Cheetahs have a stronger constitutive innate immunity than leopards

Sonja K Heinrich,Gábor Á Czirják,Jörg Melzheimer,Alexandre Courtiol,Martin Dehnhard,Bettina Wachter,Heribert Hofer

doi:10.1038/srep44837

Sonja K Heinrich, Gábor Á Czirják + Show 5 more

Open Access

https://doi.org/10.1038/srep44837

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Abstract

As a textbook case for the importance of genetics in conservation, absence of genetic variability at the major histocompatibility complex (MHC) is thought to endanger species viability, since it is considered crucial for pathogen resistance. An alternative view of the immune system inspired by life history theory posits that a strong response should evolve in other components of the immune system if there is little variation in the MHC. In contrast to the leopard (Panthera pardus), the cheetah (Acinonyx jubatus) has a relatively low genetic variability at the MHC, yet free-ranging cheetahs are healthy. By comparing the functional competence of the humoral immune system of both species in sympatric populations in Namibia, we demonstrate that cheetahs have a higher constitutive innate but lower induced innate and adaptive immunity than leopards. We conclude (1) immunocompetence of cheetahs is higher than previously thought; (2) studying both innate and adaptive components of immune systems will enrich conservation science.

Highlights

Conservation science is a discipline that can help to slow down global biodiversity loss[1,2]
We first reduced the dimensionality of the data for an overall comparison of the immunity of cheetahs and leopards by summarizing the six immune measurements into the two first principal components (PC) of a principal component analysis (PCA, Fig. 1), as suggested by Buehler et al.[67]
PC1 captured 40.1% of the total variance in immune measurements and mainly reflected constitutive innate immunity, because three of the four variables for constitutive innate immunity aligned along the x-axis, which represents PC1, in Fig. 1 – these were bacterial killing assay (BKA) ranks, haemagglutination titer and haemolysis titer

Summary

Introduction

Conservation science is a discipline that can help to slow down global biodiversity loss[1,2]. The integration of life history theory and other facets of evolutionary ecology into conservation science has the potential to provide new conservation management tools[3] This is because an evolutionary approach uses a theoretical or empirical framework which provides testable predictions on the diversity of physiological responses to disturbances in individuals under natural selection[4]. There are examples of populations with high MHC variability and a high susceptibility to diseases, as in bighorn sheep (Ovis canadensis)[26] These studies provide evidence in contrast to the expectation that low MHC variation results in an impaired immune response and vice versa[12,27,28]. We combine functional assays and measurements of several effectors of the immune system in a species with relatively low genetic variability, the cheetah (Acinonyx jubatus jubatus), and compare them with measures from a species with relatively high genetic variability, the African leopard (Panthera pardus pardus) from sympatric free-ranging populations in Namibia

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