Myoblast city (Mbc^[1]) is the Drosophila melanogaster ortholog of the mammalian protein Dock180.^[2] Mutant mbc embryos exhibit defects in dorsal closure, cytoskeletal organization, myogenesis, and neural development.^[2][3]

The Myoblast city locus was identified by deletion mapping, using this technique researchers were able to isolate the location of the gene on the right arm of the third chromosome.^[4] During the process four recessive alleles of Mbc were found; mbc^c1, mbc^c2, mbc^c3, mbc^s4, all of which are lethal and the D. melanogaster embryos fail to hatch.^[4]

During the first 9-10 hours of development, embryos with the mutant Mbc alleles show the same myosin expression as wild-type embryos.^[4] However, at about the 11th hour, most myoblasts fail to fuse. As development progresses, some myoblasts show signs of fusion, such as elongation and having multiple nuclei; but some remain round.^[4] After 13-14 hours of development, most cells in mutant embryos that failed to fuse lose myosin expression.^[4]