Live imaging shows three possible transgene/speckle dynamic events during heat shock. (A) Long-range movement of Hsp70 BAC transgenes (green) toward a ASF/SF2 speckle (red) occurred within a 5-min heat shock period (Video 1). (B) Enlargement of preexisting speckle together with decondensation and increased association and encircling of BAC transgenes around speckle exterior (Video 2). (C) Nucleation of a new ASF/SF2 speckle adjacent to the Hsp70 BAC transgenes several minutes after heat shock; newly nucleated speckle then merges with preexisting adjacent speckle forming a larger speckle (Video 3). Bar, 5 µm.