Wnt對線蟲Q細胞極性和移動的調控

Abstract

Neuronal migration is an essential process that establishes the intricate and precise connectivity of the nervous system. Here, we study the molecular mechanisms of neuronal migration, using Q neuroblast lineages in C.elegans as a model. The left and right Q neuroblasts are equivalent lineages that show distinct migratory patterns along the antero-posterior axis. The Q descendants on the left (QL) migrate posteriorly, whereas those on the right (QR) migrate anteriorly. The posterior QL descendant migration requires the EGL-20/Wnt-dependent Hox gene mab-5. mab-5 repressed another Hox gene, lin-39, whose expression would otherwise promote anterior migration. In addition to this transcriptional regulation, another Wnt CWN-1 and Frizzled receptor MOM-5 promote QR anterior migration. We found that CWN-1/MOM-5 and LIN-39 act in parallel to promote Q cell anterior migration. CWN-1 instructed QR.pa anterior polarization and also influences the polarization of QL.pa that lacked EGL-20/MAB-5 signaling. We show that the Frizzleds MIG-1 and MOM-5 were expressed and functioned autonomously in the QL and QR descendants. Furthermore, we found that the planar cell polarity gene vang-1, which is the C. elegans homolog of the mammalian Vangl2 and Drosophila van Gogh/Strabismus, strongly suppressed QL anterior migration in the mig-1 mutant, and improved QR undermigration in the cwn-1 or egl-20 mutants. These data suggest that PCP genes regulate the Q cell migration.