title: Activation of an inflammatory response is context-dependent during early development of the California sea lion.
abstract: Variations in immune function can arise owing to trade-offs, that is, the allocation of limited resources among costly competing physiological functions. Nevertheless, there is little information regarding the ontogeny of the immune system within an ecological context, and it is still unknown whether development affects the way in which resources are allocated to different immune effectors. We investigated changes in the inflammatory response during early development of the California sea lion (Zalophus californianus) and examined its association with body condition, as a proxy for the availability of energetic resources. We found that the relationship between inflammation and body condition varied according to developmental stage and circulating levels of leucocyte populations, a proxy for current infection. Body condition was related to the magnitude of the inflammatory response during two of the three developmental periods assessed, allowing for the possibility that the availability of pup energetic reserves can limit immune function. For older pups, the ability to mount an inflammatory response was related to their circulating levels of neutrophils and the neutrophil to lymphocyte ratio, implying that the infection status of an individual will influence its ability to respond to a new challenge. Our results suggest that trade-offs may occur within the immune system and highlight the importance of taking into account ontogeny in ecoimmunological studies.
authors.affiliation: Unit for Basic and Applied Microbiology , School of Natural Sciences, Autonomous University of Queretaro , Avenida de las Ciencias S/N, Queretaro 76230, México.
authors.forename: Camila
authors.initials: C
authors.lastname: Vera-Massieu
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow , Glasgow G12 8QQ, UK.
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Brock
authors.affiliation: Cabo Pulmo National Park, Comisión Nacional de Áreas Naturales Protegidas , SEMARNAT, La Ribera, BCS, Mexico.
authors.forename: Carlos
authors.initials: C
authors.lastname: Godínez-Reyes
authors.affiliation: Unit for Basic and Applied Microbiology , School of Natural Sciences, Autonomous University of Queretaro , Avenida de las Ciencias S/N, Queretaro 76230, México ; The Marine Mammal Center , 2000 Bunker Road, Sausalito, CA 94965, USA.
authors.forename: Karina
authors.initials: K
authors.lastname: Acevedo-Whitehouse
keywords: ecoimmunology; immune ontogeny; inflammation; phytohaemaglutinin; trade-off