Condition-dependent sex difference in nestling House Wren (Troglodytes aedon) response to phytohaemagglutinin injection

• Published in: Canadian journal of zoology Vol. 92; no. 1; pp. 1 - 7
• Main Authors: THOMPSON, C. F, SAKALUK, S. K, MASTERS, B. S, JOHNSON, B. G. P, VOGEL, L. A, FORSMAN, A. M, JOHNSON, L. S
• Format: Journal Article
• Language: English
• Published: Ottawa NRC Research Press 2014; National Research Council of Canada; Canadian Science Publishing NRC Research Press
• Subjects: Analysis of the immune response. Humoral and cellular immunity; Animal reproduction; Bacteria; Biological and medical sciences; Birds; Breeding seasons; Comparative analysis; essai à la PHA; Fundamental and applied biological sciences. Psychology; Fundamental immunology; House Wren; Immune response; Immune system; Immunobiology; Injection; Organs and cells involved in the immune response; PHA test; Physiological aspects; Plant lectins; plasma bactericidal assay; réaction immunitaire dépendant du sexe et de l’embonpoint; sex- and condition-dependent immune response; troglodyte familier; Troglodytes aedon; épreuve du pouvoir bactéricide du plasma; United States; Troglodytes aedon; Immune response; Body weight; Sex; Organism defense; Phytohemagglutinin; Experimental study; Nestling; Antimicrobial agent; Blood plasma; Vertebrata; Sexual dimorphism; Aves
• ISSN: 0008-4301; 1480-3283; 1480-3283; 0008-4301
• DOI: 10.1139/cjz-2013-0140

Adult male and female birds typically respond differently to immunological challenges, but whether this difference is present in altricial nestlings is not well-documented. Furthermore, the timing of the development of different axes of the immune system might vary in nestlings and also be affected by differences in condition and health state. We tested for sex-related differences in the immune response of nestling House Wrens (Troglodytes aedon Vieillot, 1809) to the injection of phytohaemagglutinin (PHA) and in the bacteria-killing capacity of their plasma. Based on prior work, we predicted that if there were sex-related differences in immune responsiveness, they would most likely occur when the sexes differed in some measure of condition or health state. Female nestlings had a stronger response to the injection of PHA than males in the one of three breeding seasons in which the condition of nestling females exceeded that of males, suggesting that the response to PHA injection is condition-dependent rather than sex-dependent. The sexes, however, did not differ in bactericidal activity, suggesting that different axes of the immune system may not be affected to the same degree by differences in sex or in condition.