Fig. 2. MYH13 mRNA is also localized to the central region of the muscle. Primers specific for MYH13 mRNA were used in semiquantitative RT-PCR of RNA prepared from different sections of the muscle. The resulting 320 bp product is abundant in the central region (a), but greatly diminished in the distal (b) and far distal (c) regions. The muscle used for RNA preparation did not include as much of the proximal region as that used for the protein samples.