Fig. 7. Clonal analysis of multipotential retinal progenitor cells using reaggregation culture. (A,E,I,M,Q) Low-magnification image of the clones visualized with anti-quail nucleus antibody, QCPN. The singly dissociated retinal progenitor cells, prepared from the central part of the E4.5 quail neural retina (A,I) or CMZ (E,M,Q), were mixed with feeder cells from E5 chicken retina, and cultured on a filter for 7 days either in the control (A,E) or chicken Wnt2b (I,M,Q)-conditioned medium. The CMZ progenitor cells produced larger clones than the central progenitor cells (A,E), and proliferation of both progenitor cells was promoted by the addition of chicken Wnt2b-conditioned medium (I,M). The CMZ progenitor cells produced secondary clones when they had been cultured in the presence of chicken Wnt2b (Q). Confocal images of progenitor clones visualized with QCPN (red), which were triple-labeled for Müller cell marker glutamine synthetase (Gln-Syn) and photoreceptor cell marker visinin (B,F,J,N,R), ganglion/amacrine cell marker Hu and visinin (C,G,K,O,S), or Hu and glutamine synthetase (D,H,L,P,T). Scale bar: 10 µm. Arrowheads indicate quail cells expressing those differentiation markers.