Chromosomal localization of the mouse titin gene and its relation to "muscular dystrophy with myositis" and nebulin genes on chromosome 2.

In the mouse, the genes for the structural components of the myofibril titin and nebulin, Ttn and Neb, map to proximal Chr 2, as does the gene for a muscle disease, "muscular dystrophy with myositis," mdm. To facilitate the evaluation of Ttn and Neb as possible candidates for mdm, we have determined their relative map positions, using a Mus spretus/Mus musculus interspecific backcross. The gene order (distances in cM) cenVim-16.9 +/- 4.7-Neb-7.6 +/- 3.0-Ttn, Acra-18.0 +/- 4.9-Pax-6-17.7 +/- 4.9-a ... has been determined. Considering the standard deviations, Neb, Ttn, and Acra could colocalize with mdm. Using Ttn and Neb probes, DNAs from mdm/mdm and mdm/+ mice were tested for restriction fragment variants in comparison to the M. musculus wildtype. No variants have been found with 11 restriction nucleases. Our data corroborate a conserved synteny comprising genes NEB, TTN, CHRNA1 on human Chr 2q.