Issue |
Genet. Sel. Evol.
Volume 35, Number 4, July-August 2003
|
|
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Page(s) | 353 - 368 | |
DOI | https://doi.org/10.1051/gse:2003028 |
DOI: 10.1051/gse:2003028
Selection against genetic defects in conservation schemes while controlling inbreeding
Anna K. Sonessona, b, Luc L.G. Janssa and Theo H.E. Meuwissenaa Institute of Animal Science and Health (ID-Lelystad), PO Box 65, 8200 AB Lelystad, The Netherlands
b Current adress: AKVAFORSK (Institute of Aquaculture Research Ltd), PO Box 5010, 1432 Ås, Norway
(Received 9 April 2002; accepted 15 January 2003)
Abstract
We studied different genetic models and evaluation systems to select
against a genetic disease with additive, recessive or polygenic
inheritance in genetic conservation schemes. When using optimum
contribution selection with a restriction on the rate of inbreeding
(
F) to select against a disease allele, selection
directly on DNA-genotypes is, as expected, the most efficient
strategy. Selection for BLUP or segregation analysis breeding value
estimates both need 1-2 generations more to halve the frequency of
the disease allele, while these methods do not require knowledge of
the disease mutation at the DNA level. BLUP and segregation analysis
methods were equally efficient when selecting against a disease with
single gene or complex polygene inheritance, i.e. knowledge about
the mode of inheritance of the disease was not needed for efficient
selection against the disease. Smaller schemes or schemes with a more
stringent restriction on
F needed more generations to
halve the frequency of the disease alleles or the fraction of diseased
animals. Optimum contribution selection maintained
F
at its predefined level, even when selection of females was at
random. It is argued that in the investigated small conservation
schemes with selection against a genetic defect, control of
F is very important.
Key words: genetic defects / selection / inbreeding / conservation
Correspondence and reprints: Anna K. Sonesson
e-mail: Anna.Sonesson@akvaforsk.nlh.no
© INRA, EDP Sciences 2003