Chronic wasting disease model of genetic selection favoring prolonged survival in Rocky Mountain elk (<i>Cervus elaphus</i>)

Williams, Amy L.; Kreeger, Terry J.; Schumaker, Brant A.

doi:10.1890/es14-00013.1

Cited by 21 publications

(27 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This line of inquiry is particularly relevant now with the spread of chronic wasting disease (CWD), a spongiform encephalopathy that affects cervids, causing global concern (Galloway et al., ; Mysterud & Rolandsen, ). It has been suggested that selection for prion disease resistance may play an important role in the long‐term dynamics of infected populations as CWD continues to spread (Monello et al., ; Robinson et al., ; Williams et al., ). Similarly, the magnitude of the effect of brucellosis on elk fitness should drive selection for increased resistance or tolerance.…”

Section: Discussionmentioning

confidence: 99%

Hidden cost of disease in a free‐ranging ungulate: brucellosis reduces mid‐winter pregnancy in elk

Cotterill

Cross

Middleton

et al. 2018

Ecology and Evolution

View full text Add to dashboard Cite

Demonstrating disease impacts on the vital rates of free‐ranging mammalian hosts typically requires intensive, long‐term study. Evidence for chronic pathogens affecting reproduction but not survival is rare, but has the potential for wide‐ranging effects. Accurately quantifying disease‐associated reductions in fecundity is important for advancing theory, generating accurate predictive models, and achieving effective management. We investigated the impacts of brucellosis (Brucella abortus) on elk (Cervus canadensis) productivity using serological data from over 6,000 captures since 1990 in the Greater Yellowstone Ecosystem, USA. Over 1,000 of these records included known age and pregnancy status. Using Bayesian multilevel models, we estimated the age‐specific pregnancy probabilities of exposed and naïve elk. We then used repeat‐capture data to investigate the full effects of the disease on life history. Brucellosis exposure reduced pregnancy rates of elk captured in mid‐ and late‐winter. In an average year, we found 60% of exposed 2‐year‐old elk were pregnant compared to 91% of their naïve counterparts (a 31 percentage point reduction, 89% HPDI = 20%–42%), whereas exposed 3‐ to 9‐year‐olds were 7 percentage points less likely to be pregnant than naïve elk of their same age (89% HPDI = 2%–11%). We found these reduced rates of pregnancy to be independent from disease‐induced abortions, which afflict a portion of exposed elk. We estimate that the combination of reduced pregnancy by mid‐winter and the abortions following mid‐winter reduces the reproductive output of exposed female elk by 24%, which affects population dynamics to a similar extent as severe winters or droughts. Exposing hidden reproductive costs of disease is essential to avoid conflating them with the effects of climate and predation. Such reproductive costs cause complex population dynamics, and the magnitude of the effect we found should drive a strong selection gradient if there is heritable resistance.

show abstract

Section: Discussionmentioning

confidence: 99%

Hidden cost of disease in a free‐ranging ungulate: brucellosis reduces mid‐winter pregnancy in elk

Cotterill

Cross

Middleton

et al. 2018

Ecology and Evolution

View full text Add to dashboard Cite

show abstract

“…This selective process, however, is slow because of the chronic nature of CWD mortality. Williams et al (2014) modelled the outcomes of a selective process on elk at the scale of decades to 100 years. The role that PrP genotypes play in shaping the population trajectories of CWD-infected cervid herds will likely be modified by hunting, which generally targets individuals in the oldest age class, of a specific sex (i.e.…”

Section: Strategies To Control the Spread Of Cwdmentioning

confidence: 99%

The ecology of chronic wasting disease in wildlife

et al. 2019

View full text Add to dashboard Cite

Prions are misfolded infectious proteins responsible for a group of fatal neurodegenerative diseases termed transmissible spongiform encephalopathy or prion diseases. Chronic Wasting Disease (CWD) is the prion disease with the highest spillover potential, affecting at least seven Cervidae (deer) species. The zoonotic potential of CWD is inconclusive and cannot be ruled out. A risk of infection for other domestic and wildlife species is also plausible. Here, we review the current status of the knowledge with respect to CWD ecology in wildlife. Our current understanding of the geographic distribution of CWD lacks spatial and temporal detail, does not consider the biogeography of infectious diseases, and is largely biased by sampling based on hunters' cooperation and funding available for each region. Limitations of the methods used for data collection suggest that the extent and prevalence of CWD in wildlife is underestimated. If the zoonotic potential of CWD is confirmed in the short term, as suggested by recent results obtained in experimental animal models, there will be limited accurate epidemiological data to inform public health. Research gaps in CWD prion ecology include the need to identify specific biological characteristics of potential CWD reservoir species that better explain susceptibility to spillover, landscape and climate configurations that are suitable for CWD transmission, and the magnitude of sampling bias in our current understanding of CWD distribution and risk. Addressing these research gaps will help anticipate novel areas and species where CWD spillover is expected, which will inform control strategies. From an ecological perspective, control strategies could include assessing restoration of natural predators of CWD reservoirs, ultrasensitive CWD detection in biotic and abiotic reservoirs, and deer density and landscape modification to reduce CWD spread and prevalence.

show abstract

“…Although there is some evidence that these cervid PrP polymorphs reflect natural selection in CWD host populations (Robinson et al 2012), it is not known if their frequency has increased within CWD-infected areas in response to selection. Even with high levels of CWD exposure, the effects of selection on cervid PrP genotype frequencies could take decades [133], maybe even centuries [134] to manifest. Further, selection may not elicit a strong genotype shift in cervids because PrP genotypes do not confer complete resistance, but merely extend CWD incubation period [135], and susceptible animals would therefore have opportunities to reproduce before infection or during clinical progression [136].…”

Section: Selection Acts On Prion Genes and Prion Variantsmentioning

confidence: 99%

Prions are affected by evolution at two levels

Wickner

Kelly

2015

Cell. Mol. Life Sci.

View full text Add to dashboard Cite

Prions, infectious proteins, can transmit diseases or be the basis of heritable traits (or both), most based on amyloid forms of the prion protein. A single protein sequence can be the basis for many prion strains/variants, with different biological properties based on different amyloid conformations, each rather stably propagating. Prions are unique in that evolution and selection work at both the level of the chromosomal gene encoding the protein, and on the prion itself selecting prion variants. Here we summarize what is known about the evolution of prion proteins, both the genes and the prions themselves. We contrast the one known functional prion, [Het-s] of Podospora anserina, with the known disease prions, the yeast prions [PSI+] and [URE3] and the transmissible spongiform encephalopathies of mammals.

show abstract

Chronic wasting disease model of genetic selection favoring prolonged survival in Rocky Mountain elk (Cervus elaphus)

Cited by 21 publications

References 28 publications

Hidden cost of disease in a free‐ranging ungulate: brucellosis reduces mid‐winter pregnancy in elk

Hidden cost of disease in a free‐ranging ungulate: brucellosis reduces mid‐winter pregnancy in elk

The ecology of chronic wasting disease in wildlife

Prions are affected by evolution at two levels

Contact Info

Product

Resources

About