Probing the Drosophila retinal determination gene network in Tribolium (I): The early retinal genes dachshund, eyes absent and sine oculis

Retinal cell fate determination in Drosophila is controlled by an interactive network of genes, including eyeless, eyes absent, sine oculis and dachshund. We have investigated the role of the TGF-beta homolog decapentaplegic in this pathway. We demonstrate that, during eye development, while eyeless transcription does not depend on decapentaplegic activity, the expression of eyes absent, sine oculis and dachshund are greatly reduced in a decapentaplegic mutant background. We also show that decapentaplegic signaling acts synergistically with and at multiple levels of the retinal determination network to induce eyes absent, sine oculis and dachshund expression and ectopic eye formation. These results suggest a mechanism by which a general patterning signal such as Decapentaplegic cooperates reiteratively with tissue-specific factors to determine distinct cell fates during development.

Download Full-text

Decision letter: Deployment of a retinal determination gene network drives directed cell migration in the sea urchin embryo

10.7554/elife.08827.022 ◽

2015 ◽

Keyword(s):

Cell Migration ◽

Sea Urchin ◽

Gene Network ◽

Directed Cell Migration ◽

Retinal Determination ◽

Sea Urchin Embryo ◽

Retinal Determination Gene Network

Download Full-text

Author response: Deployment of a retinal determination gene network drives directed cell migration in the sea urchin embryo

10.7554/elife.08827.023 ◽

2015 ◽

Cited By ~ 1

Author(s):

Megan L Martik ◽

David R McClay

Keyword(s):

Cell Migration ◽

Sea Urchin ◽

Gene Network ◽

Author Response ◽

Directed Cell Migration ◽

Retinal Determination ◽

Sea Urchin Embryo ◽

Retinal Determination Gene Network

Download Full-text

Functional Dissection of Eyes absent Reveals New Modes of Regulation within the Retinal Determination Gene Network

Molecular and Cellular Biology ◽

10.1128/mcb.23.17.5989-5999.2003 ◽

2003 ◽

Vol 23 (17) ◽

pp. 5989-5999 ◽

Cited By ~ 77

Author(s):

Serena J. Silver ◽

Erin L. Davies ◽

Laura Doyon ◽

Ilaria Rebay

Keyword(s):

Growth Factor ◽

Gene Network ◽

Transforming Growth Factor ◽

Mapk Pathway ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

Network Activity ◽

Eyes Absent ◽

Retinal Determination ◽

Transactivation Potential

ABSTRACT The retinal determination (RD) gene network encodes a group of transcription factors and cofactors necessary for eye development. Transcriptional and posttranslational regulation of RD family members is achieved through interactions within the network and with extracellular signaling pathways, including epidermal growth factor receptor/RAS/mitogen-activated protein kinase (MAPK), transforming growth factor β/DPP, Wingless, Hedgehog, and Notch. Here we present the results of structure-function analyses that reveal novel aspects of Eyes absent (EYA) function and regulation. We find that the conserved C-terminal EYA domain negatively regulates EYA transactivation potential, and that GROUCHO-SINE OCULIS (SO) interactions provide another mechanism for negative regulation of EYA-SO target genes. We have mapped the transactivation potential of EYA to an internal proline-, serine-, and threonine-rich region that includes the EYA domain 2 (ED2) and two MAPK phosphorylation consensus sites and demonstrate that activation of the RAS/MAPK pathway potentiates transcriptional output of EYA and the EYA-SO complex in certain contexts. Drosophila S2 cell two-hybrid assays were used to describe a novel homotypic interaction that is mediated by EYA's N terminus. Our data suggest that EYA requires homo- and heterotypic interactions and RAS/MAPK signaling responsiveness to ensure context-appropriate RD gene network activity.

Download Full-text

Systemic paralogy and function of retinal determination network homologs in arachnids

BMC Genomics ◽

10.1186/s12864-020-07149-x ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Guilherme Gainett ◽

Jesús A. Ballesteros ◽

Charlotte R. Kanzler ◽

Jakob T. Zehms ◽

John M. Zern ◽

...

Keyword(s):

Gene Expression ◽

Differential Gene Expression ◽

Expression Patterns ◽

Single Copy ◽

Parasteatoda Tepidariorum ◽

Sine Oculis ◽

Retinal Determination ◽

Differential Gene ◽

And Function ◽

Retinal Determination Gene Network

Abstract Background Arachnids are important components of cave ecosystems and display many examples of troglomorphisms, such as blindness, depigmentation, and elongate appendages. Little is known about how the eyes of arachnids are specified genetically, let alone the mechanisms for eye reduction and loss in troglomorphic arachnids. Additionally, duplication of Retinal Determination Gene Network (RDGN) homologs in spiders has convoluted functional inferences extrapolated from single-copy homologs in pancrustacean models. Results We investigated a sister species pair of Israeli cave whip spiders, Charinus ioanniticus and C. israelensis (Arachnopulmonata, Amblypygi), of which one species has reduced eyes. We generated embryonic transcriptomes for both Amblypygi species, and discovered that several RDGN homologs exhibit duplications. We show that duplication of RDGN homologs is systemic across arachnopulmonates (arachnid orders that bear book lungs), rather than being a spider-specific phenomenon. A differential gene expression (DGE) analysis comparing the expression of RDGN genes in field-collected embryos of both species identified candidate RDGN genes involved in the formation and reduction of eyes in whip spiders. To ground bioinformatic inference of expression patterns with functional experiments, we interrogated the function of three candidate RDGN genes identified from DGE using RNAi in the spider Parasteatoda tepidariorum. We provide functional evidence that one of these paralogs, sine oculis/Six1 A (soA), is necessary for the development of all arachnid eye types. Conclusions Our work establishes a foundation to investigate the genetics of troglomorphic adaptations in cave arachnids, and links differential gene expression to an arthropod eye phenotype for the first time outside of Pancrustacea. Our results support the conservation of at least one RDGN component across Arthropoda and provide a framework for identifying the role of gene duplications in generating arachnid eye diversity.

Download Full-text

Signaling circuitries in development: insights from the retinal determination gene network

Development ◽

10.1242/dev.01539 ◽

2004 ◽

Vol 132 (1) ◽

pp. 3-13 ◽

Cited By ~ 122

Author(s):

S. J. Silver

Keyword(s):

Gene Network ◽

Retinal Determination ◽

Retinal Determination Gene Network

Download Full-text

How spiders make their eyes: Systemic paralogy and function of retinal determination network homologs in arachnids

10.1101/2020.04.28.067199 ◽

2020 ◽

Cited By ~ 3

Author(s):

Guilherme Gainett ◽

Jesús A. Ballesteros ◽

Charlotte R. Kanzler ◽

Jakob T. Zehms ◽

John M. Zern ◽

...

Keyword(s):

Expression Patterns ◽

Single Copy ◽

Parasteatoda Tepidariorum ◽

Sine Oculis ◽

Retinal Determination ◽

Differential Gene ◽

Cave Ecosystems ◽

And Function ◽

Retinal Determination Gene Network

AbstractArachnids are important components of cave ecosystems and display many examples of troglomorphisms, such as blindness, depigmentation, and elongate appendages. Little is known about how the eyes of arachnids are specified genetically, let alone the mechanisms for eye reduction and loss in troglomorphic arachnids. Additionally, paralogy of Retinal Determination Gene Network (RDGN) homologs in spiders has convoluted functional inferences extrapolated from single-copy homologs in pancrustacean models. Here, we investigated a sister species pair of Israeli cave whip spiders (Arachnopulmonata, Amblypygi, Charinus) of which one species has reduced eyes. We generated the first embryonic transcriptomes for Amblypygi, and discovered that several RDGN homologs exhibit duplications. We show that paralogy of RDGN homologs is systemic across arachnopulmonates (arachnid orders that bear book lungs), rather than being a spider-specific phenomenon. A differential gene expression (DGE) analysis comparing the expression of RDGN genes in field-collected embryos of both species identified candidate RDGN genes involved in the formation and reduction of eyes in whip spiders. To ground bioinformatic inference of expression patterns with functional experiments, we interrogated the function of three candidate RDGN genes identified from DGE in a spider, using RNAi in the spider Parasteatoda tepidariorum. We provide functional evidence that one of these paralogs, sine oculis/Six1 A (soA), is necessary for the development of all arachnid eye types. Our results support the conservation of at least one RDGN component across Arthropoda and establish a framework for investigating the role of gene duplications in arachnid eye diversity.

Download Full-text