The eyes absent (eya) and sine oculis (so) genes in Drosophila are key components of the retinal determination (RD) network, which is essential for normal development in both flies and vertebrates. Eya functions both as a transcriptional coactivator and a protein phosphatase while so encodes a homeodomain transcription factor. Both genes are necessary and sufficient for retinal development in Drosophila. Moreover, the Eya and So proteins physically interact and act synergistically as a highly potent transcription complex that regulates development of several organ systems. Two highly conserved homologs of so, Six3 and Six6, are required for normal retinal development in vertebrates. In humans, mutations in EYA1 and SIX1 cause the autosomal dominant disorder known as BOR (branchio-oto-renal) syndrome, characterized by branchial arch abnormalities, hearing loss, and kidney defects. Despite their importance during mammalian development, the mechanism of Eya and So action remains incompletely understood. In addition, Eya and So directly regulate atonal and senseless, which are required for the first steps in photoreceptor cell differentiation and are highly conserved in mammals. Two other conserved transcriptional regulators required for normal retinal differentiation, Lozenge and Groucho, also appear to be directly regulated by So. Thus, Eya and So mediate the transition from determination to differentiation and thereby act at a critical junction in organogenesis. Our proposal focuses on understanding the role of these six genes in a well-characterized genetic system, the Drosophila eye. We will use a combination of genetics, genomics, and biochemistry to analyze the roles of Eya and So, as well as Ato, Sens, Lozenge, and Groucho, during retinal development. Since genetic pathways are often conserved and reiteratively used during organ formation across phylogeny, studying the development of simpler organisms can provide rapid and significant insight into human disease.

Public Health Relevance

The main goal of this project is to understand how the eyes absent (eya) and sine oculis (so) genes act during eye development. Both genes are highly conserved from fruit flies to humans and are known to play essential roles in human development, including the eye. We will use the unparalleled power of Drosophila genetics to decipher the function of these important but poorly understood genes.

National Institute of Health (NIH)
National Eye Institute (NEI)
Research Project (R01)
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Biology and Diseases of the Posterior Eye Study Section (BDPE)
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Neuhold, Lisa
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Baylor College of Medicine
Schools of Medicine
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Jin, Meng; Eblimit, Aiden; Pulikkathara, Merlyn et al. (2016) Conditional knockout of retinal determination genes in differentiating cells in Drosophila. FEBS J 283:2754-66
Jin, Meng; Mardon, Graeme (2016) Distinct Biochemical Activities of Eyes absent During Drosophila Eye Development. Sci Rep 6:23228
Jin, Meng; Aibar, Sara; Ge, Zhongqi et al. (2016) Identification of novel direct targets of Drosophila Sine oculis and Eyes absent by integration of genome-wide data sets. Dev Biol 415:157-67
Jusiak, Barbara; Karandikar, Umesh C; Kwak, Su-Jin et al. (2014) Regulation of Drosophila eye development by the transcription factor Sine oculis. PLoS One 9:e89695
Jusiak, Barbara; Wang, Feng; Karandikar, Umesh C et al. (2014) Genome-wide DNA binding pattern of the homeodomain transcription factor Sine oculis (So) in the developing eye of Drosophila melanogaster. Genom Data 2:153-155
Karandikar, Umesh C; Jin, Meng; Jusiak, Barbara et al. (2014) Drosophila eyes absent is required for normal cone and pigment cell development. PLoS One 9:e102143
Haase Gilbert, Erin; Kwak, Su-Jin; Chen, Rui et al. (2013) Drosophila signal peptidase complex member Spase12 is required for development and cell differentiation. PLoS One 8:e60908
Atkins, Mardelle; Jiang, Yuwei; Sansores-Garcia, Leticia et al. (2013) Dynamic rewiring of the Drosophila retinal determination network switches its function from selector to differentiation. PLoS Genet 9:e1003731
Jin, Meng; Jusiak, Barbara; Bai, Zengliang et al. (2013) Eyes absent tyrosine phosphatase activity is not required for Drosophila development or survival. PLoS One 8:e58818
Li, Yumei; Jiang, Yuwei; Chen, Yiyun et al. (2013) optix functions as a link between the retinal determination network and the dpp pathway to control morphogenetic furrow progression in Drosophila. Dev Biol 381:50-61

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