The analysis of immunological profiles in wild animals: a case study on immunodynamics in the field vole, Microtus agrestis.
A revolutionary advance in ecological immunology is that postgenomic technologies now allow molecular mediators defined in laboratory models to be measured at the mRNA level in field studies of many naturally occurring species. Here, we demonstrate the application of such an approach to generate meaningful immunological profiles for wild mammals. We sampled a natural field vole population across the year (n = 307) and developed a battery of cellular assays in which functionally different pro- and anti-inflammatory signalling responses (transcription factors and cytokines) were activated and quantified by Q-PCR. Temporal trends were the strongest feature in the expression data, although some life history stages (mating vs. nonmating males and pregnant females) were also associated with significant variation. There was a striking set of significant negative associations between inflammatory mediators and condition indices reflecting packed erythrocyte volume and relative liver size, spleen size and splenocyte count. Grouped (principal component) measures of inflammatory and anti-inflammatory expression were high in winter, with minima in the breeding season that occurred earlier for grouped anti-inflammatory responses than for grouped inflammatory responses. Some individual immunological mediators also showed patterns unrelated to the breeding season or annual periodic cues. For example, interferon regulatory factor 5 (IRF5) expression declined throughout the study period, indicating a systematic trend in antimicrobial defences. Pinpointing the causes and consequences of such variation may help identify underlying environmental drivers of individual fitness and demographic fluctuation.
Institute of Integrative Biology, The University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK. jaj11@aber.ac.uk
Joseph A
JA
Jackson
Michael
M
Begon
Richard
R
Birtles
Steve
S
Paterson
Ida M
IM
Friberg
Amy
A
Hall
Ann
A
Lowe
Catriona
C
Ralli
Andrew
A
Turner
Malgorzata
M
Zawadzka
Janette E
JE
Bradley
D000818:Animals; D000835:Animals, Wild / Q000097:blood / Q000276:immunology; D003411:Arvicolinae / Q000097:blood / Q000276:immunology*; D002478:Cells, Cultured; D004911:Erythrocyte Volume; D005260:Female; D020869:Gene Expression Profiling; D007249:Inflammation / Q000097:blood / Q000276:immunology*; D050835:Interferon Regulatory Factors / Q000378:metabolism; D008297:Male; D008934:Mitogens / Q000494:pharmacology; D015999:Multivariate Analysis; D009929:Organ Size; D011247:Pregnancy; D012621:Seasons; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D013997:Time Factors
D050835:Interferon Regulatory Factors; D008934:Mitogens