File:Pharmacological inhibition of apoptosis generates lateral line placodes in embryonic mice.jpg

Fig. 2. Pharmacological inhibition of apoptosis generates lateral line placodes in embryonic mice. (A) Micrographs of representative serial sections used to compile schematic reconstructions of Q-VD-OPh-treated mouse embryos. Exemplarily, topography and dimensions of a middle lateral line placode (m) are shown (embryo #125; relative z-positions indicated). (B,C) Reconstructions of mouse (B) and Xenopus laevis (C) embryos show ectoderm (light grey), otic vesicle with detachment site (dark grey), epibranchial placodes (orange), apoptosis (purple), and lateral line placodes (blue). (B) Inhibition of apoptosis for 24 h in whole embryo culture (wec) generates lateral line placodes (embryo #030, mirror-imaged right side). (C) Lateral line placodes in a Xenopus laevis embryo, stage 27 (adapted from Schlosser and Northcutt, 2000). (D) Frequency of anterodorsal (ad), middle (m), and posterior (p) lateral line placodes either found unilaterally or bilaterally in the posterior placodal area of mouse embryos exposed to Q-VD- OPh for 18, 24, or 36 h. Scale bar: 100 μm. ad, av, m, p, anterodorsal, anteroventral, middle, and posterior lateral line placode, respectively; asterisk and triangle, pharyngeal pouches 1 and 2, respectively; e1, e2, e3, e31 , e32 , epibranchial placodes 1, 2, 3, 31 , 32, respectively; ot, otic anlage; ov, optic vesicle; Q-VD-OPh, pan- caspase inhibitor; v, migratory primordia