Construct: The 5' regulatory region, first exon, first intron and translational start site of Act88F are fused upstream of cDNA/genomic sequences encoding the major adult form of Mhc lacking the globular head region. The Mhc coding sequences extend from 45 amino acids upstream of the head-rod junction through to the C-terminus. Exon 15a is included and a splicing choice for exon 18 is retained. A 1.5kb fragment from the 3' region of Mhc (which includes polyadenylation signals) is included downstream of the Mhc coding sequences.