You are currently browsing the monthly archive for November 2013.



For this weeks journal discussion I have decided to return to Salmonella. The paper of choice has the wonderful title of:

Genome and Transcriptome Adaptation Accompanying Emergence of the Definitive Type 2 Host-Restricted Salmonella enterica Serovar Typhimurium PathovarmBio vol. 4 no. 5 e00565-13

I have chosen this paper not only because it ends up focussing on bacterial motility and that it is Salmonella, one of the bugs I use to study motility in the lab! The title seems a bit misleading but lets read the paper before we make any comments. Following a trend of papers we have covered, this study utilises genome analysis to question species variability/adaptation. I also feel it is apt that we go back to discussing a genome paper this week with the recent announcement that Fred Sanger died. What better why to take note of the work he did by discussing a paper from one of the cohorts of microbiologists based at the Sanger Centre in the UK. I have also reused the discussion questions from week #35 as they fit with this paper


  1. Is the paper well written, easy to understand and thoroughly explained?
  2. Are the methods appropriate?
  3. What do the results tell us – how significant is the impact of this research?
  4. What research can and should this follow on to?

Two papers were recently published in the journal Science providing evidence that mammalian cells can use RNA interference (RNAi) to inhibit the replication of mammalian viruses. Sorry they are not open access by the papers are too interesting to ignore! This has become an important finding because it was widely believed that after we couldn’t find it, it didn’t occur. These papers have not come without their controversy and many do not believe that that 1) they are correct and 2) if they are right, then RNAi is not really important in mammals because we have other defences like interferons, antibodies and other innate and adaptive immune functions. 

The jury is out, so make your own mind up. Here’s a couple of questions to think about:

do you believe the data?

why did they have to use those specific viruses and cells?

do you believe RNAi is important to mammals?

why don’t mammals use RNAi?

Paper 1:

Paper 2:

Two good commentary articles are found in Science: Cell: