Mode of evolution of the satellite DNA from the bluegill sunfish Lepomis macrochirus.

Examination of the sequence of a satellite DNA (BG16) isolated from the bluegill sunfish Lepomis macrochirus revealed that the repeat unit contains regions comprised of internal subrepeats. This suggests that the BG16 satellite evolved from a shorter repeat unit into a larger composite repeat, and a stepwise expansion model of the evolution of the BG16 satellite is proposed.