Meeting Abstract
125.3 Monday, Jan. 7 Impact of food restriction on immune function in altricial house sparrow nestlings KILLPACK, T.L.*; CARREL, E; KARASOV, W.H.; Univ. of Wisconsin, Madison; MMSD High School Science Internship Program; Univ. of Wisconsin, Madison tkillpack@wisc.edu
If resources are limiting, then trade-offs may occur between immune defense and life history components such as growth and development. We tested for such trade-offs in food restricted (FR) nestling house sparrows and, particularly, that immune function would be more reduced in a defense considered costly, like the acute phase response to lipopolysaccharide (LPS), compared with one considered less costly, like complement-mediated lysis. We tested birds both early in the nestling period, when growth demands are high, and late in the nestling period, when growth has reached a plateau. We examined the long-term effects of early FR on birds refed and tested late in the nestling period. Masses of alimentary organs and heart were significantly reduced in both early and late FR birds, yet reductions resulting from early FR were reversible in refed birds. Reduced skull length and lean flight muscle mass and maturity were observed with early FR, and refed birds had persistent reductions in muscle size and maturity. As predicted, FR did not significantly impact complement-mediated lysis, a constitutive component of immune function, yet levels of acute phase protein haptoglobin (Hp), an inducible component of the innate immune system, were reduced in early and late FR birds. Early FR had no long-term impact on Hp response, as refed birds challenged with LPS late in nestling period did not significantly differ in Hp response compared with late controls. Thus, innate immune function, like organ growth, appears to be flexible to resource supply during the nestling period, and early FR during the nestling period does not permanently stunt development of the innate immune system. Support: NSF-GRFP, AOU, USDA-Hatch, Birge Fund, GWIS-Ruth Dickie.
