These include inappropriate expression of nautilus in cells that are not normally destined to be somatic musculature, and generation of mutations that disrupt nautilus function in somatic muscle precursors. Expression of nautilus in cells destined to be mesodermal derivatives other than somatic muscles them into a program of differentiation that is reminiscent of that of the somatic muscles. These modified cells exhibit altered patterns of gene expression, as well as morphological changes that appear to include adhesion, fusion and elongation. Additionally, inappropriate expression of nautilus in somatic muscle precursors in which it is not normally present induces defects in the morphological characteristics of these muscle fibers. Surprisingly, these embryos survive to adulthood, indicating that it is not essential for viability.
Embryos lacking nautilus are, however, missing a distinct and reproducible subset of muscle fibers.
These fibers are recovered by providing nautilus under artificial control, indicating that it is responsible for the observed muscle defects. Interestingly, the precursors to the missing muscles are present in the absence of nautilus , but appear to be unable to continue their differentiation program. Future efforts focus on the identification of molecules that interact with nautilus as well as molecules that serve a similar role to that of nautilus in the remaining muscle fibers. Identification and characterization of myoblast city . In an effort to identify other genes involved in myogenesis in Drosophila , we have used a genetic approach to identify mutations that disrupt muscle formation.