Hot answers tagged epigenetics
27
The phenomenon you're talking about was a fad in the 60's, called 'interanimal memory transfer'. It started out when James McConnell performed a later-discredited experiment in which he found that if you chopped up flatworms which had been exposed to some stresses, and fed them to other unexposed flatworms, the unexposed worms became wary of the source of ...
14
In general, Darwin's theory has been supported over and over again by experiments - our modern understanding of evolution is fundamentally what Darwin suggested. However, apart from appreciating many more details than Darwin ever could have, we also now know that Lamarck may not have been so crazy as he was later portrayed.
Inheritance in the Darwinian ...
13
The assertion "You cannot change in life what will be genetically inherited in any possible way" is true, as you cannot (healthily) change the DNA in your germ cells.
However, the assertion "You cannot change in life what will be inherited in any possible way" is wrong, because of epigenetics. Parts of your DNA are marked (in different ways), and this can ...
10
Epigenetic information is information that can be inherited through cell division that is not encoded in the DNA sequence. This includes, but is not limited to, DNA methylation and histone modifications (there is also non-chromatin based epigenetic information). A nice example is the centromere, the chromosomal region that binds the kinetochore and is ...
9
I don't believe anything should change in the majority of DNA->RNA transcription. DNA methylation typically occurs on the non-watson crick side of Cytosine so it shouldn't affect the base-pairing.
However, there are a few hypothetical situations that would result in alterations of the transcribed RNA. The sponatneous deamination of the 4' amine would ...
9
The idea of epigentics is that there is more info in chromatin than just in the DNA sequence it contains and that this info can be altered in vivo.
Thus, one cannot inherit epigenetic changes from a surrogate (which brings no new physical genetic material), but the fetus may develop some due to its interactions with her.
8
Methylation is increasingly seen as a consequence of gene activity rather than a regulatory mechanism. There are cases where methylation is controlled because of gene regulatory control, especially at the famous H19/Igf2 locus[1]. Here is a generally good recent review[2], note they mention that DNA methylation does not cause transcriptional silencing, and ...
7
It is proposed that prions are a good mechanism for "testing" phenotypic variation.
There are many identified proteins with prion-determining domains (PrD) in the yeast genome that can spontaneously switch between conformations with some low probability (eg: check SUP35 for one example, and [1] for a good overview of more). The theory is that:
the low ...
6
According to Choi et al. Genome Biology 2009, 10:R89, DNA methylation at both coding boundaries may regulate transcription elongation and stabilize splicing by reducing the occurrences of exon skipping.
From the abstract:
Here we report a genome-wide observation of distinct peaks of
nucleosomes and methylation at both ends of a protein coding unit.
...
6
I understand that Robin Holliday was the first to discuss the possible role of DNA methylation
in the control of Gene expression. In his paper "The inheritance of epigenetic defects"
he presents what is one of the first modern formulations of what we now regard as epigenetics. The term "epigenetics" itself was coined by Conrad Waddington although this ...
4
Infections by a retro-virus (such as HIV) can, at least in principle, be inherited.
These viruses integrate their genetic code into the host's DNA, and these changes pass to next generations as the cells split. So if a germ cell is infected, all the cells in the child would be.
The question is whether there's a retro-virus that infects germ cells. I don't ...
4
First of all, the nature of penetrance is almost entirely unknown. Likely it's a combination of epistasis and gene interactions, induced gene regulatory pathways, developmental noise, and other factors. Epigenetics (imprinting, etc) may have little to do with penetrance, while chromatin structure may be a consequence of other things (most now regard ...
3
There are few single papers that really drive the field by themselves, epigenetics has been a long slow progression (although more recently the definition has been muddied and started to include non-epigenetic modes of gene regulation). A pretty good review of a lot of research, including a more circumspect discussion about what epigenetics is can be found ...
3
The definition of an epigenetic mark I work with is the following :
- impacts gene regulation without touching to the DNA sequence
- is reversible
- is inheritable.
With this definition in mind, you could say that only DNA methylation is a true epigenetic mark, leaving histone modifications and the like to canonical transcription regulation machinery. Yet ...
3
Is the assertion "You can not change in life what will be genetically inherited in any possible way" true?
No. Does not seems the case, as other people already replied.
Here, I just want to point to two recent research articles showing evidence against your assertion.
The first, published in Cell in 2010, is from Dr Oliver Rando, and suggests that ...
3
I found two nice review papers focused of epigenetics and human disease, one from 2004, and one from 2006. But perhaps you are looking more for something like this?
I also found this article in the BBC news: The Ghost in Your Genes
They have shown that a famine at critical times in the lives of the grandparents can affect the life expectancy of the ...
3
"Are these modifications the primary regulation mechanism for chromatin structure?"
It depends on how you define primary, we might currently think of histone modifications as primary because other regulatory mechanisms have not yet been well studied. Something else you can think of are the various regulatory proteins that interact with histone marks to ...
3
I would think there have to be, though do you mean collecting samples on a regular basis and plotting out the difference at each point? Or do you simply mean the total accumulated change. If it is the latter, the answer is certainly "yes". You have probably seen the Nova documentary "Ghost in Your Genes" (The US, not BBC one). In it they show comparison of ...
3
Jon Wilkins has a nice introduction to imprinting. He does a nice job of introducing the idea methylation and how these patterns are maintained during development and cell division. Further, he links to some interesting papers on the subject.
2
This article deals with the effect of phenotypic variation brought on by epigenetic patterns, and how these are inherited to the next generation. Their conclusions?
Our results show that epigenetic variation is inherited in chickens, and we suggest that selection of
favourable epigenomes, either by selection of genotypes affecting epigenetic states, or ...
2
Starting out with RNA data is great, since you already have fully spliced entities, despite being in a different dynamic regime.
As the chromatin landscape itself is dynamic and High throughput data exploration has only begun in the last decade, consider the following tools and results with care...
You may find the following tools helpful:
Archalign , ...
1
If the question here is to perform an assay that only sequences from a specific set of segments of the genome, you probably could, but it would be a lot of work and you'd need a good reason to want to go through that trouble.
Not sure how you would limit the nucleotides you get back to a specific region of the genome say. The entire point of a CHP-Seq ...
1
I can get the ball rolling..
Found a nice paper which looks at this phenomenon in yeast.
So as a primer, 8 histone proteins come together to make a spool of sorts which DNA wraps around:
Histone proteins have many sequence variants, and each one of them can be covalently modified with methyl, acyl, phospho, SUMO, adp and many other sorts of chemical ...
1
This phenomenon is well known and can be observed in several species. In fact, if you look at the time it takes for E. coli to change its transcription program in order to react to the environment (signal->transcription->translation), you will find it can be longer than its ~20 minute doubling time. You can indeed think of it as a form of Lamarckism. ...
1
This is somewhat unrelated, and for that, I apologize, but I find it truly fascinating, and I believe you will too.
Zebra finches are a song bird that have become a popular model organism for behavioral research. They have a very stereotypical pattern for song learning: at about 70 days after hatching, the baby male song bird starts to listen to his ...
1
There is an article in PNAS Conservation and divergence in eukaryotic DNA methylation who used:
next-generation sequencing to investigate the DNA methylation patterns
in eight divergent species, including green algae, flowering plants,
insects, and vertebrates. Their data allowed a comprehensive
comparison of whole-genome methylation profiles ...
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