The phrase "a characteristic expression" is correct and usable in written English.
It can be used to describe a specific way of expressing something that is typical or distinctive of a person, group, or style.
Example: "Her smile was a characteristic expression of her warm and friendly nature."
Alternatives: "a typical expression" or "a distinctive expression".
A characteristic expression?
The researchers also found distinct patterns of aging in different tissues: neural, vascular, and endocrine tissue each had a characteristic expression profile.
I had suggested that political opposition in Damascus often seemed more gestural than real, and that making movies no one could see was therefore a characteristic expression of Syrian dissent.
Before Rosh Hashana last year, the cardinal issued a characteristic expression of sorrow for wrongs that he and fellow Catholics had done to the Jewish people, a statement widely publicized and welcomed by Jewish leaders.
"Remedies" proposed for under-age drinking are a characteristic expression of this: raise the drinking age, make drinking more expensive, prevent the sale of cheap drink in supermarkets and petrol stations.
Fraser remained a strikingly pretty woman, whose appearance was marked with a characteristic expression in which humour and tenderness were equally mixed, and which reflected her warm and constant gift for friendship.
Since the genes known to play a role in vegetative-to-flowering transition have been found to show a similar characteristic expression pattern [ 29], it suggests that OsSSRPL2 and hence the FACT complex might play a role in this important transition during the life cycle.
SPRR genes (Figure 4A, large pink bar) have a very characteristic expression pattern which is clearly different from the classical cornified envelope precursor proteins involucrin and loricrin (indicated by arrows) and is only matched by S100A8 and S100A9 (short pink bar), two genes previously implicated in wound healing [23].
A time-dependent activation of the BMP signaling pathway in collagen-induced arthritis was demonstrated with a dynamic and characteristic expression pattern of different BMP subfamily members in synovium and cartilage of arthritic knees.
To further confirm the characteristic expression, a PAL promoter was fused with a reporter gene and introduced into L. japonicus, and then the transformants were grown with a commercial inoculum of G. mosseae.
The estrous mare (especially, or exclusively, young mares in the case of the plains zebra) adopts a typical posture with legs slightly apart, tail lifted, and, except in the horse, a characteristic facial expression (the "mating face" already mentioned).
