Fig. 4. (A) JAM-1 localization in representative 2/8 couplets at 0 hours, 3 hours, 6 hours and 9 hours after division from 1/4 blastomeres. E-cadherin and negative control (secondary antibody only) are shown at the bottom. Bar, 20 µm. (B) Timing of cell-cell contact and apical polar staining of JAM-1 in 2/8 couplets at different times after division from 1/4 cells (data from single experiment comprising 39 couplets).