QTL detection and utilisation in pigs

At least 40 QTL studies have been reported in pigs (Andersson et al., 1994 a,b; Andersson-Eklund et al., 1998; Beeckmann, 2000; Bidanel et al., 2001; Cassady et al., 2001; Casas-Carrillo et al, 1997; Ciobanu et al, 2001; De Koning et al., 1999; De Koning et al., 2000; De Koning et al., 2001a,b; Desautes et al., 2002; Edfors-Lilja et al., 1998; Geldermann et al., 1999; Grindflek et al., 2001; Harlizius et al, 2000; Hirooka et al, 2001; Knott et al., 1998; Knott et al., 2002; Malek et al., 2001a,b; Marklund at al., 1999; Nezer et al, 2002; Paszek et al., 1999; Paszek et al., 2001; Pérez-Enciso et al., 2000 ; Quintanilla et al., 2002; Rathje et al., 1997; Rattink et al., 2000; Rohrer, 2000; Rohrer and Keele, 1998a,b; Rohrer et al., 1999; Rothschild et al, 1995; Short et al., 1997; Wada et al., 2000; Walling et al., 1998; Walling et al., 2000; Wang et al., 1998; Wilkie et al., 1999; Yu et al, 1999) with most being full genome scans. Most have been reviewed by Bidanel and Rothschild (2002). These studies have detected QTLs affecting growth, fatness, muscularity, reproduction, meat quality, immune function and other traits. Most have employed wide crosses between very genetically distinct breeds or populations to generate their mapping resources. Generally these wide-cross resource pedigrees use at least one non-economic breed of pig, such as Wild Boar or Meishan, and this raises some issues about the relevance of the QTLs detected to commercial populations of animals. Nevertheless there is no doubt that these studies have generated an enormous amount of useful information in their own right and have paved the way for studies on more commercially relevant populations of animals. An excellent example of such information transfer is provided by Ciobanu et al (2001) who worked from the discoveries by Malek et al (2001b) of QTLs for glycogen content in muscle and associated meat quality in a Berkshire x Yorkshire cross pedigree through to the identification of novel mutation in the protein kinase adenosine monophosphateactivated gamma(3)-subunit (PRKAG3) gene segregating in commercial populations of pigs and having an appreciable effect on meat quality.