Ectoparasites help to maintain variation in cell-mediated immunity in the blue tit-hen flea system

: Pitala N, Siitari H, Gustafsson L, Brommer JE

Publisher: EVOLUTIONARY ECOLOGY LTD

: 2009

Evolutionary Ecology Research

EVOLUTIONARY ECOLOGY RESEARCH

: EVOL ECOL RES

: 11

: 1

: 79

: 94

: 16

: 1522-0613

Results: Hen flea infestation lowered growth, cell-mediated immunocompetence, and haematocrit. Genotype-environment interactions were observed in cell-mediated immunocompetence, body mass, and haematocrit, with significant crossing reaction norms for cell-mediated immunocompetence and haematocrit. Immunoglobulin concentrations were unaffected by fleas. Thus, host-parasite interactions constrain the expression and evolvability of some traits, but also create genotype-environment interactions with the potential to maintain genetic variation in immune defence.