PARALOGOUS SM22-ALPHA (TAGLN) GENES MAP TO MOUSE CHROMOSOME-1 AND CHROMOSOME-9 - FURTHER EVIDENCE FOR A PARALOGOUS RELATIONSHIP

SM22 alpha (TAGLN) is one of the earliest markers of differentiated sm ooth muscle, being expressed exclusively in the smooth muscle cells of adult tissues and transiently in embryonic skeletal and cardiac tissu es. We have identified and mapped the mouse Tagln gene and a closely r elated gene, Sm22 alpha homolog (Tagln2). The chromosomal localization for Tagln was identified by linkage analysis to distal mouse chromoso me 9 between D9Mit154 and D9Mit330, closely linked to the anchor locus D9Nds10. The localization of Tagln2 was also determined and was found to map between Fcgr2 and D1Mit149 on distal mouse chromosome 1. This localization is homologous to a region of human 1q21-q25 to which an E ST representing human TAGLN2 was previously mapped. The two regions, d istal mouse chromosome 1 and proximal mouse chromosome 9, and the huma n regions with conserved synteny (1q21-q25 and 11q22-qter) are believe d to be paralogous, reflecting either conserved remnants of duplicated chromosomes or segments of chromosomes during vertebrate evolution. ( C) 1998 Academic Press.