Look closely at the consolidated Hfr map and the data used to build the map on page 261. Suppose a fifth Hfr strain had the F factor inserted exactly halfway between cysE and leuU and had an orientation that was the same as that of Hfr 1. List the order of gene transfer for the first six genes transferred by this Hfr and the number of minutes of conjugation at which each gene is expected to be seen.

Key Concepts

Hfr Strains

Hfr (high frequency of recombination) strains are bacterial strains that have the F factor integrated into their chromosome. This integration allows them to transfer chromosomal genes to a recipient bacterium during conjugation. The order of gene transfer is determined by the position of the F factor insertion and the direction of transfer, which is crucial for understanding genetic mapping and gene linkage.

Gene Transfer Order

The gene transfer order refers to the sequence in which genes are transferred from the donor Hfr strain to the recipient during bacterial conjugation. This order is influenced by the physical location of genes on the chromosome and the time it takes for each gene to be transferred, which is measured in minutes. Understanding this order is essential for predicting which genes will be received first by the recipient.

Conjugation Timing

Conjugation timing is the duration required for the transfer of specific genes during bacterial conjugation. Each gene has a specific transfer time, which can be used to estimate when a gene will be received by the recipient bacterium. This timing is critical for constructing genetic maps and understanding the dynamics of gene transfer in bacterial populations.