SAGE: gene expression in pigs of two commercial lines at the 3 and 9 months og age

Muscle development is associated with a modification of mass, composition and function that in productive animals are considered responsible of meat characteristics. In this study, SAGE was employed to describe gene expression in pigs of two commercial lines at the 3 and 9 months og age. The aim was to obtained a full gene expression profile that would assist in identifying genes differentially expressed in the muscle Longissimum dorsi during normal growth. The pattern of expression between lines and ages will help to elucidate the metabolic pathways modulated by these genes during muscle development. Keywords: SAGE, muscle, swine, age comparison, swine comparison Twenty castrate pigs, 10 purebred Large White (LW) and 10 Landrace X Duroc (DU), were reared from 3 to 12 months of age in the same environmental and feeding conditions were used. At the age of 3 and 9 month of age, Longissimum dorsi biopsy was collected from each animal of the two groups, using a Magnum Biopsy System (Bard, Covington, GA USA). SAGE libreries were constructed for the biopsies sampled at 3 and 9 from the one Large White and one LandraceXDuroc pig. Animals were selected on the basis of the live weight and daily gains, to have the most “fat” Large White and “lean” LandraceXDuroc.