Journal: Developmental dynamics : an official publication of the American Association of Anatomists

Article Title: Patterns of senescence and apoptosis during development of branchial arches, epibranchial placodes, and pharyngeal pouches.

doi: 10.1002/dvdy.637

Figure Lengend Snippet: FIGURE 9 3D reconstructions of p21+ senescent cells (blue), strongly Pax8+ (Pax8++, dark green) or weakly Pax8+ (Pax8+, light green) progenitors, and delaminating neuroblasts (white) in epibranchial placodes (orange) 1 (e1), 2 (e2), and 3 (e3) of 11- to 11.5-days-old mouse embryos (E11 to E11.5). A, In the regressing epibranchial placode 1, a large cluster of p21+ senescent cells overlaps both the cluster of weakly Pax8+ progenitors abundant throughout the placode and the few remaining strongly Pax8+ progenitors located in its center. B and C, Massive overlap between p21+ cells and weakly Pax8+ progenitors is also found in the highly neurogenetically active epibranchial placodes 2 and 3. In contrast, the overlap between the large cluster of strongly Pax8+ progenitors centered on the neuroblast delamination field and the senescent cells grouped ring-like around this delamination field is rather small. D, This difference is also evident in the maximally invaginated epibranchial placode 3 of the E11.5 embryo. E, Double immunofluorescence experiments performed on the epibranchial placode 2 of an E10.5 embryo show that virtually all p21+ senescent placode cells are (weakly or strongly) Pax8-immunoreactive progenitors. ca, caudal; do, dorsal; la, lateral; me, medial; ro, rostral; ve, ventral. Scale bars: 50 μm (A–D), 10 μm (E).

Article Snippet: The highly specific mouse anti-Pax8 antibody (clone BC12, ACI 438, Biocare Medical, Concord, CA, USA, RRID: AB_2864457) that we used to detect epibranchial precursors in histological serial sections has been characterized in detail in Washausen and Knabe.25 In addition, we used a rabbit polyclonal anti-Pax8 antibody (10336-1-AP, Proteintech Group, Rosemont, IL, USA; RRID: AB_2236705) to double-label Pax8 with the mouse anti-p21 antibody F-5.

Techniques: Immunofluorescence