Prof May Berenbaum on CCD

Tonight there was a live broadcast of a chat with May Berenbaum, professor at the University of Illinois. She published work on the expression of genes (from looking at RNA profiles) in CCD and non-CCD colonies. A recording is available.

http://www.treehugger.com/files/2011...-berenbaum.php

The link sent to me came ultimately from Walter Haefeker who usually sends anti-GM and anti-pesticide pieces. He couldn't have done his homework this time as Prof Berenbaum says that 'surprisingly' the genes in the bee that would be switched on in response to stress from pesticides were not up-regulated. Others were, and the finger was pointed strongly to RNA viruses instead.

'It would be convenient if CCD could be blamed on pesticides but unfortunately it is much more complicated than that. .... big surprise was that they have far fewer pesticide detoxifying genes than other insects ... they process their food behaviourally (break down plant chemicals that went into the honey) ... they are very sensitive to some types of pesticides including neonicotinoids .... less sensitive to pyrethroids (which were used to treat Varroa mites) .... for the first time in beekeeping history people started using pesticides inside hives ..... Penn State did not find much in the way of neonicotinoids inside hives .... but miticides were ... my student showed that the two synergise each other .... we may be overloading the capacity of honeybees to metabolise pesticides ..... not a simple relationship, not a healthy relationship .... '

'The long complicated and for many people unsatisfying answer is that it is not simple. ... we used a microarray to see which genes are turned on and which are turned off. We expected to see pesticide genes turned on ... what we found was surprising, no evidence of pesticide exposure, no evidence of bacterial exposure but the ribosomes were falling apart ... picornaviruses ..... what we think is that with international trade they are being exposed to more viruses than ever before ... I know that is seems pesticide friendly but .... '

Nice to hear her in her own words and see her explain this to an internet audience tonight.

Gavin

Interesting Gavin, had a watch/listen last night. Very US centric I feel but well worth a listen.

Feel the pesticides issue will rumble on and simply take the form of the "missing link" argument with creationists. Each study failing to find a conclusive link will just be dismissed as a Chemical-co sponsored whitewash.

Thanks for the interesting link, Gavin.

Here a few more extracts (with approximate locations on the video):

Quote:

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(28:00)
I am no fan of GM crops, they cause a lot of problems...
GM crop impact on pollination in general:
There is a demonstrable impact, there’s a five year study (Farm Scale Studies in Britain), documenting environmental potential impact of GM crops (principal sugar beet & canola) not through direct toxicity but because the GM crops had been bred for herbicide resistance, without weeds there is less forage, less food for butterflies and bees, reduction of availability of suitable pollen and nectar resources...


(35:00)
I am no friend of pesticides...
honeybees have far fewer detoxifying genes as they feed on inoxious substances (nectar & pollen)... bees process food behaviourly... may have lost the ability to detoxify ... very sensitive to pesticides ...exceedingly sensitive to neonics

(39:00)
overloading the metabolism of bees with pesticides (miticides + neonicotinoids)


(41:00)
search for genetic footprint

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Here the link to the GM study:
http://www.ncbi.nlm.nih.gov/pmc/arti...f/14561321.pdf

Title: Responses of plants and invertebrate trophic groups to contrasting herbicide regimes in the Farm Scale Evaluations of genetically modified herbicide-tolerant crops

From there:

Quote:

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The result of the later herbicide application in GMHT treatments was a shift in resource from the herbivore food web to the detritivore food web.

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The detritivore food web is the one that's based on rotting material, by the way.:(


Regarding the search for the genentic footprint:

I can see a problem in the way the topic of neonics and genetic response is handled here:

@ Bees are highly sensitve to neonics.
@ They have a very small array of detixifying genes.
@ There seems to be no gene response to neonics.

What if the bees are so sensitive to neonics because they have no genes to detoxify them and that's why we find no genetic response?

Quote:

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I am no fan of GM crops, they cause a lot of problems...
GM crop impact on pollination in general:
There is a demonstrable impact, there’s a five year study (Farm Scale Studies in Britain), documenting environmental potential impact of GM crops (principal sugar beet & canola) not through direct toxicity but because the GM crops had been bred for herbicide resistance, without weeds there is less forage, less food for butterflies and bees, reduction of availability of suitable pollen and nectar resources...

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Hi Doris
That's one of the problems I have with GM as well - the creation of sterile weed free fields, and the other issue is the hijacking of the technology by just a few multinationals who have a vested interest in promoting GM over heritage varieties used in developing countries. Oh dear I know who I sound like.

Re. the neonicotinoids, we are back to theory vs real life.
Why do the commercial beekeepers like Murray McGregor and many keen hobby beekeepers move colonies to fields of Imidacloprid seed treated oil seed rape during the flowering period if this is a problem? He seems like a smart bloke to me and turkeys do not get far voting for Christmas. In the lab it is a problem. In the real world things appear to be different.
Petrol kills bees at low concentrations in the lab. So does Domestos. Do we ban these products? Do they harm bees in the field? That's how the anti neonic people usually present their case. Do you want the older more toxic chemicals back again?
No evidence for field neonic damage to bees other than the well highlighted cases of misuse such as the misapplied seed coating incident in Germany. Still good to keep an open mind. It is the folk who claim that bee problems are 'definitely' caused by neonicotinoids I have a problem with. And most of these folk are environmental campaigners rather than scientists.
I think it is more logical to go with what you see rather than go with what you would 'like' to see for political or campaigning reasons.

Me too! I'm not sure about herbicide tolerant crops. They could give cleaner fields and less food for wildlife. Note that I said herbicide tolerant: you get GM and non-GM herbicide tolerant oilseed rape for example, and the changes in weed flora and biodiversity come whether or not your herbicide tolerance has a GM basis.

What about the shift from spring to winter cropping? That gives a *huge* effect on biodiversity, far in excess of what GMHT OSR would cause.

This business about a lower number of detoxifying genes. It is just a lower number, not a complete absence. There are still plenty of genes that you would see switched on if the bees were stressed by pesticides, and Prof Berenbaum was suggesting that the lack of this points away from pesticides as having a major role in CCD and towards viruses. Impartial, independent science providing answers to complex problems. Just another finger that folk seemed to expect to point at pesticide causes, yet the finger went the other way.

Gavin

I must admit to being a little confused by that statement.

Is it a case that genes "switch on" in existing bees? Or that as a result of exposure to, in this case, pesticides over a period of time genes that are helpful in detoxifying those compounds are selected for and start to appear in the bees?

I get how that could work with something like neonicotinoids, but to paraphrase Bill Bryson's book, "there's no quantity of Plutonium you could ingest that wouldn't want to make you go have a lie down". So how does that work on compounds that aren't "natural"? If I create Nellidacloprid tomorrow as a completely new compound that's extremely toxic to bees, what are the genes that you're looking for?

I get that the chances of Nellidacloprid being an entirely new, unique element is remote so at some point you can nail it down to being 1 part argon to 2.5 parts nitrogen and a pinch of platinum or something, but how do you go from there to looking for genes switching on?

Is that for the most part we aren't dealing with analogues of Plutonium?

I accept that I've got a reading the newspaper grasp on a lot of this stuff, so my apologies if these questions sound a bit dim.

Very good questions Nellie. First of all, the gene expression stuff. Whatever happens to an organism, you see some evidence of genes getting upregulated and downregulated. Compare a young animal and an old one, a well fed one with a less well fed one, one that has just eaten chips with one that hasn't, one that fell off a wall this morning with one that hasn't. Something will be happening and you will see differences. Guide to the technique here:

http://www.mun.ca/biology/scarr/cDNA...xpression.html

When genomes are sequenced, folk usually try to categorise all the genes. Bog-standard metabolism, genes that make the skeleton, genes that protect from heat or cold damage, genes that fight viruses or bacteria. Genes expected to be switched on in response to stress from pesticides would include categories of genes that make enzymes that do things like stick a sugar group on the end of small molecules or make esters out of them or cleave certain types of small molecule. These are the kinds of genes that May Berenbaum will have found had no difference in expression between CCD and non-CCD colonies, and she found that compelling.

And yes, what happens here is a dynamic response to the environment with a myriad of switches and regulators operating so the the organism fine-tunes its metabolism to every circumstance. Evolutionary selection operates over times scales of several to millions of generations, this gene expression stuff takes milliseconds, seconds, minutes and hours.

Hope that helps!

Gavin

It does. I was under the impression that things were a little more static than they apparently are which is what was throwing me.

So at the risk of asking another stupid question, does this gene expression have any effect on the organism in question or is it effectively "activating" a gene that will be passed on to offspring?

Quote:

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Originally Posted by Jon

That's one of the problems I have with GM as well - the creation of sterile weed free fields, and the other issue is the hijacking of the technology by just a few multinationals who have a vested interest in promoting GM over heritage varieties used in developing countries.

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Yes, this is a major problem not just for bees and biodiversity, but also for millions of small scale farmers world wide.

This documentary shows how 'green deserts' are created and how they can destroy independent and sustainable lifestyles:

(watch from 3:00)
http://www.youtube.com/watch?v=qmxbN...eature=related