Final answer:
The Sev RTK pathway in fruit flies involves the Sevenless receptor (Sev) and several other proteins. This pathway is responsible for the development of the R7 photoreceptor cell in the fruit fly's eye.
Step-by-step explanation:
The Sev RTK pathway in fruit flies involves several proteins. One key protein is the Sevenless receptor (Sev), which is a receptor tyrosine kinase (RTK). This receptor is activated when it binds to its ligand, called Boss.
Once activated, the Sev RTK pathway triggers a series of intracellular signaling events that ultimately lead to the development of the R7 photoreceptor cell in the fruit fly's eye. Other proteins involved in this pathway include the adaptor protein Drk, the tyrosine kinase Src64B, and the downstream transcription factor Yan.