What causes spatial and temporal differences in the expression of a single gene?

Some optical sensors are designed to detect spatial differences in electromagnetic energy.

The spatial difference between the two beams is minimal (less than the maximum resolution of the objective).

This is the action on the parcel arising from the spatial differences of atmospheric pressure p around it.

There are many reasons why such spatial differences within nations emerge and are maintained.

Moreover, they cannot be accounted for merely by reference to spatial differences in social composition.

Such standing wave represents the seasonally varying spatial difference of the Earth's surface pressure.

Cell polarity refers to spatial differences in the shape, structure, and function of cells.

This permits spatial and temporal differences in gene expression.

In most theoretical literature, price dispersion is argued as result from spatial difference and the existence of significant search cost.