The transgene contains the following elements: a 2.2 kb DNA fragment containing the promoter, exon 1 and (part of) intron 1 of the human skeletal muscle actin alpha 1 gene, the c isoform cDNA of the mouse peroxisome proliferative activated receptor gamma coactivator 1 alpha gene, and bovine growth hormone poly(A) signal sequences. The c splice variant incorporates a longer version of alternative 5' exon 1b, coding for a shorter alternative N-terminus of the peptide. Ten mouse lines (01-4, 02-5, 03-3, 03-6, 03-8, 04-1, 04-2, 04-6, 05-1, 10-4) were established. (J:138170)