Immunohistochemical Labeling of Quail Retina

The QH1 monoclonal antibody (dilution 1:4, Developmental Studies Hybridoma Bank, University of Iowa, Iowa City, IA) labels all quail hemangioblastic cells except mature erythrocytes (Pardanaud et al., 1987 (link)), including immature, ramified, and reactive microglia (Cuadros et al., 1992 (link)). Because the quail retina is avascular, QH1 only labels microglia in retinal explants (Carrasco et al., 2011 (link); Sierra et al., 2014 (link)). The 39.4D5 monoclonal antibody (dilution 1:100, Developmental Studies Hybridoma Bank, University of Iowa, Iowa City, IA) recognizes the transcription factor Islet 1 and labels most ganglion cells and other subsets of retinal neurons (Fischer et al., 2002 (link); Halfter et al., 2005 (link)). In addition, the anti-caspase-3 polyclonal antibody (dilution 1:100, R&D Systems, Minneapolis, MN) was used as marker for apoptotic cells in embryo retina (Borsello et al., 2002 (link)). As secondary antibodies we used Alexa Fluor 488-conjugated goat anti-mouse IgG (dilution 1:1,000, Molecular Probes, Eugene, OR) and Cy3-conjugated goat anti-rabbit IgG (dilution 1:1,000, Healthcare Europe, Freiburg, Germany).