Figure 5.

A,B: EMSAs performed with ³²P‐labelled L‐mir‐363 and embryo extract from uninjected controls or embryos injected with 1 ng of either (A) lin28a1 or (B) lin28a2. Embryo extract was used at 1/16 dilution for lanes 2–3, 5–6, and at 1/32 dilution for lower concentration of overexpressing extract in lane 4. Arrows indicate unbound RNA (blue), lin28‐RNA complex (red), and supershift complex of antibody‐lin28‐RNA (green). + Ab = 1/20 dilution α‐lin28a, + ser = 1/20 dilution preimmune bleed serum, both incubated with protein on ice for 20 min before addition of probe. C,D: EMSAs performed with ³²P‐labelled pre‐mir‐363 and embryo extract from uninjected controls or embryos injected with 1 ng of either (C) lin28a1 or (D) lin28a2. Embryo extract was used at 1/8 dilution for lanes 2–3, 5–6, and at 1/16 dilution for lower concentration of overexpressing extract in lane 4. Arrows indicate unbound RNA (blue), lin28‐RNA complex (red), and supershift complex of antibody‐lin28‐RNA (green). + Ab = 1/20 dilution α‐lin28a, + ser = 1/20 dilution preimmune bleed serum, both incubated with protein on ice for 20 min before addition of probe.