Interpretation and prediction in disease genetics

S.C. Bishop

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

This paper summarises general issues relating to the interpretation of field disease data and the prediction of responses to selection for disease resistance. Prioritisation of diseases to study is a non-trivial task as there are many criteria by which disease importance can be assessed; a structured approach is described herein. The interpretation of field data and the prediction of responses to selection require an understanding of disease epidemiology, as infection transmission dynamics will affect both the interpretation of genetic parameters and the likely observable outcomes. For many bacterial and viral diseases, field data will likely contain noise due to incomplete exposure to infection and imperfect diagnosis of infection. These factors will result in heritabilities or SNP associations being underestimated; hence a weak genetic signal from such data may mask stronger underlying genetic effects. Interpretation of field data for parasite resistance is more straightforward, provided animals have faced sufficient challenge. Mathematical models that predict responses to selection reveal non-linear relations between mean host genotype and outcomes such as observed infection levels, animal performance, and the likelihood and severity of epidemics. In many cases, total benefits are predicted to be larger than suggested by quantitative genetic theory alone, justifying inclusion of disease resistance in selection goals. These concepts are illustrated for nematode infections and footrot in sheep, and ruminant mastitis.
Original languageUndefined/Unknown
Title of host publicationAssociation for the advancement of animal breeding and genetics. Proceedings of the 18th conference, Barossa Valley, South Australia, 28 September - 1 October 2009
Place of PublicationAdelaide
PublisherAssociation for the Advancement of Animal Breeding and Genetics
Pages255-262
Number of pages8
Publication statusPublished - 2009
EventAssociation for the Advancement of Animal Breeding and Genetics - Barossa Valley, Australia
Duration: 28 Sep 20091 Oct 2009

Conference

ConferenceAssociation for the Advancement of Animal Breeding and Genetics
CountryAustralia
CityBarossa Valley
Period28/09/091/10/09

Keywords

  • disease epidemiology genetics Mathematical models selection

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