Figure 9V-A. Copyright: This image is from Grifone R; Demignon J; Houbron C; Souil E; Niro C; Seller MJ; Hamard G; Maire P, Development 2005; 132: 2235-49 [doi:10.1242/dev.01773] and is displayed with the permission of The Company of Biologist Limited who owns the Copyright. [PMID:15788460]