A second and third set of tissues was assayed for D1 and D2. For D1, tissues were incubated in primary antibody rat anti-D1 (1:1,000, Sigma Aldrich D2944) for 48 hours at 4°C. Specificity of D1 antibody was validated by omission of primary antibody and by a previous prebsorption and Western blot study (24 (link)). Tissues were incubated for 1 hour in donkey anti-rat/Alexa 488 (1:1,000, Life Technologies A21208) and counterstained with DAPI. For D2, tissues underwent antigen retrieval for 30 minutes in 10 mM sodium citrate buffer (pH 8.5) to unmask immunosignal and were incubated in primary antibody mouse anti-D2 (1:200, Santa Cruz sc-5303) for 48 hours at 4°C. Specificity of D2 antibody was validated by omission of primary antibody and by previous preabsorption and Western blot studies (25 (link), 26 (link)). Tissues were incubated for 1 hour in donkey anti-mouse/Alexa 488 (1:1,000, Life Technologies A21202).