FIGURE 8-5 Generation of microsatellite repeats by backward slippage of the nascent daughter strand during DNA replication. If, during replication (a), the nascent daughter strand “slips” backward relative to the template strand by one repeat, one new copy of the repeat is added to the daughter strand when DNA replication continues (b). An extra copy of the repeat forms a single-stranded loop in the daughter strand of the daughter duplex DNA molecule. If this single-stranded loop is not removed by DNA repair proteins before the next round of DNA replication (c), the extra copy of the repeat is added to one of the double-stranded daughter DNA molecules.