Intestinal digestive enzyme modulation in house sparrow nestlings occurs within 24 h of a change in diet composition

ROTT, KATHERINE H.; CAVIEDES-VIDAL, ENRIQUE; KARASOV, WILLIAM H.

JOURNAL OF EXPERIMENTAL BIOLOGY

COMPANY OF BIOLOGISTS LTD

Año: 2017 vol. 220 p. 2733 - 2742

0022-0949

Nestling house sparrows near fledging age (12 days) were previouslyfound to reversibly modulate the activity of their intestinal digestiveenzymes in response to changes in diet composition. However, it isnot known how quickly nestlings can adjust to new diets with differentsubstrate compositions, nor is it known how early in life nestlings canmodulate their enzyme activity in response to changes in diet. In thepresent study, 3-day-old nestlings were captured from the wild andfed and switched among contrasting diets ? one high in protein andlow in carbohydrate and another higher in carbohydrate and withlower, but adequate, protein ? in order to determine (1) how quicklyhouse sparrow nestlings could adjust to changes in diet composition,(2) how early in life nestlings could modulate their digestive enzymeactivity in response to these changes and (3) which digestiveenzymes could be modulated in house sparrow nestlings earlier inlife. We found that house sparrow nestlings as young as 3 days posthatchwere capable of modulating their intestinal disaccharidaseactivity within 24 h of a change in diet composition, and nestlingsgained the ability to modulate aminopeptidase-N by 6 or 7 days ofage. To our knowledge, this is the first evidence of digestive enzymemodulation completed within 24 h of a change in diet in an avianspecies and the first study to show intestinal digestive enzymemodulation in response to changes in diet composition in any animalthis early in development.