CASIS Tweeter Needs a Biology Class
Godwin: @ZEROGSI is changing the genome without changing the DNA. Avoids GMO issues. #SiSpaceBiz
— ISS National Lab (@ISS_CASIS) October 18, 2013
Keith’s note: Yes, Twitter has its limitations when it comes to saying things in 140 characters. But if CASIS is tweeting pseudoscience like this (or misquoting someone) on behalf of NASA then they need to be shut down. On Earth, a “genome” is made out of DNA (or RNA) – period. How can you “change a genome” unless you do something to the nucleic acid (DNA or RNA) that comprises the genome? And if you are going to “change a genome”, well that kind of falls right in the realm of what a GMO (Genetically Modified Organism) is.
Keith’s update: CASIS just tweeted this reply. Alas, there is still some basic Biology ignorance in evidence on the Tweeter’s part. When you start to deliberately modify gene expression in an organism you 1. are tinkering with DNA since form (structure) = function and 2. you have one foot clearly in the GMO concept – and the other about to step in.
@NASAWatch @ZEROGSI is changing the genome expression without directly altering the DNA, but thank you for the request for clarification.
— ISS National Lab (@ISS_CASIS) October 21, 2013
Keith’s 22 Oct update: Zero Gravity Solutions sent NASA Watch an email today regarding the @NASAWatch response to what @ISS_CASIS tweeted yesterday: “We would request the clarification to state: We are changing the genome expression without adding foreign genes.”
What I like best about this exchange is that is shows that CASIS is feeling the heat of the much-needed light you shine on their operations, Keith. Thank you!
It helps that Keith has degrees in Biology as well.
Two, actually.
Aren’t some of the issues with GMOs the spread of the modified genes? If you affect expression in a particular plant but it passes on the same old genes in its seeds, doesn’t this effectively eliminate at least one issue that people have with GMOs?
Gene expression is modified all the time by normal environmental factors, promoters and inhibitors. Genomes have been modified since the beginnings of agriculture by selective breeding and the induction and selection of mutations.
No argument. Just to defend my honor – I know gene modification is pretty old, I was just alluding to a common complaint (“new genes will spread”).
Am I right to assume the CASIS twit is trying to explain epigenetic changes?
Yes (you are very observant) that seems to be what they are stumbling over. Altering phenotypic expression, selective gene expression/repression, etc. There seems to be a fundamental lack in their understanding of how genetic systems are designed and how they operate.
The critical issue to me is not the errors in terminology. The real issue is whether there is any scientific evidence that microgravity has any unique effect on on genetics. I have read the literature and I cannot find any. Such an effect is hardly to be expected since the effect of gravity on DNA is negligible. Gravity does affect organisms, plants respond to gravity through specialized receptors and in some animals eggs are so large that disturbing their orientation in gravity can disrupt development. But if there is any evidence of a direct effect on gene expression that is unique to the _absence_ of gravity I would be most interested in hearing about it.
Actually there is substantial evidence that exposure to microgravity, hypogravity, and hypergravity alters gene expression. No I am not going to give you links. You can use Google as easily as I can.
You mean like the virulence transition in salmonella? A glance at the literature shows the virulence transition can be easily triggered in normal gravity by changes in pH, oxygen tension or ion concentrations.
See for example,
http://www.cell.com/retriev…
In space these environmental changes could easily be produced by changes in patterns of flow and oxygen exchange in the culture system. Even the PI has taken to using a rotating culture vessel in 1G, calling it “simulated” microgravity.
Somehow this space-based research is essential to produce a vaccine for salmonella. Except that an excellent vaccine already exists, and has virtually eliminated salmonella infection in England. But the US poultry industry has successfully lobbied against any requirement to use it in the US, even though they are happy to pay for antibiotics. That’s the only reason we still have salmonella in the US.
http://www.nytimes.com/2010…
Of course there are effects on gene _expression_. Humans in space experience muscle and bone atrophy. However this is not a direct effect of gravity on genes or gene expression, it’s an effect of gravity on the amount of muscle activity people must make to get around. The mechanism of the changes in gene expression is the same as the mechanism of disuse atrophy in normal gravity.
Obviously no NASA-funded researcher is going to go out of his/her way to say that changes in gene expression in weightlessness are indirect and not unique to changes in gravity. But if you google without the words “space” or “gravity” in your search you’ll find plenty of literature.
http://discovermagazine.com…
If gravity had the major direct effects on gene expression suggested by the article then one would expect all the cells in the human body to demonstrate the same dramatic changes.
Gene expression is certainly affected by many factors including contact with a surface, contact with other cells, and fluid shear, as well as the concentration of oxygen and nutrients in the media. All these factors are affected by gravity, but they can also be manipulated on the ground, just as muscle and bone disuse can be modeled on the ground simply by placing the body at rest. Similarly tissue scaffolds permit the growth of cells in three-dimensional structures on earth despite the presence of gravity.
http://www.lifetechnologies…
Good job keeping them honest Keith. However the tweet was probably posted by some co-op/intern or publications person with no science background, not to mention limiting the characters to make a twitter post on making scientific discoveries… how about just posting a truncated link