Practice question

In interrupted mating, transfer rate of chromosomal DNA via conjugative pilus is approximately constant, roughly 45 kilobases per minute under standard conditions at 37°C for HfrH, so physical distance translates to temporal separation. Therefore map length is expressed as minutes needed for marker to enter recipient after mating starts, representing minutes of transfer time. Whole E. coli chromosome maps as about 100 minutes. Different Hfr strains with origins at distinct sites generate overlapping time maps, allowing assembly of complete circular linkage map and orientation determination from entry order.