodile is required for stomodeum development by activating Tc-forkhead. Finally, a morphogenetic movement not found in Drosophila shapes the embryonic head of Tribolium. Apparently, with anterior displacement of the head anlagen during long germ evolution of Drosophila, the ancestral regulation by the bilaterian anterior control gene six3 was replaced by the anterior and terminal maternal systems, which were further elaborated by adding bicoid, tailless and huckebein as anterior regionalization genes.
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Affiliation(s)
- Sebastian Kittelmann
- Department of Evolutionary Genetics, Göttingen Center of Molecular Biology, Georg-August-Universität Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany.
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Zondag L, Dearden PK, Wilson MJ. Deep sequencing and expression of microRNAs from early honeybee (Apis mellifera) embryos reveals a role in regulating early embryonic patterning. BMC Evol Biol 2012; 12:211. [PMID: 23121997 PMCID: PMC3562263 DOI: 10.1186/1471-2148-12-211] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 10/22/2012] [Indexed: 01/23/2023] Open
Abstract
Background Recent evidence supports the proposal that the observed diversity of animal body plans has been produced through alterations to the complexity of the regulatory genome rather than increases in the protein-coding content of a genome. One significant form of gene regulation is the contribution made by the non-coding content of the genome. Non-coding RNAs play roles in embryonic development of animals and these functions might be expected to evolve rapidly. Using next-generation sequencing and in situ hybridization, we have examined the miRNA content of early honeybee embryos. Results Through small RNA sequencing we found that 28% of known miRNAs are expressed in the early embryo. We also identified developmentally expressed microRNAs that are unique to the Apoidea clade. Examination of expression patterns implied these miRNAs have roles in patterning the anterior-posterior and dorso-ventral axes as well as the extraembryonic membranes. Knockdown of Dicer, a key component of miRNA processing, confirmed that miRNAs are likely to have a role in patterning these tissues. Conclusions Examination of the expression patterns of novel miRNAs, some unique to the Apis group, indicated that they are likely to play a role in early honeybee development. Known miRNAs that are deeply conserved in animal phyla display differences in expression pattern between honeybee and Drosophila, particularly at early stages of development. This may indicate miRNAs play a rapidly evolving role in regulating developmental pathways, most likely through changes to the way their expression is regulated.
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Affiliation(s)
- Lisa Zondag
- Laboratory for Evolution and Development, Genetics Otago and National Research Centre for Growth and Development, Department of Biochemistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand
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Wilson MJ, Dearden PK. Pair-rule gene orthologues have unexpected maternal roles in the honeybee (Apis mellifera). PLoS One 2012; 7:e46490. [PMID: 23029534 PMCID: PMC3460886 DOI: 10.1371/journal.pone.0046490] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 09/04/2012] [Indexed: 02/04/2023] Open
Abstract
Pair-rule genes are a class of segmentation genes first identified in Drosophila melanogaster. In Drosophila, these genes act to translate non-periodic information produced by the overlapping patterns of gap gene expression into patterns of gene expression in every other segment. While pair-rule genes are, for the most part, conserved in metazoans, their function in pair-rule patterning is not. Many of these genes do, however, regulate segmentation in arthropods and do so with dual-segment periodicity. Here we examine the expression and function of honeybee orthologues of Drosophila pair-rule genes. Knockdown of the expression of these genes leads to extensive patterning defects, implying that they act in early patterning, as well as segmentation in honeybee embryos. We show that these pair-rule gene orthologues indeed regulate the expression of honeybee maternal and gap genes implying roles in maternal patterning of the honeybee embryo.
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Affiliation(s)
- Megan J. Wilson
- Laboratory for Evolution and Development, National Research Centre for Growth and Development and Genetics Otago, Biochemistry Department, University of Otago, Dunedin, New Zealand-Aotearoa
| | - Peter K. Dearden
- Laboratory for Evolution and Development, National Research Centre for Growth and Development and Genetics Otago, Biochemistry Department, University of Otago, Dunedin, New Zealand-Aotearoa
- * E-mail:
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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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29
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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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Wilson MJ, Dearden PK. Diversity in insect axis formation: two orthodenticle genes and hunchback act in anterior patterning and influence dorsoventral organization in the honeybee (Apis mellifera). Development 2011; 138:3497-507. [DOI: 10.1242/dev.067926] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Axis formation is a key step in development, but studies indicate that genes involved in insect axis formation are relatively fast evolving. Orthodenticle genes have conserved roles, often with hunchback, in maternal anterior patterning in several insect species. We show that two orthodenticle genes, otd1 and otd2, and hunchback act as maternal anterior patterning genes in the honeybee (Apis mellifera) but, unlike other insects, act to pattern the majority of the anteroposterior axis. These genes regulate the expression domains of anterior, central and posterior gap genes and may directly regulate the anterior gap gene giant. We show otd1 and hunchback also influence dorsoventral patterning by regulating zerknült (zen) as they do in Tribolium, but that zen does not regulate the expression of honeybee gap genes. This suggests that interactions between anteroposterior and dorsal-ventral patterning are ancestral in holometabolous insects. Honeybee axis formation, and the function of the conserved anterior patterning gene orthodenticle, displays unique characters that indicate that, even when conserved genes pattern the axis, their regulatory interactions differ within orders of insects, consistent with relatively fast evolution in axis formation pathways.
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Affiliation(s)
- Megan J. Wilson
- Laboratory for Evolution and Development, National Research Centre for Growth and Development and Genetics Otago, Biochemistry Department, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Peter K. Dearden
- Laboratory for Evolution and Development, National Research Centre for Growth and Development and Genetics Otago, Biochemistry Department, University of Otago, PO Box 56, Dunedin 9054, New Zealand
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Wilson MJ, Abbott H, Dearden PK. The evolution of oocyte patterning in insects: multiple cell-signaling pathways are active during honeybee oogenesis and are likely to play a role in axis patterning. Evol Dev 2011; 13:127-37. [DOI: 10.1111/j.1525-142x.2011.00463.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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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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Control of germline torso expression by the BTB/POZ domain protein pipsqueak is required for embryonic terminal patterning in Drosophila. Genetics 2010; 187:513-21. [PMID: 21098720 DOI: 10.1534/genetics.110.121624] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Early embryogenesis in Drosophila melanogaster is controlled by maternal gene products, which are deposited in the egg during oogenesis. It is not well understood how maternal gene expression is controlled during germline development. pipsqueak (psq) is a complex locus that encodes several nuclear protein variants containing a PSQ DNA-binding domain and a BTB/POZ domain. Psq proteins are thought to regulate germline gene expression through epigenetic silencing. While psq was originally identified as a posterior-group gene, we show here a novel role of psq in embryonic terminal patterning. We characterized a new psq loss-of-function allele, psq(rum), which specifically affects signaling by the Torso (Tor) receptor tyrosine kinase (RTK). Using genetic epistasis, gene expression analyses, and rescue experiments, we demonstrate that the sole function impaired by the psq(rum) mutation in the terminal system is an essential requirement for controlling transcription of the tor gene in the germline. In contrast, the expression of several other maternal genes, including those encoding Tor pathway components, is not affected by the mutation. Rescue of the psq(rum) terminal phenotype does not require the BTB/POZ domain, suggesting that the PSQ DNA-binding domain can function independently of the BTB/POZ domain. Our finding that tor expression is subject to dedicated transcriptional regulation suggests that different maternal genes may be regulated by multiple distinct mechanisms, rather than by a general program controlling nurse-cell transcription.
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Notch signaling does not regulate segmentation in the honeybee, Apis mellifera. Dev Genes Evol 2010; 220:179-90. [DOI: 10.1007/s00427-010-0340-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Accepted: 10/08/2010] [Indexed: 01/09/2023]
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36
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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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EGF signaling and the origin of axial polarity among the insects. Curr Biol 2010; 20:1042-7. [PMID: 20471269 DOI: 10.1016/j.cub.2010.04.023] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Revised: 04/08/2010] [Accepted: 04/09/2010] [Indexed: 01/07/2023]
Abstract
The eggs of insects are unusual in that they often have bilateral symmetry when they are laid, indicating that both anterior-posterior (AP) and dorsal-ventral (DV) symmetries are broken during oogenesis. The molecular basis of this process is well understood in Drosophila melanogaster, in which symmetry breaking events for both axes depend on the asymmetric position of the oocyte nucleus and on germline-soma signaling mediated by the Tgf alpha-like epidermal growth factor (EGF) ligand Gurken. Germline-soma signaling interactions centered around the oocyte nucleus have been proposed in other insect species, but the molecular nature of these interactions has not been elucidated. We have examined the behavior of the oocyte nucleus and the function of EGF signaling components in the ovaries of the wasp Nasonia vitripennis, the beetle Tribolium castaneum, and the cricket Gryllus bimaculatus. We have found that EGF signaling has broadly conserved roles in mediating the encapsulation of oocytes by the somatic follicle cell layer, in establishing polarity of the egg chambers, and in setting up the DV axis of the embryo. These results provide insights into the evolutionary origins of the unique strategy employed by insects to establish embryonic axial polarity during oogenesis.
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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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