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Kitamata M, Otake Y, Kitagori H, Zhang X, Maki Y, Boku R, Takeuchi M, Nakagoshi H. Functional opsin patterning for Drosophila color vision is established through signaling pathways in adjacent object-detection neurons. Development 2024; 151:dev202388. [PMID: 38421315 PMCID: PMC10984275 DOI: 10.1242/dev.202388] [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: 09/29/2023] [Accepted: 02/22/2024] [Indexed: 03/02/2024]
Abstract
Vision is mainly based on two different tasks, object detection and color discrimination, carried out by photoreceptor (PR) cells. The Drosophila compound eye consists of ∼800 ommatidia. Every ommatidium contains eight PR cells, six outer cells (R1-R6) and two inner cells (R7 and R8), by which object detection and color vision are achieved, respectively. Expression of opsin genes in R7 and R8 is highly coordinated through the instructive signal from R7 to R8, and two major ommatidial subtypes are distributed stochastically; pale type expresses Rh3/Rh5 and yellow type expresses Rh4/Rh6 in R7/R8. The homeodomain protein Defective proventriculus (Dve) is expressed in yellow-type R7 and in six outer PRs, and it is involved in Rh3 repression to specify the yellow-type R7. dve mutant eyes exhibited atypical coupling, Rh3/Rh6 and Rh4/Rh5, indicating that Dve activity is required for proper opsin coupling. Surprisingly, Dve activity in R1 is required for the instructive signal, whereas activity in R6 and R7 blocks the signal. Our results indicate that functional coupling of two different neurons is established through signaling pathways from adjacent neurons that are functionally different.
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Affiliation(s)
- Manabu Kitamata
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Yoshiaki Otake
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Hideaki Kitagori
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Xuanshuo Zhang
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Yusuke Maki
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Rika Boku
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Masato Takeuchi
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Hideki Nakagoshi
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
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2
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Kobayashi S, Cox AG, Harvey KF, Hogan BM. Vasculature is getting Hip(po): Hippo signaling in vascular development and disease. Dev Cell 2023; 58:2627-2640. [PMID: 38052179 DOI: 10.1016/j.devcel.2023.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 05/29/2023] [Accepted: 11/01/2023] [Indexed: 12/07/2023]
Abstract
The Hippo signaling pathway regulates developmental organ growth, regeneration, and cell fate decisions. Although the role of the Hippo pathway, and its transcriptional effectors YAP and TAZ, has been well documented in many cell types and species, only recently have the roles for this pathway come to light in vascular development and disease. Experiments in mice, zebrafish, and in vitro have uncovered roles for the Hippo pathway, YAP, and TAZ in vasculogenesis, angiogenesis, and lymphangiogenesis. In addition, the Hippo pathway has been implicated in vascular cancers and cardiovascular diseases, thus identifying it as a potential therapeutic target for the treatment of these conditions. However, despite recent advances, Hippo's role in the vasculature is still underappreciated compared with its role in epithelial tissues. In this review, we appraise our current understanding of the Hippo pathway in blood and lymphatic vessel development and highlight the current knowledge gaps and opportunities for further research.
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Affiliation(s)
- Sakurako Kobayashi
- Organogenesis and Cancer Program, Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Andrew G Cox
- Organogenesis and Cancer Program, Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC 3010, Australia; Department of Biochemistry and Pharmacology, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Kieran F Harvey
- Organogenesis and Cancer Program, Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC 3010, Australia; Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC 3800, Australia
| | - Benjamin M Hogan
- Organogenesis and Cancer Program, Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC 3010, Australia; Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC 3010, Australia.
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3
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Mishra AK, Sprecher SG. Eye Development in Drosophila : From Photoreceptor Specification to Terminal Differentiation. Neurogenetics 2023. [DOI: 10.1007/978-3-031-07793-7_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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4
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Bunker J, Bashir M, Bailey S, Boodram P, Perry A, Delaney R, Tsachaki M, Sprecher SG, Nelson E, Call GB, Rister J. Blimp-1/PRDM1 and Hr3/RORβ specify the blue-sensitive photoreceptor subtype in Drosophila by repressing the hippo pathway. Front Cell Dev Biol 2023; 11:1058961. [PMID: 36960411 PMCID: PMC10027706 DOI: 10.3389/fcell.2023.1058961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 02/20/2023] [Indexed: 03/09/2023] Open
Abstract
During terminal differentiation of the mammalian retina, transcription factors control binary cell fate decisions that generate functionally distinct subtypes of photoreceptor neurons. For instance, Otx2 and RORβ activate the expression of the transcriptional repressor Blimp-1/PRDM1 that represses bipolar interneuron fate and promotes rod photoreceptor fate. Moreover, Otx2 and Crx promote expression of the nuclear receptor Nrl that promotes rod photoreceptor fate and represses cone photoreceptor fate. Mutations in these four transcription factors cause severe eye diseases such as retinitis pigmentosa. Here, we show that a post-mitotic binary fate decision in Drosophila color photoreceptor subtype specification requires ecdysone signaling and involves orthologs of these transcription factors: Drosophila Blimp-1/PRDM1 and Hr3/RORβ promote blue-sensitive (Rh5) photoreceptor fate and repress green-sensitive (Rh6) photoreceptor fate through the transcriptional repression of warts/LATS, the nexus of the phylogenetically conserved Hippo tumor suppressor pathway. Moreover, we identify a novel interaction between Blimp-1 and warts, whereby Blimp-1 represses a warts intronic enhancer in blue-sensitive photoreceptors and thereby gives rise to specific expression of warts in green-sensitive photoreceptors. Together, these results reveal that conserved transcriptional regulators play key roles in terminal cell fate decisions in both the Drosophila and the mammalian retina, and the mechanistic insights further deepen our understanding of how Hippo pathway signaling is repurposed to control photoreceptor fates for Drosophila color vision.
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Affiliation(s)
- Joseph Bunker
- Department of Biology, Integrated Sciences Complex, University of Massachusetts Boston, Boston, MA, United States
| | - Mhamed Bashir
- Department of Biology, Integrated Sciences Complex, University of Massachusetts Boston, Boston, MA, United States
| | - Sydney Bailey
- Department of Biology, Integrated Sciences Complex, University of Massachusetts Boston, Boston, MA, United States
| | - Pamela Boodram
- Department of Biology, Integrated Sciences Complex, University of Massachusetts Boston, Boston, MA, United States
- NYU Langone Medical Center, New York, NY, United States
| | - Alexis Perry
- Department of Biology, Integrated Sciences Complex, University of Massachusetts Boston, Boston, MA, United States
| | - Rory Delaney
- Department of Biology, Integrated Sciences Complex, University of Massachusetts Boston, Boston, MA, United States
| | - Maria Tsachaki
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Simon G. Sprecher
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Erik Nelson
- Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ, United States
| | - Gerald B. Call
- Department of Pharmacology, College of Graduate Studies, Midwestern University, Glendale, AZ, United States
| | - Jens Rister
- Department of Biology, Integrated Sciences Complex, University of Massachusetts Boston, Boston, MA, United States
- *Correspondence: Jens Rister,
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5
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McCulloch KJ, Macias-Muñoz A, Briscoe AD. Insect opsins and evo-devo: what have we learned in 25 years? Philos Trans R Soc Lond B Biol Sci 2022; 377:20210288. [PMID: 36058243 PMCID: PMC9441233 DOI: 10.1098/rstb.2021.0288] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 01/16/2022] [Indexed: 12/16/2022] Open
Abstract
The visual pigments known as opsins are the primary molecular basis for colour vision in animals. Insects are among the most diverse of animal groups and their visual systems reflect a variety of life histories. The study of insect opsins in the fruit fly Drosophila melanogaster has led to major advances in the fields of neuroscience, development and evolution. In the last 25 years, research in D. melanogaster has improved our understanding of opsin genotype-phenotype relationships while comparative work in other insects has expanded our understanding of the evolution of insect eyes via gene duplication, coexpression and homologue switching. Even so, until recently, technology and sampling have limited our understanding of the fundamental mechanisms that evolution uses to shape the diversity of insect eyes. With the advent of genome editing and in vitro expression assays, the study of insect opsins is poised to reveal new frontiers in evolutionary biology, visual neuroscience, and animal behaviour. This article is part of the theme issue 'Understanding colour vision: molecular, physiological, neuronal and behavioural studies in arthropods'.
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Affiliation(s)
- Kyle J. McCulloch
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN 55108, USA
| | - Aide Macias-Muñoz
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA
| | - Adriana D. Briscoe
- Department of Ecology and Evolutionary Biology, University of California, 321 Steinhaus Hall, Irvine, CA 92697, USA
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6
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Neal SJ, Zhou Q, Pignoni F. Protein Phosphatase 2A with B' specificity subunits regulates the Hippo-Yorkie signaling axis in the Drosophila eye disc. J Cell Sci 2022; 135:jcs259558. [PMID: 36205125 PMCID: PMC10614058 DOI: 10.1242/jcs.259558] [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: 12/06/2021] [Accepted: 09/22/2022] [Indexed: 11/20/2022] Open
Abstract
Hippo-Yorkie (Hpo-Yki) signaling is central to diverse developmental processes. Although its redeployment has been amply demonstrated, its context-specific regulation remains poorly understood. The Drosophila eye disc is a continuous epithelium folded into two layers, the peripodial epithelium (PE) and the retinal progenitor epithelium. Here, Yki acts in the PE, first to promote PE identity by suppressing retina fate, and subsequently to maintain proper disc morphology. In the latter process, loss of Yki results in the displacement of a portion of the differentiating retinal epithelium onto the PE side. We show that Protein Phosphatase 2A (PP2A) complexes comprising different substrate-specificity B-type subunits govern the Hpo-Yki axis in this context. These include holoenzymes containing the B‴ subunit Cka and those containing the B' subunits Wdb or Wrd. Whereas PP2A(Cka), as part of the STRIPAK complex, is known to regulate Hpo directly, PP2A(Wdb) acts genetically upstream of the antagonistic activities of the Hpo regulators Sav and Rassf. These in vivo data provide the first evidence of PP2A(B') heterotrimer function in Hpo pathway regulation and reveal pathway diversification at distinct developmental times in the same tissue.
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Affiliation(s)
- Scott J. Neal
- Department of Neuroscience & Physiology, Upstate Medical University, 505 Irving Avenue, NRB 4610, Syracuse, NY 13210, USA
| | - Qingxiang Zhou
- Department of Ophthalmology and Visual Sciences, Upstate Medical University, 505 Irving Avenue, NRB 4610, Syracuse, NY 13210, USA
| | - Francesca Pignoni
- Department of Neuroscience & Physiology, Upstate Medical University, 505 Irving Avenue, NRB 4610, Syracuse, NY 13210, USA
- Department of Ophthalmology and Visual Sciences, Upstate Medical University, 505 Irving Avenue, NRB 4610, Syracuse, NY 13210, USA
- Department of Biochemistry and Molecular Biology, Department of Cell and Developmental Biology, Upstate Medical University, 505 Irving Avenue, NRB 4610, Syracuse, NY 13210, USA
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7
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Voortman L, Johnston RJ. Transcriptional repression in stochastic gene expression, patterning, and cell fate specification. Dev Biol 2022; 481:129-138. [PMID: 34688689 PMCID: PMC8665150 DOI: 10.1016/j.ydbio.2021.10.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 10/04/2021] [Accepted: 10/09/2021] [Indexed: 01/03/2023]
Abstract
Development is often driven by signaling and lineage-specific cues, yielding highly uniform and reproducible outcomes. Development also involves mechanisms that generate noise in gene expression and random patterns across tissues. Cells sometimes randomly choose between two or more cell fates in a mechanism called stochastic cell fate specification. This process diversifies cell types in otherwise homogenous tissues. Stochastic mechanisms have been extensively studied in prokaryotes where noisy gene activation plays a pivotal role in controlling cell fates. In eukaryotes, transcriptional repression stochastically limits gene expression to generate random patterns and specify cell fates. Here, we review our current understanding of repressive mechanisms that produce random patterns of gene expression and cell fates in flies, plants, mice, and humans.
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Affiliation(s)
- Lukas Voortman
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD, 21218, USA
| | - Robert J Johnston
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD, 21218, USA.
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8
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Sang Q, Wang G, Morton DB, Wu H, Xie B. The ZO-1 protein Polychaetoid as an upstream regulator of the Hippo pathway in Drosophila. PLoS Genet 2021; 17:e1009894. [PMID: 34748546 PMCID: PMC8610254 DOI: 10.1371/journal.pgen.1009894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 11/23/2021] [Accepted: 10/19/2021] [Indexed: 01/15/2023] Open
Abstract
The generation of a diversity of photoreceptor (PR) subtypes with different spectral sensitivities is essential for color vision in animals. In the Drosophila eye, the Hippo pathway has been implicated in blue- and green-sensitive PR subtype fate specification. Specifically, Hippo pathway activation promotes green-sensitive PR fate at the expense of blue-sensitive PRs. Here, using a sensitized triple heterozygote-based genetic screening approach, we report the identification of the single Drosophila zonula occludens-1 (ZO-1) protein Polychaetoid (Pyd) as a new regulator of the Hippo pathway during the blue- and green-sensitive PR subtype binary fate choice. We demonstrate that Pyd acts upstream of the core components and the upstream regulator Pez in the Hippo pathway. Furthermore, We found that Pyd represses the activity of Su(dx), a E3 ligase that negatively regulates Pez and can physically interact with Pyd, during PR subtype fate specification. Together, our results identify a new mechanism underlying the Hippo signaling pathway in post-mitotic neuronal fate specification. The Hippo signaling pathway was originally discovered for its critical role in tissue growth and organ size control. Its evolutionarily conserved roles in various biological processes, including cell differentiation, stem cell regeneration and homeostasis, innate immune biology, as well as tumorigenesis, have been subsequently found in other species. During the development of the Drosophila eye, the Hippo pathway promotes green- and represses blue-sensitive photoreceptor (PR) subtype fate specification. Taking advantage of this binary PR fate choice, we screened Drosophila chromosomal deficiency lines to seek new regulators of the Hippo signaling pathway. We identified the Drosophila membrane-associated ZO-1 protein Pyd as an upstream regulator of the Hippo pathway to specify PR subtypes. Our results have demonstrated that Pyd represses Su(dx)’s activity in the Hippo pathway to specify PR subtypes. Our results demonstrate a new mechanism underlying the Hippo signaling pathway in post-mitotic neuronal fate specification.
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Affiliation(s)
- Qingliang Sang
- Integrative Biomedical and Diagnostic Sciences Department, School of Dentistry, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Gang Wang
- Integrative Biomedical and Diagnostic Sciences Department, School of Dentistry, Oregon Health and Science University, Portland, Oregon, United States of America
| | - David B. Morton
- Integrative Biomedical and Diagnostic Sciences Department, School of Dentistry, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Hui Wu
- Integrative Biomedical and Diagnostic Sciences Department, School of Dentistry, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Baotong Xie
- Integrative Biomedical and Diagnostic Sciences Department, School of Dentistry, Oregon Health and Science University, Portland, Oregon, United States of America
- * E-mail:
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Pojer JM, Manning SA, Kroeger B, Kondo S, Harvey KF. The Hippo pathway uses different machinery to control cell fate and organ size. iScience 2021; 24:102830. [PMID: 34355153 PMCID: PMC8322298 DOI: 10.1016/j.isci.2021.102830] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 06/01/2021] [Accepted: 07/07/2021] [Indexed: 11/21/2022] Open
Abstract
The Hippo pathway is a conserved signaling network that regulates organ growth and cell fate. One such cell fate decision is that of R8 photoreceptor cells in the Drosophila eye, where Hippo specifies whether cells sense blue or green light. We show that only a subset of proteins that control organ growth via the Hippo pathway also regulate R8 cell fate choice, including the STRIPAK complex, Tao, Pez, and 14-3-3 proteins. Furthermore, key Hippo pathway proteins were primarily cytoplasmic in R8 cells rather than localized to specific membrane domains, as in cells of growing epithelial organs. Additionally, Warts was the only Hippo pathway protein to be differentially expressed between R8 subtypes, while central Hippo pathway proteins were expressed at dramatically lower levels in adult and pupal eyes than in growing larval eyes. Therefore, we reveal several important differences in Hippo signaling in the contexts of organ growth and cell fate.
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Affiliation(s)
- Jonathan M. Pojer
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Samuel A. Manning
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia
- Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC 3800, Australia
| | - Benjamin Kroeger
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia
- Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC 3800, Australia
| | - Shu Kondo
- Laboratory of Invertebrate Genetics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, Japan
| | - Kieran F. Harvey
- Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC 3010, Australia
- Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC 3800, Australia
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Pojer JM, Saiful Hilmi AJ, Kondo S, Harvey KF. Crumbs and the apical spectrin cytoskeleton regulate R8 cell fate in the Drosophila eye. PLoS Genet 2021; 17:e1009146. [PMID: 34097697 PMCID: PMC8211197 DOI: 10.1371/journal.pgen.1009146] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 06/17/2021] [Accepted: 05/11/2021] [Indexed: 12/31/2022] Open
Abstract
The Hippo pathway is an important regulator of organ growth and cell fate. In the R8 photoreceptor cells of the Drosophila melanogaster eye, the Hippo pathway controls the fate choice between one of two subtypes that express either the blue light-sensitive Rhodopsin 5 (Hippo inactive R8 subtype) or the green light-sensitive Rhodopsin 6 (Hippo active R8 subtype). The degree to which the mechanism of Hippo signal transduction and the proteins that mediate it are conserved in organ growth and R8 cell fate choice is currently unclear. Here, we identify Crumbs and the apical spectrin cytoskeleton as regulators of R8 cell fate. By contrast, other proteins that influence Hippo-dependent organ growth, such as the basolateral spectrin cytoskeleton and Ajuba, are dispensable for the R8 cell fate choice. Surprisingly, Crumbs promotes the Rhodopsin 5 cell fate, which is driven by Yorkie, rather than the Rhodopsin 6 cell fate, which is driven by Warts and the Hippo pathway, which contrasts with its impact on Hippo activity in organ growth. Furthermore, neither the apical spectrin cytoskeleton nor Crumbs appear to regulate the Hippo pathway through mechanisms that have been observed in growing organs. Together, these results show that only a subset of Hippo pathway proteins regulate the R8 binary cell fate decision and that aspects of Hippo signalling differ between growing organs and post-mitotic R8 cells.
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Affiliation(s)
- Jonathan M. Pojer
- Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia
| | - Abdul Jabbar Saiful Hilmi
- Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia
| | - Shu Kondo
- Laboratory of Invertebrate Genetics, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Kieran F. Harvey
- Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
- * E-mail:
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11
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Sancer G, Wernet MF. The development and function of neuronal subtypes processing color and skylight polarization in the optic lobes of Drosophila melanogaster. ARTHROPOD STRUCTURE & DEVELOPMENT 2021; 61:101012. [PMID: 33618155 DOI: 10.1016/j.asd.2020.101012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 11/01/2020] [Accepted: 11/19/2020] [Indexed: 06/12/2023]
Abstract
The retinal mosaics of many insects contain different ommatidial subtypes harboring photoreceptors that are both molecularly and morphologically specialized for comparing between different wavelengths versus detecting the orientation of skylight polarization. The neural circuits underlying these different inputs and the characterization of their specific cellular elements are the subject of intense research. Here we review recent progress on the description of both assembly and function of color and skylight polarization circuitry, by focusing on two cell types located in the distal portion of the medulla neuropil of the fruit fly Drosophila melanogaster's optic lobes, called Dm8 and Dm9. In the main part of the retina, Dm8 cells fall into two molecularly distinct subtypes whose center becomes specifically connected to either one of randomly distributed 'pale' or 'yellow' R7 photoreceptor fates during development. Only in the 'dorsal rim area' (DRA), both polarization-sensitive R7 and R8 photoreceptors are connected to different Dm8-like cell types, called Dm-DRA1 and Dm-DRA2, respectively. An additional layer of interommatidial integration is introduced by Dm9 cells, which receive input from multiple neighboring R7 and R8 cells, as well as providing feedback synapses back into these photoreceptors. As a result, the response properties of color-sensitive photoreceptor terminals are sculpted towards being both maximally decorrelated, as well as harboring several levels of opponency (both columnar as well as intercolumnar). In the DRA, individual Dm9 cells appear to mix both polarization and color signals, thereby potentially serving as the first level of integration of different celestial stimuli. The molecular mechanisms underlying the establishment of these synaptic connections are beginning to be revealed, by using a combination of live imaging, developmental genetic studies, and cell type-specific transcriptomics.
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Affiliation(s)
- Gizem Sancer
- Freie Universität Berlin, Fachbereich Biologie, Chemie und Pharmazie, Institut für Biologie - Neurobiologie, Königin-Luise Strasse 1-3, 14195 Berlin, Germany
| | - Mathias F Wernet
- Freie Universität Berlin, Fachbereich Biologie, Chemie und Pharmazie, Institut für Biologie - Neurobiologie, Königin-Luise Strasse 1-3, 14195 Berlin, Germany.
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Identification of Genes Involved in the Differentiation of R7y and R7p Photoreceptor Cells in Drosophila. G3-GENES GENOMES GENETICS 2020; 10:3949-3958. [PMID: 32972998 PMCID: PMC7642934 DOI: 10.1534/g3.120.401370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The R7 and R8 photoreceptor cells of the Drosophila compound eye mediate color vision. Throughout the majority of the eye, these cells occur in two principal types of ommatidia. Approximately 35% of ommatidia are of the pale type and express Rh3 in R7 cells and Rh5 in R8 cells. The remaining 65% are of the yellow type and express Rh4 in R7 cells and Rh6 in R8 cells. The specification of an R8 cell in a pale or yellow ommatidium depends on the fate of the adjacent R7 cell. However, pale and yellow R7 cells are specified by a stochastic process that requires the genes spineless, tango and klumpfuss. To identify additional genes involved in this process we performed genetic screens using a collection of 480 P{EP} transposon insertion strains. We identified genes in gain of function and loss of function screens that significantly altered the percentage of Rh3 expressing R7 cells (Rh3%) from wild-type. 36 strains resulted in altered Rh3% in the gain of function screen where the P{EP} insertion strains were crossed to a sevEP-GAL4 driver line. 53 strains resulted in altered Rh3% in the heterozygous loss of function screen. 4 strains showed effects that differed between the two screens, suggesting that the effect found in the gain of function screen was either larger than, or potentially masked by, the P{EP} insertion alone. Analyses of homozygotes validated many of the candidates identified. These results suggest that R7 cell fate specification is sensitive to perturbations in mRNA transcription, splicing and localization, growth inhibition, post-translational protein modification, cleavage and secretion, hedgehog signaling, ubiquitin protease activity, GTPase activation, actin and cytoskeletal regulation, and Ser/Thr kinase activity, among other diverse signaling and cell biological processes.
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13
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Tan H, Fulton RE, Chou WH, Birkholz DA, Mannino MP, Yamaguchi DM, Aldrich JC, Jacobsen TL, Britt SG. Drosophila R8 photoreceptor cell subtype specification requires hibris. PLoS One 2020; 15:e0240451. [PMID: 33052948 PMCID: PMC7556441 DOI: 10.1371/journal.pone.0240451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 09/25/2020] [Indexed: 11/18/2022] Open
Abstract
Cell differentiation and cell fate determination in sensory systems are essential for stimulus discrimination and coding of environmental stimuli. Color vision is based on the differential color sensitivity of retinal photoreceptors, however the developmental programs that control photoreceptor cell differentiation and specify color sensitivity are poorly understood. In Drosophila melanogaster, there is evidence that the color sensitivity of different photoreceptors in the compound eye is regulated by inductive signals between cells, but the exact nature of these signals and how they are propagated remains unknown. We conducted a genetic screen to identify additional regulators of this process and identified a novel mutation in the hibris gene, which encodes an irre cell recognition module protein (IRM). These immunoglobulin super family cell adhesion molecules include human KIRREL and nephrin (NPHS1). hibris is expressed dynamically in the developing Drosophila melanogaster eye and loss-of-function mutations give rise to a diverse range of mutant phenotypes including disruption of the specification of R8 photoreceptor cell diversity. We demonstrate that hibris is required within the retina, and that hibris over-expression is sufficient to disrupt normal photoreceptor cell patterning. These findings suggest an additional layer of complexity in the signaling process that produces paired expression of opsin genes in adjacent R7 and R8 photoreceptor cells.
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Affiliation(s)
- Hong Tan
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Ruth E. Fulton
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Wen-Hai Chou
- Department of Molecular Medicine, University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - Denise A. Birkholz
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Meridee P. Mannino
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - David M. Yamaguchi
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - John C. Aldrich
- Department of Neurology, Department of Ophthalmology, Dell Medical School, University of Texas at Austin, Austin, Texas, United States of America
| | - Thomas L. Jacobsen
- Department of Neurology, Department of Ophthalmology, Dell Medical School, University of Texas at Austin, Austin, Texas, United States of America
| | - Steven G. Britt
- Department of Neurology, Department of Ophthalmology, Dell Medical School, University of Texas at Austin, Austin, Texas, United States of America
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14
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Neal SJ, Zhou Q, Pignoni F. STRIPAK-PP2A regulates Hippo-Yorkie signaling to suppress retinal fate in the Drosophila eye disc peripodial epithelium. J Cell Sci 2020; 133:jcs237834. [PMID: 32184260 PMCID: PMC7272332 DOI: 10.1242/jcs.237834] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 03/09/2020] [Indexed: 12/30/2022] Open
Abstract
The specification of organs, tissues and cell types results from cell fate restrictions enacted by nuclear transcription factors under the control of conserved signaling pathways. The progenitor epithelium of the Drosophila compound eye, the eye imaginal disc, is a premier model for the study of such processes. Early in development, apposing cells of the eye disc are established as either retinal progenitors or support cells of the peripodial epithelium (PE), in a process whose genetic and mechanistic determinants are poorly understood. We have identified protein phosphatase 2A (PP2A), and specifically a STRIPAK-PP2A complex that includes the scaffolding and substrate-specificity components Cka, Strip and SLMAP, as a critical player in the retina-PE fate choice. We show that these factors suppress ectopic retina formation in the presumptive PE and do so via the Hippo signaling axis. STRIPAK-PP2A negatively regulates Hippo kinase, and consequently its substrate Warts, to release the transcriptional co-activator Yorkie into the nucleus. Thus, a modular higher-order PP2A complex refines the activity of this general phosphatase to act in a precise specification of cell fate.
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Affiliation(s)
- Scott J Neal
- Department of Ophthalmology and Visual Sciences, Upstate Medical University, 505 Irving Avenue, NRB 4610, Syracuse, NY 13210, USA
| | - Qingxiang Zhou
- Department of Ophthalmology and Visual Sciences, Upstate Medical University, 505 Irving Avenue, NRB 4610, Syracuse, NY 13210, USA
| | - Francesca Pignoni
- Department of Ophthalmology and Visual Sciences, Upstate Medical University, 505 Irving Avenue, NRB 4610, Syracuse, NY 13210, USA
- Department of Neuroscience and Physiology; Department of Biochemistry and Molecular Biology; Department of Cell and Developmental Biology, Upstate Medical University, 505 Irving Avenue, NRB 4610, Syracuse, NY 13210, USA
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15
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The Hippo Pathway as a Driver of Select Human Cancers. Trends Cancer 2020; 6:781-796. [PMID: 32446746 DOI: 10.1016/j.trecan.2020.04.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/20/2020] [Accepted: 04/20/2020] [Indexed: 12/11/2022]
Abstract
The Hippo pathway regulates myriad biological processes in diverse species and is a key cancer signaling network in humans. Although Hippo has been linked to multiple aspects of cancer, its role in this disease is incompletely understood. Large-scale pan-cancer analyses of core Hippo pathway genes reveal that the pathway is mutated at a high frequency only in select human cancers, including malignant mesothelioma and meningioma. Hippo pathway deregulation is also enriched in squamous epithelial cancers. We discuss cancer-related functions of the Hippo pathway and potential explanations for the cancer-restricted mutation profile of core Hippo pathway genes. Greater understanding of Hippo pathway deregulation in cancers will be essential to guide the imminent use of Hippo-targeted therapies.
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16
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Pla‐Martín D, Schatton D, Wiederstein JL, Marx M, Khiati S, Krüger M, Rugarli EI. CLUH granules coordinate translation of mitochondrial proteins with mTORC1 signaling and mitophagy. EMBO J 2020; 39:e102731. [PMID: 32149416 PMCID: PMC7196838 DOI: 10.15252/embj.2019102731] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 02/05/2020] [Accepted: 02/07/2020] [Indexed: 11/09/2022] Open
Abstract
Mitochondria house anabolic and catabolic processes that must be balanced and adjusted to meet cellular demands. The RNA-binding protein CLUH (clustered mitochondria homolog) binds mRNAs of nuclear-encoded mitochondrial proteins and is highly expressed in the liver, where it regulates metabolic plasticity. Here, we show that in primary hepatocytes, CLUH coalesces in specific ribonucleoprotein particles that define the translational fate of target mRNAs, such as Pcx, Hadha, and Hmgcs2, to match nutrient availability. Moreover, CLUH granules play signaling roles, by recruiting mTOR kinase and the RNA-binding proteins G3BP1 and G3BP2. Upon starvation, CLUH regulates translation of Hmgcs2, involved in ketogenesis, inhibits mTORC1 activation and mitochondrial anabolic pathways, and promotes mitochondrial turnover, thus allowing efficient reprograming of metabolic function. In the absence of CLUH, a mitophagy block causes mitochondrial clustering that is rescued by rapamycin treatment or depletion of G3BP1 and G3BP2. Our data demonstrate that metabolic adaptation of liver mitochondria to nutrient availability depends on a compartmentalized CLUH-dependent post-transcriptional mechanism that controls both mTORC1 and G3BP signaling and ensures survival.
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Affiliation(s)
- David Pla‐Martín
- Institute for GeneticsUniversity of CologneCologneGermany
- Institute for Vegetative PhysiologyUniversity of CologneCologneGermany
| | - Désirée Schatton
- Institute for GeneticsUniversity of CologneCologneGermany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Janica L Wiederstein
- Institute for GeneticsUniversity of CologneCologneGermany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Marie‐Charlotte Marx
- Institute for GeneticsUniversity of CologneCologneGermany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Salim Khiati
- MitoLab TeamInstitut MitoVascUMR CNRS 6015INSERM U1083Université d'AngersAngersFrance
| | - Marcus Krüger
- Institute for GeneticsUniversity of CologneCologneGermany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
- Center for Molecular Medicine (CMMC)University of CologneCologneGermany
| | - Elena I Rugarli
- Institute for GeneticsUniversity of CologneCologneGermany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
- Center for Molecular Medicine (CMMC)University of CologneCologneGermany
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17
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King TD, Johnson JE, Bateman JR. Position Effects Influence Transvection in Drosophila melanogaster. Genetics 2019; 213:1289-1299. [PMID: 31611231 PMCID: PMC6893391 DOI: 10.1534/genetics.119.302583] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 10/03/2019] [Indexed: 01/14/2023] Open
Abstract
Transvection is an epigenetic phenomenon wherein regulatory elements communicate between different chromosomes in trans, and is thereby dependent upon the three-dimensional organization of the genome. Transvection is best understood in Drosophila, where homologous chromosomes are closely paired in most somatic nuclei, although similar phenomena have been observed in other species. Previous data have supported that the Drosophila genome is generally permissive to enhancer action in trans, a form of transvection where an enhancer on one homolog activates gene expression from a promoter on a paired homolog. However, the capacity of different genomic positions to influence the quantitative output of transvection has yet to be addressed. To investigate this question, we employed a transgenic system that assesses and compares enhancer action in cis and in trans at defined chromosomal locations. Using the strong synthetic eye-specific enhancer GMR, we show that loci supporting strong cis-expression tend to support robust enhancer action in trans, whereas locations with weaker cis-expression show reduced transvection in a fluorescent reporter assay. Our subsequent analysis is consistent with a model wherein the chromatin state of the transgenic insertion site is a primary determinant of the degree to which enhancer action in trans will be supported, whereas other factors such as locus-specific variation in somatic homolog pairing are of less importance in influencing position effects on transvection.
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Affiliation(s)
- Thomas D King
- Biology Department, Bowdoin College, Brunswick, Maine 04011
| | | | - Jack R Bateman
- Biology Department, Bowdoin College, Brunswick, Maine 04011
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18
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Vujovic F, Hunter N, Farahani RM. Notch pathway: a bistable inducer of biological noise? Cell Commun Signal 2019; 17:133. [PMID: 31640734 PMCID: PMC6805690 DOI: 10.1186/s12964-019-0453-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 10/04/2019] [Indexed: 12/11/2022] Open
Abstract
Notch signalling pathway is central to development of metazoans. The pathway codes a binary fate switch. Upon activation, downstream signals contribute to resolution of fate dichotomies such as proliferation/differentiation or sub-lineage differentiation outcome. There is, however, an interesting paradox in the Notch signalling pathway. Despite remarkable predictability of fate outcomes instructed by the Notch pathway, the associated transcriptome is versatile and plastic. This inconsistency suggests the presence of an interface that compiles input from the plastic transcriptome of the Notch pathway but communicates only a binary output in biological decisions. Herein, we address the interface that determines fate outcomes. We provide an alternative hypothesis for the Notch pathway as a biological master switch that operates by induction of genetic noise and bistability in order to facilitate resolution of dichotomous fate outcomes in development.
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Affiliation(s)
- Filip Vujovic
- IDR/Westmead Institute for Medical Research, Sydney, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2145 Australia
| | - Neil Hunter
- IDR/Westmead Institute for Medical Research, Sydney, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2145 Australia
| | - Ramin M. Farahani
- IDR/Westmead Institute for Medical Research, Sydney, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2145 Australia
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19
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Rezaei-Lotfi S, Hunter N, Farahani RM. β-Catenin: A Metazoan Filter for Biological Noise? Front Genet 2019; 10:1004. [PMID: 31681432 PMCID: PMC6805772 DOI: 10.3389/fgene.2019.01004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 09/20/2019] [Indexed: 01/08/2023] Open
Abstract
Molecular noise refers to fluctuations of biological signals that facilitate phenotypic heterogeneity in a population. While endogenous mechanisms exist to limit genetic noise in biological systems, such restrictions are sometimes removed to propel phenotypic variability as an adaptive strategy. Herein, we review evidence for the potential role of β-catenin in restricting gene expression noise by transcriptional and post-transcriptional mechanisms. We discuss mechanisms that restrict intrinsic noise subsequent to nuclear mobilization of β-catenin. Nuclear β-catenin promotes initiation of transcription but buffers against the resultant noise by restraining transcription elongation. Acceleration of cell cycle, mediated via Wnt/β-catenin downstream signals, further diminishes intrinsic noise by curtailing the efficiency of protein synthesis. Extrinsic noise, on the other hand, is restricted by β-catenin–mediated regulation of major cellular stress pathways.
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Affiliation(s)
- Saba Rezaei-Lotfi
- IDR/Westmead Institute for Medical Research, Sydney, NSW, Australia.,Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Neil Hunter
- IDR/Westmead Institute for Medical Research, Sydney, NSW, Australia.,Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Ramin M Farahani
- IDR/Westmead Institute for Medical Research, Sydney, NSW, Australia.,Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
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20
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Courgeon M, Desplan C. Coordination between stochastic and deterministic specification in the Drosophila visual system. Science 2019; 366:science.aay6727. [PMID: 31582524 DOI: 10.1126/science.aay6727] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 09/18/2019] [Indexed: 01/05/2023]
Abstract
Sensory systems use stochastic fate specification to increase their repertoire of neuronal types. How these stochastic decisions are coordinated with the development of their targets is unknown. In the Drosophila retina, two subtypes of ultraviolet-sensitive R7 photoreceptors are stochastically specified. In contrast, their targets in the brain are specified through a deterministic program. We identified subtypes of the main target of R7, the Dm8 neurons, each specific to the different subtypes of R7s. Dm8 subtypes are produced in excess by distinct neuronal progenitors, independently from R7. After matching with their cognate R7, supernumerary Dm8s are eliminated by apoptosis. Two interacting cell adhesion molecules, Dpr11 and DIPγ, are essential for the matching of one of the synaptic pairs. These mechanisms allow the qualitative and quantitative matching of R7 and Dm8 and thereby permit the stochastic choice made in R7 to propagate to the brain.
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Affiliation(s)
| | - Claude Desplan
- Department of Biology, New York University, New York, NY 10003, USA.
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21
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Abstract
The Hippo signalling pathway and its transcriptional co-activator targets Yorkie/YAP/TAZ first came to attention because of their role in tissue growth control. Over the past 15 years, it has become clear that, like other developmental pathways (e.g. the Wnt, Hedgehog and TGFβ pathways), Hippo signalling is a 'jack of all trades' that is reiteratively used to mediate a range of cellular decision-making processes from proliferation, death and morphogenesis to cell fate determination. Here, and in the accompanying poster, we briefly outline the core pathway and its regulation, and describe the breadth of its roles in animal development.
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Affiliation(s)
- John Robert Davis
- Apoptosis and Proliferation Control Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Nicolas Tapon
- Apoptosis and Proliferation Control Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
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22
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Brown TJ, Kollara A, Shathasivam P, Ringuette MJ. Ventricular Zone Expressed PH Domain Containing 1 (VEPH1): an adaptor protein capable of modulating multiple signaling transduction pathways during normal and pathological development. Cell Commun Signal 2019; 17:116. [PMID: 31500637 PMCID: PMC6734325 DOI: 10.1186/s12964-019-0433-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 08/29/2019] [Indexed: 01/01/2023] Open
Abstract
Ventricular Zone Expressed PH Domain-Containing 1 (VEPH1) is an 833-amino acid protein encoded by an evolutionarily conserved single-copy gene that emerged with pseudocoelomates. This gene has no paralog in any species identified to date and few studies have investigated the function of its encoded protein. Loss of expression of its ortholog, melted, in Drosophila results in a severe neural phenotype and impacts TOR, FoxO, and Hippo signaling. Studies in mammals indicate a role for VEPH1 in modulating TGFβ signaling and AKT activation, while numerous studies indicate VEPH1 expression is altered in several pathological conditions, including cancer. Although often referred to as an uncharacterized protein, available evidence supports VEPH1 as an adaptor protein capable of modulating multiple signal transduction networks. Further studies are required to define these adaptor functions and the role of VEPH1 in development and disease progression.
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Affiliation(s)
- Theodore J Brown
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, 60 Murray Street, Box 42, Toronto, ON, M5T 3L9, Canada. .,Department of Obstetrics and Gynecology, University of Toronto, Toronto, ON, Canada.
| | - Alexandra Kollara
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, 60 Murray Street, Box 42, Toronto, ON, M5T 3L9, Canada.,Department of Obstetrics and Gynecology, University of Toronto, Toronto, ON, Canada
| | - Premalatha Shathasivam
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, 60 Murray Street, Box 42, Toronto, ON, M5T 3L9, Canada.,Department of Obstetrics and Gynecology, University of Toronto, Toronto, ON, Canada
| | - Maurice J Ringuette
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
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23
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Zheng Y, Pan D. The Hippo Signaling Pathway in Development and Disease. Dev Cell 2019; 50:264-282. [PMID: 31386861 PMCID: PMC6748048 DOI: 10.1016/j.devcel.2019.06.003] [Citation(s) in RCA: 480] [Impact Index Per Article: 96.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 05/23/2019] [Accepted: 06/09/2019] [Indexed: 12/13/2022]
Abstract
The Hippo signaling pathway regulates diverse physiological processes, and its dysfunction has been implicated in an increasing number of human diseases, including cancer. Here, we provide an updated review of the Hippo pathway; discuss its roles in development, homeostasis, regeneration, and diseases; and highlight outstanding questions for future investigation and opportunities for Hippo-targeted therapies.
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Affiliation(s)
- Yonggang Zheng
- Department of Physiology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA
| | - Duojia Pan
- Department of Physiology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9040, USA.
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24
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Xie B, Morton DB, Cook TA. Opposing transcriptional and post-transcriptional roles for Scalloped in binary Hippo-dependent neural fate decisions. Dev Biol 2019; 455:51-59. [PMID: 31265830 DOI: 10.1016/j.ydbio.2019.06.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 06/28/2019] [Accepted: 06/28/2019] [Indexed: 01/07/2023]
Abstract
The Hippo tumor suppressor pathway plays many fundamental cell biological roles during animal development. Two central players in controlling Hippo-dependent gene expression are the TEAD transcription factor Scalloped (Sd) and its transcriptional co-activator Yorkie (Yki). Hippo signaling phosphorylates Yki, thereby blocking Yki-dependent transcriptional control. In post-mitotic Drosophila photoreceptors, a bistable negative feedback loop forms between the Hippo-dependent kinase Warts/Lats and Yki to lock in green vs blue-sensitive neuronal subtype choices, respectively. Previous experiments indicate that sd and yki mutants phenocopy each other's functions, both being required for promoting the expression of the blue photoreceptor fate determinant melted (melt) and the blue-sensitive opsin Rh5. Here, we demonstrate that Sd ensures the robustness of this neuronal fate decision via multiple antagonistic gene regulatory roles. In Hippo-positive (green) photoreceptors, Sd directly represses both melt and Rh5 gene expression through defined TEAD binding sites, a mechanism that is antagonized by Yki in Hippo-negative (blue) cells. Additionally, in blue photoreceptors, Sd is required to promote the translation of the Rh5 protein through a 3'UTR-dependent and microRNA-mediated process. Together, these studies reveal that Sd can drive context-dependent cell fate decisions through opposing transcriptional and post-transcriptional mechanisms.
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Affiliation(s)
- Baotong Xie
- Department of Integrative Biosciences, Oregon Health & Science University, Portland, OR, 97239, USA.
| | - David B Morton
- Department of Integrative Biosciences, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Tiffany A Cook
- Center of Molecular Medicine and Genetics and Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, 48201, USA.
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25
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Coordination of neural patterning in the Drosophila visual system. Curr Opin Neurobiol 2019; 56:153-159. [PMID: 30849690 DOI: 10.1016/j.conb.2019.01.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 01/30/2019] [Indexed: 01/07/2023]
Abstract
Precise formation of neuronal circuits requires the coordinated development of the different components of the circuit. Here, we review examples of coordination at multiples scales of development in one of the best-studied systems for neural patterning and circuit assembly, the Drosophila visual system, from coordination of gene expression in photoreceptors to the coordinated patterning of the different neuropiles of the optic lobe.
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26
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Abstract
The Hippo Pathway comprises a vast network of components that integrate diverse signals including mechanical cues and cell surface or cell-surface-associated molecules to define cellular outputs of growth, proliferation, cell fate, and cell survival on both the cellular and tissue level. Because of the importance of the regulators, core components, and targets of this pathway in human health and disease, individual components were often identified by efforts in mammalian models or for a role in a specific process such as stress response or cell death. However, multiple components were originally discovered in the Drosophila system, and the breakthrough of conceiving that these components worked together in a signaling pathway came from a series of Drosophila genetic screens and fundamental genetic and phenotypic characterization efforts. In this chapter, we will review the original discoveries leading to the conceptual framework of these components as a tumor suppressor network. We will review chronologically the early efforts that established our initial understanding of the core machinery that then launched the growing and vibrant field to be discussed throughout later chapters of this book.
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Affiliation(s)
- Rewatee Gokhale
- Department of Oncological Sciences, The Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Cathie M Pfleger
- Department of Oncological Sciences, The Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- The Tisch Cancer Institute, The Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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27
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Zheng C, Jin FQ, Trippe BL, Wu J, Chalfie M. Inhibition of cell fate repressors secures the differentiation of the touch receptor neurons of Caenorhabditis elegans. Development 2018; 145:dev.168096. [PMID: 30291162 DOI: 10.1242/dev.168096] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 09/24/2018] [Indexed: 12/14/2022]
Abstract
Terminal differentiation generates the specialized features and functions that allow postmitotic cells to acquire their distinguishing characteristics. This process is thought to be controlled by transcription factors called 'terminal selectors' that directly activate a set of downstream effector genes. In Caenorhabditis elegans, the differentiation of both the mechanosensory touch receptor neurons (TRNs) and the multidendritic nociceptor FLP neurons uses the terminal selectors UNC-86 and MEC-3. The FLP neurons fail to activate TRN genes, however, because a complex of two transcriptional repressors (EGL-44/EGL-46) prevents their expression. Here, we show that the ZEB family transcriptional factor ZAG-1 promotes TRN differentiation not by activating TRN genes but by preventing the expression of EGL-44/EGL-46. As EGL-44/EGL-46 also inhibits the production of ZAG-1, these proteins form a bistable, negative-feedback loop that regulates the choice between the two neuronal fates.
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Affiliation(s)
- Chaogu Zheng
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Felix Qiaochu Jin
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Brian Loeber Trippe
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Ji Wu
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Martin Chalfie
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
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28
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Chiku T, Hayashishita M, Saito T, Oka M, Shinno K, Ohtake Y, Shimizu S, Asada A, Hisanaga SI, Iijima KM, Ando K. S6K/p70S6K1 protects against tau-mediated neurodegeneration by decreasing the level of tau phosphorylated at Ser262 in a Drosophila model of tauopathy. Neurobiol Aging 2018; 71:255-264. [DOI: 10.1016/j.neurobiolaging.2018.07.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 07/27/2018] [Accepted: 07/29/2018] [Indexed: 02/08/2023]
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29
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Furth N, Pateras IS, Rotkopf R, Vlachou V, Rivkin I, Schmitt I, Bakaev D, Gershoni A, Ainbinder E, Leshkowitz D, Johnson RL, Gorgoulis VG, Oren M, Aylon Y. LATS1 and LATS2 suppress breast cancer progression by maintaining cell identity and metabolic state. Life Sci Alliance 2018; 1:e201800171. [PMID: 30456386 PMCID: PMC6238411 DOI: 10.26508/lsa.201800171] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 10/13/2018] [Accepted: 10/15/2018] [Indexed: 02/04/2023] Open
Abstract
In luminal B tumors LATS2 depletion results in metabolic rewiring whereas LATS1 depletion promotes the expression of basal-like features. Deregulated activity of LArge Tumor Suppressor (LATS) tumor suppressors has broad implications on cellular and tissue homeostasis. We examined the consequences of down-regulation of either LATS1 or LATS2 in breast cancer. Consistent with their proposed tumor suppressive roles, expression of both paralogs was significantly down-regulated in human breast cancer, and loss of either paralog accelerated mammary tumorigenesis in mice. However, each paralog had a distinct impact on breast cancer. Thus, LATS2 depletion in luminal B tumors resulted in metabolic rewiring, with increased glycolysis and reduced peroxisome proliferator-activated receptor γ (PPARγ) signaling. Furthermore, pharmacological activation of PPARγ elicited LATS2-dependent death in luminal B-derived cells. In contrast, LATS1 depletion augmented cancer cell plasticity, skewing luminal B tumors towards increased expression of basal-like features, in association with increased resistance to hormone therapy. Hence, these two closely related paralogs play distinct roles in protection against breast cancer; tumors with reduced expression of either LATS1 or LATS2 may rewire signaling networks differently and thus respond differently to anticancer treatments.
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Affiliation(s)
- Noa Furth
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Ioannis S Pateras
- Laboratory of Histology and Embryology Medical School, University of Athens, Athens, Greece
| | - Ron Rotkopf
- Department of Life Sciences Core Facilities, Faculty of Biochemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Vassiliki Vlachou
- Laboratory of Histology and Embryology Medical School, University of Athens, Athens, Greece
| | - Irina Rivkin
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Ina Schmitt
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Deborah Bakaev
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Anat Gershoni
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Elena Ainbinder
- Department of Life Sciences Core Facilities, Faculty of Biochemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Dena Leshkowitz
- Department of Life Sciences Core Facilities, Faculty of Biochemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Randy L Johnson
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Vassilis G Gorgoulis
- Laboratory of Histology and Embryology Medical School, University of Athens, Athens, Greece.,Biomedical Research Foundation of the Academy of Athens, Athens, Greece.,Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Moshe Oren
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Yael Aylon
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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30
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Li T, Dong Y, Zhang X, Ji X, Luo C, Lou C, Zhang HM, Ouyang Q. Engineering of a genetic circuit with regulatable multistability. Integr Biol (Camb) 2018; 10:474-482. [DOI: 10.1039/c8ib00030a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Tingting Li
- Centre for Quantitative Biology and Peking-Tsinghua Joint Centre for Life Sciences, Peking University, Beijing 100871, China
| | - Yiming Dong
- Centre for Quantitative Biology and Peking-Tsinghua Joint Centre for Life Sciences, Peking University, Beijing 100871, China
| | - Xuanqi Zhang
- Centre for Quantitative Biology and Peking-Tsinghua Joint Centre for Life Sciences, Peking University, Beijing 100871, China
| | - Xiangyu Ji
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100871, China
| | - Chunxiong Luo
- Centre for Quantitative Biology and Peking-Tsinghua Joint Centre for Life Sciences, Peking University, Beijing 100871, China
- The State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Chunbo Lou
- CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100871, China
| | - Haoqian M. Zhang
- Centre for Quantitative Biology and Peking-Tsinghua Joint Centre for Life Sciences, Peking University, Beijing 100871, China
- Bluepha Co., Ltd., Beijing 102206, China
| | - Qi Ouyang
- Centre for Quantitative Biology and Peking-Tsinghua Joint Centre for Life Sciences, Peking University, Beijing 100871, China
- The State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
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31
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Anderson C, Reiss I, Zhou C, Cho A, Siddiqi H, Mormann B, Avelis CM, Deford P, Bergland A, Roberts E, Taylor J, Vasiliauskas D, Johnston RJ. Natural variation in stochastic photoreceptor specification and color preference in Drosophila. eLife 2017; 6:29593. [PMID: 29251595 PMCID: PMC5745083 DOI: 10.7554/elife.29593] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 12/15/2017] [Indexed: 11/25/2022] Open
Abstract
Each individual perceives the world in a unique way, but little is known about the genetic basis of variation in sensory perception. In the fly eye, the random mosaic of color-detecting R7 photoreceptor subtypes is determined by stochastic on/off expression of the transcription factor Spineless (Ss). In a genome-wide association study, we identified a naturally occurring insertion in a regulatory DNA element in ss that lowers the ratio of SsON to SsOFF cells. This change in photoreceptor fates shifts the innate color preference of flies from green to blue. The genetic variant increases the binding affinity for Klumpfuss (Klu), a zinc finger transcriptional repressor that regulates ss expression. Klu is expressed at intermediate levels to determine the normal ratio of SsON to SsOFF cells. Thus, binding site affinity and transcription factor levels are finely tuned to regulate stochastic expression, setting the ratio of alternative fates and ultimately determining color preference.
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Affiliation(s)
- Caitlin Anderson
- Department of Biology, Johns Hopkins University, Baltimore, United States
| | - India Reiss
- Department of Biology, Johns Hopkins University, Baltimore, United States
| | - Cyrus Zhou
- Department of Biology, Johns Hopkins University, Baltimore, United States
| | - Annie Cho
- Department of Biology, Johns Hopkins University, Baltimore, United States
| | - Haziq Siddiqi
- Department of Biology, Johns Hopkins University, Baltimore, United States
| | - Benjamin Mormann
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
| | - Cameron M Avelis
- Department of Biophysics, Johns Hopkins University, Baltimore, United States
| | - Peter Deford
- Department of Biology, Johns Hopkins University, Baltimore, United States
| | - Alan Bergland
- Department of Biology, University of Virginia, Charlottesville, United States
| | - Elijah Roberts
- Department of Biophysics, Johns Hopkins University, Baltimore, United States
| | - James Taylor
- Department of Biology, Johns Hopkins University, Baltimore, United States
| | - Daniel Vasiliauskas
- Paris-Saclay Institute of Neuroscience, Université Paris Sud, Centre National de la Recherche Scientifque, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Robert J Johnston
- Department of Biology, Johns Hopkins University, Baltimore, United States
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32
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Mechanisms of Photoreceptor Patterning in Vertebrates and Invertebrates. Trends Genet 2017; 32:638-659. [PMID: 27615122 DOI: 10.1016/j.tig.2016.07.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 07/25/2016] [Accepted: 07/28/2016] [Indexed: 11/22/2022]
Abstract
Across the animal kingdom, visual systems have evolved to be uniquely suited to the environments and behavioral patterns of different species. Visual acuity and color perception depend on the distribution of photoreceptor (PR) subtypes within the retina. Retinal mosaics can be organized into three broad categories: stochastic/regionalized, regionalized, and ordered. We describe here the retinal mosaics of flies, zebrafish, chickens, mice, and humans, and the gene regulatory networks controlling proper PR specification in each. By drawing parallels in eye development between these divergent species, we identify a set of conserved organizing principles and transcriptional networks that govern PR subtype differentiation.
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33
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Wells BS, Pistillo D, Barnhart E, Desplan C. Parallel Activin and BMP signaling coordinates R7/R8 photoreceptor subtype pairing in the stochastic Drosophila retina. eLife 2017; 6:25301. [PMID: 28853393 PMCID: PMC5599232 DOI: 10.7554/elife.25301] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 08/25/2017] [Indexed: 12/27/2022] Open
Abstract
Drosophila color vision is achieved by comparing outputs from two types of color-sensitive photoreceptors, R7 and R8. Ommatidia (unit eyes) are classified into two subtypes, known as 'pale' or 'yellow', depending on Rhodopsin expression in R7 and R8. Subtype specification is controlled by a stochastic decision in R7 and instructed to the underlying R8. We find that the Activin receptor Baboon is required in R8 to receive non-redundant signaling from the three Activin ligands, activating the transcription factor dSmad2. Concomitantly, two BMP ligands activate their receptor, Thickveins, and the transcriptional effector, Mad. The Amon TGFβ processing factor appears to regulate components of the TGFβ pathway specifically in pale R7. Mad and dSmad2 cooperate to modulate the Hippo pathway kinase Warts and the growth regulator Melted; two opposing factors of a bi-stable loop regulating R8 Rhodopsin expression. Therefore, TGFβ and growth pathways interact in postmitotic cells to precisely coordinate cell-specific output.
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Affiliation(s)
- Brent S Wells
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
| | - Daniela Pistillo
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
| | - Erin Barnhart
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
| | - Claude Desplan
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
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34
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McCulloch KJ, Yuan F, Zhen Y, Aardema ML, Smith G, Llorente-Bousquets J, Andolfatto P, Briscoe AD. Sexual Dimorphism and Retinal Mosaic Diversification following the Evolution of a Violet Receptor in Butterflies. Mol Biol Evol 2017; 34:2271-2284. [DOI: 10.1093/molbev/msx163] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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35
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Shathasivam P, Kollara A, Spybey T, Park S, Clarke B, Ringuette MJ, Brown TJ. VEPH1 expression decreases vascularisation in ovarian cancer xenografts and inhibits VEGFA and IL8 expression through inhibition of AKT activation. Br J Cancer 2017; 116:1065-1076. [PMID: 28301874 PMCID: PMC5396109 DOI: 10.1038/bjc.2017.51] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 01/24/2017] [Accepted: 02/02/2017] [Indexed: 01/07/2023] Open
Abstract
Background: VEPH1 is amplified in several cancers including ovarian but its impact on tumour progression is unknown. Previous work has shown that VEPH1 inhibits TGFβ signalling while its Drosophila ortholog increases tissue growth, raising the possibility that VEPH1 could impact tumour growth or progression. Methods: A CRISPR approach was used to disrupt VEPH1 expression in ovarian cancer ES-2 cells, while VEPH1-negative SKOV3 cells were stably transfected with VEPH1 cDNA. The impact of altered VEPH1 expression was assessed using in vitro and in vivo assays and mechanistic studies were performed in vitro. Results: VEPH1 expression in SKOV3 cells resulted in a reduced tumour growth rate associated with increased necrotic area, and decreased microvessel density and VEGF-A levels relative to tumours formed by mock-transfected cells. VEPH1 expression also decreased VEGFA and IL8 expression in SKOV3 cells and was associated with decreased activated AKT levels. These effects were not observed in ES-2 cells, which bear a BRAFV600E activating mutation that leads to constitutively increased IL8 and VEGFA expression. Conclusions: VEPH1 expression in SKOV3 ovarian cancer cells inhibits AKT activation to decrease VEGFA and IL8 expression, which leads to decreased tumour vascularisation and progression.
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Affiliation(s)
- Premalatha Shathasivam
- Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, 60 Murray Street, Toronto, M5T 3L9 ON, Canada.,Department of Obstetrics and Gynecology, University of Toronto, 123 Edward Street, Toronto, M5G 1E2 ON, Canada
| | - Alexandra Kollara
- Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, 60 Murray Street, Toronto, M5T 3L9 ON, Canada.,Department of Obstetrics and Gynecology, University of Toronto, 123 Edward Street, Toronto, M5G 1E2 ON, Canada
| | - Thomasina Spybey
- Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, 60 Murray Street, Toronto, M5T 3L9 ON, Canada.,Department of Obstetrics and Gynecology, University of Toronto, 123 Edward Street, Toronto, M5G 1E2 ON, Canada.,Department of Physiology, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8 ON, Canada
| | - Soyeon Park
- Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, 60 Murray Street, Toronto, M5T 3L9 ON, Canada
| | - Blaise Clarke
- Department of Laboratory Medicine, University Health Network, 190 Elizabeth Street, Toronto, M5G 2C4 ON, Canada
| | - Maurice J Ringuette
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, M5S 3G5 ON, Canada
| | - Theodore J Brown
- Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital, 60 Murray Street, Toronto, M5T 3L9 ON, Canada.,Department of Obstetrics and Gynecology, University of Toronto, 123 Edward Street, Toronto, M5G 1E2 ON, Canada.,Department of Physiology, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8 ON, Canada
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36
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Chang AY, Marshall WF. Organelles - understanding noise and heterogeneity in cell biology at an intermediate scale. J Cell Sci 2017; 130:819-826. [PMID: 28183729 DOI: 10.1242/jcs.181024] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Many studies over the years have shown that non-genetic mechanisms for producing cell-to-cell variation can lead to highly variable behaviors across genetically identical populations of cells. Most work to date has focused on gene expression noise as the primary source of phenotypic heterogeneity, yet other sources may also contribute. In this Commentary, we explore organelle-level heterogeneity as a potential secondary source of cellular 'noise' that contributes to phenotypic heterogeneity. We explore mechanisms for generating organelle heterogeneity and present evidence of functional links between organelle morphology and cellular behavior. Given the many instances in which molecular-level heterogeneity has been linked to phenotypic heterogeneity, we posit that organelle heterogeneity may similarly contribute to overall phenotypic heterogeneity and underline the importance of studying organelle heterogeneity to develop a more comprehensive understanding of phenotypic heterogeneity. Finally, we conclude with a discussion of the medical challenges associated with phenotypic heterogeneity and outline how improved methods for characterizing and controlling this heterogeneity may lead to improved therapeutic strategies and outcomes for patients.
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Affiliation(s)
- Amy Y Chang
- Department of Biochemistry and Biophysics, Center for Cellular Construction, University of California, San Francisco, CA 94158, USA
| | - Wallace F Marshall
- Department of Biochemistry and Biophysics, Center for Cellular Construction, University of California, San Francisco, CA 94158, USA
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37
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Yan J, Anderson C, Viets K, Tran S, Goldberg G, Small S, Johnston RJ. Regulatory logic driving stable levels of defective proventriculus expression during terminal photoreceptor specification in flies. Development 2017; 144:844-855. [PMID: 28126841 DOI: 10.1242/dev.144030] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 01/02/2017] [Indexed: 12/13/2022]
Abstract
How differential levels of gene expression are controlled in post-mitotic neurons is poorly understood. In the Drosophila retina, expression of the transcription factor Defective Proventriculus (Dve) at distinct cell type-specific levels is required for terminal differentiation of color- and motion-detecting photoreceptors. Here, we find that the activities of two cis-regulatory enhancers are coordinated to drive dve expression in the fly eye. Three transcription factors act on these enhancers to determine cell-type specificity. Negative autoregulation by Dve maintains expression from each enhancer at distinct homeostatic levels. One enhancer acts as an inducible backup ('dark' shadow enhancer) that is normally repressed but becomes active in the absence of the other enhancer. Thus, two enhancers integrate combinatorial transcription factor input, feedback and redundancy to generate cell type-specific levels of dve expression and stable photoreceptor fate. This regulatory logic may represent a general paradigm for how precise levels of gene expression are established and maintained in post-mitotic neurons.
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Affiliation(s)
- Jenny Yan
- Department of Biology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2685, USA
| | - Caitlin Anderson
- Department of Biology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2685, USA
| | - Kayla Viets
- Department of Biology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2685, USA
| | - Sang Tran
- Department of Biology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2685, USA
| | - Gregory Goldberg
- Center for Developmental Genetics, Department of Biology, New York University, 100 Washington Square East, New York, NY 10003-6688, USA
| | - Stephen Small
- Center for Developmental Genetics, Department of Biology, New York University, 100 Washington Square East, New York, NY 10003-6688, USA
| | - Robert J Johnston
- Department of Biology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2685, USA
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38
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Pfleger CM. The Hippo Pathway: A Master Regulatory Network Important in Development and Dysregulated in Disease. Curr Top Dev Biol 2017; 123:181-228. [PMID: 28236967 DOI: 10.1016/bs.ctdb.2016.12.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The Hippo Pathway is a master regulatory network that regulates proliferation, cell growth, stemness, differentiation, and cell death. Coordination of these processes by the Hippo Pathway throughout development and in mature organisms in response to diverse external and internal cues plays a role in morphogenesis, in controlling organ size, and in maintaining organ homeostasis. Given the importance of these processes, the Hippo Pathway also plays an important role in organismal health and has been implicated in a variety of diseases including eye disease, cardiovascular disease, neurodegeneration, and cancer. This review will focus on Drosophila reports that identified the core components of the Hippo Pathway revealing specific downstream biological outputs of this complicated network. A brief description of mammalian reports will complement review of the Drosophila studies. This review will also survey upstream regulation of the core components with a focus on feedback mechanisms.
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Affiliation(s)
- Cathie M Pfleger
- The Icahn School of Medicine at Mount Sinai, New York, NY, United States; The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, New York, NY, United States.
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39
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Fallahi E, O'Driscoll NA, Matallanas D. The MST/Hippo Pathway and Cell Death: A Non-Canonical Affair. Genes (Basel) 2016; 7:genes7060028. [PMID: 27322327 PMCID: PMC4929427 DOI: 10.3390/genes7060028] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 06/07/2016] [Accepted: 06/09/2016] [Indexed: 01/06/2023] Open
Abstract
The MST/Hippo signalling pathway was first described over a decade ago in Drosophila melanogaster and the core of the pathway is evolutionary conserved in mammals. The mammalian MST/Hippo pathway regulates organ size, cell proliferation and cell death. In addition, it has been shown to play a central role in the regulation of cellular homeostasis and it is commonly deregulated in human tumours. The delineation of the canonical pathway resembles the behaviour of the Hippo pathway in the fly where the activation of the core kinases of the pathway prevents the proliferative signal mediated by the key effector of the pathway YAP. Nevertheless, several lines of evidence support the idea that the mammalian MST/Hippo pathway has acquired new features during evolution, including different regulators and effectors, crosstalk with other essential signalling pathways involved in cellular homeostasis and the ability to actively trigger cell death. Here we describe the current knowledge of the mechanisms that mediate MST/Hippo dependent cell death, especially apoptosis. We include evidence for the existence of complex signalling networks where the core proteins of the pathway play a central role in controlling the balance between survival and cell death. Finally, we discuss the possible involvement of these signalling networks in several human diseases such as cancer, diabetes and neurodegenerative disorders.
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Affiliation(s)
- Emma Fallahi
- Systems Biology Ireland, University College Dublin, Belfield, Dublin 4, Ireland. emma.fallahi---
- School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland. emma.fallahi---
| | - Niamh A O'Driscoll
- Systems Biology Ireland, University College Dublin, Belfield, Dublin 4, Ireland.
- School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland.
| | - David Matallanas
- Systems Biology Ireland, University College Dublin, Belfield, Dublin 4, Ireland.
- School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland.
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40
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Jukam D, Viets K, Anderson C, Zhou C, DeFord P, Yan J, Cao J, Johnston RJ. The insulator protein BEAF-32 is required for Hippo pathway activity in the terminal differentiation of neuronal subtypes. Development 2016; 143:2389-97. [PMID: 27226322 DOI: 10.1242/dev.134700] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 05/11/2016] [Indexed: 01/07/2023]
Abstract
The Hippo pathway is crucial for not only normal growth and apoptosis but also cell fate specification during development. What controls Hippo pathway activity during cell fate specification is incompletely understood. In this article, we identify the insulator protein BEAF-32 as a regulator of Hippo pathway activity in Drosophila photoreceptor differentiation. Though morphologically uniform, the fly eye is composed of two subtypes of R8 photoreceptor neurons defined by expression of light-detecting Rhodopsin proteins. In one R8 subtype, active Hippo signaling induces Rhodopsin 6 (Rh6) and represses Rhodopsin 5 (Rh5), whereas in the other subtype, inactive Hippo signaling induces Rh5 and represses Rh6. The activity state of the Hippo pathway in R8 cells is determined by the expression of warts, a core pathway kinase, which interacts with the growth regulator melted in a double-negative feedback loop. We show that BEAF-32 is required for expression of warts and repression of melted Furthermore, BEAF-32 plays a second role downstream of Warts to induce Rh6 and prevent Rh5 fate. BEAF-32 is dispensable for Warts feedback, indicating that BEAF-32 differentially regulates warts and Rhodopsins. Loss of BEAF-32 does not noticeably impair the functions of the Hippo pathway in eye growth regulation. Our study identifies a context-specific regulator of Hippo pathway activity in post-mitotic neuronal fate, and reveals a developmentally specific role for a broadly expressed insulator protein.
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Affiliation(s)
- David Jukam
- Center for Developmental Genetics, Department of Biology, New York University, 100 Washington Square East, New York, NY 10003-6688, USA
| | - Kayla Viets
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218-2685, USA
| | - Caitlin Anderson
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218-2685, USA
| | - Cyrus Zhou
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218-2685, USA
| | - Peter DeFord
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218-2685, USA
| | - Jenny Yan
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218-2685, USA
| | - Jinshuai Cao
- Center for Developmental Genetics, Department of Biology, New York University, 100 Washington Square East, New York, NY 10003-6688, USA
| | - Robert J Johnston
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218-2685, USA
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41
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Macpherson LJ, Zaharieva EE, Kearney PJ, Alpert MH, Lin TY, Turan Z, Lee CH, Gallio M. Dynamic labelling of neural connections in multiple colours by trans-synaptic fluorescence complementation. Nat Commun 2015; 6:10024. [PMID: 26635273 PMCID: PMC4686661 DOI: 10.1038/ncomms10024] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 10/27/2015] [Indexed: 12/19/2022] Open
Abstract
Determining the pattern of activity of individual connections within a neural circuit could provide insights into the computational processes that underlie brain function. Here, we develop new strategies to label active synapses by trans-synaptic fluorescence complementation in Drosophila. First, we demonstrate that a synaptobrevin-GRASP chimera functions as a powerful activity-dependent marker for synapses in vivo. Next, we create cyan and yellow variants, achieving activity-dependent, multi-colour fluorescence reconstitution across synapses (X-RASP). Our system allows for the first time retrospective labelling of synapses (rather than whole neurons) based on their activity, in multiple colours, in the same animal. As individual synapses often act as computational units in the brain, our method will promote the design of experiments that are not possible using existing techniques. Moreover, our strategies are easily adaptable to circuit mapping in any genetic system.
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Affiliation(s)
- Lindsey J Macpherson
- Howard Hughes Medical Institute and Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, USA
| | - Emanuela E Zaharieva
- Department of Neurobiology, Northwestern University, Evanston, Illinois 60208, USA
| | - Patrick J Kearney
- Department of Neurobiology, Northwestern University, Evanston, Illinois 60208, USA
| | - Michael H Alpert
- Department of Neurobiology, Northwestern University, Evanston, Illinois 60208, USA
| | - Tzu-Yang Lin
- Section on Neuronal Connectivity, Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Zeynep Turan
- Howard Hughes Medical Institute and Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, USA
| | - Chi-Hon Lee
- Section on Neuronal Connectivity, Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Marco Gallio
- Department of Neurobiology, Northwestern University, Evanston, Illinois 60208, USA
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42
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Macias-Muñoz A, Smith G, Monteiro A, Briscoe AD. Transcriptome-Wide Differential Gene Expression in Bicyclus anynana Butterflies: Female Vision-Related Genes Are More Plastic. Mol Biol Evol 2015; 33:79-92. [PMID: 26371082 DOI: 10.1093/molbev/msv197] [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: 12/31/2022] Open
Abstract
Vision is energetically costly to maintain. Consequently, over time many cave-adapted species downregulate the expression of vision genes or even lose their eyes and associated eye genes entirely. Alternatively, organisms that live in fluctuating environments, with different requirements for vision at different times, may evolve phenotypic plasticity for expression of vision genes. Here, we use a global transcriptomic and candidate gene approach to compare gene expression in the heads of a polyphenic butterfly. Bicyclus anynana have two seasonal forms that display sexual dimorphism and plasticity in eye morphology, and female-specific plasticity in opsin gene expression. Nonchoosy dry season females downregulate opsin expression, consistent with the high physiological cost of vision. To identify other genes associated with sexually dimorphic and seasonally plastic differences in vision, we analyzed RNA-sequencing data from whole head tissues. We identified two eye development genes (klarsicht and warts homologs) and an eye pigment biosynthesis gene (henna) differentially expressed between seasonal forms. By comparing sex-specific expression across seasonal forms, we found that klarsicht, warts, henna, and another eye development gene (domeless) were plastic in a female-specific manner. In a male-only analysis, white (w) was differentially expressed between seasonal forms. Reverse transcription polymerase chain reaction confirmed that warts and white are expressed in eyes only, whereas klarsicht, henna and domeless are expressed in both eyes and brain. We find that differential expression of eye development and eye pigment genes is associated with divergent eye phenotypes in B. anynana seasonal forms, and that there is a larger effect of season on female vision-related genes.
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Affiliation(s)
- Aide Macias-Muñoz
- Ecology and Evolutionary Biology, University of California, Irvine BEACON Center for the Study of Evolution in Action
| | - Gilbert Smith
- Ecology and Evolutionary Biology, University of California, Irvine BEACON Center for the Study of Evolution in Action
| | - Antónia Monteiro
- Biological Sciences, National University of Singapore, Singapore Yale-NUS College, Singapore
| | - Adriana D Briscoe
- Ecology and Evolutionary Biology, University of California, Irvine BEACON Center for the Study of Evolution in Action
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Abstract
Microbes transiently differentiate into distinct, specialized cell types to generate functional diversity and cope with changing environmental conditions. Though alternate programs often entail radically different physiological and morphological states, recent single-cell studies have revealed that these crucial decisions are often left to chance. In these cases, the underlying genetic circuits leverage the intrinsic stochasticity of intracellular chemistry to drive transition between states. Understanding how these circuits transform transient gene expression fluctuations into lasting phenotypic programs will require a combination of quantitative modeling and extensive, time-resolved observation of switching events in single cells. In this article, we survey microbial cell fate decisions demonstrated to involve a random element, describe theoretical frameworks for understanding stochastic switching between states, and highlight recent advances in microfluidics that will enable characterization of key dynamic features of these circuits.
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Affiliation(s)
- Thomas M Norman
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115; , ,
| | - Nathan D Lord
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115; , ,
| | - Johan Paulsson
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115; , ,
| | - Richard Losick
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138;
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Gamba P, Jonker MJ, Hamoen LW. A Novel Feedback Loop That Controls Bimodal Expression of Genetic Competence. PLoS Genet 2015; 11:e1005047. [PMID: 26110430 PMCID: PMC4482431 DOI: 10.1371/journal.pgen.1005047] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Accepted: 02/01/2015] [Indexed: 01/25/2023] Open
Abstract
Gene expression can be highly heterogeneous in isogenic cell populations. An extreme type of heterogeneity is the so-called bistable or bimodal expression, whereby a cell can differentiate into two alternative expression states. Stochastic fluctuations of protein levels, also referred to as noise, provide the necessary source of heterogeneity that must be amplified by specific genetic circuits in order to obtain a bimodal response. A classical model of bimodal differentiation is the activation of genetic competence in Bacillus subtilis. The competence transcription factor ComK activates transcription of its own gene, and an intricate regulatory network controls the switch to competence and ensures its reversibility. However, it is noise in ComK expression that determines which cells activate the ComK autostimulatory loop and become competent for genetic transformation. Despite its important role in bimodal gene expression, noise remains difficult to investigate due to its inherent stochastic nature. We adapted an artificial autostimulatory loop that bypasses all known ComK regulators to screen for possible factors that affect noise. This led to the identification of a novel protein Kre (YkyB) that controls the bimodal regulation of ComK. Interestingly, Kre appears to modulate the induction of ComK by affecting the stability of comK mRNA. The protein influences the expression of many genes, however, Kre is only found in bacteria that contain a ComK homologue and, importantly, kre expression itself is downregulated by ComK. The evolutionary significance of this new feedback loop for the reduction of transcriptional noise in comK expression is discussed. Our findings show the importance of mRNA stability in bimodal regulation, a factor that requires more attention when studying and modelling this non-deterministic developmental mechanism. Gene expression can be highly heterogeneous in clonal cell populations. An extreme type of heterogeneity is the so-called bistable or bimodal expression, whereby a cell can differentiate into two alternative expression states, and consequently a population will be composed of cells that are ‘ON’ and cells that are ‘OFF’. Stochastic fluctuations of protein levels, also referred to as noise, provide the necessary source of heterogeneity that must be amplified by autostimulatory feedback regulation to obtain the bimodal response. A classical model of bistable differentiation is the development of genetic competence in Bacillus subtilis. Noise in expression of the transcription factor ComK ultimately determines the fraction of cells that enter the competent state. Due to its intrinsic random nature, noise is difficult to investigate. We adapted an artificial autostimulatory loop that bypasses all known ComK regulators, to screen for possible factors that affect noise in the bimodal regulation of ComK. This led to the discovery of Kre, a novel factor that controls the bimodal expression of ComK. Kre appears to affect the stability of comK mRNA. Interestingly, ComK itself represses the expression of kre, adding a new double negative feedback loop to the intricate ComK regulation circuit. Our data emphasize that mRNA stability is an important factor in bimodal regulation.
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Affiliation(s)
- Pamela Gamba
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
- * E-mail: (PG); (LWH)
| | - Martijs J. Jonker
- MicroArray Department and Integrative Bioinformatics Unit, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Leendert W. Hamoen
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
- * E-mail: (PG); (LWH)
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45
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Human ortholog of Drosophila Melted impedes SMAD2 release from TGF-β receptor I to inhibit TGF-β signaling. Proc Natl Acad Sci U S A 2015; 112:E3000-9. [PMID: 26039994 DOI: 10.1073/pnas.1504671112] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Drosophila melted encodes a pleckstrin homology (PH) domain-containing protein that enables normal tissue growth, metabolism, and photoreceptor differentiation by modulating Forkhead box O (FOXO), target of rapamycin, and Hippo signaling pathways. Ventricular zone expressed PH domain-containing 1 (VEPH1) is the mammalian ortholog of melted, and although it exhibits tissue-restricted expression during mouse development and is potentially amplified in several human cancers, little is known of its function. Here we explore the impact of VEPH1 expression in ovarian cancer cells by gene-expression profiling. In cells with elevated VEPH1 expression, transcriptional programs associated with metabolism and FOXO and Hippo signaling were affected, analogous to what has been reported for Melted. We also observed altered regulation of multiple transforming growth factor-β (TGF-β) target genes. Global profiling revealed that elevated VEPH1 expression suppressed TGF-β-induced transcriptional responses. This inhibitory effect was verified on selected TGF-β target genes and by reporter gene assays in multiple cell lines. We further demonstrated that VEPH1 interacts with TGF-β receptor I (TβRI) and inhibits nuclear accumulation of activated Sma- and Mad-related protein 2 (SMAD2). We identified two TβRI-interacting regions (TIRs) with opposing effects on TGF-β signaling. TIR1, located at the N terminus, inhibits canonical TGF-β signaling and promotes SMAD2 retention at TβRI, similar to full-length VEPH1. In contrast, TIR2, located at the C-terminal region encompassing the PH domain, decreases SMAD2 retention at TβRI and enhances TGF-β signaling. Our studies indicate that VEPH1 inhibits TGF-β signaling by impeding the release of activated SMAD2 from TβRI and may modulate TGF-β signaling during development and cancer initiation or progression.
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Wernet MF, Huberman AD, Desplan C. So many pieces, one puzzle: cell type specification and visual circuitry in flies and mice. Genes Dev 2014; 28:2565-84. [PMID: 25452270 PMCID: PMC4248288 DOI: 10.1101/gad.248245.114] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The visual system is a powerful model for probing the development, connectivity, and function of neural circuits. Two genetically tractable species, mice and flies, are together providing a great deal of understanding of these processes. Current efforts focus on integrating knowledge gained from three cross-fostering fields of research: (1) understanding how the fates of different cell types are specified during development, (2) revealing the synaptic connections between identified cell types ("connectomics") by high-resolution three-dimensional circuit anatomy, and (3) causal testing of how identified circuit elements contribute to visual perception and behavior. Here we discuss representative examples from fly and mouse models to illustrate the ongoing success of this tripartite strategy, focusing on the ways it is enhancing our understanding of visual processing and other sensory systems.
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Affiliation(s)
- Mathias F Wernet
- Department of Neurobiology, Stanford University, Stanford, California 94305, USA; New York University Abu Dhabi, Saadiyat Island, Abu Dhabi 129188, United Arab Emirates; Department of Biology, New York University, New York, New York 10003, USA
| | - Andrew D Huberman
- Department of Neurosciences, Neurobiology Section, Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093, USA
| | - Claude Desplan
- New York University Abu Dhabi, Saadiyat Island, Abu Dhabi 129188, United Arab Emirates; Department of Biology, New York University, New York, New York 10003, USA
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Milton CC, Grusche FA, Degoutin JL, Yu E, Dai Q, Lai EC, Harvey KF. The Hippo pathway regulates hematopoiesis in Drosophila melanogaster. Curr Biol 2014; 24:2673-80. [PMID: 25454587 PMCID: PMC4269548 DOI: 10.1016/j.cub.2014.10.031] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 08/26/2014] [Accepted: 10/13/2014] [Indexed: 12/13/2022]
Abstract
The Salvador-Warts-Hippo (Hippo) pathway is an evolutionarily conserved regulator of organ growth and cell fate. It performs these functions in epithelial and neural tissues of both insects and mammals, as well as in mammalian organs such as the liver and heart. Despite rapid advances in Hippo pathway research, a definitive role for this pathway in hematopoiesis has remained enigmatic. The hematopoietic compartments of Drosophila melanogaster and mammals possess several conserved features. D. melanogaster possess three types of hematopoietic cells that most closely resemble mammalian myeloid cells: plasmatocytes (macrophage-like cells), crystal cells (involved in wound healing), and lamellocytes (which encapsulate parasites). The proteins that control differentiation of these cells also control important blood lineage decisions in mammals. Here, we define the Hippo pathway as a key mediator of hematopoiesis by showing that it controls differentiation and proliferation of the two major types of D. melanogaster blood cells, plasmatocytes and crystal cells. In animals lacking the downstream Hippo pathway kinase Warts, lymph gland cells overproliferated, differentiated prematurely, and often adopted a mixed lineage fate. The Hippo pathway regulated crystal cell numbers by both cell-autonomous and non-cell-autonomous mechanisms. Yorkie and its partner transcription factor Scalloped were found to regulate transcription of the Runx family transcription factor Lozenge, which is a key regulator of crystal cell fate. Further, Yorkie or Scalloped hyperactivation induced ectopic crystal cells in a non-cell-autonomous and Notch-pathway-dependent fashion.
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Affiliation(s)
- Claire C Milton
- Cell Growth and Proliferation Laboratory, Peter MacCallum Cancer Centre, 7 St. Andrews Place, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia; Department of Pathology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Felix A Grusche
- Cell Growth and Proliferation Laboratory, Peter MacCallum Cancer Centre, 7 St. Andrews Place, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Joffrey L Degoutin
- Cell Growth and Proliferation Laboratory, Peter MacCallum Cancer Centre, 7 St. Andrews Place, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Eefang Yu
- Cell Growth and Proliferation Laboratory, Peter MacCallum Cancer Centre, 7 St. Andrews Place, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Qi Dai
- Department of Developmental Biology, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
| | - Eric C Lai
- Department of Developmental Biology, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
| | - Kieran F Harvey
- Cell Growth and Proliferation Laboratory, Peter MacCallum Cancer Centre, 7 St. Andrews Place, East Melbourne, VIC 3002, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC 3010, Australia; Department of Pathology, University of Melbourne, Parkville, VIC 3010, Australia.
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48
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Brás-Pereira C, Zhang T, Pignoni F, Janody F. Homeostasis of theDrosophilaadult retina by Actin-Capping Protein and the Hippo pathway. Commun Integr Biol 2014. [DOI: 10.4161/cib.16853] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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49
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Jagadish S, Barnea G, Clandinin TR, Axel R. Identifying functional connections of the inner photoreceptors in Drosophila using Tango-Trace. Neuron 2014; 83:630-44. [PMID: 25043419 PMCID: PMC4126867 DOI: 10.1016/j.neuron.2014.06.025] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2014] [Indexed: 11/21/2022]
Abstract
In Drosophila, the four inner photoreceptor neurons exhibit overlapping but distinct spectral sensitivities and mediate behaviors that reflect spectral preference. We developed a genetic strategy, Tango-Trace, that has permitted the identification of the connections of the four chromatic photoreceptors. Each of the four stochastically distributed chromatic photoreceptor subtypes make distinct connections in the medulla with four different TmY cells. Moreover, each class of TmY cells forms a retinotopic map in both the medulla and the lobula complex, generating four overlapping topographic maps that could carry different color information. Thus, the four inner photoreceptors transmit spectral information through distinct channels that may converge in both the medulla and lobula complex. These projections could provide an anatomic basis for color vision and may relay information about color to motion sensitive areas. Moreover, the Tango-Trace strategy we used may be applied more generally to identify neural circuits in the fly brain.
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Affiliation(s)
- Smitha Jagadish
- Department of Neuroscience and the Howard Hughes Medical Institute, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Gilad Barnea
- Department of Neuroscience, Brown University, Providence, RI 02912 USA
| | - Thomas R Clandinin
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA.
| | - Richard Axel
- Department of Neuroscience and the Howard Hughes Medical Institute, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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50
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Hsieh YW, Alqadah A, Chuang CF. Asymmetric neural development in the Caenorhabditis elegans olfactory system. Genesis 2014; 52:544-54. [PMID: 24478264 PMCID: PMC4065219 DOI: 10.1002/dvg.22744] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 01/17/2014] [Accepted: 01/23/2014] [Indexed: 02/02/2023]
Abstract
Asymmetries in the nervous system have been observed throughout the animal kingdom. Deviations of brain asymmetries are associated with a variety of neurodevelopmental disorders; however, there has been limited progress in determining how normal asymmetry is established in vertebrates. In the Caenorhabditis elegans chemosensory system, two pairs of morphologically symmetrical neurons exhibit molecular and functional asymmetries. This review focuses on the development of antisymmetry of the pair of amphid wing "C" (AWC) olfactory neurons, from transcriptional regulation of general cell identity, establishment of asymmetry through neural network formation and calcium signaling, to the maintenance of asymmetry throughout the life of the animal. Many of the factors that are involved in AWC development have homologs in vertebrates, which may potentially function in the development of vertebrate brain asymmetry.
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Affiliation(s)
- Yi-Wen Hsieh
- Division of Developmental Biology, Cincinnati Children’s Hospital Research Foundation, Cincinnati, OH, USA
| | - Amel Alqadah
- Division of Developmental Biology, Cincinnati Children’s Hospital Research Foundation, Cincinnati, OH, USA
- Molecular and Developmental Biology Graduate Program, University of Cincinnati, OH, USA
| | - Chiou-Fen Chuang
- Division of Developmental Biology, Cincinnati Children’s Hospital Research Foundation, Cincinnati, OH, USA
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