Thinking about the fraction-competent issues

The post-doc is polishing up has latest manuscript, and on reading it over yesterday I realized that we have data to clarify a very old issue.  Here's a link to an old post on this topic: http://rrresearch.fieldofscience.com/2011/05/fraction-competent-problem.htmlIn the old days, the best way to estimate the distribution of competence among the cells of a 'competent' culture was to measure the proportion of cells that became transformed by selectable markers that were on two separate DNA fragments (usually markers carried by a single donor strain, but far enough apart on the chromosome that they were never taken up on the same fragment. Such assays typically find that cells that have been transformed by one marker are enriched for cells transformed by the other marker - the fraction of double transformants is higher than expected from the fractions of either single transformants - and this is used to estimate the fraction of the cells in the culture that are not competent.Now, from the post-doc's work, we have data telling us what fractions of the cells have acquired one selected marker have also acquired one, two, three or more unselected fragments of donor DNA, and we want to use this data to unpack the relationship above.IF:1. all parts of the donor chromosome are equally likely to be taken up and recombined into the recipient chromosome,and2. all the cells in the competent culture are equally likely to take up DNAand3. taking up and recombining one DNA fragment does ...
Source: RRResearch - Category: Medical Scientists Authors: Source Type: blogs