Laboratory for Sensory Development

A common theme in organogenesis, perhaps the most important, is the use of localized activities of molecules to direct development. This regionalization continues throughout development orchestrating the proper development of organs, coordinating not only the correct location of the organ but also allowing integration of the organ with structures required for correct function. One example is the initiation of the inner ear. The otic placode, the precursor of the inner ear, is induced as a result of the localized action of a newly cloned member of the chick fibroblast growth factor family, fgf-19 in the cephalic paraxial mesoderm of the chick embryo; however, fgf-19 is inhibitory to later differentiation. The development of the ear provides an ideal model system, whereby the molecular mechanisms and tissue interactions governing the induction, differentiation and integration (the mechanisms by which organ development is coordinated with the development of 'ancillary' structures that are required for proper function) can be studied.

Research Subjects

• What are the steps in making a fully functioning organ?
• What do these steps do?
• How are organs developmentally integrated to form a organ system?

Publications

1. Yang L, O'Neill P, Martin K, Maass JC, Vassilev V, Ladher R*, Groves AK*.:
   "Analysis of FGF-Dependent and FGF-Independent Pathways in Otic Placode Induction."
   PLoS One. (2013) 8(1): e55011
2. Freter S., Muta Y., O’Neill P., Vassilev V. S., Kuraku S., Ladher R. K.:
   "A role for Pax2 in precursor maintenance during inner ear and epibranchial specification."
   Dev Dyn (2012) 241, 1716-1728
3. O'Neill P, Mak SS, Fritzsch B, Ladher RK*, Baker CV*.:
   "The amniote paratympanic organ develops from a previously undiscovered sensory placode."
   Nat Commun. (2012) 2012; 3:1041
4. Zou Y, Mak S. S., Liu H. Z., Han D. Y., Zhuang H. X., Yang S. M., Ladher R. K.:
   "Induction of the chick columella and its integration with the inner ear."
   Dev. Dyn (2012) 241, 1104-1110
5. Ladher R. K.:
   "Squeezing into differentiation"
   Dev. Cell (2011) 21, 607-608
6. Nagai H, Mak SS, Weng W, Nakaya Y, Ladher R, Sheng G.:
   "Embryonic development of the emu, Dromaius novaehollandiae."
   Dev. Dyn (2011) 240, 162-175
7. Ladher RK, O'Neill P, Begbie J.:
   "From shared lineage to distinct functions: the development of the inner ear and epibranchial placodes"
   Development (2010) 137, 1777-1785
8. Teraoka ME, Paschaki M, Muta Y, Ladher RK.:
   "Rostral paraxial mesoderm regulates refinement of the eye field through the bone morphogenetic protein (BMP) pathway."
   Dev Biol. (2009) 330: 389-98
9. Freter S., Muta Y, Mak S.S. and Ladher R. K.:
   "Progressive restriction of otic fate: the role of FGF and Wnt in resolving inner ear potential."
   Development (2008) 135, 3415-3424
10. Sai X. and Ladher R. K.:
    "FGF signaling regulates cytoskeletal remodeling during epithelial morphogenesis."
    Curr Biol 18, 976-81(2008)