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Posnien N, Hunnekuhl VS, Bucher G. Gene expression mapping of the neuroectoderm across phyla - conservation and divergence of early brain anlagen between insects and vertebrates. eLife 2023; 12:e92242. [PMID: 37750868 PMCID: PMC10522337 DOI: 10.7554/elife.92242] [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: 09/07/2023] [Accepted: 09/18/2023] [Indexed: 09/27/2023] Open
Abstract
Gene expression has been employed for homologizing body regions across bilateria. The molecular comparison of vertebrate and fly brains has led to a number of disputed homology hypotheses. Data from the fly Drosophila melanogaster have recently been complemented by extensive data from the red flour beetle Tribolium castaneum with its more insect-typical development. In this review, we revisit the molecular mapping of the neuroectoderm of insects and vertebrates to reconsider homology hypotheses. We claim that the protocerebrum is non-segmental and homologous to the vertebrate fore- and midbrain. The boundary between antennal and ocular regions correspond to the vertebrate mid-hindbrain boundary while the deutocerebrum represents the anterior-most ganglion with serial homology to the trunk. The insect head placode is shares common embryonic origin with the vertebrate adenohypophyseal placode. Intriguingly, vertebrate eyes develop from a different region compared to the insect compound eyes calling organ homology into question. Finally, we suggest a molecular re-definition of the classic concepts of archi- and prosocerebrum.
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Affiliation(s)
- Nico Posnien
- Department of Developmental Biology, Johann-Friedrich-Blumenbach Institute, University GoettingenGöttingenGermany
| | - Vera S Hunnekuhl
- Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, University of GöttingenGöttingenGermany
| | - Gregor Bucher
- Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, University of GöttingenGöttingenGermany
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2
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Ponte G, Chiandetti C, Edelman DB, Imperadore P, Pieroni EM, Fiorito G. Cephalopod Behavior: From Neural Plasticity to Consciousness. Front Syst Neurosci 2022; 15:787139. [PMID: 35495582 PMCID: PMC9039538 DOI: 10.3389/fnsys.2021.787139] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/22/2021] [Indexed: 11/18/2022] Open
Abstract
It is only in recent decades that subjective experience - or consciousness - has become a legitimate object of scientific inquiry. As such, it represents perhaps the greatest challenge facing neuroscience today. Subsumed within this challenge is the study of subjective experience in non-human animals: a particularly difficult endeavor that becomes even more so, as one crosses the great evolutionary divide between vertebrate and invertebrate phyla. Here, we explore the possibility of consciousness in one group of invertebrates: cephalopod molluscs. We believe such a review is timely, particularly considering cephalopods' impressive learning and memory abilities, rich behavioral repertoire, and the relative complexity of their nervous systems and sensory capabilities. Indeed, in some cephalopods, these abilities are so sophisticated that they are comparable to those of some higher vertebrates. Following the criteria and framework outlined for the identification of hallmarks of consciousness in non-mammalian species, here we propose that cephalopods - particularly the octopus - provide a unique test case among invertebrates for examining the properties and conditions that, at the very least, afford a basal faculty of consciousness. These include, among others: (i) discriminatory and anticipatory behaviors indicating a strong link between perception and memory recall; (ii) the presence of neural substrates representing functional analogs of thalamus and cortex; (iii) the neurophysiological dynamics resembling the functional signatures of conscious states in mammals. We highlight the current lack of evidence as well as potentially informative areas that warrant further investigation to support the view expressed here. Finally, we identify future research directions for the study of consciousness in these tantalizing animals.
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Affiliation(s)
- Giovanna Ponte
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | | | - David B. Edelman
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH, United States
- Association for Cephalopod Research ‘CephRes' a non-profit Organization, Naples, Italy
| | - Pamela Imperadore
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | | | - Graziano Fiorito
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
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3
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Lacalli T. An evolutionary perspective on chordate brain organization and function: insights from amphioxus, and the problem of sentience. Philos Trans R Soc Lond B Biol Sci 2022; 377:20200520. [PMID: 34957845 PMCID: PMC8710876 DOI: 10.1098/rstb.2020.0520] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The similarities between amphioxus and vertebrate brains, in their regional subdivision, cell types and circuitry, make the former a useful benchmark for understanding the evolutionary innovations that shaped the latter. Locomotory control systems were already well developed in basal chordates, with the ventral neuropile of the dien-mesencephalon serving to set levels of activity and initiate locomotory actions. A chief deficit in amphioxus is the absence of complex vertebrate-type sense organs. Hence, much of vertebrate story is one of progressive improvement both to these and to sensory experience more broadly. This has two aspects: (i) anatomical and neurocircuitry innovations in the organs of special sense and the brain centres that process and store their output, and (ii) the emergence of primary consciousness, i.e. sentience. With respect to the latter, a bottom up, evolutionary perspective has a different focus from a top down human-centric one. At issue: the obstacles to the emergence of sentience in the first instance, the sequence of addition of new contents to evolving consciousness, and the homology relationship between them. A further question, and a subject for future investigation, is how subjective experience is optimized for each sensory modality. This article is part of the theme issue 'Systems neuroscience through the lens of evolutionary theory'.
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Affiliation(s)
- Thurston Lacalli
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada V8 W-3N5
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4
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Canesi L, Miglioli A, Balbi T, Fabbri E. Physiological Roles of Serotonin in Bivalves: Possible Interference by Environmental Chemicals Resulting in Neuroendocrine Disruption. Front Endocrinol (Lausanne) 2022; 13:792589. [PMID: 35282445 PMCID: PMC8913902 DOI: 10.3389/fendo.2022.792589] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 01/25/2022] [Indexed: 11/15/2022] Open
Abstract
Contaminants of Emerging Concerns (CECs) are defined as chemicals not commonly monitored in aquatic ecosystems, but with the potential to cause adverse effects on biota. CECs include Endocrine Disrupting Chemicals (EDCs) and Neuro-Endocrine disruptors (NEDs) of vertebrates. However, most invertebrates only rely on neuroendocrine systems to maintain homeostatic processes. Although conserved neuroendocrine components have been characterized in ecologically relevant groups, limited knowledge on invertebrate neuroendocrinology makes it difficult to define EDCs and NEDs in most species. The monoamine serotonin (5-hydroxytryptamine, 5-HT) acts both as a neurotransmitter and as a peripheral hormone in mammals. In molluscs, 5-HT is involved in multiple physiological roles and molecular components of the serotonergic system have been identified. This review is focused on the effects of CECs on the serotonergic system of bivalve molluscs. Bivalves are widespread in all aquatic environments, estuarine and coastal areas in particular, where they are exposed to a variety of chemicals. In bivalves, 5-HT is involved in gametogenesis and spawning, oocyte maturation and sperm motility, regulates heart function, gill ciliary beating, mantle/siphon function, the ''catch'' state of smooth muscle and immune responses. Components of 5-HT transduction (receptors and signaling pathways) are being identified in several bivalve species. Different CECs have been shown to affect bivalve serotonergic system. This particularly applies to antidepressants, among the most commonly detected human pharmaceuticals in the aquatic environment. In particular, selective serotonin reuptake inhibitors (SSRIs) are frequently detected in seawater and in bivalve tissues. Information available on the effects and mechanisms of action of SSRIs on the serotonergic system of adult bivalves is summarized. Data are also reported on the effects of CECs on development of neuroendocrine pathways of early larval stages, in particular on the effects of model EDCs in the marine mussel Mytilus galloprovincialis. Overall, available data point at the serotonergic system as a sensitive target for neuroendocrine disruption in bivalves. The results contribute drawing Adverse Outcome Pathways (AOPs) for model EDCs and SSRIs in larvae and adults. However, basic research on neuroendocrine signaling is still needed to evaluate the potential impact of neuroendocrine disruptors in key invertebrate groups of aquatic ecosystems.
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Affiliation(s)
- Laura Canesi
- Environmental Physiology Laboratory, Department of Earth, Environment and Life Sciences, University of Genoa, Genoa, Italy
- *Correspondence: Laura Canesi,
| | - Angelica Miglioli
- Environmental Physiology Laboratory, Department of Earth, Environment and Life Sciences, University of Genoa, Genoa, Italy
- Laboratoire de Biologie du Developpement de Villefranche-sur-mer, Institut de la mer, Sorbonne Université, CNRS, Villefranche-sur-mer, France
| | - Teresa Balbi
- Environmental Physiology Laboratory, Department of Earth, Environment and Life Sciences, University of Genoa, Genoa, Italy
| | - Elena Fabbri
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Ravenna, Italy
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5
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Revilla-i-Domingo R, Rajan VBV, Waldherr M, Prohaczka G, Musset H, Orel L, Gerrard E, Smolka M, Stockinger A, Farlik M, Lucas RJ, Raible F, Tessmar-Raible K. Characterization of cephalic and non-cephalic sensory cell types provides insight into joint photo- and mechanoreceptor evolution. eLife 2021; 10:e66144. [PMID: 34350831 PMCID: PMC8367381 DOI: 10.7554/elife.66144] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 08/04/2021] [Indexed: 12/11/2022] Open
Abstract
Rhabdomeric opsins (r-opsins) are light sensors in cephalic eye photoreceptors, but also function in additional sensory organs. This has prompted questions on the evolutionary relationship of these cell types, and if ancient r-opsins were non-photosensory. A molecular profiling approach in the marine bristleworm Platynereis dumerilii revealed shared and distinct features of cephalic and non-cephalic r-opsin1-expressing cells. Non-cephalic cells possess a full set of phototransduction components, but also a mechanosensory signature. Prompted by the latter, we investigated Platynereis putative mechanotransducer and found that nompc and pkd2.1 co-expressed with r-opsin1 in TRE cells by HCR RNA-FISH. To further assess the role of r-Opsin1 in these cells, we studied its signaling properties and unraveled that r-Opsin1 is a Gαq-coupled blue light receptor. Profiling of cells from r-opsin1 mutants versus wild-types, and a comparison under different light conditions reveals that in the non-cephalic cells light - mediated by r-Opsin1 - adjusts the expression level of a calcium transporter relevant for auditory mechanosensation in vertebrates. We establish a deep-learning-based quantitative behavioral analysis for animal trunk movements and identify a light- and r-Opsin-1-dependent fine-tuning of the worm's undulatory movements in headless trunks, which are known to require mechanosensory feedback. Our results provide new data on peripheral cell types of likely light sensory/mechanosensory nature. These results point towards a concept in which such a multisensory cell type evolved to allow for fine-tuning of mechanosensation by light. This implies that light-independent mechanosensory roles of r-opsins may have evolved secondarily.
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Affiliation(s)
- Roger Revilla-i-Domingo
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform "Single-Cell Regulation of Stem Cells", University of Vienna, Vienna BioCenterViennaAustria
| | - Vinoth Babu Veedin Rajan
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Monika Waldherr
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Günther Prohaczka
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Hugo Musset
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Lukas Orel
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Elliot Gerrard
- Division of Neuroscience & Experimental Psychology, University of ManchesterManchesterUnited Kingdom
| | - Moritz Smolka
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
- Center for Integrative Bioinformatics Vienna, Max Perutz Labs, University of Vienna and Medical University of ViennaViennaAustria
| | - Alexander Stockinger
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform "Single-Cell Regulation of Stem Cells", University of Vienna, Vienna BioCenterViennaAustria
| | - Matthias Farlik
- CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
- Department of Dermatology, Medical University of ViennaViennaAustria
| | - Robert J Lucas
- Division of Neuroscience & Experimental Psychology, University of ManchesterManchesterUnited Kingdom
| | - Florian Raible
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform "Single-Cell Regulation of Stem Cells", University of Vienna, Vienna BioCenterViennaAustria
| | - Kristin Tessmar-Raible
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
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6
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Fritzsche S, Hunnekuhl VS. Cell-specific expression and individual function of prohormone convertase PC1/3 in Tribolium larval growth highlights major evolutionary changes between beetle and fly neuroendocrine systems. EvoDevo 2021; 12:9. [PMID: 34187565 PMCID: PMC8244231 DOI: 10.1186/s13227-021-00179-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 06/14/2021] [Indexed: 11/15/2022] Open
Abstract
Background The insect neuroendocrine system acts in the regulation of physiology, development and growth. Molecular evolution of this system hence has the potential to allow for major biological differences between insect groups. Two prohormone convertases, PC1/3 and PC2, are found in animals and both function in the processing of neuropeptide precursors in the vertebrate neurosecretory pathway. Whereas PC2-function is conserved between the fly Drosophila and vertebrates, ancestral PC1/3 was lost in the fly lineage and has not been functionally studied in any protostome. Results In order to understand its original functions and the changes accompanying the gene loss in the fly, we investigated PC1/3 and PC2 expression and function in the beetle Tribolium castaneum. We found that PC2 is broadly expressed in the nervous system, whereas surprisingly, PC1/3 expression is restricted to specific cell groups in the posterior brain and suboesophageal ganglion. Both proteases have parallel but non-redundant functions in adult beetles’ viability and fertility. Female infertility following RNAi is caused by a failure to deposit sufficient yolk to the developing oocytes. Larval RNAi against PC2 produced moulting defects where the larvae were not able to shed their old cuticle. This ecdysis phenotype was also observed in a small subset of PC1/3 knockdown larvae and was strongest in a double knockdown. Unexpectedly, most PC1/3-RNAi larvae showed strongly reduced growth, but went through larval moults despite minimal to zero weight gain. Conclusions The cell type-specific expression of PC1/3 and its essential requirement for larval growth highlight the important role of this gene within the insect neuroendocrine system. Genomic conservation in most insect groups suggests that it has a comparable individual function in other insects as well, which has been replaced by alternative mechanisms in flies. Supplementary Information The online version contains supplementary material available at 10.1186/s13227-021-00179-w.
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Affiliation(s)
- Sonja Fritzsche
- Johann-Friedrich-Blumenbach Institute, GZMB, Göttingen University, Göttingen, Germany
| | - Vera S Hunnekuhl
- Johann-Friedrich-Blumenbach Institute, GZMB, Göttingen University, Göttingen, Germany.
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7
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Jékely G. The chemical brain hypothesis for the origin of nervous systems. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190761. [PMID: 33550946 PMCID: PMC7935135 DOI: 10.1098/rstb.2019.0761] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2020] [Indexed: 12/13/2022] Open
Abstract
In nervous systems, there are two main modes of transmission for the propagation of activity between cells. Synaptic transmission relies on close contact at chemical or electrical synapses while volume transmission is mediated by diffusible chemical signals and does not require direct contact. It is possible to wire complex neuronal networks by both chemical and synaptic transmission. Both types of networks are ubiquitous in nervous systems, leading to the question which of the two appeared first in evolution. This paper explores a scenario where chemically organized cellular networks appeared before synapses in evolution, a possibility supported by the presence of complex peptidergic signalling in all animals except sponges. Small peptides are ideally suited to link up cells into chemical networks. They have unlimited diversity, high diffusivity and high copy numbers derived from repetitive precursors. But chemical signalling is diffusion limited and becomes inefficient in larger bodies. To overcome this, peptidergic cells may have developed projections and formed synaptically connected networks tiling body surfaces and displaying synchronized activity with pulsatile peptide release. The advent of circulatory systems and neurohemal organs further reduced the constraint imposed on chemical signalling by diffusion. This could have contributed to the explosive radiation of peptidergic signalling systems in stem bilaterians. Neurosecretory centres in extant nervous systems are still predominantly chemically wired and coexist with the synaptic brain. This article is part of the theme issue 'Basal cognition: multicellularity, neurons and the cognitive lens'.
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Affiliation(s)
- Gáspár Jékely
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
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8
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Nässel DR, Zandawala M. Hormonal axes in Drosophila: regulation of hormone release and multiplicity of actions. Cell Tissue Res 2020; 382:233-266. [PMID: 32827072 PMCID: PMC7584566 DOI: 10.1007/s00441-020-03264-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 07/20/2020] [Indexed: 12/16/2022]
Abstract
Hormones regulate development, as well as many vital processes in the daily life of an animal. Many of these hormones are peptides that act at a higher hierarchical level in the animal with roles as organizers that globally orchestrate metabolism, physiology and behavior. Peptide hormones can act on multiple peripheral targets and simultaneously convey basal states, such as metabolic status and sleep-awake or arousal across many central neuronal circuits. Thereby, they coordinate responses to changing internal and external environments. The activity of neurosecretory cells is controlled either by (1) cell autonomous sensors, or (2) by other neurons that relay signals from sensors in peripheral tissues and (3) by feedback from target cells. Thus, a hormonal signaling axis commonly comprises several components. In mammals and other vertebrates, several hormonal axes are known, such as the hypothalamic-pituitary-gonad axis or the hypothalamic-pituitary-thyroid axis that regulate reproduction and metabolism, respectively. It has been proposed that the basic organization of such hormonal axes is evolutionarily old and that cellular homologs of the hypothalamic-pituitary system can be found for instance in insects. To obtain an appreciation of the similarities between insect and vertebrate neurosecretory axes, we review the organization of neurosecretory cell systems in Drosophila. Our review outlines the major peptidergic hormonal pathways known in Drosophila and presents a set of schemes of hormonal axes and orchestrating peptidergic systems. The detailed organization of the larval and adult Drosophila neurosecretory systems displays only very basic similarities to those in other arthropods and vertebrates.
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Affiliation(s)
- Dick R. Nässel
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Meet Zandawala
- Department of Neuroscience, Brown University, Providence, RI USA
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9
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Arnone MI, Oliveri P. Unravelling the evolutionary history of kisspeptin. eLife 2020; 9:58599. [PMID: 32538354 PMCID: PMC7295571 DOI: 10.7554/elife.58599] [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: 06/10/2020] [Accepted: 06/10/2020] [Indexed: 11/22/2022] Open
Abstract
Experiments in sea cucumbers reveal how the physiological responses regulated by a neuropeptide called kisspeptin have evolved.
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Affiliation(s)
- Maria I Arnone
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Paola Oliveri
- Centre for Life's Origins and Evolution, University College London, London, United Kingdom.,Research Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
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10
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Wang T, Cao Z, Shen Z, Yang J, Chen X, Yang Z, Xu K, Xiang X, Yu Q, Song Y, Wang W, Tian Y, Sun L, Zhang L, Guo S, Zhou N. Existence and functions of a kisspeptin neuropeptide signaling system in a non-chordate deuterostome species. eLife 2020; 9:53370. [PMID: 32513385 PMCID: PMC7282810 DOI: 10.7554/elife.53370] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 04/29/2020] [Indexed: 12/12/2022] Open
Abstract
The kisspeptin system is a central modulator of the hypothalamic-pituitary-gonadal axis in vertebrates. Its existence outside the vertebrate lineage remains largely unknown. Here, we report the identification and characterization of the kisspeptin system in the sea cucumber Apostichopus japonicus. The gene encoding the kisspeptin precursor generates two mature neuropeptides, AjKiss1a and AjKiss1b. The receptors for these neuropeptides, AjKissR1 and AjKissR2, are strongly activated by synthetic A. japonicus and vertebrate kisspeptins, triggering a rapid intracellular mobilization of Ca2+, followed by receptor internalization. AjKissR1 and AjKissR2 share similar intracellular signaling pathways via Gαq/PLC/PKC/MAPK cascade, when activated by C-terminal decapeptide. The A. japonicus kisspeptin system functions in multiple tissues that are closely related to seasonal reproduction and metabolism. Overall, our findings uncover for the first time the existence and function of the kisspeptin system in a non-chordate species and provide new evidence to support the ancient origin of intracellular signaling and physiological functions that are mediated by this molecular system.
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Affiliation(s)
- Tianming Wang
- National Engineering Research Center of Marine Facilities Aquaculture, Marine Science College, Zhejiang Ocean University, Zhoushan, China.,Programs in Human Genetics and Biological Sciences, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States
| | - Zheng Cao
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, China
| | - Zhangfei Shen
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, China
| | - Jingwen Yang
- National Engineering Research Center of Marine Facilities Aquaculture, Marine Science College, Zhejiang Ocean University, Zhoushan, China.,Programs in Human Genetics and Biological Sciences, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States
| | - Xu Chen
- National Engineering Research Center of Marine Facilities Aquaculture, Marine Science College, Zhejiang Ocean University, Zhoushan, China
| | - Zhen Yang
- National Engineering Research Center of Marine Facilities Aquaculture, Marine Science College, Zhejiang Ocean University, Zhoushan, China
| | - Ke Xu
- National Engineering Research Center of Marine Facilities Aquaculture, Marine Science College, Zhejiang Ocean University, Zhoushan, China
| | - Xiaowei Xiang
- National Engineering Research Center of Marine Facilities Aquaculture, Marine Science College, Zhejiang Ocean University, Zhoushan, China
| | - Qiuhan Yu
- National Engineering Research Center of Marine Facilities Aquaculture, Marine Science College, Zhejiang Ocean University, Zhoushan, China
| | - Yimin Song
- National Engineering Research Center of Marine Facilities Aquaculture, Marine Science College, Zhejiang Ocean University, Zhoushan, China
| | - Weiwei Wang
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, China
| | - Yanan Tian
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, China
| | - Lina Sun
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Libin Zhang
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Su Guo
- Programs in Human Genetics and Biological Sciences, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States
| | - Naiming Zhou
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, China
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11
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Treffkorn S, Mayer G. Expression of NK genes that are not part of the NK cluster in the onychophoran Euperipatoides rowelli (Peripatopsidae). BMC DEVELOPMENTAL BIOLOGY 2019; 19:7. [PMID: 30987579 PMCID: PMC6466738 DOI: 10.1186/s12861-019-0185-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 03/12/2019] [Indexed: 12/25/2022]
Abstract
Background NK genes are a group of homeobox transcription factors that are involved in various molecular pathways across bilaterians. They are typically divided into two subgroups, the NK cluster (NKC) and NK-linked genes (NKL). While the NKC genes have been studied in various bilaterians, corresponding data of many NKL genes are missing to date. To further investigate the ancestral roles of NK family genes, we analyzed the expression patterns of NKL genes in the onychophoran Euperipatoides rowelli. Results The NKL gene complement of E. rowelli comprises eight genes, including BarH, Bari, Emx, Hhex, Nedx, NK2.1, vax and NK2.2, of which only NK2.2 was studied previously. Our data for the remaining seven NKL genes revealed expression in different structures associated with the developing nervous system in embryos of E. rowelli. While NK2.1 and vax are expressed in distinct medial regions of the developing protocerebrum early in development, BarH, Bari, Emx, Hhex and Nedx are expressed in late developmental stages, after all major structures of the nervous system have been established. Furthermore, BarH and Nedx are expressed in distinct mesodermal domains in the developing limbs. Conclusions Comparison of our expression data to those of other bilaterians revealed similar patterns of NK2.1, vax, BarH and Emx in various aspects of neural development, such as the formation of anterior neurosecretory cells mediated by a conserved molecular mechanism including NK2.1 and vax, and the development of the central and peripheral nervous system involving BarH and Emx. A conserved role in neural development has also been reported from NK2.2, suggesting that the NKL genes might have been primarily involved in neural development in the last common ancestor of bilaterians or at least nephrozoans (all bilaterians excluding xenacoelomorphs). The lack of comparative data for many of the remaining NKL genes, including Bari, Hhex and Nedx currently hampers further evolutionary conclusions. Hence, future studies should focus on the expression of these genes in other bilaterians, which would provide a basis for comparative studies and might help to better understand the role of NK genes in the diversification of bilaterians. Electronic supplementary material The online version of this article (10.1186/s12861-019-0185-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sandra Treffkorn
- Department of Zoology, Institute of Biology, University of Kassel, Kassel, Germany.
| | - Georg Mayer
- Department of Zoology, Institute of Biology, University of Kassel, Kassel, Germany
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12
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Shigeno S, Andrews PLR, Ponte G, Fiorito G. Cephalopod Brains: An Overview of Current Knowledge to Facilitate Comparison With Vertebrates. Front Physiol 2018; 9:952. [PMID: 30079030 PMCID: PMC6062618 DOI: 10.3389/fphys.2018.00952] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 06/28/2018] [Indexed: 11/13/2022] Open
Abstract
Cephalopod and vertebrate neural-systems are often highlighted as a traditional example of convergent evolution. Their large brains, relative to body size, and complexity of sensory-motor systems and behavioral repertoires offer opportunities for comparative analysis. Despite various attempts, questions on how cephalopod 'brains' evolved and to what extent it is possible to identify a vertebrate-equivalence, assuming it exists, remain unanswered. Here, we summarize recent molecular, anatomical and developmental data to explore certain features in the neural organization of cephalopods and vertebrates to investigate to what extent an evolutionary convergence is likely. Furthermore, and based on whole body and brain axes as defined in early-stage embryos using the expression patterns of homeodomain-containing transcription factors and axonal tractography, we describe a critical analysis of cephalopod neural systems showing similarities to the cerebral cortex, thalamus, basal ganglia, midbrain, cerebellum, hypothalamus, brain stem, and spinal cord of vertebrates. Our overall aim is to promote and facilitate further, hypothesis-driven, studies of cephalopod neural systems evolution.
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Affiliation(s)
- Shuichi Shigeno
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Paul L. R. Andrews
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
- Division of Biomedical Sciences, St. George’s University of London, London, United Kingdom
| | - Giovanna Ponte
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Graziano Fiorito
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
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13
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Cellular populations and thermosensing mechanisms of the hypothalamic thermoregulatory center. Pflugers Arch 2018; 470:809-822. [DOI: 10.1007/s00424-017-2101-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 12/17/2017] [Accepted: 12/19/2017] [Indexed: 10/18/2022]
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14
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Williams EA, Verasztó C, Jasek S, Conzelmann M, Shahidi R, Bauknecht P, Mirabeau O, Jékely G. Synaptic and peptidergic connectome of a neurosecretory center in the annelid brain. eLife 2017; 6:26349. [PMID: 29199953 PMCID: PMC5747525 DOI: 10.7554/elife.26349] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 12/02/2017] [Indexed: 12/15/2022] Open
Abstract
Neurosecretory centers in animal brains use peptidergic signaling to influence physiology and behavior. Understanding neurosecretory center function requires mapping cell types, synapses, and peptidergic networks. Here we use transmission electron microscopy and gene expression mapping to analyze the synaptic and peptidergic connectome of an entire neurosecretory center. We reconstructed 78 neurosecretory neurons and mapped their synaptic connectivity in the brain of larval Platynereis dumerilii, a marine annelid. These neurons form an anterior neurosecretory center expressing many neuropeptides, including hypothalamic peptide orthologs and their receptors. Analysis of peptide-receptor pairs in spatially mapped single-cell transcriptome data revealed sparsely connected networks linking specific neuronal subsets. We experimentally analyzed one peptide-receptor pair and found that a neuropeptide can couple neurosecretory and synaptic brain signaling. Our study uncovered extensive networks of peptidergic signaling within a neurosecretory center and its connection to the synaptic brain.
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Affiliation(s)
| | - Csaba Verasztó
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Sanja Jasek
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | | | - Réza Shahidi
- Max Planck Institute for Developmental Biology, Tübingen, Germany.,Living Systems Institute, University of Exeter, Exeter, United Kingdom
| | | | - Olivier Mirabeau
- Genetics and Biology of Cancers Unit, Institut Curie, INSERM U830, Paris Sciences et Lettres Research University, Paris, France
| | - Gáspár Jékely
- Max Planck Institute for Developmental Biology, Tübingen, Germany.,Living Systems Institute, University of Exeter, Exeter, United Kingdom
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15
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Heinrich R, Günther V, Miljus N. Erythropoietin-Mediated Neuroprotection in Insects Suggests a Prevertebrate Evolution of Erythropoietin-Like Signaling. VITAMINS AND HORMONES 2017. [PMID: 28629517 DOI: 10.1016/bs.vh.2017.02.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The cytokine erythropoietin (Epo) mediates protective and regenerative functions in mammalian nervous systems via activation of poorly characterized receptors that differ from the "classical" homodimeric Epo receptor expressed on erythroid progenitor cells. Epo genes have been identified in vertebrate species ranging from human to fish, suggesting that Epo signaling evolved earlier than the vertebrate lineage. Studies on insects (Locusta migratoria, Chorthippus biguttulus, Tribolium castaneum) revealed Epo-mediated neuroprotection and neuroregeneration. Recombinant human Epo (rhEpo) prevents apoptosis by binding to a janus kinase-associated receptor, stimulation of STAT transcription factors, and generation of factors that prevent the activation of proapoptotic caspases. Insect neurons were also protected by a neuroprotective but nonerythropoietic Epo splice variant, suggesting similarity with mammalian neuroprotective but not with homodimeric "classical" Epo receptors. Additionally, rhEpo promotes the regeneration of neurites in primary cultured insect brain neurons and after nerve crush in an in vivo preparation. In contrast to neuroprotective and regenerative effects shared with mammalian species, no evidence for a role of Epo signaling in the regulation of neuro- or gliogenesis was found in insects. Similar structural and functional characteristics of the Epo binding receptors, partly shared transduction pathways that prevent apoptosis and the functional implication in neuroprotective and neuroregenerative processes in both mammalian and insect species, suggest that Epo-like signaling was already established in their last common ancestor. Originally functioning as a tissue-protective response to unfavorable physiological situations, cell injury, and pathogen invasion, Epo was later adapted as a humoral regulator of erythropoiesis in the vertebrate lineage.
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Affiliation(s)
- Ralf Heinrich
- Institute for Zoology and Anthropology, Georg-August-University Goettingen, Goettingen, Germany.
| | - Verena Günther
- Institute for Zoology and Anthropology, Georg-August-University Goettingen, Goettingen, Germany
| | - Natasa Miljus
- Institute for Zoology and Anthropology, Georg-August-University Goettingen, Goettingen, Germany
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16
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Corthals K, Heukamp AS, Kossen R, Großhennig I, Hahn N, Gras H, Göpfert MC, Heinrich R, Geurten BRH. Neuroligins Nlg2 and Nlg4 Affect Social Behavior in Drosophila melanogaster. Front Psychiatry 2017; 8:113. [PMID: 28740469 PMCID: PMC5502276 DOI: 10.3389/fpsyt.2017.00113] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 06/12/2017] [Indexed: 12/20/2022] Open
Abstract
The genome of Drosophila melanogaster includes homologs to approximately one-third of the currently known human disease genes. Flies and humans share many biological processes, including the principles of information processing by excitable neurons, synaptic transmission, and the chemical signals involved in intercellular communication. Studies on the molecular and behavioral impact of genetic risk factors of human neuro-developmental disorders [autism spectrum disorders (ASDs), schizophrenia, attention deficit hyperactivity disorders, and Tourette syndrome] increasingly use the well-studied social behavior of D. melanogaster, an organism that is amenable to a large variety of genetic manipulations. Neuroligins (Nlgs) are a family of phylogenetically conserved postsynaptic adhesion molecules present (among others) in nematodes, insects, and mammals. Impaired function of Nlgs (particularly of Nlg 3 and 4) has been associated with ASDs in humans and impaired social and communication behavior in mice. Making use of a set of behavioral and social assays, we, here, analyzed the impact of two Drosophila Nlgs, Dnlg2 and Dnlg4, which are differentially expressed at excitatory and inhibitory central nervous synapses, respectively. Both Nlgs seem to be associated with diurnal activity and social behavior. Even though deficiencies in Dnlg2 and Dnlg4 appeared to have no effects on sensory or motor systems, they differentially impacted on social interactions, suggesting that social behavior is distinctly regulated by these Nlgs.
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Affiliation(s)
- Kristina Corthals
- Department of Cellular Neurobiology, Institute for Zoology and Anthropology, University of Göttingen, Göttingen, Germany
| | - Alina Sophia Heukamp
- Department of Cellular Neurobiology, Institute for Zoology and Anthropology, University of Göttingen, Göttingen, Germany
| | - Robert Kossen
- Department of Cellular Neurobiology, Institute for Zoology and Anthropology, University of Göttingen, Göttingen, Germany
| | - Isabel Großhennig
- Department of Cellular Neurobiology, Institute for Zoology and Anthropology, University of Göttingen, Göttingen, Germany
| | - Nina Hahn
- Department of Cellular Neurobiology, Institute for Zoology and Anthropology, University of Göttingen, Göttingen, Germany
| | - Heribert Gras
- Department of Cellular Neurobiology, Institute for Zoology and Anthropology, University of Göttingen, Göttingen, Germany
| | - Martin C Göpfert
- Department of Cellular Neurobiology, Institute for Zoology and Anthropology, University of Göttingen, Göttingen, Germany
| | - Ralf Heinrich
- Department of Cellular Neurobiology, Institute for Zoology and Anthropology, University of Göttingen, Göttingen, Germany
| | - Bart R H Geurten
- Department of Cellular Neurobiology, Institute for Zoology and Anthropology, University of Göttingen, Göttingen, Germany
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17
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Kraus JEM, Fredman D, Wang W, Khalturin K, Technau U. Adoption of conserved developmental genes in development and origin of the medusa body plan. EvoDevo 2015; 6:23. [PMID: 26075050 PMCID: PMC4464714 DOI: 10.1186/s13227-015-0017-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 05/08/2015] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND The metagenesis of sessile polyps into pelagic medusae in cnidarians represents one of the most ancient complex life cycles in animals. Interestingly, scyphozoans and hydrozoans generate medusae by apparently fundamentally different processes. It is therefore unclear whether medusa formation has evolved independently in different medusozoans. To this end, a thorough understanding of the correspondence of polyp and medusa is required. RESULTS We monitored the expression patterns of conserved developmental genes in developing medusae of Clytia hemisphaerica (Hydrozoa) and Aurelia aurita (Scyphozoa) and found that developing medusae and polyps share similarities in their morphology and developmental gene expression. Unexpectedly, however, polyp tentacle marker genes were consistently expressed in the developing medusa bell, suggesting that the bell of medusae corresponds to modified and fused polyp tentacle anlagen. CONCLUSIONS Our data represent the first comparative gene expression analysis of developing medusae in two representatives of Scyphozoa and Hydrozoa. The results challenge prevailing views about polyp medusa body plan homology. We propose that the evolution of a new life stage may be facilitated by the adoption of existing developmental genes.
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Affiliation(s)
- Johanna E. M. Kraus
- />Department for Molecular Evolution and Development, Centre for Organismal Systems Biology, University of Vienna, Althanstraße 14, Wien, Vienna 1090 Austria
| | - David Fredman
- />Department for Molecular Evolution and Development, Centre for Organismal Systems Biology, University of Vienna, Althanstraße 14, Wien, Vienna 1090 Austria
- />Present address: Computational Biology Unit, University of Bergen, Thormohlensgate 55, 5008 Bergen, Norway
| | - Wei Wang
- />Zoologisches Institut, Christian-Albrechts Universität zu Kiel, Am Botanischen Garten 1-9, Kiel, 24118 Germany
| | - Konstantin Khalturin
- />Marine Genomics Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495 Japan
| | - Ulrich Technau
- />Department for Molecular Evolution and Development, Centre for Organismal Systems Biology, University of Vienna, Althanstraße 14, Wien, Vienna 1090 Austria
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18
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Schlosser G. Vertebrate cranial placodes as evolutionary innovations--the ancestor's tale. Curr Top Dev Biol 2015; 111:235-300. [PMID: 25662263 DOI: 10.1016/bs.ctdb.2014.11.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Evolutionary innovations often arise by tinkering with preexisting components building new regulatory networks by the rewiring of old parts. The cranial placodes of vertebrates, ectodermal thickenings that give rise to many of the cranial sense organs (ear, nose, lateral line) and ganglia, originated as such novel structures, when vertebrate ancestors elaborated their head in support of a more active and exploratory life style. This review addresses the question of how cranial placodes evolved by tinkering with ectodermal patterning mechanisms and sensory and neurosecretory cell types that have their own evolutionary history. With phylogenetic relationships among the major branches of metazoans now relatively well established, a comparative approach is used to infer, which structures evolved in which lineages and allows us to trace the origin of placodes and their components back from ancestor to ancestor. Some of the core networks of ectodermal patterning and sensory and neurosecretory differentiation were already established in the common ancestor of cnidarians and bilaterians and were greatly elaborated in the bilaterian ancestor (with BMP- and Wnt-dependent patterning of dorsoventral and anteroposterior ectoderm and multiple neurosecretory and sensory cell types). Rostral and caudal protoplacodal domains, giving rise to some neurosecretory and sensory cells, were then established in the ectoderm of the chordate and tunicate-vertebrate ancestor, respectively. However, proper cranial placodes as clusters of proliferating progenitors producing high-density arrays of neurosecretory and sensory cells only evolved and diversified in the ancestors of vertebrates.
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Affiliation(s)
- Gerhard Schlosser
- School of Natural Sciences & Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, Ireland.
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19
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Hunnekuhl VS, Akam M. An anterior medial cell population with an apical-organ-like transcriptional profile that pioneers the central nervous system in the centipede Strigamia maritima. Dev Biol 2014; 396:136-49. [PMID: 25263198 DOI: 10.1016/j.ydbio.2014.09.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 08/19/2014] [Accepted: 09/18/2014] [Indexed: 12/24/2022]
Abstract
The apical plate of primary marine larvae is characterized by a common set of transcription factors comprising six3, rx, hbn, nk2.1 and FoxQ2. It harbours the apical organ, a neural and ciliary structure with neurosecretory properties. Recent studies in lophotrochozoans have found that apical organ cells form the anterior tip of the developing central nervous system. We identify an anterior medial tissue in the embryonic centipede head that shares the transcriptional profile of the apical plate of marine larvae, including nested domains of FoxQ2 and six3 expression. This domain gives rise to an anterior medial population of neural precursors distinct from those arising within the segmental neuroectoderm. These medial cells do not express achaete scute homologue in proneural clusters, but express collier, a marker for post mitotic cells committed to a neural fate, while they are still situated in the surface ectodermal layer. They then sink under the surface to form a compact cell cluster. Once internalized these cells extend axons that pioneer the primary axonal scaffold of the central nervous system. The same cells express phc2, a neural specific prohormone convertase, which suggests that they form an early active neurosecretory centre. Some also express markers of hypothalamic neurons, including otp, vtn and vax1. These medial neurosecretory cells of the centipede are distinct from those of the pars intercerebralis, the anterior neurosecretory part of the insect brain. The pars intercerebralis derives from vsx positive placodal-like invagination sites. In the centipede, vsx expressing invaginating ectoderm is situated bilaterally adjacent to the medial pioneer cell population. Hence the pars intercerebralis is present in both insect and centipede brains, whereas no prominent anterior medial cluster of pioneer neurons is present in insects. These observations suggest that the arthropod brain retained ancestrally an anterior medial population of neurosecretory cells homologous to those of the apical plate in other invertebrate phyla, but that this cell population has been lost or greatly reduced in insects.
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Affiliation(s)
- Vera S Hunnekuhl
- Laboratory for Development and Evolution, Department of Zoology, Downing Street, Cambridge CB2 3EJ, UK.
| | - Michael Akam
- Laboratory for Development and Evolution, Department of Zoology, Downing Street, Cambridge CB2 3EJ, UK.
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20
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Ubuka T, Tsutsui K. Evolution of gonadotropin-inhibitory hormone receptor and its ligand. Gen Comp Endocrinol 2014; 209:148-61. [PMID: 25220854 DOI: 10.1016/j.ygcen.2014.09.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 08/15/2014] [Accepted: 09/04/2014] [Indexed: 12/13/2022]
Abstract
Gonadotropin-inhibitory hormone (GnIH) is a neuropeptide inhibitor of gonadotropin secretion, which was first identified in the Japanese quail hypothalamus. GnIH peptides share a C-terminal LPXRFamide (X=L or Q) motif in most vertebrates. The receptor for GnIH (GnIHR) is the seven-transmembrane G protein-coupled receptor 147 (GPR147) that inhibits cAMP production. GPR147 is also named neuropeptide FF (NPFF) receptor 1 (NPFFR1), because it also binds NPFF that has a C-terminal PQRFamide motif. To understand the evolutionary history of the GnIH system in the animal kingdom, we searched for receptors structurally similar to GnIHR in the genome of six mammals (human, mouse, rat, cattle, cat, and rabbit), five birds (pigeon, chicken, turkey, budgerigar, and zebra finch), one reptile (green anole), one amphibian (Western clawed flog), six fishes (zebrafish, Nile tilapia, Fugu, coelacanth, spotted gar, and lamprey), one hemichordate (acorn worm), one echinoderm (purple sea urchin), one mollusk (California sea hare), seven insects (pea aphid, African malaria mosquito, honey bee, buff-tailed bumblebee, fruit fly, jewel wasp, and red flour beetle), one cnidarian (hydra), and constructed phylogenetic trees by neighbor joining (NJ) and maximum likelihood (ML) methods. A multiple sequence alignment of the receptors showed highly conserved seven-transmembrane domains as well as disulfide bridge sites between the first and second extracellular loops, including the receptor of hydra. Both NJ and ML analyses grouped the receptors of vertebrates into NPFFR1 and NPFFR2 (GPR74), and the receptors of insects into the receptor for SIFamide peptides that share a C-terminal YRKPPFNGSIFamide motif. Although human, quail and zebrafish GnIHR (NPFFR1) were most structurally similar to SIFamide receptor of fruit fly in the Famide peptide (FMRFamide, neuropeptide F, short neuropeptide F, drosulfakinin, myosuppressin, SIFamide) receptor families, the amino acid sequences and the peptide coding regions of GnIH precursors were most similar to FMRFamide precursor of fruit fly in the precursors of Famide peptide families. Chromosome synteny analysis of the precursor genes of human, quail and zebrafish GnIH and fruit fly Famide peptides further identified conserved synteny in vertebrate GnIH and fruit fly FMRFa precursor genes as well as other Famide peptide precursor genes. These results suggest that GnIH and its receptor pair and SIFamide and its receptor pair may have diverged and co-evolved independently in vertebrates and insects, respectively, from their ancestral Famide peptide and its receptor pair, during diversification and evolution of deuterostomian and protostomian species.
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Affiliation(s)
- Takayoshi Ubuka
- Department of Biology, Waseda University, 2-2 Wakamatsu-cho, Shinjuku, Tokyo 162-8480, Japan
| | - Kazuyoshi Tsutsui
- Department of Biology, Waseda University, 2-2 Wakamatsu-cho, Shinjuku, Tokyo 162-8480, Japan.
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21
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Gutierrez-Triana JA, Herget U, Lichtner P, Castillo-Ramírez LA, Ryu S. A vertebrate-conserved cis-regulatory module for targeted expression in the main hypothalamic regulatory region for the stress response. BMC DEVELOPMENTAL BIOLOGY 2014; 14:41. [PMID: 25427861 PMCID: PMC4248439 DOI: 10.1186/s12861-014-0041-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 11/11/2014] [Indexed: 01/30/2023]
Abstract
Background The homeodomain transcription factor orthopedia (Otp) is an evolutionarily conserved regulator of neuronal fates. In vertebrates, Otp is necessary for the proper development of different regions of the brain and is required in the diencephalon to specify several hypothalamic cell types, including the cells that control the stress response. To understand how this widely expressed transcription factor accomplishes hypothalamus-specific functions, we performed a comprehensive screening of otp cis-regulatory regions in zebrafish. Results Here, we report the identification of an evolutionarily conserved vertebrate enhancer module with activity in a restricted area of the forebrain, which includes the region of the hypothalamus that controls the stress response. This region includes neurosecretory cells producing Corticotropin-releasing hormone (Crh), Oxytocin (Oxt) and Arginine vasopressin (Avp), which are key components of the stress axis. Lastly, expression of the bacterial nitroreductase gene under this specific enhancer allowed pharmacological attenuation of the stress response in zebrafish larvae. Conclusion Vertebrates share many cellular and molecular components of the stress response and our work identified a striking conservation at the cis-regulatory level of a key hypothalamic developmental gene. In addition, this enhancer provides a useful tool to manipulate and visualize stress-regulatory hypothalamic cells in vivo with the long-term goal of understanding the ontogeny of the stress axis in vertebrates. Electronic supplementary material The online version of this article (doi:10.1186/s12861-014-0041-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jose Arturo Gutierrez-Triana
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120, Heidelberg, Germany. .,Current address: Centre for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 230, D-69120, Heidelberg, Germany.
| | - Ulrich Herget
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120, Heidelberg, Germany. .,The Hartmut Hoffmann-Berling International Graduate School of Molecular and Cellular Biology, University of Heidelberg, Heidelberg, Germany.
| | - Patrick Lichtner
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120, Heidelberg, Germany.
| | - Luis A Castillo-Ramírez
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120, Heidelberg, Germany. .,The Hartmut Hoffmann-Berling International Graduate School of Molecular and Cellular Biology, University of Heidelberg, Heidelberg, Germany.
| | - Soojin Ryu
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120, Heidelberg, Germany.
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22
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Dunn CW, Giribet G, Edgecombe GD, Hejnol A. Animal Phylogeny and Its Evolutionary Implications. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2014. [DOI: 10.1146/annurev-ecolsys-120213-091627] [Citation(s) in RCA: 261] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Casey W. Dunn
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island 02912;
| | - Gonzalo Giribet
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138;
| | - Gregory D. Edgecombe
- Department of Earth Sciences, The Natural History Museum, London SW7 5BD, United Kingdom;
| | - Andreas Hejnol
- Sars International Centre for Marine Molecular Biology, University of Bergen, 5008 Bergen, Norway;
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23
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Oliveri P, Fortunato AE, Petrone L, Ishikawa-Fujiwara T, Kobayashi Y, Todo T, Antonova O, Arboleda E, Zantke J, Tessmar-Raible K, Falciatore A. The Cryptochrome/Photolyase Family in aquatic organisms. Mar Genomics 2014; 14:23-37. [DOI: 10.1016/j.margen.2014.02.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/05/2014] [Accepted: 02/10/2014] [Indexed: 01/12/2023]
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24
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Patthey C, Schlosser G, Shimeld SM. The evolutionary history of vertebrate cranial placodes--I: cell type evolution. Dev Biol 2014; 389:82-97. [PMID: 24495912 DOI: 10.1016/j.ydbio.2014.01.017] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 01/21/2014] [Accepted: 01/24/2014] [Indexed: 10/25/2022]
Abstract
Vertebrate cranial placodes are crucial contributors to the vertebrate cranial sensory apparatus. Their evolutionary origin has attracted much attention from evolutionary and developmental biologists, yielding speculation and hypotheses concerning their putative homologues in other lineages and the developmental and genetic innovations that might have underlain their origin and diversification. In this article we first briefly review our current understanding of placode development and the cell types and structures they form. We next summarise previous hypotheses of placode evolution, discussing their strengths and caveats, before considering the evolutionary history of the various cell types that develop from placodes. In an accompanying review, we also further consider the evolution of ectodermal patterning. Drawing on data from vertebrates, tunicates, amphioxus, other bilaterians and cnidarians, we build these strands into a scenario of placode evolutionary history and of the genes, cells and developmental processes that underlie placode evolution and development.
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Affiliation(s)
- Cedric Patthey
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.
| | - Gerhard Schlosser
- Zoology, School of Natural Sciences & Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, University Road, Galway, Ireland
| | - Sebastian M Shimeld
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
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25
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Wirmer A, Bradler S, Heinrich R. Homology of insect corpora allata and vertebrate adenohypophysis? ARTHROPOD STRUCTURE & DEVELOPMENT 2012; 41:409-417. [PMID: 22595331 DOI: 10.1016/j.asd.2012.04.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 04/25/2012] [Accepted: 04/25/2012] [Indexed: 05/31/2023]
Abstract
Animal species of various phyla possess neuroendocrine glands whose hormonal products regulate developmental and physiological mechanisms and directly impact behavior. Two examples, the corpora allata of insects and the vertebrate adenohypophysis have previously been regarded as analogous tissues that evolved independently from diffuse epidermal nerve nets of early metazoans. More recent developmental and functional studies accumulated evidence suggesting that the bilaterian nervous systems including its modern parts (e.g. pallium or cortex and mushroom bodies) and its neuroendocrine appendages (that are considered to be more ancient structures) possess a single evolutionary origin. The corpora allata of insects and the vertebrate adenohypophysis share a number of characteristics in respect of morphology, control of hormone release by RFamides, metabolites produced by closely related cytochrome P450 enzymes and gene expression during embryonic development. This review incorporates latest findings into an extensive description of similarities between insect corpora allata and vertebrate adenohypophysis that should encourage further studies about the onto- and phylogenetic origin of these neuroendocrine glands.
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Affiliation(s)
- Andrea Wirmer
- Institute for Neurobiology, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
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Moreno N, Domínguez L, Morona R, González A. Subdivisions of the turtle Pseudemys scripta hypothalamus based on the expression of regulatory genes and neuronal markers. J Comp Neurol 2012; 520:453-78. [PMID: 21935937 DOI: 10.1002/cne.22762] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The patterns of distribution of a set of conserved brain developmental regulatory transcription factors and neuronal markers were analyzed in the hypothalamus of the juvenile turtle, Pseudemys scripta. Combined immunohistochemical techniques were used for the identification of the main boundaries and subdivisions in the optic, paraventricular, tuberal, and mammillary hypothalamic regions. The combination of Tbr1 and Pax6 with Nkx2.1 allowed identification of the boundary between the telencephalic preoptic area, rich in Nkx2.1 expression, and the prethalamic eminence, rich in Tbr1 expression. In addition, at this level Nkx2.2 expression defined the boundary between the telencephalon and the hypothalamus. The dorsalmost hypothalamic domain was the supraoptoparaventricular region that was defined by the expression of Otp/Pax6 and the lack of Nkx2.1/Isl1. It is subdivided into rostral, rich in Otp and Nkx2.2, and caudal, only Otp-positive, portions. Ventrally, the suprachiasmatic area was identified by its catecholaminergic groups and the lack of Otp, and could be further divided into a rostral portion, rich in Nkx2.1 and Nkx2.2, and a caudal portion, rich in Isl1 and devoid of Nkx2.1 expression. The expressions of Nkx2.1 and Isl1 defined the tuberal hypothalamus, whereas only the rostral portion expressed Otp. Its caudal boundary was evident by the lack of Isl1 in the adjacent mammillary area, which expressed Nkx2.1 and Otp. All these results provide an important set of data on the interpretation of the hypothalamic organization in a reptile, and hence make a useful contribution to the understanding of hypothalamic evolution.
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Affiliation(s)
- Nerea Moreno
- Department of Cell Biology, Faculty of Biology, University Complutense of Madrid, 28040, Madrid, Spain.
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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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Tessmar-Raible K, Raible F, Arboleda E. Another place, another timer: Marine species and the rhythms of life. Bioessays 2011; 33:165-72. [PMID: 21254149 PMCID: PMC3182551 DOI: 10.1002/bies.201000096] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The marine ecosystem is governed by a multitude of environmental cycles, all of which are linked to the periodical recurrence of the sun or the moon. In accordance with these cycles, marine species exhibit a variety of biological rhythms, ranging from circadian and circatidal rhythms to circalunar and seasonal rhythms. However, our current molecular understanding of biological rhythms and clocks is largely restricted to solar-controlled circadian and seasonal rhythms in land model species. Here, we discuss the first molecular data emerging for circalunar and circatidal rhythms and present selected species suitable for further molecular analyses. We argue that a re-focus on marine species will be crucial to understand the principles, interactions and evolution of rhythms that govern a broad range of eukaryotes, including ourselves.
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O'Kane CJ. Drosophila as a model organism for the study of neuropsychiatric disorders. Curr Top Behav Neurosci 2011; 7:37-60. [PMID: 21225410 DOI: 10.1007/7854_2010_110] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The fruitfly Drosophila offers a model system in which powerful genetic tools can be applied to understanding the neurobiological bases of a range of complex behaviors. The Drosophila and human lineages diverged several hundred million years ago, and despite their obvious differences, flies and humans share many fundamental cellular and neurobiological processes. The similarities include fundamental mechanisms of neuronal signaling, a conserved underlying brain architecture and the main classes of neurotransmitter system. Drosophila also have a sophisticated behavioral repertoire that includes extensive abilities to adapt to experience and other circumstances, and is therefore susceptible to the same kinds of insults that can cause neuropsychiatric disorders in humans. Given the different physiologies, lifestyles, and cognitive abilities of flies and humans, many higher order behavioral features of the human disorders cannot be modeled readily in flies. However, an increasing understanding of the genetics of human neuropsychiatric disorders is suggesting parallels with underlying neurobiological mechanisms in flies, thus providing important insights into the possible mechanisms of these poorly understood disorders.
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Affiliation(s)
- Cahir J O'Kane
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, UK,
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Jékely G. Origin and early evolution of neural circuits for the control of ciliary locomotion. Proc Biol Sci 2010; 278:914-22. [PMID: 21123265 DOI: 10.1098/rspb.2010.2027] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Behaviour evolved before nervous systems. Various single-celled eukaryotes (protists) and the ciliated larvae of sponges devoid of neurons can display sophisticated behaviours, including phototaxis, gravitaxis or chemotaxis. In single-celled eukaryotes, sensory inputs directly influence the motor behaviour of the cell. In swimming sponge larvae, sensory cells influence the activity of cilia on the same cell, thereby steering the multicellular larva. In these organisms, the efficiency of sensory-to-motor transformation (defined as the ratio of sensory cells to total cell number) is low. With the advent of neurons, signal amplification and fast, long-range communication between sensory and motor cells became possible. This may have first occurred in a ciliated swimming stage of the first eumetazoans. The first axons may have had en passant synaptic contacts to several ciliated cells to improve the efficiency of sensory-to-motor transformation, thereby allowing a reduction in the number of sensory cells tuned for the same input. This could have allowed the diversification of sensory modalities and of the behavioural repertoire. I propose that the first nervous systems consisted of combined sensory-motor neurons, directly translating sensory input into motor output on locomotor ciliated cells and steering muscle cells. Neuronal circuitry with low levels of integration has been retained in cnidarians and in the ciliated larvae of some marine invertebrates. This parallel processing stage could have been the starting point for the evolution of more integrated circuits performing the first complex computations such as persistence or coincidence detection. The sensory-motor nervous systems of cnidarians and ciliated larvae of diverse phyla show that brains, like all biological structures, are not irreducibly complex.
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Affiliation(s)
- Gáspár Jékely
- Max Planck Institute for Developmental Biology, Tübingen, Germany.
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Posnien N, Koniszewski N, Bucher G. Insect Tc-six4 marks a unit with similarity to vertebrate placodes. Dev Biol 2010; 350:208-16. [PMID: 21034730 DOI: 10.1016/j.ydbio.2010.10.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Revised: 10/18/2010] [Accepted: 10/19/2010] [Indexed: 11/20/2022]
Abstract
Cranial placodes are specialized ectodermal regions in the developing vertebrate head that give rise to both neural and non-neural cell types of the neuroendocrine system and the sense organs of the visual, olfactory and acoustic systems. The cranial placodes develop from a panplacodal region which is specifically marked by genes of the eyes absent/eya and two "six homeobox" family members (sine oculis/six1 and six4). It had been believed that cranial placodes are evolutionary novelties of vertebrates. However, data from non-vertebrate chordates suggest that placode-like structures evolved in the chordate ancestor already. Here, we identify a morphological structure in the embryonic head of the beetle Tribolium castaneum with placode-like features. It is marked by the orthologs of the panplacodal markers Tc-six4, Tc-eya and Tc-sine oculis/six1 (Tc-six1) and expresses several genes known to be involved in adenohypophyseal placode development in vertebrates. Moreover, it contributes to both epidermal and neural tissues. We identify Tc-six4 as a specific marker for this structure that we term the insect head placode. Finally, we reveal the regulatory gene network of the panplacodal genes Tc-six4, Tc-eya and Tc-six1 and identify them as head epidermis patterning genes. Our finding of a placode-like structure in an insect suggests that a placode precursor was already present in the last common ancestor of bilaterian animals.
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Affiliation(s)
- Nico Posnien
- Center of Molecular Brain Physiology, Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
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Lacalli TC. Serial EM analysis of a copepod larval nervous system: Naupliar eye, optic circuitry, and prospects for full CNS reconstruction. ARTHROPOD STRUCTURE & DEVELOPMENT 2009; 38:361-375. [PMID: 19376268 DOI: 10.1016/j.asd.2009.04.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 04/07/2009] [Accepted: 04/08/2009] [Indexed: 05/27/2023]
Abstract
The medial eye and optic center of the first nauplius of Dactylopusia (=Dactylopodia) tisboides, a harpacticoid copepod, were reconstructed from serial EM micrographs. Axons from the eye project to a set of matching cartridges defined by glial cells processes, and input is then processed in sequence through two synaptic fields. A single class of local relay neurons provides the main pathway between these, subject to modulatory input from a class of densely stained neurons with distinctive dense terminals. The importance of other outside sources of synaptic input to the second synaptic field indicates that the latter is a major site for integrating the optic input with signals originating elsewhere in the CNS. This accords with physiological data on the shadow response in barnacles, whose visual system is also derived from a naupliar eye. With a body length of ca. 80microns, copepod larvae like that of Dactylopusia are arguably among the smallest functional metazoans with a complex nervous system. Hence they are promising subjects for full reconstruction of neural circuitry at the EM level that could, in principle, reveal where key decision-making functions are localized.
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Tando Y, Kubokawa K. Expression of the gene for ancestral glycoprotein hormone beta subunit in the nerve cord of amphioxus. Gen Comp Endocrinol 2009; 162:329-39. [PMID: 19393658 DOI: 10.1016/j.ygcen.2009.04.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2008] [Revised: 04/16/2009] [Accepted: 04/17/2009] [Indexed: 11/20/2022]
Abstract
Amphioxus belongs to the subphylum cephalochordata, a clade of chordates phylogenetically placed at the most basal position. Despite many studies on the endocrine system of amphioxus, there were no confident lines of evidence on the presence of pituitary hormones, whereas recent amphioxus genome analysis reported that amphioxus has no pituitary hormone except for thyrostimulin, which is a glycoprotein hormone in the pituitary, brain, and other organs of vertebrates. In the present study, we cloned cDNA for one glycoprotein hormone beta subunit (GPB) from amphioxus, AmpGPB5, and phylogenetically indicated that AmpGPB5 is the ancestral molecule of glycoprotein hormone beta subunits of vertebrates including pituitary glycoprotein hormones. Synteny analyses showed conservation of chromosomal location of genes near GPB genes from amphioxus through human. The AmpGPB5 gene was expressed in a restricted region of the dorsal part of the nerve cord, glandular atrial cells of gills, and pre-vitellogenic oocytes in amphioxus. However, expression was not detected in the Hatschek's pit which is considered to be a primitive pituitary gland. On the basis of present results, we hypothesize that a portion of vertebrate pituitary hormones might be derived from an ancestral glycoprotein hormone of amphioxus that functions as a neuroendocrine hormone.
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Affiliation(s)
- Yukiko Tando
- Center for Advance Marine Research, Ocean Research Institute, The University of Tokyo, 1-15-1, Minamidai, Nakano, Tokyo 164-8639, Japan
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Neurodevelopment genes in lampreys reveal trends for forebrain evolution in craniates. PLoS One 2009; 4:e5374. [PMID: 19399187 PMCID: PMC2671401 DOI: 10.1371/journal.pone.0005374] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Accepted: 04/01/2009] [Indexed: 12/27/2022] Open
Abstract
The forebrain is the brain region which has undergone the most dramatic changes through vertebrate evolution. Analyses conducted in lampreys are essential to gain insight into the broad ancestral characteristics of the forebrain at the dawn of vertebrates, and to understand the molecular basis for the diversifications that have taken place in cyclostomes and gnathostomes following their splitting. Here, we report the embryonic expression patterns of 43 lamprey genes, coding for transcription factors or signaling molecules known to be involved in cell proliferation, stemcellness, neurogenesis, patterning and regionalization in the developing forebrain. Systematic expression patterns comparisons with model organisms highlight conservations likely to reflect shared features present in the vertebrate ancestors. They also point to changes in signaling systems –pathways which control the growth and patterning of the neuroepithelium-, which may have been crucial in the evolution of forebrain anatomy at the origin of vertebrates.
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The evolution of cell types in animals: emerging principles from molecular studies. Nat Rev Genet 2008; 9:868-82. [PMID: 18927580 DOI: 10.1038/nrg2416] [Citation(s) in RCA: 303] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cell types are fundamental units of multicellular life but their evolution is obscure. How did the first cell types emerge and become distinct in animal evolution? What were the sets of cell types that existed at important evolutionary nodes that represent eumetazoan or bilaterian ancestors? How did these ancient cell types diversify further during the evolution of organ systems in the descending evolutionary lines? The recent advent of cell type molecular fingerprinting has yielded initial insights into the evolutionary interrelationships of cell types between remote animal phyla and has allowed us to define some first principles of cell type diversification in animal evolution.
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