Amanda Simcox


We study EGF receptor signaling in the early wing disc. This simple system is about 30 cells in a just hatched larva and grows to about 150 cells in two days. Our goal is to decipher the complete gene regulatory network that operates in this short period of time to specify the adult wing and body wall of the thorax. The simplicity and small size of the tissue make this a good system to analyze. We found that a paracrine Dpp (BMP/TGF-β) signal induces an EGF ligand called Vn (similar to the vertebrate neuregulins). Once Vn is induced it maintains its own expression in an autocrine loop. The finding that these conserved signaling pathways are operating leads to an expectation that the circuit in the wing will be used in other tissues and animals. 

Simcox Figure 1 - A paracrine Dpp signal induces vn.

Flies have four EGF ligands—one called Vn (a neuregulin) and three that are like TGF-α (including Spi). Surprisingly, we found that any of the TGF-α ligands can replace Vn and rescue a mutant. We had to titrate the dose of the TFG-α ligand, because each is more potent that Vn. Our results support the idea that ligand identity is not critical, but that a certain level of signaling is required for the correct cellular response.

Figure 2 - vn null with increasing vnG4>spi expression

We have discovered genetic ways to generate Drosophila cell lines very efficiently. Expression of the Ras oncogene is one very powerful way to do this and we are using the cell lines to find new genes in the Ras pathway. We are using the cells to analyze tumor phenotypes. To enhance the range of possible experiments in Drosophila tissue culture we have developed a protocol to insert single transgenes into the same genomic site using site-specific recombination and a double drug selection.

Figure 3 - Green cells have undergone site-specific recombination.




Simcox lab staff

Simcox Lab Members:

Graduate students:

  • Geeta Palsule
  • Ashley Heinaman

Undergraduate Students:

  • Molly Josifov
  • Sam Chen
  • Nanki Hura

Research Associate:

  • Shiva Singh

Postdoctoral Fellow:

  • Uyen Tram





Areas of Expertise
  • The role of oncogenes, tumor suppressors and Egfr signaling

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