The result of Notch-mediated competitive lateral inhibition in a patch of wild-type cells is depicted on the left in the following schematic drawing, in which the black cells have become specialized. Consider a genetic mutation that interferes with intracellular Notch signaling in such a way that Notch can no longer regulate Delta effectively. Which drawing (1 or 2) better represents the outcome with cells bearing this mutation? Do the specialized cells (black hexagons) have active or inactive Notch at their surface?
A) Drawing 1; active Notch
B) Drawing 1; inactive Notch
C) Drawing 2; active Notch
D) Drawing 2; inactive Notch

Question

The result of Notch-mediated competitive lateral inhibition in a patch of wild-type cells is depicted on the left in the following schematic drawing, in which the black cells have become specialized. Consider a genetic mutation that interferes with intracellular Notch signaling in such a way that Notch can no longer regulate Delta effectively. Which drawing (1 or 2) better represents the outcome with cells bearing this mutation? Do the specialized cells (black hexagons) have active or inactive Notch at their surface? 
A) Drawing 1; active Notch 
B) Drawing 1; inactive Notch 
C) Drawing 2; active Notch 
D) Drawing 2; inactive Notch

Quizplus · Accepted Answer

In lateral inhibition, Notch signaling typically leads to inhibition of the differentiation program as well as to reduction in the cell's display of Delta. Interfering with Notch signaling would therefore impair lateral inhibition-generating patterns in which two neighboring cells undergo specialization (drawing 1)-since Notch signaling can be off in both cells.

The Result of Notch-Mediated Competitive Lateral Inhibition in a Patch