Fig. 1. Schematic representation of myomesin sequencing strategy. Myomesin 1 cDNAs were amplified and sequenced from E18 cardiac and P45 hindlimb muscle. The approximate position of the four primers used for sequencing (pr1 to pr4) is indicated. Myom1 is present in two splice variants, with and without the EH (embryonic heart) domain. Primers pr1 and pr2 yielded a 393-bp fragment from hindlimb muscle that lacked the EH domain. The alternatively spliced EH domain is shown here relative to two of the conserved fibronectin III repeats (My6 and My7 domains shown) that dominate the central portion of myomesin 1. Primers pr1 and pr4 yielded a 542-bp fragment, and primers pr3 and pr2 yielded a 389-bp fragment, from E18 heart muscle. Collectively, sequencing of these fragments gave full-length coverage to the cDNA of the EH domain. The assembled EH-myomesin 1 sequence was then used in a BLASTn search of GenBank.