Proper orchestration of quiescence and activation of progenitor cells is crucial during embryonic development and adult homeostasis. activation of Fgf signaling controls sensory organ differentiation, but not progenitor proliferation. In addition to the lateral line, these findings have important implications for understanding how niche-progenitor cells segregate Triisopropylsilane interactions during development, and how they may go wrong in disease says. DOI: http://dx.doi.org/10.7554/eLife.01832.001 mutants and pharmacological inhibition of ErbB signaling mimics the phenotype. (BCE) Double in situ hybridization was performed to label Schwann cells with (and neuromasts with at 5 dpf. (B) Control siblings with Schwann cells (arrows) along the lateral line nerve and normal neuromast number. mutants mimic and mutants in that they lack Schwann cells along the lateral line and have increased neuromast number (C). The brown cells along the midline in both sibling and are pigment cells. (D and E) Triisopropylsilane Double in situ hybridization for and in DMSO or AG1478 treated larvae from 50 hpf. Compared to DMSO treatment (D), increased neuromasts are seen in AG1478 treated larvae (E). expression along the midline shows that Schwann cells (arrows) are still present at 5 dpf when AG1478 was given at 50 hpf (E), compare to DMSO treated (D). DOI: http://dx.doi.org/10.7554/eLife.01832.003 Figure 1figure supplement 1. Open in a separate windows Mutations in the signaling pathway show precocious neuromast formation by 5 dpf.Alkaline phosphatase staining of control (A), (B), (C) and (D) zebrafish at 5 dpf. Quantification of alkaline phosphatase stained larvae shows significant increase in neuromast number in all mutants compared to control siblings (E, Student’s mutants have defects in adult pigment pattern.Control siblings at one month of age show typical stripe pattern of melanophores (ACA). at 1-month-old show patchy placement of melanophores in the anterior trunk with a more adult like pattern in the posterior region reminiscent of mutants (BCB). DOI: http://dx.doi.org/10.7554/eLife.01832.005 Figure 1figure supplement 3. Open in a separate window mutants drop neuromasts as they age.Control sibling (A) or (B), were imaged at 1 month of age. Neuromasts that stay along the midline can be seen in control siblings (A, arrowhead). These neuromasts are lost from the more posterior region in adult zebrafish (B, arrowhead). Similarly neuromasts are also lost from the more ventral lateral line (arrows), which are mostly derived from primI, in (B)(CCD) At 4 months of age the degeneration of neuromasts is usually even more severe. In controls at four months multiple stitches of neuromasts can be seen after DASPEI staining along the ventral line (C) and tail fin (C). have no ventral lateral line (D) or tail fin (D) neuromasts remaining at 4 months. DOI: http://dx.doi.org/10.7554/eLife.01832.006 Figure Triisopropylsilane 1figure supplement 4. Open in a Triisopropylsilane separate windows ErbB inhibition after Mouse monoclonal to KID lateral line migration is complete causes a decrease in proliferation and number of lateral line Schwann cells.BrdU plus DMSO or AG1478 was given to fish at 48 hpf then fixed at 6, 14, or 24 hr post treatment. BrdU index is usually decreased (A, Student’s and the ErbB pathway members intercalary neuromasts form precociously (Grant et al., 2005; Rojas-Munoz et al., 2009; Perlin et al., 2011). As Schwann cells require axons for migration along the lateral line, mutants that lack a posterior lateral line ganglion, also show extra neuromasts (Lopez-Schier and Hudspeth, 2005). Likewise, extra neuromasts form after posterior lateral line ganglion extirpation or Schwann cell ablation (Grant et al., 2005; Lopez-Schier and Hudspeth, 2005). These experiments suggest that Schwann cells contribute to an inhibitory niche that maintains lateral line progenitor cells from undergoing precocious proliferation and differentiation. The signaling pathways that orchestrate intercalary neuromast formation are currently unknown. In contrast, the early development of the migrating lateral line has been extensively studied. Complex cell signaling interactions between Wnt/-catenin, Fgf, Notch and chemokine pathways regulate proliferation, neuromast formation and migration (Aman and Piotrowski, 2009; Ma and Raible, 2009; Chitnis et al., 2012). Wnt/-catenin signaling in the leading region of the primordium restricts and initiates Fgf signaling to the trailing region. In.