Corrections for Tuesday’s lecture (2/15/11) In lecture on Tuesday (2/15/11), we talked about recombination in viruses. We started by discussing the following Table for two traits and two genes of the T2 phage. T2 PHAGES Plaque size Plaque appearance r + – small h + – cloudy r – large h – clear Mixed infection progeny #progeny plaques r + h 42 r h + 34 r + h + 12 r h 12 Total 100 This Table is given on your handouts for 2/15/11 and 2/17/11. I just checked a number of different references and the above information is correct. As a reminder, the main message from this part of the lecture is that the T2 phage can undergo crossing over in a mixed infection. Furthermore, in the same way that eukaryotic genes are mapped according to their crossover frequencies, one can map the genetic (cM) distance between the r and h genes using the #progeny above. Our lecture on 2/15/11 then discussed the complementation studies by Seymour Benzer. In lecture (2/15/11), I stated that these complementation studies used the T2 phage.
This is the end of the preview.
access the rest of the document.
Seymour Benzer, mixed infection, normal wild type