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Zheng Q, Gao N, Sun Q, Li X, Wang Y, Xiao H. bfc, a novel serpent co-factor for the expression of croquemort, regulates efferocytosis in Drosophila melanogaster. PLoS Genet 2021; 17:e1009947. [PMID: 34860835 PMCID: PMC8673676 DOI: 10.1371/journal.pgen.1009947] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 12/15/2021] [Accepted: 11/15/2021] [Indexed: 01/01/2023] Open
Abstract
Efferocytosis is the process by which phagocytes recognize, engulf, and digest (or clear) apoptotic cells during development. Impaired efferocytosis is associated with developmental defects and autoimmune diseases. In Drosophila melanogaster, recognition of apoptotic cells requires phagocyte surface receptors, including the scavenger receptor CD36-related protein, Croquemort (Crq, encoded by crq). In fact, Crq expression is upregulated in the presence of apoptotic cells, as well as in response to excessive apoptosis. Here, we identified a novel gene bfc (booster for croquemort), which plays a role in efferocytosis, specifically the regulation of the crq expression. We found that Bfc protein interacts with the zinc finger domain of the GATA transcription factor Serpent (Srp), to enhance its direct binding to the crq promoter; thus, they function together in regulating crq expression and efferocytosis. Overall, we show that Bfc serves as a Srp co-factor to upregulate the transcription of the crq encoded receptor, and consequently boosts macrophage efferocytosis in response to excessive apoptosis. Therefore, this study clarifies how phagocytes integrate apoptotic cell signals to mediate efferocytosis.
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Affiliation(s)
- Qian Zheng
- College of Life Sciences, Shaanxi Normal University, Xi’an, China
| | - Ning Gao
- College of Life Sciences, Shaanxi Normal University, Xi’an, China
| | - Qiling Sun
- College of Life Sciences, Shaanxi Normal University, Xi’an, China
| | - Xiaowen Li
- College of Life Sciences, Shaanxi Normal University, Xi’an, China
| | - Yanzhe Wang
- College of Life Sciences, Shaanxi Normal University, Xi’an, China
| | - Hui Xiao
- College of Life Sciences, Shaanxi Normal University, Xi’an, China
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2
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Mishra N, Heisenberg CP. Dissecting Organismal Morphogenesis by Bridging Genetics and Biophysics. Annu Rev Genet 2021; 55:209-233. [PMID: 34460295 DOI: 10.1146/annurev-genet-071819-103748] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Multicellular organisms develop complex shapes from much simpler, single-celled zygotes through a process commonly called morphogenesis. Morphogenesis involves an interplay between several factors, ranging from the gene regulatory networks determining cell fate and differentiation to the mechanical processes underlying cell and tissue shape changes. Thus, the study of morphogenesis has historically been based on multidisciplinary approaches at the interface of biology with physics and mathematics. Recent technological advances have further improved our ability to study morphogenesis by bridging the gap between the genetic and biophysical factors through the development of new tools for visualizing, analyzing, and perturbing these factors and their biochemical intermediaries. Here, we review how a combination of genetic, microscopic, biophysical, and biochemical approaches has aided our attempts to understand morphogenesis and discuss potential approaches that may be beneficial to such an inquiry in the future. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Nikhil Mishra
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria; ,
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3
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Buchberger E, Bilen A, Ayaz S, Salamanca D, Matas de las Heras C, Niksic A, Almudi I, Torres-Oliva M, Casares F, Posnien N. Variation in Pleiotropic Hub Gene Expression Is Associated with Interspecific Differences in Head Shape and Eye Size in Drosophila. Mol Biol Evol 2021; 38:1924-1942. [PMID: 33386848 PMCID: PMC8097299 DOI: 10.1093/molbev/msaa335] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Revealing the mechanisms underlying the breathtaking morphological diversity observed in nature is a major challenge in Biology. It has been established that recurrent mutations in hotspot genes cause the repeated evolution of morphological traits, such as body pigmentation or the gain and loss of structures. To date, however, it remains elusive whether hotspot genes contribute to natural variation in the size and shape of organs. As natural variation in head morphology is pervasive in Drosophila, we studied the molecular and developmental basis of differences in compound eye size and head shape in two closely related Drosophila species. We show differences in the progression of retinal differentiation between species and we applied comparative transcriptomics and chromatin accessibility data to identify the GATA transcription factor Pannier (Pnr) as central factor associated with these differences. Although the genetic manipulation of Pnr affected multiple aspects of dorsal head development, the effect of natural variation is restricted to a subset of the phenotypic space. We present data suggesting that this developmental constraint is caused by the coevolution of expression of pnr and its cofactor u-shaped (ush). We propose that natural variation in expression or function of highly connected developmental regulators with pleiotropic functions is a major driver for morphological evolution and we discuss implications on gene regulatory network evolution. In comparison to previous findings, our data strongly suggest that evolutionary hotspots are not the only contributors to the repeated evolution of eye size and head shape in Drosophila.
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Affiliation(s)
- Elisa Buchberger
- Department of Developmental Biology, University of Göttingen, Göttingen, Germany
| | - Anıl Bilen
- Department of Developmental Biology, University of Göttingen, Göttingen, Germany
| | - Sanem Ayaz
- Department of Developmental Biology, University of Göttingen, Göttingen, Germany
| | - David Salamanca
- Department of Developmental Biology, University of Göttingen, Göttingen, Germany
- Present address: Department of Integrative Zoology, University of Vienna, Vienna, Austria
| | | | - Armin Niksic
- Department of Developmental Biology, University of Göttingen, Göttingen, Germany
| | - Isabel Almudi
- CABD (CSIC/UPO/JA), DMC2 Unit, Pablo de Olavide University Campus, Seville, Spain
| | - Montserrat Torres-Oliva
- Department of Developmental Biology, University of Göttingen, Göttingen, Germany
- Present address: Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, University Hospital Schleswig-Holstein, Kiel, Germany
| | - Fernando Casares
- CABD (CSIC/UPO/JA), DMC2 Unit, Pablo de Olavide University Campus, Seville, Spain
| | - Nico Posnien
- Department of Developmental Biology, University of Göttingen, Göttingen, Germany
- Corresponding author: E-mail:
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4
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Ush regulates hemocyte-specific gene expression, fatty acid metabolism and cell cycle progression and cooperates with dNuRD to orchestrate hematopoiesis. PLoS Genet 2021; 17:e1009318. [PMID: 33600407 PMCID: PMC7891773 DOI: 10.1371/journal.pgen.1009318] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 12/20/2020] [Indexed: 12/13/2022] Open
Abstract
The generation of lineage-specific gene expression programmes that alter proliferation capacity, metabolic profile and cell type-specific functions during differentiation from multipotent stem cells to specialised cell types is crucial for development. During differentiation gene expression programmes are dynamically modulated by a complex interplay between sequence-specific transcription factors, associated cofactors and epigenetic regulators. Here, we study U-shaped (Ush), a multi-zinc finger protein that maintains the multipotency of stem cell-like hemocyte progenitors during Drosophila hematopoiesis. Using genomewide approaches we reveal that Ush binds to promoters and enhancers and that it controls the expression of three gene classes that encode proteins relevant to stem cell-like functions and differentiation: cell cycle regulators, key metabolic enzymes and proteins conferring specific functions of differentiated hemocytes. We employ complementary biochemical approaches to characterise the molecular mechanisms of Ush-mediated gene regulation. We uncover distinct Ush isoforms one of which binds the Nucleosome Remodeling and Deacetylation (NuRD) complex using an evolutionary conserved peptide motif. Remarkably, the Ush/NuRD complex specifically contributes to the repression of lineage-specific genes but does not impact the expression of cell cycle regulators or metabolic genes. This reveals a mechanism that enables specific and concerted modulation of functionally related portions of a wider gene expression programme. Finally, we use genetic assays to demonstrate that Ush and NuRD regulate enhancer activity during hemocyte differentiation in vivo and that both cooperate to suppress the differentiation of lamellocytes, a highly specialised blood cell type. Our findings reveal that Ush coordinates proliferation, metabolism and cell type-specific activities by isoform-specific cooperation with an epigenetic regulator.
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5
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Winbush A, Singh ND. Genomics of Recombination Rate Variation in Temperature-Evolved Drosophila melanogaster Populations. Genome Biol Evol 2020; 13:6008691. [PMID: 33247719 PMCID: PMC7851596 DOI: 10.1093/gbe/evaa252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/24/2020] [Indexed: 12/14/2022] Open
Abstract
Meiotic recombination is a critical process that ensures proper segregation of chromosome homologs through DNA double-strand break repair mechanisms. Rates of recombination are highly variable among various taxa, within species, and within genomes with far-reaching evolutionary and genomic consequences. The genetic basis of recombination rate variation is therefore crucial in the study of evolutionary biology but remains poorly understood. In this study, we took advantage of a set of experimental temperature-evolved populations of Drosophila melanogaster with heritable differences in recombination rates depending on the temperature regime in which they evolved. We performed whole-genome sequencing and identified several chromosomal regions that appear to be divergent depending on temperature regime. In addition, we identify a set of single-nucleotide polymorphisms and associated genes with significant differences in allele frequency when the different temperature populations are compared. Further refinement of these gene candidates emphasizing those expressed in the ovary and associated with DNA binding reveals numerous potential candidate genes such as Hr38, EcR, and mamo responsible for observed differences in recombination rates in these experimental evolution lines thus providing insight into the genetic basis of recombination rate variation.
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Affiliation(s)
- Ari Winbush
- Department of Biology, Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon, USA
| | - Nadia D Singh
- Department of Biology, Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon, USA
- Corresponding author: E-mail:
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Furman DP, Bukharina TV. The bristle pattern development in Drosophila melanogaster: the prepattern and achaete-scute genes. Vavilovskii Zhurnal Genet Selektsii 2019. [DOI: 10.18699/vj18.449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- D. P. Furman
- Institute of Cytology and Genetics, SB RAS; Novosibirsk State University
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7
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Liang Q, Peng T, Sun B, Tu J, Cheng X, Tian Y, Fan X, Yang D, Gaur U, Yang M. Gene expression patterns determine the differential numbers of dorsocentral macrochaetes between Musca domestica
and Drosophila melanogaster. Genesis 2018; 56:e23258. [DOI: 10.1002/dvg.23258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 10/17/2018] [Accepted: 10/18/2018] [Indexed: 01/21/2023]
Affiliation(s)
- Qing Liang
- Department of Animal Science, Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province; Sichuan Agricultural University; Chengdu China
| | - Tingting Peng
- Department of Animal Science, Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province; Sichuan Agricultural University; Chengdu China
| | - Boyuan Sun
- Department of Animal Science, Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province; Sichuan Agricultural University; Chengdu China
| | - Jianbo Tu
- Department of Animal Science, Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province; Sichuan Agricultural University; Chengdu China
| | - Xingyi Cheng
- Department of Animal Science, Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province; Sichuan Agricultural University; Chengdu China
| | - Yuanliangzi Tian
- Department of Animal Science, Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province; Sichuan Agricultural University; Chengdu China
| | - Xiaolan Fan
- Department of Animal Science, Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province; Sichuan Agricultural University; Chengdu China
| | - Deying Yang
- Department of Animal Science, Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province; Sichuan Agricultural University; Chengdu China
| | - Uma Gaur
- Department of Animal Science, Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province; Sichuan Agricultural University; Chengdu China
| | - Mingyao Yang
- Department of Animal Science, Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province; Sichuan Agricultural University; Chengdu China
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8
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The Repo Homeodomain Transcription Factor Suppresses Hematopoiesis in Drosophila and Preserves the Glial Fate. J Neurosci 2018; 39:238-255. [PMID: 30504274 DOI: 10.1523/jneurosci.1059-18.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 10/08/2018] [Accepted: 10/12/2018] [Indexed: 01/12/2023] Open
Abstract
Despite their different origins, Drosophila glia and hemocytes are related cell populations that provide an immune function. Drosophila hemocytes patrol the body cavity and act as macrophages outside the nervous system, whereas glia originate from the neuroepithelium and provide the scavenger population of the nervous system. Drosophila glia are hence the functional orthologs of vertebrate microglia, even though the latter are cells of immune origin that subsequently move into the brain during development. Interestingly, the Drosophila immune cells within (glia) and outside (hemocytes) the nervous system require the same transcription factor glial cells deficient/glial cells missing (Glide/Gcm) for their development. This raises the issue of how do glia specifically differentiate in the nervous system, and hemocytes in the procephalic mesoderm. The Repo homeodomain transcription factor and panglial direct target of Glide/Gcm is known to ensure glial terminal differentiation. Here we show that Repo also takes center stage in the process that discriminates between glia and hemocytes. First, Repo expression is repressed in the hemocyte anlagen by mesoderm-specific factors. Second, Repo ectopic activation in the procephalic mesoderm is sufficient to repress the expression of hemocyte-specific genes. Third, the lack of Repo triggers the expression of hemocyte markers in glia. Thus, a complex network of tissue-specific cues biases the potential of Glide/Gcm. These data allow us to revise the concept of fate determinants and help us to understand the bases of cell specification. Both sexes were analyzed.SIGNIFICANCE STATEMENT Distinct cell types often require the same pioneer transcription factor, raising the issue of how one factor triggers different fates. In Drosophila, glia and hemocytes provide a scavenger activity within and outside the nervous system, respectively. While they both require the glial cells deficient/glial cells missing (Glide/Gcm) transcription factor, glia originate from the ectoderm, and hemocytes from the mesoderm. Here we show that tissue-specific factors inhibit the gliogenic potential of Glide/Gcm in the mesoderm by repressing the expression of the homeodomain protein Repo, a major glial-specific target of Glide/Gcm. Repo expression in turn inhibits the expression of hemocyte-specific genes in the nervous system. These cell-specific networks secure the establishment of the glial fate only in the nervous system and allow cell diversification.
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9
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Ligand-Bound GeneSwitch Causes Developmental Aberrations in Drosophila that Are Alleviated by the Alternative Oxidase. G3-GENES GENOMES GENETICS 2016; 6:2839-46. [PMID: 27412986 PMCID: PMC5015941 DOI: 10.1534/g3.116.030882] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Culture of Drosophila expressing the steroid-dependent GeneSwitch transcriptional activator under the control of the ubiquitous α-tubulin promoter was found to produce extensive pupal lethality, as well as a range of dysmorphic adult phenotypes, in the presence of high concentrations of the inducing drug RU486. Prominent among these was cleft thorax, seen previously in flies bearing mutant alleles of the nuclear receptor Ultraspiracle and many other mutants, as well as notched wings, leg malformations, and bristle abnormalities. Neither the α-tubulin-GeneSwitch driver nor the inducing drug on their own produced any of these effects. A second GeneSwitch driver, under the control of the daughterless promoter, which gave much lower and more tissue-restricted transgene expression, exhibited only mild bristle abnormalities in the presence of high levels of RU486. Coexpression of the alternative oxidase (AOX) from Ciona intestinalis produced a substantial shift in the developmental outcome toward a wild-type phenotype, which was dependent on the AOX expression level. Neither an enzymatically inactivated variant of AOX, nor GFP, or the alternative NADH dehydrogenase Ndi1 from yeast gave any such rescue. Users of the GeneSwitch system should be aware of the potential confounding effects of its application in developmental studies.
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10
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Galazo MJ, Emsley JG, Macklis JD. Corticothalamic Projection Neuron Development beyond Subtype Specification: Fog2 and Intersectional Controls Regulate Intraclass Neuronal Diversity. Neuron 2016; 91:90-106. [PMID: 27321927 DOI: 10.1016/j.neuron.2016.05.024] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 03/16/2016] [Accepted: 05/16/2016] [Indexed: 01/05/2023]
Abstract
Corticothalamic projection neurons (CThPN) are a diverse set of neurons, critical for function of the neocortex. CThPN development and diversity need to be precisely regulated, but little is known about molecular controls over their differentiation and functional specialization, critically limiting understanding of cortical development and complexity. We report the identification of a set of genes that both define CThPN and likely control their differentiation, diversity, and function. We selected the CThPN-specific transcriptional coregulator Fog2 for functional analysis. We identify that Fog2 controls CThPN molecular differentiation, axonal targeting, and diversity, in part by regulating the expression level of Ctip2 by CThPN, via combinatorial interactions with other molecular controls. Loss of Fog2 specifically disrupts differentiation of subsets of CThPN specialized in motor function, indicating that Fog2 coordinates subtype and functional-area differentiation. These results confirm that we identified key controls over CThPN development and identify Fog2 as a critical control over CThPN diversity.
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Affiliation(s)
- Maria J Galazo
- Department of Stem Cell and Regenerative Biology, Center for Brain Science, and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Jason G Emsley
- Department of Stem Cell and Regenerative Biology, Center for Brain Science, and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Jeffrey D Macklis
- Department of Stem Cell and Regenerative Biology, Center for Brain Science, and Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA.
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11
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Bukharina TA, Furman DP. The mechanisms determining bristle pattern in Drosophila melanogaster. Russ J Dev Biol 2015. [DOI: 10.1134/s1062360415030029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Cassidy JJ, Jha AR, Posadas DM, Giri R, Venken KJT, Ji J, Jiang H, Bellen HJ, White KP, Carthew RW. miR-9a minimizes the phenotypic impact of genomic diversity by buffering a transcription factor. Cell 2014; 155:1556-67. [PMID: 24360277 DOI: 10.1016/j.cell.2013.10.057] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 09/16/2013] [Accepted: 10/29/2013] [Indexed: 12/22/2022]
Abstract
Gene expression has to withstand stochastic, environmental, and genomic perturbations. For example, in the latter case, 0.5%-1% of the human genome is typically variable between any two unrelated individuals. Such diversity might create problematic variability in the activity of gene regulatory networks and, ultimately, in cell behaviors. Using multigenerational selection experiments, we find that for the Drosophila proneural network, the effect of genomic diversity is dampened by miR-9a-mediated regulation of senseless expression. Reducing miR-9a regulation of the Senseless transcription factor frees the genomic landscape to exert greater phenotypic influence. Whole-genome sequencing identified genomic loci that potentially exert such effects. A larger set of sequence variants, including variants within proneural network genes, exhibits these characteristics when miR-9a concentration is reduced. These findings reveal that microRNA-target interactions may be a key mechanism by which the impact of genomic diversity on cell behavior is dampened.
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Affiliation(s)
- Justin J Cassidy
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Aashish R Jha
- Institute for Genomics and Systems Biology, Departments of Human Genetics and Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA
| | - Diana M Posadas
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Ritika Giri
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Koen J T Venken
- Department of Molecular and Human Genetics, Howard Hughes Medical Institute, Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jingran Ji
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Hongmei Jiang
- Department of Statistics, Northwestern University, Evanston, IL 60208, USA
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Howard Hughes Medical Institute, Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Kevin P White
- Institute for Genomics and Systems Biology, Departments of Human Genetics and Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA
| | - Richard W Carthew
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.
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Terriente-Felix A, Li J, Collins S, Mulligan A, Reekie I, Bernard F, Krejci A, Bray S. Notch cooperates with Lozenge/Runx to lock haemocytes into a differentiation programme. Development 2013; 140:926-37. [PMID: 23325760 DOI: 10.1242/dev.086785] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The diverse functions of Notch signalling imply that it must elicit context-specific programmes of gene expression. With the aim of investigating how Notch drives cells to differentiate, we have used a genome-wide approach to identify direct Notch targets in Drosophila haemocytes (blood cells), where Notch promotes crystal cell differentiation. Many of the identified Notch-regulated enhancers contain Runx and GATA motifs, and we demonstrate that binding of the Runx protein Lozenge (Lz) is required for enhancers to be competent to respond to Notch. Functional studies of targets, such as klumpfuss (ERG/WT1 family) and pebbled/hindsight (RREB1 homologue), show that Notch acts both to prevent the cells adopting alternate cell fates and to promote morphological characteristics associated with crystal cell differentiation. Inappropriate activity of Klumpfuss perturbs the differentiation programme, resulting in melanotic tumours. Thus, by acting as a master regulator, Lz directs Notch to activate selectively a combination of target genes that correctly locks cells into the differentiation programme.
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Affiliation(s)
- Ana Terriente-Felix
- Department of Physiology Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK.
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14
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Chlon TM, Crispino JD. Combinatorial regulation of tissue specification by GATA and FOG factors. Development 2012; 139:3905-16. [PMID: 23048181 DOI: 10.1242/dev.080440] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The development of complex organisms requires the formation of diverse cell types from common stem and progenitor cells. GATA family transcriptional regulators and their dedicated co-factors, termed Friend of GATA (FOG) proteins, control cell fate and differentiation in multiple tissue types from Drosophila to man. FOGs can both facilitate and antagonize GATA factor transcriptional regulation depending on the factor, cell, and even the specific gene target. In this review, we highlight recent studies that have elucidated mechanisms by which FOGs regulate GATA factor function and discuss how these factors use these diverse modes of gene regulation to control cell lineage specification throughout metazoans.
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Affiliation(s)
- Timothy M Chlon
- Department of Medicine, Northwestern University, Chicago, IL 60611, USA
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15
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Jin H, Kim VN, Hyun S. Conserved microRNA miR-8 controls body size in response to steroid signaling in Drosophila. Genes Dev 2012; 26:1427-32. [PMID: 22751499 DOI: 10.1101/gad.192872.112] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Body size determination is a process that is tightly linked with developmental maturation. Ecdysone, an insect maturation hormone, contributes to this process by antagonizing insulin signaling and thereby suppressing juvenile growth. Here, we report that the microRNA miR-8 and its target, u-shaped (USH), a conserved microRNA/target axis that regulates insulin signaling, are critical for ecdysone-induced body size determination in Drosophila. We found that the miR-8 level is reduced in response to ecdysone, while the USH level is up-regulated reciprocally, and that miR-8 is transcriptionally repressed by ecdysone's early response genes. Furthermore, modulating the miR-8 level correlatively changes the fly body size; either overexpression or deletion of miR-8 abrogates ecdysone-induced growth control. Consistently, perturbation of USH impedes ecdysone's effect on body growth. Thus, miR-8 acts as a molecular rheostat that tunes organismal growth in response to a developmental maturation signal.
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Affiliation(s)
- Hua Jin
- School of Biological Sciences, Seoul National University, Seoul 151-742, Korea
| | - V Narry Kim
- School of Biological Sciences, Seoul National University, Seoul 151-742, Korea
| | - Seogang Hyun
- School of Biological Sciences, Seoul National University, Seoul 151-742, Korea.,School of Biological Sciences, Chung-Ang University, Seoul 156-756, Korea
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16
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Fossett N. Signal transduction pathways, intrinsic regulators, and the control of cell fate choice. Biochim Biophys Acta Gen Subj 2012; 1830:2375-84. [PMID: 22705942 DOI: 10.1016/j.bbagen.2012.06.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2012] [Revised: 05/10/2012] [Accepted: 06/07/2012] [Indexed: 12/14/2022]
Abstract
BACKGROUND Information regarding changes in organismal status is transmitted to the stem cell regulatory machinery by a limited number of signal transduction pathways. Consequently, these pathways derive their functional specificity through interactions with stem cell intrinsic master regulators, notably transcription factors. Identifying the molecular underpinnings of these interactions is critical to understanding stem cell function. SCOPE OF REVIEW This review focuses on studies in Drosophila that identify the gene regulatory basis for interactions between three different signal transduction pathways and an intrinsic master transcriptional regulator in the context of hematopoietic stem-like cell fate choice. Specifically, the interface between the GATA:FOG regulatory complex and the JAK/STAT, BMP, and Hedgehog pathways is examined. MAJOR CONCLUSIONS The GATA:FOG complex coordinates information transmitted by at least three different signal transduction pathways as a means to control stem-like cell fate choice. This illustrates emerging principles concerning regulation of stem cell function and describes a gene regulatory link between changes in organismal status and stem cell response. GENERAL SIGNIFICANCE The Drosophila model system offers a powerful approach to identify the molecular basis of how stem cells receive, interpret, and then respond to changes in organismal status. This article is part of a Special Issue entitled: Biochemistry of Stem Cells.
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Affiliation(s)
- Nancy Fossett
- Center for Vascular and Inflammatory Diseases and the Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Del Signore SJ, Hayashi T, Hatini V. odd-skipped genes and lines organize the notum anterior-posterior axis using autonomous and non-autonomous mechanisms. Mech Dev 2012; 129:147-61. [PMID: 22613630 DOI: 10.1016/j.mod.2012.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 04/27/2012] [Accepted: 05/06/2012] [Indexed: 10/28/2022]
Abstract
The growth and patterning of Drosophila wing and notum primordia depend on their subdivision into progressively smaller domains by secreted signals that emanate from localized sources termed organizers. While the mechanisms that organize the wing primordium have been studied extensively, those that organize the notum are incompletely understood. The genes odd-skipped (odd), drumstick (drm), sob, and bowl comprise the odd-skipped family of C(2)H(2) zinc finger genes, which has been implicated in notum growth and patterning. Here we show that drm, Bowl, and eyegone (eyg), a gene required for notum patterning, accumulate in nested domains in the anterior notum. Ectopic drm organized the nested expression of these anterior notum genes and downregulated the expression of posterior notum genes. The cell-autonomous induction of Bowl and Eyg required bowl, while the non-autonomous effects were independent of bowl. The homeodomain protein Bar is expressed along the anterior border of the notum adjacent to cells expressing the Notch (N) ligand Delta (Dl). bowl was required to promote Bar and repress Dl expression to pattern the anterior notum in a cell-autonomous manner, while lines acted antagonistically to bowl posterior to the Bowl domain. Our data suggest that the odd-skipped genes act at the anterior notum border to organize the notum anterior-posterior (AP) axis using both autonomous and non-autonomous mechanisms.
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Affiliation(s)
- Steven J Del Signore
- Department of Anatomy & Cellular Biology, Tufts University School of Medicine, USA
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18
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Hainaut M, Sagnier T, Berenger H, Pradel J, Graba Y, Miotto B. The MYST-containing protein Chameau is required for proper sensory organ specification during Drosophila thorax morphogenesis. PLoS One 2012; 7:e32882. [PMID: 22412942 PMCID: PMC3295779 DOI: 10.1371/journal.pone.0032882] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 02/04/2012] [Indexed: 12/15/2022] Open
Abstract
The adult thorax of Drosophila melanogaster is covered by a stereotyped pattern of mechanosensory bristles called macrochaetes. Here, we report that the MYST containing protein Chameau (Chm) contributes to the establishment of this pattern in the most dorsal part of the thorax. Chm mutant pupae present extra-dorsocentral (DC) and scutellar (SC) macrochaetes, but a normal number of the other macrochaetes. We provide evidences that chm restricts the singling out of sensory organ precursors from proneural clusters and genetically interacts with transcriptional regulators involved in the regulation of achaete and scute in the DC and SC proneural cluster. This function of chm likely relies on chromatin structure regulation since a protein with a mutation in the conserved catalytic site fails to rescue the formation of supernumerary DC and SC bristles in chm mutant flies. This is further supported by the finding that mutations in genes encoding chromatin modifiers and remodeling factors, including Polycomb group (PcG) and Trithorax group (TrxG) members, dominantly modulate the penetrance of chm extra bristle phenotype. These data support a critical role for chromatin structure modulation in the establishment of the stereotyped sensory bristle pattern in the fly thorax.
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Affiliation(s)
- Matthieu Hainaut
- Institut de Biologie du Développement de Marseille-Luminy, CNRS UMR6216/Université de la Méditerranée, Marseille, France
| | - Thierry Sagnier
- Institut de Biologie du Développement de Marseille-Luminy, CNRS UMR6216/Université de la Méditerranée, Marseille, France
| | - Hélène Berenger
- Institut de Biologie du Développement de Marseille-Luminy, CNRS UMR6216/Université de la Méditerranée, Marseille, France
| | - Jacques Pradel
- Institut de Biologie du Développement de Marseille-Luminy, CNRS UMR6216/Université de la Méditerranée, Marseille, France
| | - Yacine Graba
- Institut de Biologie du Développement de Marseille-Luminy, CNRS UMR6216/Université de la Méditerranée, Marseille, France
- * E-mail: (YG); (BM)
| | - Benoit Miotto
- Institut de Biologie du Développement de Marseille-Luminy, CNRS UMR6216/Université de la Méditerranée, Marseille, France
- * E-mail: (YG); (BM)
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19
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Abstract
Micro-ribonucleic acids (miRNAs) are small (21-24 nucleotide), endogenously expressed, noncoding RNAs that have emerged as important posttranscriptional regulators of gene expression. MiRNAs have been identified and cloned from diverse eukaryotic organisms where they have been shown to control important physiological and developmental processes such as apoptosis, cell division, and differentiation. A high level of conservation of some miRNAs across phyla further emphasizes their importance as posttranscriptional regulators. Research in a variety of model systems has been instrumental in dissecting the biological functions of miRNAs. In this chapter, we discuss the current literature on the role of miRNAs as developmental regulators in Drosophila.
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20
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Zaytouni T, Efimenko EE, Tevosian SG. GATA transcription factors in the developing reproductive system. ADVANCES IN GENETICS 2011; 76:93-134. [PMID: 22099693 DOI: 10.1016/b978-0-12-386481-9.00004-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Previous work has firmly established the role for both GATA4 and FOG2 in the initial global commitment to sexual fate, but their (joint or individual) function in subsequent steps remained unknown. Hence, gonad-specific deletions of these genes in mice were required to reveal their roles in sexual development and gene regulation. The development of tissue-specific Cre lines allowed for substantial advances in the understanding of the function of GATA proteins in sex determination, gonadal differentiation and reproductive development in mice. Here we summarize the recent work that examined the requirement of GATA4 and FOG2 proteins at several critical stages in testis and ovarian differentiation. We also discuss the molecular mechanisms involved in this regulation through the control of Dmrt1 gene expression in the testis and the canonical Wnt/ß-catenin pathway in the ovary.
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Affiliation(s)
- Tamara Zaytouni
- Department of Genetics, Dartmouth Medical School, Hanover, NH, USA
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21
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Tokusumi Y, Tokusumi T, Stoller-Conrad J, Schulz RA. Serpent, suppressor of hairless and U-shaped are crucial regulators of hedgehog niche expression and prohemocyte maintenance during Drosophila larval hematopoiesis. Development 2010; 137:3561-8. [PMID: 20876645 DOI: 10.1242/dev.053728] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The lymph gland is a specialized organ for hematopoiesis, utilized during larval development in Drosophila. This tissue is composed of distinct cellular domains populated by blood cell progenitors (the medullary zone), niche cells that regulate the choice between progenitor quiescence and hemocyte differentiation [the posterior signaling center (PSC)], and mature blood cells of distinct lineages (the cortical zone). Cells of the PSC express the Hedgehog (Hh) signaling molecule, which instructs cells within the neighboring medullary zone to maintain a hematopoietic precursor state while preventing hemocyte differentiation. As a means to understand the regulatory mechanisms controlling Hh production, we characterized a PSC-active transcriptional enhancer that drives hh expression in supportive niche cells. Our findings indicate that a combination of positive and negative transcriptional inputs program the precise PSC expression of the instructive Hh signal. The GATA factor Serpent (Srp) is essential for hh activation in niche cells, whereas the Suppressor of Hairless [Su(H)] and U-shaped (Ush) transcriptional regulators prevent hh expression in blood cell progenitors and differentiated hemocytes. Furthermore, Srp function is required for the proper differentiation of niche cells. Phenotypic analyses also indicated that the normal activity of all three transcriptional regulators is essential for maintaining the progenitor population and preventing premature hemocyte differentiation. Together, these studies provide mechanistic insights into hh transcriptional regulation in hematopoietic progenitor niche cells, and demonstrate the requirement of the Srp, Su(H) and Ush proteins in the control of niche cell differentiation and blood cell precursor maintenance.
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Affiliation(s)
- Yumiko Tokusumi
- Department of Biological Sciences, University of Notre Dame, 147 Galvin Life Sciences Hall, Notre Dame, IN 46556, USA
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22
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Fromental-Ramain C, Taquet N, Ramain P. Transcriptional interactions between the pannier isoforms and the cofactor U-shaped during neural development in Drosophila. Mech Dev 2010; 127:442-57. [PMID: 20709169 DOI: 10.1016/j.mod.2010.08.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Revised: 08/06/2010] [Accepted: 08/10/2010] [Indexed: 11/15/2022]
Abstract
The pannier (pnr) gene of Drosophila melanogaster encodes two isoforms that belong to the family of GATA transcription factors. The isoforms share an expression domain in the wing discs where they exhibit distinct functions during regulation of the proneural achaete/scute (ac/sc) genes. We previously identified two regions in the pnr locus that drive reporter expression in transgenic lines in patterns that recapitulate the essential features of expression of the two isoforms. Here, we identify promoter regions driving isoform expression, showing that pnr-α regulatory sequences are close to the transcription start site while pnr-β expression requires functional interactions between proximal and distal regulatory elements. We find that the promoter domains necessary for reporter expression also mediate autoregulation of Pnr-β and repression of pnr-α by Pnr-β. The cofactor U-shaped (Ush), which is known to down-regulate the function of Pnr during thorax patterning postranscriptionally, in addition represses pnr-β required for ac/sc activation. Moreover, Ush negatively regulates its own expression, while the pnr isoforms positively regulate ush. Our study uncovers complex transcriptional interactions between the pnr isoforms and the cofactor Ush that may be important for regulation of proneural expression and thorax patterning.
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Affiliation(s)
- Catherine Fromental-Ramain
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, 67404 Illkirch Cedex, France
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23
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The pronotum LIM-HD gene tailup is both a positive and a negative regulator of the proneural genes achaete and scute of Drosophila. Mech Dev 2010; 127:393-406. [PMID: 20580820 DOI: 10.1016/j.mod.2010.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 05/10/2010] [Accepted: 05/14/2010] [Indexed: 01/14/2023]
Abstract
Early in the development of the imaginal wing disc of Drosophila, the LIM-HD gene tailup (islet), together with the HD genes of the iroquois complex, specify the notum territory of the disc. Later, tailup has been shown to act as a prepattern gene that antagonizes formation of sensory bristles on the notum of this fly. It has been proposed that Tailup downregulates the expression of the proneural genes achaete and scute by interfering with factors needed to activate these genes in the dorsocentral and scutellar regions of the disc. By means of a clonal analysis performed with tailup null alleles, here we show that, on the one hand, tailup is necessary to prevent formation of extra macrochaetae on most of the 11 sites where these landmark bristles arise on the fly notum. On the other hand, tailup is required to activate achaete and scute at the dorsocentral region, probably by acting as an hexameric complex with the cofactor Chip and the transcriptional activator Sspd on the dorsocentral enhancer of the achaete-scute complex. In contrast, in the scutellar region Tailup acts downstream of achaete-scute, antagonizing the proneural function of these genes probably in cooperation with Chip. We conclude that tailup acts on bristle development by several, even antagonistic, mechanisms.
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24
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Valanne S, Myllymäki H, Kallio J, Schmid MR, Kleino A, Murumägi A, Airaksinen L, Kotipelto T, Kaustio M, Ulvila J, Esfahani SS, Engström Y, Silvennoinen O, Hultmark D, Parikka M, Rämet M. Genome-wide RNA interference in Drosophila cells identifies G protein-coupled receptor kinase 2 as a conserved regulator of NF-kappaB signaling. THE JOURNAL OF IMMUNOLOGY 2010; 184:6188-98. [PMID: 20421637 DOI: 10.4049/jimmunol.1000261] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Because NF-kappaB signaling pathways are highly conserved in evolution, the fruit fly Drosophila melanogaster provides a good model to study these cascades. We carried out an RNA interference (RNAi)-based genome-wide in vitro reporter assay screen in Drosophila for components of NF-kappaB pathways. We analyzed 16,025 dsRNA-treatments and identified 10 novel NF-kappaB regulators. Of these, nine dsRNA-treatments affect primarily the Toll pathway. G protein-coupled receptor kinase (Gprk)2, CG15737/Toll pathway activation mediating protein, and u-shaped were required for normal Drosomycin response in vivo. Interaction studies revealed that Gprk2 interacts with the Drosophila IkappaB homolog Cactus, but is not required in Cactus degradation, indicating a novel mechanism for NF-kappaB regulation. Morpholino silencing of the zebrafish ortholog of Gprk2 in fish embryos caused impaired cytokine expression after Escherichia coli infection, indicating a conserved role in NF-kappaB signaling. Moreover, small interfering RNA silencing of the human ortholog GRK5 in HeLa cells impaired NF-kappaB reporter activity. Gprk2 RNAi flies are susceptible to infection with Enterococcus faecalis and Gprk2 RNAi rescues Toll(10b)-induced blood cell activation in Drosophila larvae in vivo. We conclude that Gprk2/GRK5 has an evolutionarily conserved role in regulating NF-kappaB signaling.
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Affiliation(s)
- Susanna Valanne
- Institute of Medical Technology, University of Tampere, Tampere, Finland
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25
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Hyun S, Lee JH, Jin H, Nam J, Namkoong B, Lee G, Chung J, Kim VN. Conserved MicroRNA miR-8/miR-200 and its target USH/FOG2 control growth by regulating PI3K. Cell 2010; 139:1096-108. [PMID: 20005803 DOI: 10.1016/j.cell.2009.11.020] [Citation(s) in RCA: 235] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 09/21/2009] [Accepted: 11/10/2009] [Indexed: 02/01/2023]
Abstract
How body size is determined is a long-standing question in biology, yet its regulatory mechanisms remain largely unknown. Here, we find that a conserved microRNA miR-8 and its target, USH, regulate body size in Drosophila. miR-8 null flies are smaller in size and defective in insulin signaling in fat body that is the fly counterpart of liver and adipose tissue. Fat body-specific expression and clonal analyses reveal that miR-8 activates PI3K, thereby promoting fat cell growth cell-autonomously and enhancing organismal growth non-cell-autonomously. Comparative analyses identify USH and its human homolog, FOG2, as the targets of fly miR-8 and human miR-200, respectively. USH/FOG2 inhibits PI3K activity, suppressing cell growth in both flies and humans. FOG2 directly binds to p85alpha, the regulatory subunit of PI3K, and interferes with the formation of a PI3K complex. Our study identifies two novel regulators of insulin signaling, miR-8/miR-200 and USH/FOG2, and suggests their roles in adolescent growth, aging, and cancer.
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Affiliation(s)
- Seogang Hyun
- School of Biological Sciences and National Creative Research Center, Seoul National University, Seoul, 151-742, Korea
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26
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Shalaby NA, Parks AL, Morreale EJ, Osswalt MC, Pfau KM, Pierce EL, Muskavitch MAT. A screen for modifiers of notch signaling uncovers Amun, a protein with a critical role in sensory organ development. Genetics 2009; 182:1061-76. [PMID: 19448274 PMCID: PMC2728848 DOI: 10.1534/genetics.108.099986] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2009] [Accepted: 05/11/2009] [Indexed: 12/14/2022] Open
Abstract
Notch signaling is an evolutionarily conserved pathway essential for many cell fate specification events during metazoan development. We conducted a large-scale transposon-based screen in the developing Drosophila eye to identify genes involved in Notch signaling. We screened 10,447 transposon lines from the Exelixis collection for modifiers of cell fate alterations caused by overexpression of the Notch ligand Delta and identified 170 distinct modifier lines that may affect up to 274 genes. These include genes known to function in Notch signaling, as well as a large group of characterized and uncharacterized genes that have not been implicated in Notch pathway function. We further analyze a gene that we have named Amun and show that it encodes a protein that localizes to the nucleus and contains a putative DNA glycosylase domain. Genetic and molecular analyses of Amun show that altered levels of Amun function interfere with cell fate specification during eye and sensory organ development. Overexpression of Amun decreases expression of the proneural transcription factor Achaete, and sensory organ loss caused by Amun overexpression can be rescued by coexpression of Achaete. Taken together, our data suggest that Amun acts as a transcriptional regulator that can affect cell fate specification by controlling Achaete levels.
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Affiliation(s)
- Nevine A Shalaby
- Biology Department, Boston College, Chestnut Hill, Massachusetts 02467, USA
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27
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Stern MD, Aihara H, Roccaro GA, Cheung L, Zhang H, Negeri D, Nibu Y. CtBP is required for proper development of peripheral nervous system in Drosophila. Mech Dev 2008; 126:68-79. [PMID: 18992810 DOI: 10.1016/j.mod.2008.10.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Revised: 09/19/2008] [Accepted: 10/08/2008] [Indexed: 10/21/2022]
Abstract
C-terminal binding protein (CtBP) is an evolutionarily and functionally conserved transcriptional corepressor known to integrate diverse signals to regulate transcription. Drosophila CtBP (dCtBP) regulates tissue specification and segmentation during early embryogenesis. Here, we investigated the roles of dCtBP during development of the peripheral nervous system (PNS). Our study includes a detailed quantitative analysis of how altered dCtBP activity affects the formation of adult mechanosensory bristles. We found that dCtBP loss-of-function resulted in a series of phenotypes with the most prevalent being supernumerary bristles. These dCtBP phenotypes are more complex than those caused by Hairless, a known dCtBP-interacting factor that regulates bristle formation. The emergence of additional bristles correlated with the appearance of extra sensory organ precursor (SOP) cells in earlier stages, suggesting that dCtBP may directly or indirectly inhibit SOP cell fates. We also found that development of a subset of bristles was regulated by dCtBP associated with U-shaped through the PxDLS dCtBP-interacting motif. Furthermore, the double bristle with sockets phenotype induced by dCtBP mutations suggests the involvement of this corepressor in additional molecular pathways independent of both Hairless and U-shaped. We therefore propose that dCtBP is part of a gene circuitry that controls the patterning and differentiation of the fly PNS via multiple mechanisms.
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Affiliation(s)
- Mark D Stern
- Department of Cell and Developmental Biology, Weill Medical College of Cornell University, New York, NY 10065, USA
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28
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Biryukova I, Heitzler P. Drosophila C-terminal binding protein, dCtBP is required for sensory organ prepattern and sharpens proneural transcriptional activity of the GATA factor Pnr. Dev Biol 2008; 323:64-75. [PMID: 18773887 DOI: 10.1016/j.ydbio.2008.08.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 07/23/2008] [Accepted: 08/09/2008] [Indexed: 11/15/2022]
Abstract
The peripheral nervous system is required for animals to detect and to relay environmental stimuli to central nervous system for the information processing. In Drosophila, the precise spatial and temporal expression of two proneural genes achaete (ac) and scute (sc), is necessary for development of the sensory organs. Here we present an evidence that the transcription co-repressor, dCtBP acts as a negative regulator of sensory organ prepattern. Loss of dCtBP function mutant exhibits ectopic sensory organs, while overexpression of dCtBP results in a dramatic loss of sensory organs. These phenotypes are correlated with mis-emerging of sensory organ precursors and perturbated expression of proneural transcription activator Ac. Mammalian CtBP-1 was identified via interaction with the consensus motif PXDLSX(K/R) of adenovirus E1A oncoprotein. We demonstrated that dCtBP binds directly to PLDLS motif of Drosophila Friend of GATA-1 protein, U-shaped and sharpens the adult sensory organ development. Moreover, we found that dCtBP mediates multivalent interaction with the GATA transcriptional activator Pannier and acts as a direct co-repressor of the Pannier-mediated activation of proneural genes. We demonstrated that Pannier genetically interacts with dCtBP-interacting protein HDAC1, suggesting that the dCtBP-dependent regulation of Pannier activity could utilize a repressive mechanism involving alteration of local chromatine structure.
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Affiliation(s)
- Inna Biryukova
- Department of Developmental Biology, Institut de Génétique et de Biologie, Moléculaire et Cellulaire, Illkirch Cedex, BP 10142, France.
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29
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Asmar J, Biryukova I, Heitzler P. Drosophila dLMO-PA isoform acts as an early activator of achaete/scute proneural expression. Dev Biol 2008; 316:487-97. [PMID: 18329012 DOI: 10.1016/j.ydbio.2008.01.040] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 01/11/2008] [Accepted: 01/19/2008] [Indexed: 10/22/2022]
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30
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Tanaka-Matakatsu M, Du W. Direct control of the proneural gene atonal by retinal determination factors during Drosophila eye development. Dev Biol 2008; 313:787-801. [PMID: 18083159 PMCID: PMC2231519 DOI: 10.1016/j.ydbio.2007.11.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 11/13/2007] [Accepted: 11/14/2007] [Indexed: 01/04/2023]
Abstract
The determination of neuronal identity in Drosophila cells depends on the accurate expression of proneural genes. The proneural gene atonal (ato) encodes a basic-HLH protein required for photoreceptor and chordotonal organ formation. The initial expression of ato in imaginal discs is regulated by sequences that lie 3' to its open reading frame. In this report, we show that the initial ato transcription in different imaginal discs is regulated by distinct 3' cis-regulatory sequences. The eye-specific ato 3' cis-regulatory sequence consists of two distinct elements we term 2.8 PB and 3.6 BP that regulate ato transcription during different stages of eye development. The 2.8 PB enhancer contains a highly conserved consensus binding site for the retinal determination (RD) factor Sine oculis (So). Mutation of this So binding site abolishes 2.8 PB enhancer activity. Furthermore the RD factors So and Eyes absent (Eya) are required for 2.8 PB enhancer activity and can induce ectopic 2.8 PB reporter expression. In contrast, ectopic Dpp signaling is not sufficient to induce ato 3' enhancer activation but can induce increased levels of RD factor Dachshund (Dac) and synergize with So and Eya to increase ato 3' enhancer activity. These results demonstrate a direct mechanism by which the RD factors regulate ato expression and suggest an important role of Dpp in the activation of ato 3' enhancer is to regulate the levels of RD factors.
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MESH Headings
- Animals
- Animals, Genetically Modified
- Basic Helix-Loop-Helix Transcription Factors/genetics
- Basic Helix-Loop-Helix Transcription Factors/metabolism
- Binding Sites
- Drosophila/embryology
- Drosophila/genetics
- Drosophila Proteins/chemistry
- Drosophila Proteins/genetics
- Drosophila Proteins/metabolism
- Embryo, Nonmammalian
- Enhancer Elements, Genetic
- Eye/embryology
- Eye Proteins/genetics
- Eye Proteins/metabolism
- Fluorescent Antibody Technique, Indirect
- Gene Expression Regulation, Developmental
- Genes, Insect
- Genes, Reporter
- Green Fluorescent Proteins/metabolism
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Immunohistochemistry
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Organogenesis
- Protein Binding
- Protein Structure, Tertiary
- RNA, Messenger/metabolism
- Regulatory Elements, Transcriptional
- Retina/embryology
- Retina/metabolism
- Sequence Analysis, DNA
- Transcription, Genetic
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Affiliation(s)
- Miho Tanaka-Matakatsu
- Ben May Department for Cancer Research, The University of Chicago, 929 E. 57th Street, Chicago, IL 60637, USA
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31
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Ikmi A, Netter S, Coen D. Prepatterning the Drosophila notum: the three genes of the iroquois complex play intrinsically distinct roles. Dev Biol 2008; 317:634-48. [PMID: 18394597 DOI: 10.1016/j.ydbio.2007.12.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Revised: 12/21/2007] [Accepted: 12/22/2007] [Indexed: 12/24/2022]
Abstract
The Drosophila thorax exhibits 11 pairs of large sensory organs (macrochaetes) identified by their unique position. Remarkably precise, this pattern provides an excellent model system to study the genetic basis of pattern formation. In imaginal wing discs, the achaete-scute proneural genes are expressed in clusters of cells that prefigure the positions of each macrochaete. The activities of prepatterning genes provide positional cues controlling this expression pattern. The three homeobox genes clustered in the iroquois complex (araucan, caupolican and mirror) are such prepattern genes. mirror is generally characterized as performing functions predominantly different from the other iroquois genes. Conversely, araucan and caupolican are described in previous studies as performing redundant functions in most if not all processes in which they are involved. We have addressed the question of the specific role of each iroquois gene in the prepattern of the notum and we clearly demonstrate that they are intrinsically different in their contribution to this process: caupolican and mirror, but not araucan, are required for the neural patterning of the lateral notum. However, when caupolican and/or mirror expression is reduced, araucan loss of function has an effect on thoracic bristles development. Moreover, the overexpression of araucan is able to rescue caupolican loss of function. We conclude that, although retaining some common functionalities, the Drosophila iroquois genes are in the process of diversification. In addition, caupolican and mirror are required for stripe expression and, therefore, to specify the muscular attachment sites prepattern. Thus, caupolican and mirror may act as common prepattern genes for all structures in the lateral notum.
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Affiliation(s)
- Aissam Ikmi
- Développement, Morphogenèse et Evolution, CNRS UMR 8080, Université Paris-Sud, 91405 Orsay, France
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32
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Simpson P, Ayyar S. Chapter 3 Evolution of Cis‐Regulatory Sequences in Drosophila. LONG-RANGE CONTROL OF GENE EXPRESSION 2008; 61:67-106. [DOI: 10.1016/s0065-2660(07)00003-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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33
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Fromental-Ramain C, Vanolst L, Delaporte C, Ramain P. pannier encodes two structurally related isoforms that are differentially expressed during Drosophila development and display distinct functions during thorax patterning. Mech Dev 2007; 125:43-57. [PMID: 18042352 DOI: 10.1016/j.mod.2007.10.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2007] [Revised: 09/28/2007] [Accepted: 10/11/2007] [Indexed: 02/06/2023]
Abstract
Previous studies have shown that the pannier (pnr) gene of Drosophila encodes a GATA transcription factor which is involved in various biological processes, including heart development, dorsal closure during embryogenesis as well as neurogenesis and regulation of wingless (wg) expression during imaginal development. We demonstrate here that pnr encodes two highly related isoforms that share functional domains but are differentially expressed during development. Moreover, we describe two genomic regions of the pnr locus that drive expression of a reporter in transgenic flies in patterns that recapitulate essential features of the expression of the isoforms, suggesting that these regions encompass crucial regulatory elements. These elements contain, in particular, sequences mediating regulation of expression by Decapentaplegic (Dpp) signaling, during both embryogenesis and imaginal development. Analysis of pnr alleles reveals that the isoforms differentially regulate expression of both wg and proneural achaete/scute (as/sc) targets during imaginal development. Pnr function has been demonstrated to be necessary both for activation of wg and, together with U-shaped (Ush), for its repression in the dorsal-most region of the presumptive notum. Expression of the isoforms define distinct longitudinal domains and, in this regard, we importantly show that the dual function of pnr during regulation of wg is achieved by one isoform repressing expression of the morphogen in the dorsal-most region of the disc while the other laterally promotes activation of the notal wg expression. Our study provides novel insights into pnr function during Drosophila development and extends our knowledge of the roles of prepattern factors during thorax patterning.
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The Friend of GATA protein U-shaped functions as a hematopoietic tumor suppressor in Drosophila. Dev Biol 2007; 311:311-23. [PMID: 17936744 DOI: 10.1016/j.ydbio.2007.08.011] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2007] [Revised: 07/20/2007] [Accepted: 08/06/2007] [Indexed: 11/22/2022]
Abstract
Drosophila has emerged as an important model system to discover and analyze genes controlling hematopoiesis. One regulatory network known to control hemocyte differentiation is the Janus kinase (JAK)/Signal Transducer and Activator of Transcription (STAT) signal-transduction pathway. A constitutive activation mutation of the Janus kinase Hopscotch (hopscotch(Tumorous-lethal); hop(Tum-l)) results in a leukemia-like over-proliferation of hemocytes and copious differentiation of lamellocytes during larval stages. Here we show that the Friend of GATA (FOG) protein U-shaped (Ush) is expressed in circulating and lymph gland hemocytes, where it plays a critical role in controlling blood cell proliferation and differentiation. Our findings demonstrate that a reduction in ush function results in hematopoietic phenotypes strikingly similar to those observed in hop(Tum-l) animals. These include lymph gland hypertrophy, increased circulating hemocyte concentration, and abundant production of lamellocytes. Forced expression of N-terminal truncated versions of Ush likewise leads to larvae with severe hematopoietic anomalies. In contrast, expression of wild-type Ush results in a strong suppression of hop(Tum-l) phenotypes. Taken together, our findings demonstrate that U-shaped acts to control larval hemocyte proliferation and suppress lamellocyte differentiation, likely regulating hematopoietic events downstream of Hop kinase activity. Such functions appear to be facilitated through Ush interaction with the hematopoietic GATA factor Serpent (Srp).
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Simpson P. The stars and stripes of animal bodies: evolution of regulatory elements mediating pigment and bristle patterns in Drosophila. Trends Genet 2007; 23:350-8. [PMID: 17499383 DOI: 10.1016/j.tig.2007.04.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Revised: 04/11/2007] [Accepted: 04/23/2007] [Indexed: 11/22/2022]
Abstract
Evolution has generated enormous morphological diversity in animals and one of the genetic processes that might have contributed to this is evolution of the cis-regulatory sequences responsible for the temporal and spatial expression of genes regulating embryonic development. This could be particularly relevant to pleiotropic genes with multiple independently acting regulatory modules. Loss or gain of modules enables altered expression without loss of other functions. Here I focus on recent studies correlating differences in morphological traits between related species of Drosophila to changes in cis-regulatory sequences. They show that ancestral regulatory modules have evolved to mediate different transcriptional outputs and suggest that evolution of cis-regulatory sequences might reflect a general mechanism driving evolutionary change.
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Affiliation(s)
- Pat Simpson
- Department of Zoology, University of Cambridge, Cambridge, UK.
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36
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de Navascués J, Modolell J. tailup, a LIM-HD gene, and Iro-C cooperate in Drosophila dorsal mesothorax specification. Development 2007; 134:1779-88. [PMID: 17409113 DOI: 10.1242/dev.02844] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The LIM-HD gene tailup (tup; also known as islet) has been categorised as a prepattern gene that antagonises the formation of sensory bristles on the notum of Drosophila by downregulating the expression of the proneural achaete-scutegenes. Here we show that tup has an earlier function in the development of the imaginal wing disc; namely, the specification of the notum territory. Absence of tup function causes cells of this anlage to upregulate different wing-hinge genes and to lose expression of some notum genes. Consistently, these cells differentiate hinge structures or modified notum cuticle. The LIM-HD co-factors Chip and Ssdp are also necessary for notum specification. This suggests that Tup acts in this process in a complex with Chip and Ssdp. Overexpression of tup, together with araucan, a `pronotum' gene of the iroquois complex (Iro-C),synergistically reinforces the weak capacity of either gene, when overexpressed singly, to induce ectopic notum-like development. Whereas the Iro-C genes are activated in the notum anlage by EGFR signalling, tupis positively regulated by Dpp signalling. Our data support a model in which the EGFR and Dpp signalling pathways, with their respective downstream Iro-C and tup genes, converge and cooperate to commit cells to the notum developmental fate.
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Affiliation(s)
- Joaquín de Navascués
- Centro de Biología Molecular Severo Ochoa, CSIC and UAM, Cantoblanco, Madrid, Spain
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37
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Tokusumi T, Russell M, Gajewski K, Fossett N, Schulz RA. U-shaped protein domains required for repression of cardiac gene expression in Drosophila. Differentiation 2007; 75:166-74. [PMID: 17316386 DOI: 10.1111/j.1432-0436.2006.00120.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
U-shaped is a zinc finger protein that functions predominantly as a negative transcriptional regulator of cell fate determination during Drosophila development. In the early stages of dorsal vessel formation, the protein acts to control cardioblast specification, working as a negative attenuator of the cardiogenic GATA factor Pannier. Pannier and the homeodomain protein Tinman normally work together to specify heart cells and activate cardioblast gene expression. One target of this positive regulation is a heart enhancer of the D-mef2 gene and U-shaped has been shown to antagonize enhancer activation by Pannier and Tinman. We have mapped protein domains of U-shaped required for its repression of cardioblast gene expression. Such studies showed GATA factor interacting zinc fingers of U-shaped are required for enhancer repression, as well as three small motifs that are likely needed for co-factor binding and/or protein modification. These analyses have also allowed for the definition of a 253 amino acid interval of U-shaped that is essential for its nuclear localization. Together, these findings provide molecular insights into the function of U-shaped as a negative regulator of heart development in Drosophila.
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Affiliation(s)
- Tsuyoshi Tokusumi
- Department of Biochemistry and Molecular Biology, Program in Genes & Development, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
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Letizia A, Barrio R, Campuzano S. Antagonistic and cooperative actions of the EGFR and Dpp pathways on the iroquois genes regulate Drosophila mesothorax specification and patterning. Development 2007; 134:1337-46. [PMID: 17329358 DOI: 10.1242/dev.02823] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In Drosophila, restricted expression of the Iroquois complex (Iro-C) genes in the proximal region of the wing imaginal disc contributes to its territorial subdivision, specifying first the development of the notum versus the wing hinge, and subsequently, that of the lateral versus medial notum. Iro-C expression is under the control of the EGFR and Dpp signalling pathways. To analyze how both pathways cooperate in the regulation of Iro-C, we isolated several wing disc-specific cis-regulatory elements of the complex. One of these (IroRE(2)) integrates competing inputs of the EGFR and Dpp pathways, mediated by the transcription factors Pointed (downstream of EGFR pathway) and Pannier/U-shaped and Mothers against Dpp (Mad), in the case of Dpp. By contrast, a second element (IroRE(1)) mediates activation by both the EGFR and Dpp pathways, thus promoting expression of Iro-C in a region of elevated levels of Dpp signalling, the prospective lateral notum near the anterior-posterior compartment boundary. These results help define the molecular mechanisms of the interplay between the EGFR and Dpp pathways in the specification and patterning of the notum.
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Affiliation(s)
- Annalisa Letizia
- Centro de Biología Molecular Severo Ochoa, CSIC and UAM, Cantoblanco, 28049 Madrid, Spain
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39
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Marcellini S, Simpson P. Two or four bristles: functional evolution of an enhancer of scute in Drosophilidae. PLoS Biol 2007; 4:e386. [PMID: 17105353 PMCID: PMC1635746 DOI: 10.1371/journal.pbio.0040386] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Accepted: 09/14/2006] [Indexed: 12/04/2022] Open
Abstract
Changes in cis-regulatory sequences are proposed to underlie much of morphological evolution. Yet, little is known about how such modifications translate into phenotypic differences. To address this problem, we focus on the dorsocentral bristles of Drosophilidae. In Drosophila melanogaster, development of these bristles depends on a cis-regulatory element, the dorsocentral enhancer, to activate scute in a cluster of cells from which two bristles on the posterior scutum arise. A few species however, such as D. quadrilineata, bear anterior dorsocentral bristles as well as posterior ones, a derived feature. This correlates with an anterior expansion of the scute expression domain. Here, we show that the D. quadrilineata enhancer has evolved, and is now active in more anterior regions. When used to rescue scute expression in transgenic D. melanogaster, the D. quadrilineata enhancer is able to induce anterior bristles. Importantly, these properties are not displayed by homologous enhancers from control species bearing only two posterior bristles. We also provide evidence that upstream regulation of the enhancer, by the GATA transcription factor Pannier, has been evolutionarily conserved. This work illustrates how, in the context of a conserved trans-regulatory landscape, evolutionary tinkering of pre-existing enhancers can modify gene expression patterns and contribute to morphological diversification. Evolutionary change in function of the dorsocentral enhancer (DCE) of scute has resulted in altered bristle formation between two species of Drosophila.
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Affiliation(s)
- Sylvain Marcellini
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.
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40
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Simpson P, Marcellini S. The origin and evolution of stereotyped patterns of macrochaetes on the nota of cyclorraphous Diptera. Heredity (Edinb) 2006; 97:148-56. [PMID: 16850036 DOI: 10.1038/sj.hdy.6800874] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
A long-standing problem in evolutionary biology is how genetic variation arises within populations and evolves to make species anatomically different. Many of the morphological differences in body plans between animal groups are thought to result from changes in gene expression during development. The rules governing the structure and evolution of cis-regulatory gene sequences are unknown, however, and the evolution of traits between closely related species remains relatively unexplored at a molecular level. To study the evolution of gene regulation, it is necessary to find a tractable trait that varies between species and for which the genetic regulation is well known in at least one of the species. The stereotyped, two-dimensional pattern of bristles on the thorax of Drosophila has been intensively investigated and is due to a precise spatial expression of proneural genes. Other species of flies have different bristle patterns and so comparisons between them provide a good paradigm for the study of changes in gene regulation. Here, we review the current state of understanding of these changes.
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Affiliation(s)
- P Simpson
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
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41
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Simpson P, Lewis M, Richardson J. Conservation of upstream regulators of scute on the notum of cyclorraphous Diptera. Dev Genes Evol 2006; 216:363-71. [PMID: 16670872 DOI: 10.1007/s00427-006-0077-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2005] [Accepted: 04/04/2006] [Indexed: 11/25/2022]
Abstract
Bristles on the notum of many cyclorraphous flies are arranged into species-specific stereotyped patterns. Differences in the spatial expression of the proneural gene scute correlate with the positions of bristles in those species looked at so far. However, the examination of a number of genes encoding trans-regulatory factors, such as pannier, stripe, u-shaped, caupolican and wingless, indicates that they are expressed in conserved domains on the prospective notum. This suggests that the function of a trans-regulatory network of genes is relatively unchanged in derived Diptera, and that many differences are likely to be due to changes in cis-regulatory sequences of scute. In contrast, in Anopheles gambiae, a basal species with no stereotyped bristle pattern, the expression patterns of pannier and wingless are not conserved, and expression of AgASH, the Anopheles proneural gene, does not correlate in a similar manner with the bristle pattern. We discuss the possibility that independently acting cis-regulatory sequences at the scute locus may have arisen in the lineage giving rise to cyclorraphous flies.
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Affiliation(s)
- Pat Simpson
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
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42
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Muratoglu S, Garratt B, Hyman K, Gajewski K, Schulz RA, Fossett N. Regulation of Drosophila friend of GATA gene, u-shaped, during hematopoiesis: a direct role for serpent and lozenge. Dev Biol 2006; 296:561-79. [PMID: 16730345 DOI: 10.1016/j.ydbio.2006.04.455] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2006] [Revised: 04/12/2006] [Accepted: 04/19/2006] [Indexed: 10/24/2022]
Abstract
Friend of GATA proteins interact with GATA factors to regulate development in a variety of tissues. We analyzed cis- and trans-regulation of the Drosophila gene, u-shaped, to better understand the transcriptional control of this important gene family during hematopoiesis. Using overlapping genomic fragments driving tissue-specific reporter-gene (lacZ) expression, we identified two minimal hematopoietic enhancers within the 7.4 kb region upstream of the transcription start site. One enhancer was active in all classes of hemocytes, whereas the other was active in hemocyte precursors and plasmatocytes only. The GATA factor, Serpent, directly regulated the activity of both enhancers. However, activity in the crystal cell lineage not only required Serpent but also the RUNX homologue, Lozenge. This is the first demonstration of GATA and RUNX direct regulation of Friend of GATA gene expression and provides additional evidence for the combinatorial control of crystal cell lineage commitment by Serpent, Lozenge, and U-shaped. In addition, we analyzed cis-regulation of ush expression in the lymph gland and identified similarities and differences between regulatory strategies used during embryonic and lymph gland hematopoiesis. The results of these studies provide information to analyze further the regulation of this conserved gene family and its role during hematopoietic lineage commitment.
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Affiliation(s)
- Selen Muratoglu
- Center for Vascular and Inflammatory Diseases and the Department of Pathology, University of Maryland School of Medicine, 800 W. Baltimore Street, Baltimore, MD 21201, USA
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43
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Biryukova I, Heitzler P. The Drosophila LIM-homeodomain protein Islet antagonizes proneural cell specification in the peripheral nervous system. Dev Biol 2005; 288:559-70. [PMID: 16259974 DOI: 10.1016/j.ydbio.2005.09.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2005] [Revised: 09/12/2005] [Accepted: 09/18/2005] [Indexed: 10/25/2022]
Abstract
The pattern of the external sensory organs (SO) in Drosophila depends on the activity of the basic helix-loop-helix (bHLH) transcriptional activators Achaete/Scute (Ac/Sc) that are expressed in clusters of cells (pro-neural clusters) and provide the cells with the potential to develop a neural fate. In the mesothorax, the GATA1 transcription factor Pannier (Pnr), together with its cofactor Chip, activates ac/sc genes directly through binding to the dorso-central enhancer (DC) of ac/sc. We identify the LIM-homeo domain (LIM-HD) transcription factor Islet (Isl) by genetic screening and investigate its role in the thoracic pre-patterning. We show that isl loss-of-function mutations result in expanded Ac expression in DC and scutellar (SC) pro-neural clusters and formation of ectopic sensory organs. Overexpression of Isl decreases pro-neural expression and suppresses bristle development. Moreover, Isl is coexpressed with Pnr in the posterior region of the mesothorax. In the DC pro-neural cluster, Isl antagonizes Pnr activity both by dimerization with the DNA-binding domain of Pnr and via competitive inhibition of the Chip-bHLH interaction. We propose that sensory organ pre-patterning relies on the antagonistic activity of individual Chip-binding factors. The differential affinities of these binding-factors and their precise stoichiometry are crucial in specifying pre-patterns within the different pro-neural clusters.
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Affiliation(s)
- Inna Biryukova
- Department of Developmental Biology/IGBMC, 1, rue Laurent Fries, BP 10142, 67404 Illkirch CEDEX, France
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44
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Richardson J, Simpson P. A conserved trans-regulatory landscape for scute expression on the notum of cyclorraphous Diptera. Dev Genes Evol 2005; 216:29-38. [PMID: 16193319 DOI: 10.1007/s00427-005-0028-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2005] [Accepted: 08/30/2005] [Indexed: 10/25/2022]
Abstract
Bristles on the notum of many cyclorraphous flies are arranged into species-specific stereotyped patterns. The positions of bristles correlate with differences in the spatial expression of the scute (sc) gene in those species examined so far. However, a major upstream activator of scute, Pannier (Pnr), is expressed in a conserved domain over the entire medial notum. Here we examine the expression patterns in Calliphora vicina of stripe (sr), u-shaped (ush), caupolican (caup) and wingless (wg), genes known to modify the activity of Pnr or to act downstream of Pnr in Drosophila. We find that, with minor differences, their expression patterns are conserved. This suggests that the function of a trans-regulatory network of genes is relatively unchanged in derived Diptera and that many differences are likely to be due to changes in cis-regulatory sequences of scute.
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Affiliation(s)
- Joanna Richardson
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK
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45
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Vanolst L, Fromental-Ramain C, Ramain P. Toutatis, a TIP5-related protein, positively regulates Pannier function during Drosophila neural development. Development 2005; 132:4327-38. [PMID: 16141224 DOI: 10.1242/dev.02014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The GATA factor Pannier (Pnr) activates proneural expression through binding to a remote enhancer of the achaete-scute (ac-sc) complex. Chip associates both with Pnr and with the (Ac-Sc)-Daughterless heterodimer bound to the ac-sc promoters to give a proneural complex that facilitates enhancer-promoter communication during development. Using a yeast two-hybrid screening, we have identified Toutatis (Tou), which physically interacts with both Pnr and Chip. Loss-of-function and gain-of-function experiments indicate that Tou cooperates with Pnr and Chip during neural development. Tou shares functional domains with chromatin remodelling proteins, including TIP5 (termination factor TTFI-interacting protein 5) of NoRC (nucleolar remodelling complex), which mediates repression of RNA polymerase 1 transcription. In contrast, Tou acts positively to activate proneural gene expression. Moreover, we show that Iswi associates with Tou, Pnr and Chip, and is also required during Pnr-driven neural development. The results suggest that Tou and Iswi may belong to a complex that directly regulates the activity of Pnr and Chip during enhancer-promoter communication, possibly through chromatin remodelling.
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Affiliation(s)
- Luc Vanolst
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Department of Developmental Biology, CNRS/INSERM/ULP, Boite Postale 10142, 67404 Illkirch Cedex, France
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46
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Sorrentino RP, Gajewski KM, Schulz RA. GATA factors in Drosophila heart and blood cell development. Semin Cell Dev Biol 2005; 16:107-16. [PMID: 15659345 DOI: 10.1016/j.semcdb.2004.10.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
GATA transcription factors comprise an evolutionarily conserved family of proteins that function in the specification and differentiation of various cell types during animal development. In this review, we examine current knowledge of the structure, expression, and function of the Pannier and Serpent GATA factors as they relate to cardiogenesis and hematopoiesis in the Drosophila system. We also assess the molecular and genetic characteristics of the Friend of GATA protein U-shaped, which serves as a regulator of Pannier and Serpent function in these two developmental processes.
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Affiliation(s)
- Richard Paul Sorrentino
- Department of Biochemistry and Molecular Biology, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
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47
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Xu M, Kirov N, Rushlow C. Peak levels of BMP in theDrosophilaembryo control target genes by a feed-forward mechanism. Development 2005; 132:1637-47. [PMID: 15728670 DOI: 10.1242/dev.01722] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Gradients of morphogens determine cell fates by specifying discrete thresholds of gene activities. In the Drosophila embryo, a BMP gradient subdivides the dorsal ectoderm into amnioserosa and dorsal epidermis,and also inhibits neuroectoderm formation. A number of genes are differentially expressed in response to the gradient, but how their borders of expression are established is not well understood. We present evidence that the BMP gradient, via the Smads, provides a two-fold input in regulating the amnioserosa-specific target genes such as Race. Peak levels of Smads in the presumptive amnioserosa set the expression domain of zen, and then Smads act in combination with Zen to directly activate Race. This situation resembles a feed-forward mechanism of transcriptional regulation. In addition, we demonstrate that ectopically expressed Zen can activate targets like Race in the presence of low level Smads,indicating that the role of the highest activity of the BMP gradient is to activate zen.
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Affiliation(s)
- Mu Xu
- Department of Biology, New York University, 100 Washington Square East, New York, NY 10003, USA
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48
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Usui-Ishihara A, Simpson P. Differences in sensory projections between macro- and microchaetes in Drosophilid flies. Dev Biol 2005; 277:170-83. [PMID: 15572148 DOI: 10.1016/j.ydbio.2004.09.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2004] [Accepted: 09/12/2004] [Indexed: 11/29/2022]
Abstract
From examination of the central axonal projections of sensory bristles on the notum of several species of Drosophilidae, we demonstrate different features that may indicate different functions for macro- and microchaetes. The large macrochaetes have conserved arborizations that correlate with their conserved position. Nevertheless, we find evidence for only two discrete projection patterns for bristles in the dorsocentral (DC) row, even when there may be four or five bristles present. We show that the small microchaetes of Drosophila melanogaster display regional specificity and subsets of contiguous bristles project to a common region in the thoracic ganglion. Interestingly, the axons of each of these subsets also form a specific fasciculation group on the scutum before joining the axon of a particular macrochaete. The positions of microchaetes on the scutum and the shape of the fasciculation groups vary between closely related species. There is no correlation between body size, bristle patterns, and fasciculation patterns. Furthermore, none of these traits correlate with the phylogenetic relationships between the species studied. We discuss the possibility that macro- and microchaetes may have different functions and that these have implications for evolutionary constraints on bristle patterns.
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Affiliation(s)
- Akiko Usui-Ishihara
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, United Kingdom
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49
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Stultz BG, Ray RP, Hursh DA. Analysis of the shortvein cis-regulatory region of thedecapentaplegic gene ofDrosophila melanogaster. Genesis 2005; 42:181-92. [PMID: 15986479 DOI: 10.1002/gene.20134] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In mammals, the Transforming Growth Factor-beta (TGF-beta) superfamily controls a variety of developmental processes. In Drosophila, by contrast, a single member of the superfamily, decapentaplegic (dpp) performs most TGF-beta developmental functions. The complexity of dpp functions is reflected in the complex cis-regulatory sequences that flank the gene. Dpp is divided into three regions: Hin, including the protein-coding exons; disk, including 3' cis-regulatory sequences; and shortvein (shv), including noncoding exons and 5' cis-regulatory sequences. We analyzed the cis-regulatory structure of the shortvein region using a nested series of rearrangement breakpoints and rescue constructs. We delimit the molecular regions responsible for three mutant phenotypes: larval lethality, wing venation defects, and head capsule defects. Multiple overlapping elements are responsible for larval lethality and wing venation defects. However, the area regulating head capsule formation is distinct, and resides 5' to these elements. We have demonstrated this by isolating and describing two novel dpp alleles, which affect only the adult head capsule.
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Affiliation(s)
- Brian G Stultz
- Division of Cell and Gene Therapy, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA
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50
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Dorsoventral boundary for organizing growth and planar polarity in the Drosophila eye. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s1574-3349(05)14004-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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