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| GGG managers are SunkenCiv, StayAt HomeMother & Ernest_at_the_Beach | |
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Thanks decimon. |
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Posted on 07/24/2011 7:28:13 PM PDT by decimon
Researchers funded by the Biotechnology and Biological Sciences Research Council (BBSRC) at the John Innes Centre have made a discovery, reported this evening (24 July) in Nature, that explains how an organism can create a biological memory of some variable condition, such as quality of nutrition or temperature. The discovery explains the mechanism of this memory – a sort of biological switch – and how it can also be inherited by offspring.
The work was led by Professor Martin Howard and Professor Caroline Dean at the John Innes Centre, which receives strategic funding from BBSRC. Funding for the project came from BBSRC, the European Research Council, and The Royal Society.
Professor Dean said "There are quite a few examples that we now know of where the activity of genes can be affected in the long term by environmental factors. And in some cases the environment of an individual can actually affect the biology or physiology of their offspring but there is no change to the genome sequence."
For example, some studies have shown that in families where there was a severe food shortage in the grandparents' generation, the children and grandchildren have a greater risk of cardiovascular disease and diabetes, which could be explained by epigenetic memory. But until now there hasn't been a clear mechanism to explain how individuals could develop a "memory" of a variable factor, such as nutrition.
The team used the example of how plants "remember" the length of the cold winter period in order to exquisitely time flowering so that pollination, development, seed dispersal and germination can all happen at the appropriate time.
Professor Howard said "We already knew quite a lot about the genes involved in flowering and it was clear that something goes on in winter that affects the timing of flowering, according to the length of the cold period."
Using a combination of mathematical modelling and experimental analysis the team has uncovered the system by which a key gene called FLC is either completely off or completely on in any one cell and also later in its progeny. They found that the longer the cold period, the higher the proportion of cells that have FLC stably flipped to the off position. This delays flowering and is down to a phenomenon known as epigenetic memory.
Epigenetic memory comes in various guises, but one important form involves histones - the proteins around which DNA is wrapped. Particular chemical modifications can be attached to histones and these modifications can then affect the expression of nearby genes, turning them on or off. These modifications can be inherited by daughter cells, when the cells divide, and if they occur in the cells that form gametes (e.g. sperm in mammals or pollen in plants) then they can also pass on to offspring.
Together with Dr Andrew Angel (also at the John Innes Centre), Professor Howard produced a mathematical model of the FLC system. The model predicted that inside each individual cell, the FLC gene should be either completely activated or completely silenced, with the fraction of cells switching to the silenced state increasing with longer periods of cold.
To provide experimental evidence to back up the model, Dr Jie Song in Prof. Dean's group used a technique where any cell that had the FLC gene switched on, showed up blue under a microscope. From her observations, it was clear that cells were either completely switched or not switched at all, in agreement with the theory.
Dr Song also showed that the histone proteins near the FLC gene were modified during the cold period, in such a way that would account for the switching off of the gene.
Professor Douglas Kell, Chief Executive, BBSRC said "This work not only gives us insight into a phenomenon that is crucial for future food security – the timing of flowering according to climate variation – but it uncovers an important mechanism that is at play right across biology. This is a great example of where the research that BBSRC funds can provide not only a focus on real life problems, but also a grounding in the fundamental tenets of biology that will underpin the future of the field. It also demonstrates the value of multidisciplinary working at the interface between biology, physics and mathematics."
Food for thought ping.
Ping
If this report reflects reality imagine the effect of Television and computer games on young forming brains. Constant change will produce a brain that is unable to focus upon one thing. No wonder there has been a rise in hyperactivity.
This is quite a concept. What exactly can be passed on to offspring?
Gays are switch hitters.
Epigentic changes are most probably the key to nearly all adaptation. A lot of stock has been put into natural selection but the problem with it was the lack of a clear mechanism for feedback to fuel the selection engine. There has always been a good deal of evidence for Lamarkian type of inheritability. There has been a lot of evidence that points to the conservation of immunity and not just through transfer of mother’s antibodies through that clearly plays a role. One of the reasons epigentics is not widely discussed is because it muddies the waters of those who like their genes in nice neat packages. The idea of acquired traits through environmental feedback changes everything. It means our behaviors do make a difference in no only our genetic makeup but that of our children.
This raises many questions and I think these researchers may have their hands full in fielding them.
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| GGG managers are SunkenCiv, StayAt HomeMother & Ernest_at_the_Beach | |
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Thanks decimon. |
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I’m in way over my head here but this is the internet so that won’t stop me. ;-)
If I have this right then they propose no change to genetic makeup but rather to genetic utilization. If that makes any sense.
I do believe my parents experiences during the Great Depression has affected me. I always thought it was things I'd 'picked-up' from them during my childhood but that couldn't explain everything.
So...maybe?
Maybe. I hope this story has legs cuz I'd like to see where it goes.
Fascinating. Thanks for posting this.
You’re welcome.
“Constant change will produce a brain that is unable to focus upon one thing. No wonder there has been a rise in hyperactivity”
Maybe autism is a natural response for the survival of the species under this constant flicker.
How many autistic kids go on to breed?
Cheers!
The 'random mutation factor', caused by radiation or perhaps chemicals absorbed by the parent, has always been tough for me to embrace. Too many 'bad' mutations would crowd out the 'good' mutations, since only a percent of a percent of random mutations are helpful.
This new concept of the environment informing the DNA itself about desirable behavior and traits, if applied to humans, is analagous to a parent giving verbal advice to his/her sons and daughters. IOW, "Son, don't make the same mistake I made when I was young. Avoid certain types of people. Plan ahead for bad times. Etc."
The implications for evolutionary science are staggering. If proven to be true and pervasive, then Lamark will be vindicated to a degree. Just cutting off the tails of mice did not produce mice with no tails. But it may have produced mice with a strong aversion to shiny metallic objects! And people in white lab coats, LOL.
~:<)
A lot of stock has been put into natural selection but the problem with it was the lack of a clear mechanism for feedback to fuel the selection engine.
That appears to be changing! The next thing you know, scientists will discover that space is curved, there is no time, and the universe has no center.
I have to admit, that was my first thought as well.
OTOH, those on the low end of the “autism spectrum” seem to do smashingly well for themselves and have long term pairings, which would be the most beneficial situation for the species, no?
By that I mean the geeky, slightly strange sorts who tend towards being smart, frequently end up quite well off from endeavours in the technology fields, and attract a “boring”, bookish but extremely stable mate who was looking for similar traits. IOW, your typical traditional computer programmer, etc. Somewhat risk averse, willing and capable to intently focus on a goal even at the cost of repetitive, boring work, not very fussed at all about social standing or likely to fall into the “partying” trap.
I recall that as a child, a casual comment by one of my parents or grandparents about their experiences often produced a clear image in my mind. Did I inherit my parents genetic memories?
This also has implications for shared racial memories and the Jungian shared primal sub-conscious mind.
I am currently reading the People of the Wolf series by Michael and Kathleen O'neil Gear. It's a narrative of human pre-history; the migration to the Americas via the vanished land bridge, and subsequent explorations and settlements.
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