Seasonal variations in immunoreactive cortisol and fecal immunoglobulin levels in Sichuan golden monkey (Rhinopithecus roxellana)

Ecoimmunological patterns and processes remain understudied in wild primates, in part because of the lack of noninvasive methods to measure immunity. Secretory immunoglobulin A (sIgA) is the most abundant antibody present at mammalian mucosal surfaces and provides an important first line of defense against pathogens. Recent studies show that sIgA can be measured noninvasively in feces and is a good marker of mucosal immunity. Here we validated a commercial ELISA kit to measure fecal IgA in baboons, tested the robustness of its results to variation in collection and storage conditions, and developed a cost‐effective in‐house ELISA for baboon fecal IgA. Using data from the custom ELISA, we assessed the relationship between fecal IgA concentrations and gastrointestinal parasite burden, and tested how sex, age, and reproductive effort predict fecal IgA in wild baboons. We find that IgA concentrations can be measured in baboon feces using an in‐house ELISA and are highly correlated to the values obtained with a commercial kit. Fecal IgA concentrations are stable when extracts are stored for up to 22 months at −20°C. Fecal IgA concentrations were negatively correlated with parasite egg counts (Trichuris trichiura), but not parasite richness. Fecal IgA did not vary between the sexes, but for males, concentrations were higher in adults versus adolescents. Lactating females had significantly lower fecal IgA than pregnant females, but neither pregnant nor lactating female concentrations differed significantly from cycling females. Males who engaged in more mate‐guarding exhibited similar IgA concentrations to those who engaged in little mate‐guarding. These patterns may reflect the low energetic costs of mucosal immunity, or the complex dependence of IgA excretion on individual condition. Adding a noninvasive measure of mucosal immunity will promote a better understanding of how ecology modulates possible tradeoffs between the immune system and other energetically costly processes in the wild.

Section: Discussionsupporting

confidence: 75%

Section: Introductionmentioning

confidence: 99%

Noninvasive measurement of mucosal immunity in a free‐ranging baboon population

Gesquiere

Habig

Hansen

et al. 2020

“…Colobines have evolved several physiological specializations to consume hard‐to‐digest food, including sharp molars, enlarged salivary glands, and enlarged and multi‐chambered stomach with diverse microorganisms (Hale et al, ; Kay & Davies, ; Zhou et al, ). Edward and Ullrey () reported the apparent digestibility and digesta passage of some captive tropical/semitropical dwelling colobines ( Colobus guereza kikuyuensis , Pygathrix nemaeus , and Trachypithecus francoisi francoisi ), Huang () and Kirkpatrick, Zou, Dierenfeld, and Zhou () determined the same parameters for two temperate‐living colobines, R. roxellana, and R. bieti . These comparative studies indicate that temperate‐living colobines have higher digestibility of dry matter, neutral detergent fiber (NDF, total fiber fraction), and energy than tropical/semitropical dwelling colobines (dry matter: 81.3% vs.76.6%; NDF: 77.6% vs. 74.7%; energy: 78.9% vs. 75.6%, respectively).…”

Section: Introductionmentioning

confidence: 93%

Seasonal variation in diet and nutrition of the northern‐most population of Rhinopithecus roxellana

Hou

et al. 2018

There is a great deal of spatial and temporal variation in the availability and nutritional quality of foods eaten by animals, particularly in temperate regions where winter brings lengthy periods of leaf and fruit scarcity. We analyzed the availability, dietary composition, and macronutrients of the foods eaten by the northern-most golden snub-nosed monkey (Rhinopithecus roxellana) population in the Qinling Mountains, China to understand food choice in a highly seasonal environment dominated by deciduous trees. During the warm months between April and November, leaves are consumed in proportion to their availability, while during the leaf-scarce months between December and March, bark and leaf/flower buds comprise most of their diet. When leaves dominated their diet, golden snub-nosed monkeys preferentially selected leaves with higher ratios of crude protein to acid detergent fiber. While when leaves were less available, bark and leaf/flower buds that were high in nonstructural carbohydrates and energy, and low in acid detergent fiber were selected. Southern populations of golden snub-nosed monkey can turn to eating lichen, however, the population studied here in this lichen-absent area have adapted to their cool deciduous habitat by instead consuming buds and bark. Carbohydrate and energy rich foods appear to be the critical resources required for the persistence of this species in temperate habitat. The dietary flexibility of these monkeys, both among seasons and populations, likely contributes to their wide distribution over a range of habitats and environments.

“…Parasite species presence, prevalence, and/or richness is thought to provide an indication as to how well an animal harboring such organisms can control infection, and indirectly the state of its immune system [Muehlenbein, ]. More recently, the use of IgA enzyme immunoassays (ELISAs) has allowed for the development of a more direct indication of immunocompetence in laboratory rats [Hau et al, ] and subsequently other mammals, e.g., cynomolgus monkeys ( Macaca fascicularis [Paramastri et al, ]), Sichuan golden monkeys ( Rhinopothecus roxellana [Huang et al, ]), reindeer ( Rangifer tarandus tarandus [Rehbinder & Hau, ]).…”

Section: Introductionmentioning

confidence: 99%

Non‐invasive quantification of immunoglobulin A in chimpanzees (Pan troglodytes schweinfurthii) at Gombe National Park, Tanzania

Lantz

Lonsdorf

Heintz

et al. 2016

Immunoglobulin A (IgA) is the primary antibody responsible for mucosal defense in mammals and has been used as a marker for chronic stress and immune status. Therefore, this antibody may provide a more reliable indicator of an individual's immunocompetence than is currently available through other methods. Immunoglobulin A has never before been quantified in a wild population of non-human primates using non-invasive sample collection techniques. In this study, we present methodology for non-invasive IgA extraction in the field and provide quantification of mean fecal IgA concentrations in wild chimpanzees (Pan troglodytes schweinfurthii). During the study period (November 2009-October 2010), we collected fecal samples (N = 1463) from 59 individuals at Gombe National Park, Tanzania. We modified a field extraction technique for steroidal hormones to extract IgA from the fecal samples and then quantified mean IgA concentrations (ng/g) using a commercial human IgA enzyme immunoassay. Mean IgA concentration varied among individuals but not by sex or reproductive status. Mature animals tended toward higher mean IgA concentration than immature. Mean IgA concentration differed by quartile season, following a similar pattern previously observed for respiratory illness rates in this population, with the late dry season having significantly higher averages than the late wet. A circadian rhythm was also evident with mean IgA concentrations higher in samples collected in the latter half of the day. These demographic and temporal patterns of IgA concentration provide baseline values necessary to interpret future results, which may be combined with other health values to better understand the role of health and long-term stress in wild great ape populations. Am. J. Primatol. 80:e22558, 2018. © 2016 Wiley Periodicals, Inc.