Genet. Sel. Evol.
Volume 39, Number 3, May-June 2007
|Page(s)||301 - 317|
|Published online||14 April 2007|
Within-family marker-assisted selection for aquaculture speciesAnna K. Sonesson
AKVAFORSK (Institute of Aquaculture Research Ltd), P.O. Box 5010, 1432 Ås, Norway
(Received 25 August 2006; accepted 10 January 2007; published online 14 April 2007)
Abstract - A within-family marker-assisted selection scheme was designed for typical aquaculture breeding schemes, where most traits are recorded on sibs of the candidates. Here, sibs of candidates were tested for the trait and genotyped to establish genetic marker effects on the trait. BLUP breeding values were calculated, including information of the markers (MAS) or not (NONMAS). These breeding values were identical for all family members in the NONMAS schemes, but differed between family members in the MAS schemes, making within-family selection possible. MAS had up to twice the total genetic gain of the corresponding NONMAS scheme. MAS was somewhat less effective when heritability increased from 0.06 to 0.12 or when the frequency of the positive allele was <0.5. The relative efficiency of MAS was higher for schemes with more candidates, because of larger fullsib family sizes. MAS was also more efficient when male:female mating ratio changed from 1:1 to 1:5 or when the QTL explained more of the total genetic variation. Four instead of two markers linked to the QTL increased genetic gain somewhat. There was no significant difference in polygenic genetic gain between MAS and NONMAS for most schemes. The rates of inbreeding were lower for MAS than NON-MAS schemes, because fewer full-sibs were selected by MAS.
Key words: marker-assisted selection / aquaculture / breeding
Correspondence and reprints: Anna.Sonesson@akvaforsk.no
© INRA, EDP Sciences 2007