Technical Reference #3079

3079.

EphB–ephrin-B2 interactions are required for thymus migration during organogenesis Katie E. Foster; Julie Gordon; Kim Cardenas; Henrique Veiga-Fernandes; Taija Makinen; Elena Grigorieva; David G. Wilkinson; C. Clare Blackburn; Ellen Richie; Nancy R. Manley; Ralf H. Adams; Dimitris Kioussis; and Mark C. Colesa, National Institute of Medical Research, PNAS, 107(3079), (2010)
Link To Paper

Abstract:
Thymus organogenesis requires coordinated interactions of multiple cell types including neural crest (NC) cells to orchestrate the formation separation and subsequent migration of the developing thymus from the third pharyngeal pouch to the thoracic cavity. The molecular mechanisms driving these processes are unclear; however NC-derived mesenchyme has been shownto play an important role. Here we show that in the absence of ephrin-B2 expression on thymic NC-derived mesenchyme the thymus remains in the cervical area instead of migrating into the thoracic cavity. Analysis of individual NC-derived thymic mesenchymal cells shows that in the absence of ephrin-B2 their motility is impaired as a result of defective EphB receptor signaling. This implies a NC-derived cellspecific role of EphB–ephrin-B2 interactions in the collective migration of the thymic rudiment during organogenesis.

Keywords:
collective cell migration | thymus organogenesis | ephrin-B2 | Eph receptor | neural crest

Materials & Methods:
Video Microscopy. Thymic rudiments from E13.5 Wnt1-Cre;Rosa26eYfp control or Ephrin-B2Lx/Lx;Wnt1-Cre;Rosa26eYfp mutant embryos were dissected digested with collagenaseD(Roche) seeded in glass-bottomed dishes (MatTek) and incubated for 2 h or overnight in serum-free Iscove’s Modified Dulbecco Medium with or without ephrin-B2/Fc cross-linked with IgG or EphB4/Fc as indicated on the figure. Images (Fig. 4) were obtained at 5-min intervals on a Deltavision microscope. Images were analyzed in SoftWorx (Applied Precision) and Volocity (Improvision).

Microscopic Technique
Video Microscopy

Cell Type(s)
Thymic rudiments from embryos