EGL-17(FGF) EXPRESSION COORDINATES THE ATTRACTION OF THE MIGRATING SEX MYOBLASTS WITH VULVAL INDUCTION IN C-ELEGANS

During the development of the egg-laying system in Caenorhabditis eleg ans hermaphrodites, central gonadal cells organize the alignment of th e vulva with the sex myoblasts, the progenitors of the egg-laying musc les, A fibroblast growth factor [EGL-17(FGF)] and an FGF receptor [EGL -15(FGFR)] are involved in the gonadal signals that guide the migratio ns of the sex myoblasts. Here we show that EGL-17(FGF) can act as an i nstructive guidance cue to direct the sex myoblasts to their final des tinations. We find that egl-17 reporter constructs are expressed in th e primary vulval cell and that EGL-17(FGF) expression in this cell cor relates with the precise positioning of the sex myoblasts. We postulat e that EGL-17(FGF) helps to coordinate the development of a functional egg-laying system, linking vulval induction with proper sex myoblast migration.