1
|
Jean‐Guillaume CB, Kumar JP. Development of the ocellar visual system in Drosophila melanogaster. FEBS J 2022; 289:7411-7427. [PMID: 35490409 PMCID: PMC9805374 DOI: 10.1111/febs.16468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 03/28/2022] [Accepted: 04/29/2022] [Indexed: 01/14/2023]
Abstract
The adult visual system of the fruit fly, Drosophila melanogaster, contains seven eyes-two compound eyes, a pair of Hofbauer-Buchner eyelets, and three ocelli. Each of these eye types has a specialized and essential role to play in visual and/or circadian behavior. As such, understanding how each is specified, patterned, and wired is of primary importance to vision biologists. Since the fruit fly is amenable to manipulation by an enormous array of genetic and molecular tools, its development is one of the best and most studied model systems. After more than a century of experimental investigations, our understanding of how each eye type is specified and patterned is grossly uneven. The compound eye has been the subject of several thousand studies; thus, our knowledge of its development is the deepest. By comparison, very little is known about the specification and patterning of the other two visual systems. In this Viewpoint article, we will describe what is known about the function and development of the Drosophila ocelli.
Collapse
|
2
|
Weasner BM, Kumar JP. The timing of cell fate decisions is crucial for initiating pattern formation in the Drosophila eye. Development 2022; 149:274084. [PMID: 35072208 PMCID: PMC8917411 DOI: 10.1242/dev.199634] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 12/09/2021] [Indexed: 01/26/2023]
Abstract
The eye-antennal disc of Drosophila is composed of three cell layers: a columnar epithelium called the disc proper (DP); an overlying sheet of squamous cells called the peripodial epithelium (PE); and a strip of cuboidal cells that joins the other two cellular sheets to each other and comprises the outer margin (M) of the disc. The M cells play an important role in patterning the eye because it is here that the Hedgehog (Hh), Decapentaplegic (Dpp) and JAK/STAT pathways function to initiate pattern formation. Dpp signaling is lost from the margin of eyes absent (eya) mutant discs and, as a result, the initiation of retinal patterning is blocked. Based on these observations, Eya has been proposed to control the initiation of the morphogenetic furrow via regulation of Dpp signaling within the M. We show that the failure in pattern formation surprisingly results from M cells prematurely adopting a head epidermis fate. This switch in fate normally takes place during pupal development after the eye has been patterned. Our results suggest that the timing of cell fate decisions is essential for correct eye development.
Collapse
|
3
|
Nguyen H, Tran D, Tran B, Pehlivan B, Nguyen T. A comprehensive survey of regulatory network inference methods using single cell RNA sequencing data. Brief Bioinform 2021; 22:bbaa190. [PMID: 34020546 PMCID: PMC8138892 DOI: 10.1093/bib/bbaa190] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 06/19/2020] [Accepted: 07/24/2020] [Indexed: 12/13/2022] Open
Abstract
Gene regulatory network is a complicated set of interactions between genetic materials, which dictates how cells develop in living organisms and react to their surrounding environment. Robust comprehension of these interactions would help explain how cells function as well as predict their reactions to external factors. This knowledge can benefit both developmental biology and clinical research such as drug development or epidemiology research. Recently, the rapid advance of single-cell sequencing technologies, which pushed the limit of transcriptomic profiling to the individual cell level, opens up an entirely new area for regulatory network research. To exploit this new abundant source of data and take advantage of data in single-cell resolution, a number of computational methods have been proposed to uncover the interactions hidden by the averaging process in standard bulk sequencing. In this article, we review 15 such network inference methods developed for single-cell data. We discuss their underlying assumptions, inference techniques, usability, and pros and cons. In an extensive analysis using simulation, we also assess the methods' performance, sensitivity to dropout and time complexity. The main objective of this survey is to assist not only life scientists in selecting suitable methods for their data and analysis purposes but also computational scientists in developing new methods by highlighting outstanding challenges in the field that remain to be addressed in the future development.
Collapse
Affiliation(s)
- Hung Nguyen
- Department of Computer Science and Engineering, University of Nevada, Reno, NV 89557
| | - Duc Tran
- Department of Computer Science and Engineering, University of Nevada, Reno, NV 89557
| | - Bang Tran
- Department of Computer Science and Engineering, University of Nevada, Reno, NV 89557
| | - Bahadir Pehlivan
- Department of Computer Science and Engineering, University of Nevada, Reno, NV 89557
| | - Tin Nguyen
- Department of Computer Science and Engineering, University of Nevada, Reno, NV 89557
| |
Collapse
|
4
|
Ordway AJ, Teeters GM, Weasner BM, Weasner BP, Policastro R, Kumar JP. A multi-gene knockdown approach reveals a new role for Pax6 in controlling organ number in Drosophila. Development 2021; 148:263924. [PMID: 33982759 DOI: 10.1242/dev.198796] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 04/07/2021] [Indexed: 11/20/2022]
Abstract
Genetic screens are designed to target individual genes for the practical reason of establishing a clear association between a mutant phenotype and a single genetic locus. This allows for a developmental or physiological role to be assigned to the wild-type gene. We previously observed that the concurrent loss of Pax6 and Polycomb epigenetic repressors in Drosophila leads the eye to transform into a wing. This fate change is not seen when either factor is disrupted separately. An implication of this finding is that standard screens may miss the roles that combinations of genes play in development. Here, we show that this phenomenon is not limited to Pax6 and Polycomb but rather applies more generally. We demonstrate that in the Drosophila eye-antennal disc, the simultaneous downregulation of Pax6 with either the NURF nucleosome remodeling complex or the Pointed transcription factor transforms the head epidermis into an antenna. This is a previously unidentified fate change that is also not observed with the loss of individual genes. We propose that the use of multi-gene knockdowns is an essential tool for unraveling the complexity of development.
Collapse
Affiliation(s)
- Alison J Ordway
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Gary M Teeters
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Bonnie M Weasner
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Brandon P Weasner
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Robert Policastro
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Justin P Kumar
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| |
Collapse
|
5
|
Quiquand M, Rimesso G, Qiao N, Suo S, Zhao C, Slattery M, White KP, Han JJ, Baker NE. New regulators of Drosophila eye development identified from temporal transcriptome changes. Genetics 2021; 217:6117222. [PMID: 33681970 DOI: 10.1093/genetics/iyab007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 12/28/2020] [Indexed: 11/12/2022] Open
Abstract
In the last larval instar, uncommitted progenitor cells in the Drosophila eye primordium start to adopt individual retinal cell fates, arrest their growth and proliferation, and initiate terminal differentiation into photoreceptor neurons and other retinal cell types. To explore the regulation of these processes, we have performed mRNA-Seq studies of the larval eye and antennal primordial at multiple developmental stages. A total of 10,893 fly genes were expressed during these stages and could be adaptively clustered into gene groups, some of whose expression increases or decreases in parallel with the cessation of proliferation and onset of differentiation. Using in situ hybridization of a sample of 98 genes to verify spatial and temporal expression patterns, we estimate that 534 genes or more are transcriptionally upregulated during retinal differentiation, and 1367 or more downregulated as progenitor cells differentiate. Each group of co-expressed genes is enriched for regulatory motifs recognized by co-expressed transcription factors, suggesting that they represent coherent transcriptional regulatory programs. Using available mutant strains, we describe novel roles for the transcription factors SoxNeuro (SoxN), H6-like homeobox (Hmx), CG10253, without children (woc), Structure specific recognition protein (Ssrp), and multisex combs (mxc).
Collapse
Affiliation(s)
- Manon Quiquand
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Gerard Rimesso
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Nan Qiao
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Shengbao Suo
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Chunyu Zhao
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Matthew Slattery
- Institute for Genomics & Systems Biology, University of Chicago, Chicago, IL 60637, USA
| | - Kevin P White
- Institute for Genomics & Systems Biology, University of Chicago, Chicago, IL 60637, USA
| | - Jackie J Han
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Nicholas E Baker
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.,Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA.,Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| |
Collapse
|
6
|
Oh JG, Jang SP, Yoo J, Lee MA, Lee SH, Lim T, Jeong E, Kho C, Kook H, Hajjar RJ, Park WJ, Jeong D. Role of the PRC2-Six1-miR-25 signaling axis in heart failure. J Mol Cell Cardiol 2019; 129:58-68. [DOI: 10.1016/j.yjmcc.2019.01.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 12/25/2018] [Accepted: 01/21/2019] [Indexed: 01/14/2023]
|
7
|
Torres-Oliva M, Schneider J, Wiegleb G, Kaufholz F, Posnien N. Dynamic genome wide expression profiling of Drosophila head development reveals a novel role of Hunchback in retinal glia cell development and blood-brain barrier integrity. PLoS Genet 2018; 14:e1007180. [PMID: 29360820 PMCID: PMC5796731 DOI: 10.1371/journal.pgen.1007180] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 02/02/2018] [Accepted: 01/01/2018] [Indexed: 01/01/2023] Open
Abstract
Drosophila melanogaster head development represents a valuable process to study the developmental control of various organs, such as the antennae, the dorsal ocelli and the compound eyes from a common precursor, the eye-antennal imaginal disc. While the gene regulatory network underlying compound eye development has been extensively studied, the key transcription factors regulating the formation of other head structures from the same imaginal disc are largely unknown. We obtained the developmental transcriptome of the eye-antennal discs covering late patterning processes at the late 2nd larval instar stage to the onset and progression of differentiation at the end of larval development. We revealed the expression profiles of all genes expressed during eye-antennal disc development and we determined temporally co-expressed genes by hierarchical clustering. Since co-expressed genes may be regulated by common transcriptional regulators, we combined our transcriptome dataset with publicly available ChIP-seq data to identify central transcription factors that co-regulate genes during head development. Besides the identification of already known and well-described transcription factors, we show that the transcription factor Hunchback (Hb) regulates a significant number of genes that are expressed during late differentiation stages. We confirm that hb is expressed in two polyploid subperineurial glia cells (carpet cells) and a thorough functional analysis shows that loss of Hb function results in a loss of carpet cells in the eye-antennal disc. Additionally, we provide for the first time functional data indicating that carpet cells are an integral part of the blood-brain barrier. Eventually, we combined our expression data with a de novo Hb motif search to reveal stage specific putative target genes of which we find a significant number indeed expressed in carpet cells. The development of different cell types must be tightly coordinated, and the eye-antennal imaginal discs of Drosophila melanogaster represent an excellent model to study the molecular mechanisms underlying this coordination. These imaginal discs contain the anlagen of nearly all adult head structures, such as the antennae, the head cuticle, the ocelli and the compound eyes. While large scale screens have been performed to unravel the gene regulatory network underlying compound eye development, a comprehensive understanding of genome wide expression dynamics throughout head development is still missing to date. We studied the genome wide gene expression dynamics during eye-antennal disc development in D. melanogaster to identify new central regulators of the underlying gene regulatory network. Expression based gene clustering and transcription factor motif enrichment analyses revealed a central regulatory role of the transcription factor Hunchback (Hb). We confirmed that hb is expressed in two polyploid retinal subperineurial glia cells (carpet cells). Our functional analysis shows that Hb is necessary for carpet cell development and we show for the first time that the carpet cells are an integral part of the blood-brain barrier.
Collapse
Affiliation(s)
- Montserrat Torres-Oliva
- Universität Göttingen, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Abteilung für Entwicklungsbiologie, GZMB Ernst-Caspari-Haus, Göttingen, Germany
| | - Julia Schneider
- Universität Göttingen, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Abteilung für Entwicklungsbiologie, GZMB Ernst-Caspari-Haus, Göttingen, Germany
| | - Gordon Wiegleb
- Universität Göttingen, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Abteilung für Entwicklungsbiologie, GZMB Ernst-Caspari-Haus, Göttingen, Germany
| | - Felix Kaufholz
- Universität Göttingen, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Abteilung für Entwicklungsbiologie, GZMB Ernst-Caspari-Haus, Göttingen, Germany
| | - Nico Posnien
- Universität Göttingen, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Abteilung für Entwicklungsbiologie, GZMB Ernst-Caspari-Haus, Göttingen, Germany
- * E-mail:
| |
Collapse
|
8
|
Riddiford N, Schlosser G. Dissecting the pre-placodal transcriptome to reveal presumptive direct targets of Six1 and Eya1 in cranial placodes. eLife 2016; 5. [PMID: 27576864 PMCID: PMC5035141 DOI: 10.7554/elife.17666] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 08/29/2016] [Indexed: 11/13/2022] Open
Abstract
The pre-placodal ectoderm, marked by the expression of the transcription factor Six1 and its co-activator Eya1, develops into placodes and ultimately into many cranial sensory organs and ganglia. Using RNA-Seq in Xenopus laevis we screened for presumptive direct placodal target genes of Six1 and Eya1 by overexpressing hormone-inducible constructs of Six1 and Eya1 in pre-placodal explants, and blocking protein synthesis before hormone-inducing nuclear translocation of Six1 or Eya1. Comparing the transcriptome of explants with non-induced controls, we identified hundreds of novel Six1/Eya1 target genes with potentially important roles for placode development. Loss-of-function studies confirmed that target genes encoding known transcriptional regulators of progenitor fates (e.g. Sox2, Hes8) and neuronal/sensory differentiation (e.g. Ngn1, Atoh1, Pou4f1, Gfi1) require Six1 and Eya1 for their placodal expression. Our findings provide insights into the gene regulatory network regulating placodal neurogenesis downstream of Six1 and Eya1 suggesting new avenues of research into placode development and disease.
Collapse
Affiliation(s)
- Nick Riddiford
- School of Natural Sciences, National University of Ireland, Galway, Ireland.,Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, Ireland
| | - Gerhard Schlosser
- School of Natural Sciences, National University of Ireland, Galway, Ireland.,Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, Ireland
| |
Collapse
|