Edinburgh Research Explorer

Exploring the assumptions underlying genetic variation in host nematode resistance (Open Access Publication)

Research output: Contribution to journalArticle

Related Edinburgh Organisations

Open Access permissions

Open

Documents

  • Download as Adobe PDF

    Rights statement: This is an Open-Access article.

    Final published version, 424 KB, PDF-document

http://www.gse-journal.org/index.php?option=com_article&access=doi&doi=10.1051/gse:2008001&Itemid=129
Original languageEnglish
Pages (from-to)241-264
Number of pages24
JournalGenetics Selection Evolution
Volume40
Issue number3
DOIs
StatePublished - 2008

Abstract

The wide range of genetic parameter estimates for production traits and nematode resistance in sheep obtained from field studies gives rise to much speculation. Using a mathematical model describing host - parasite interactions in a genetically heterogeneous lamb population, we investigated the consequence of: ( i) genetic relationships between underlying growth and immunological traits on estimated genetic parameters for performance and nematode resistance, and ( ii) alterations in resource allocation on these parameter estimates. Altering genetic correlations between underlying growth and immunological traits had large impacts on estimated genetic parameters for production and resistance traits. Extreme parameter values observed from field studies could only be reproduced by assuming genetic relationships between the underlying input traits. Altering preferences in the resource allocation had less pronounced effects on the genetic parameters for the same traits. E. ects were stronger when allocation shifted towards growth, in which case worm burden and faecal egg counts increased and genetic correlations between these resistance traits and body weight became stronger. Our study has implications for the biological interpretation of field data, and for the prediction of selection response from breeding for nematode resistance. It demonstrates the profound impact that moderate levels of pleiotropy and linkage may have on observed genetic parameters, and hence on outcomes of selection for nematode resistance.

    Research areas

  • disease resistance, LITTER SIZE, TRAITS, CONSEQUENCES, GASTROINTESTINAL PARASITISM, OSTERTAGIA-CIRCUMCINCTA INFECTION, modelling, MODEL, LAMBS, genetic parameters, gastro-intestinal parasites, sheep, NUTRITION, SHEEP, SELECTION

Download statistics

No data available

ID: 7553788