Limits...
Dynamic rewiring of the Drosophila retinal determination network switches its function from selector to differentiation.

Atkins M, Jiang Y, Sansores-Garcia L, Jusiak B, Halder G, Mardon G - PLoS Genet. (2013)

Bottom Line: Organ development is directed by selector gene networks.We found that central to the transition is a switch from positive regulation of ey transcription to negative regulation and that both types of regulation require so.We conclude that changes in the regulatory relationships among members of the retinal determination gene network are a driving force for key transitions in retinal development.

View Article: PubMed Central - PubMed

Affiliation: Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America.

ABSTRACT
Organ development is directed by selector gene networks. Eye development in the fruit fly Drosophila melanogaster is driven by the highly conserved selector gene network referred to as the "retinal determination gene network," composed of approximately 20 factors, whose core comprises twin of eyeless (toy), eyeless (ey), sine oculis (so), dachshund (dac), and eyes absent (eya). These genes encode transcriptional regulators that are each necessary for normal eye development, and sufficient to direct ectopic eye development when misexpressed. While it is well documented that the downstream genes so, eya, and dac are necessary not only during early growth and determination stages but also during the differentiation phase of retinal development, it remains unknown how the retinal determination gene network terminates its functions in determination and begins to promote differentiation. Here, we identify a switch in the regulation of ey by the downstream retinal determination genes, which is essential for the transition from determination to differentiation. We found that central to the transition is a switch from positive regulation of ey transcription to negative regulation and that both types of regulation require so. Our results suggest a model in which the retinal determination gene network is rewired to end the growth and determination stage of eye development and trigger terminal differentiation. We conclude that changes in the regulatory relationships among members of the retinal determination gene network are a driving force for key transitions in retinal development.

Show MeSH

Related in: MedlinePlus

So and Eya cooperate with Dac in vivo to complete Ey repression.(A) UAS-so and UAS-dac7c4 were co-overexpressed anterior to the furrow. (A′) Grayscale image of GFP expression in A; GFP marks the clone. (A″) Grayscale image of Ey expression in A. (B) MARCM clones that are  for dac while overexpressing so and eya. (B′) Grayscale image of GFP expression in B; GFP marks the clone. (B″) Grayscale image of Ey expression in B. (B″) Grayscale image of ELAV expression in B shows differentiating photoreceptors.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3757064&req=5

pgen-1003731-g008: So and Eya cooperate with Dac in vivo to complete Ey repression.(A) UAS-so and UAS-dac7c4 were co-overexpressed anterior to the furrow. (A′) Grayscale image of GFP expression in A; GFP marks the clone. (A″) Grayscale image of Ey expression in A. (B) MARCM clones that are for dac while overexpressing so and eya. (B′) Grayscale image of GFP expression in B; GFP marks the clone. (B″) Grayscale image of Ey expression in B. (B″) Grayscale image of ELAV expression in B shows differentiating photoreceptors.

Mentions: We next overexpressed Dac with Eya or So to see if they were sufficient to suppress Ey expression anterior to the furrow. Overexpression of dac or eya alone did not alter Ey expression (data not shown). Co-overexpression of eya and dac also had no effect on Ey expression (data not shown). However, co-overexpression of so with dac was sufficient to repress Ey expression to modest levels (Figure 8A). We conclude that Dac and So can cooperate to reduce Ey expression in vivo.


Dynamic rewiring of the Drosophila retinal determination network switches its function from selector to differentiation.

Atkins M, Jiang Y, Sansores-Garcia L, Jusiak B, Halder G, Mardon G - PLoS Genet. (2013)

So and Eya cooperate with Dac in vivo to complete Ey repression.(A) UAS-so and UAS-dac7c4 were co-overexpressed anterior to the furrow. (A′) Grayscale image of GFP expression in A; GFP marks the clone. (A″) Grayscale image of Ey expression in A. (B) MARCM clones that are  for dac while overexpressing so and eya. (B′) Grayscale image of GFP expression in B; GFP marks the clone. (B″) Grayscale image of Ey expression in B. (B″) Grayscale image of ELAV expression in B shows differentiating photoreceptors.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3757064&req=5

pgen-1003731-g008: So and Eya cooperate with Dac in vivo to complete Ey repression.(A) UAS-so and UAS-dac7c4 were co-overexpressed anterior to the furrow. (A′) Grayscale image of GFP expression in A; GFP marks the clone. (A″) Grayscale image of Ey expression in A. (B) MARCM clones that are for dac while overexpressing so and eya. (B′) Grayscale image of GFP expression in B; GFP marks the clone. (B″) Grayscale image of Ey expression in B. (B″) Grayscale image of ELAV expression in B shows differentiating photoreceptors.
Mentions: We next overexpressed Dac with Eya or So to see if they were sufficient to suppress Ey expression anterior to the furrow. Overexpression of dac or eya alone did not alter Ey expression (data not shown). Co-overexpression of eya and dac also had no effect on Ey expression (data not shown). However, co-overexpression of so with dac was sufficient to repress Ey expression to modest levels (Figure 8A). We conclude that Dac and So can cooperate to reduce Ey expression in vivo.

Bottom Line: Organ development is directed by selector gene networks.We found that central to the transition is a switch from positive regulation of ey transcription to negative regulation and that both types of regulation require so.We conclude that changes in the regulatory relationships among members of the retinal determination gene network are a driving force for key transitions in retinal development.

View Article: PubMed Central - PubMed

Affiliation: Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America.

ABSTRACT
Organ development is directed by selector gene networks. Eye development in the fruit fly Drosophila melanogaster is driven by the highly conserved selector gene network referred to as the "retinal determination gene network," composed of approximately 20 factors, whose core comprises twin of eyeless (toy), eyeless (ey), sine oculis (so), dachshund (dac), and eyes absent (eya). These genes encode transcriptional regulators that are each necessary for normal eye development, and sufficient to direct ectopic eye development when misexpressed. While it is well documented that the downstream genes so, eya, and dac are necessary not only during early growth and determination stages but also during the differentiation phase of retinal development, it remains unknown how the retinal determination gene network terminates its functions in determination and begins to promote differentiation. Here, we identify a switch in the regulation of ey by the downstream retinal determination genes, which is essential for the transition from determination to differentiation. We found that central to the transition is a switch from positive regulation of ey transcription to negative regulation and that both types of regulation require so. Our results suggest a model in which the retinal determination gene network is rewired to end the growth and determination stage of eye development and trigger terminal differentiation. We conclude that changes in the regulatory relationships among members of the retinal determination gene network are a driving force for key transitions in retinal development.

Show MeSH
Related in: MedlinePlus