In reading the coverage of the transgenes in canola story, two ideas continue to come up that bother be because they’re just plain wrong. I don’t have exact citations for these, but I’ve seen both concepts repeated multiple times on multiple sites.
1. “What’s a crop growing outside of the field where it’s planted? A weed that’s what!”
In an admirably calm and collected piece, Andrew Pollack writing at the nytimes, reports on a study that will be discussed at the Ecological Society of America meeting. The finding? Canola plant growing by the side of the road (outside of fields) often carry genetically engineered traits for herbicide resistance. It sounds like a fun study to do: (more…)
This is close to, or past, the peak of pollinating season across much of the midwest. I, having migrated into computational work, am no longer called upon to put my life on hold, arriving at the corn field before the sun rises and leaving when it becomes too dark to see for a cold shower and a few brief hours of sleep before the next day arrives. But across the country graduate students, post-docs, professors, and professional crop breeders are doing just that and without the solace I could take back when I was doing the same (that I was an hourly employee and so making loads of overtime!). So to all of you out sweating in the fields, whether it’s in pursuit of greater understanding of the mysteries of live itself, or a new hybrid that will allow farmers to grow even more corn to feed the world, using even less water and fertilizer, we, who do not share your suffering, salute you!
Thus, the field researcher expects to attend to the crossing nursery continuously through the pollinating period (in the Midwest, approximately July 10-August 15). … The seven-day week is a shocking surprise to those not having “interned” in such a program during their graduate days.
Don’t you just love creative commons licensed images?
Cover image from Rosas et al 2010 PLoS Biology. (Click the image to view it in its original context)
In this case the story behind the image in a paper on hybrid vigor, another subject close to the heart of any biologist who has ever worked with corn, although this group worked with snapdragon, a species that is used as a model system for flower morphology. Snapdragon flowers are interesting genetically because they are only symmetric along one axis. The genes behind this trait have been studied for quite some time and have names like Cycloidea, Radialis and Divaricata. <– Snapdragon folks generally come up with classier sounding names for their genes than the communities for many other model species.
Snapdragon flowers can be symmetrically folder over one axis, but not the other. (Modified from the image above).
The authors of this paper found that the expression* of a number of these genes varied between different species within the snapdragon genus (Antirrhinum). So far so good, but the really exciting bit of this paper is that the authors use the version of these genes from different species (with significantly different levels of expression) to show that while the changes in expression observed between different species don’t make much of a difference to the final shape of snapdragon flowers, being stuck with a low expression version of a gene to begin with means a snapdragon plant has a much more altered shape when one of the copies of that gene is completely broken. (more…)
One controversy I seem to have completely missed out during my break was the protests over seed donations to Haiti this summer.
Yup, I said protests over donated seeds.
Well, (you might think): if these people are honestly convinced genetically engineered crops are dangerous (and clearly there are people in the world who really believe that) you can see how they’d react badly to feeling like they were be offered something that could harm their health, even (or perhaps especially) if it was being given freely as a gift.
Unfortunately even that rationalization isn’t any use here, since none of the donated seeds were genetically modified, as (almost) all the coverage eventually gets around to mentioning.
As far as I can tell at this late date the reasons people are upset boil down to three issues: (more…)
Photo Rainer Ebert, Flickr (click to view in original context)
The rice of my childhood was brown rice, incompletely stripped of its outer coating to retain more vitamins and minerals. Frankly it wasn’t very appetizing, and it was a pleasant surprise to discover rice can actually be delicious when it’s not also trying to be a health food. Never the less I consider myself to be a relatively unsophisticated rice-eater. If my rice is a different color I’ll probably notice, but a lot of the more subtle variations between different breeds slip by without grabbing my attention. (more…)
What an clever rule of thumb!
Domestication, then, seems to be associated with changes in transcriptional regulatory networks, whereas crop diversification involves a larger proportion of enzyme-encoding loci.
In other words, when it comes to transforming a wild plant species into one that is adapted to being grown by humans for food, in other words, changing the shape or function of the plant itself, you’ll usually want to mess around with the regulation of transcription factors (the genes that regulate how other genes are expressed), but when it comes to selecting for the qualities of the food itself (for example: different tastes, colors, smells, or nutritional values) it makes more sense to mess around with the genes that are directly involved in changing one kind of molecule into another. I wonder how generalizable that is?
Some examples from the paper:
Reading reviews like this one make me remember why it was the genetics of domestication that got me hooked on plant genetics in the first. Even if I have to go through a few intellectual contortions to tie my own research back into this field.
And completely unrelated to the subject of this post, I just want to say thank you to everyone who commented on my last entry. Has it been more than a month already?.
*Also golden rice, but that’s the result of a much more conscious form of selection.
Michael D. Purugganan and Dorian Q. Fuller, “The nature of selection during plant domestication,” Nature 457, no. 7231 (February 12, 2009): 843-848. doi: 10.1038/nature07895
Excerpt from a fascinating talk (go and read the whole transcript!):
There’s only one way to feed a city, at least historically, and that’s to feed it with grains—rice, wheat, maize, barley, sorghum, etc.. …
And what do you need in terms of grains? For most of history—really, until about 150 years ago—most people in most cities, except for the very wealthy, lived almost exclusively on grains. They got about ninety percent of their calories from grains.
That meant that for every single person in a city you had to have 2 lbs of grains a day, turned into something that people could eat. …
Depending on how good you are, it takes somewhere between fifty minutes and an hour to do enough maize for tortillas for one person. That means for a family of five someone is going to be spending four or five hours a day doing nothing but grind. It’s very exhausting, grinding.
It’s particularly fascinating when she gets into why milling came later to mexico (has too do with the consistency and nutrition of corn that’s ground while dry vs corn that’s ground wet). I wish I had time to say more on this subject, but I’m only one week out from my qualifying exam and falling to pieces mentally (which I’m told is all a part of the process).
So this was not the week to embark on an epic tale of transposons. Just got back from lab and I’m completely beat. The last two installments of transposon week are really cool stories and I want to do them justice. Will try to have them up as soon as I can manage.
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