Respuesta :
Answer and Explanation:
Cells directed their growth by getting the signals from distant or local bases and respond by directing signals. Each signal changes the cell state and decides how cells reply to consequent signals. RTK (receptor tyrosine kinase) signaling is needed for the arrangement of the R1-R7 photoreceptors. It activates the phyllopod transcription through the Ras/MAPK pathway. The Phyllopod transcription codes an adapter protein that guides the ubiquitin ligase Sina to target the transcription factor named Ttk (tram track) for deprivation. Tram track (Ttk) is the main inhibitor of the development of photoreceptors. The cells that do not damage Ttk become the ommatidium components, while those cells that damage it continues to develop photoreceptors. Receptor tyrosine kinase signaling is also involved in the development of ommatidium. Receptor tyrosine kinase signaling controls the propagation and existence of cells before they are employed in the cluster. RTK also regulates the differentiation of cone cells. Whether a cell becomes a photoreceptor or not is also decided by RTK signaling events.
