“…For the Nrx-IV antibody, CNS were fixed for 3 minutes in Bouin’s fixative solution (Sigma Aldrich, HT10132), and the rest of the protocol was identical. Primary antibodies used were: guinea pig anti-Dpn (1:5000,[25]), chicken anti-GFP (1:2000, Abcam ab13970), rat anti-ELAV (1:100, 7E8A10-c, DSHB), mouse anti-ELAV (1:100, 9F8A9-c, DSHB), rat anti-dE-cadherin (1:50, DCAD2, DSHB), mouse anti-Armadillo (1:50, N2 7A1, DSHB), rabbit anti-Repo (1:10000, kind gift from B. Altenheim), mouse anti-Repo 1:100 (DSHB, 8D12-c), mouse anti-Prospero (1:100, MR1A, DSHB), rabbit anti-Asense (1:3000, kind gift from the Yan lab). rabbit anti-Phospho-histone H3 (1:100, Millipore 06-570), rabbit anti-Nrx-IV (1:1000, [46]) mouse anti-wrapper (1:20, DSHB 10D3, supernatant), mouse anti-Nrg 180 (1:50, DSHB BP104, supernatant).…”