3 ms·

What you are calling "epigenetic factors" have been known as regulatory molecules since the origins of biology. Epigenetics refers to the theory that some of a

What you are calling "epigenetic factors" have been known as regulatory molecules since the origins of biology. Epigenetics refers to the theory that some of a parent organism's phenotypes arise as a consequence of its environment/experiences and those traits can be passed on to its offspring without alterations to the gamete's DNA sequence. With that in mind, how does any of this relates to epigenetics? Everything described here fits under the umbrella of 'basic regulatory milieu' required for sperm maturation, so it can fertilize an egg and commence embryonic development. The Smithsonian article is trying to spin this as something it's not... "It turns out that sperm small RNAs undergo post-testes turnover, picking up intel on the father’s physical health (or lack thereof) after they’re manufactured, but before they exit the body." It seems like they are trying to sell a classical misconception. They might as well have said: along the way the sperm picks up epigenetic information by absorbing its fathers tRNA, which pass on a variety of information about the father's life experiences, like that he was a body-builder, but also an alcoholic; and so this offspring will likely develop into that sort of person.

matheusmoreira 8y ago
> how does any of this relates to epigenetics? Epigenetics is the study of changes in organisms caused by modification of gene expression. If these articles are to be believed, then these tRNA fragments positively influence the expression of regulatory factors. It seems like an example of epigenetics to me. > It seems like they are trying to sell a classical misconception. I don't disagree with this assessment. The study I cited¹ said something about tRNA fragments being a conserved response to oxidative stress. The news article apparently takes this and somehow turns it into a "your children will feel the consequences of your bad dietary habits" argument. There is some discussion and references about diets and epigenetics in the scientific text but that's not what the article is about. The articles say (1) the epididymis sends some RNA to the sperm cells, and (2) that the lack of this RNA can compromise embryo viability. It's interesting and all, but the clinical relevance of this information has yet to be determined: I'm not aware of any evidence that supports the notion that bad lifestyle habits will affect this sperm maturation process in any way. ¹ https://www.ncbi.nlm.nih.gov/pubmed/21976287 https://www.ncbi.nlm.nih.gov/pubmed/21976287 > Accumulation of RNAs of 30–35 nucleotides that correspond to tRNA halves were first reported in Tetrahymena thermophila, and subsequently shown to be a conserved response to oxidative stress in a wide variety of eukaryotes.² ² https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2553748/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2553748/
- subroutine 8y ago
  This definition you provide... Epigenetics is the study of changes in organisms caused by modification of gene expression. ...is not sufficient. The crux of epigenetics is that it involves >heritable< changes in gene expression. At least that's what it originally meant. Now I feel like the definition is transforming into the definition you gave. However the author of the smithsonian article is confusing the two usages, because in several places the article alludes to the heritability.

matheusmoreira 8y ago

> how does any of this relates to epigenetics? Epigenetics is the study of changes in organisms caused by modification of gene expression. If these articles are to be believed, then these tRNA fragments positively influence the expression of regulatory factors. It seems like an example of epigenetics to me. > It seems like they are trying to sell a classical misconception. I don't disagree with this assessment. The study I cited¹ said something about tRNA fragments being a conserved response to oxidative stress. The news article apparently takes this and somehow turns it into a "your children will feel the consequences of your bad dietary habits" argument. There is some discussion and references about diets and epigenetics in the scientific text but that's not what the article is about. The articles say (1) the epididymis sends some RNA to the sperm cells, and (2) that the lack of this RNA can compromise embryo viability. It's interesting and all, but the clinical relevance of this information has yet to be determined: I'm not aware of any evidence that supports the notion that bad lifestyle habits will affect this sperm maturation process in any way. ¹ https://www.ncbi.nlm.nih.gov/pubmed/21976287 https://www.ncbi.nlm.nih.gov/pubmed/21976287 > Accumulation of RNAs of 30–35 nucleotides that correspond to tRNA halves were first reported in Tetrahymena thermophila, and subsequently shown to be a conserved response to oxidative stress in a wide variety of eukaryotes.² ² https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2553748/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2553748/

subroutine 8y ago
This definition you provide... Epigenetics is the study of changes in organisms caused by modification of gene expression. ...is not sufficient. The crux of epigenetics is that it involves >heritable< changes in gene expression. At least that's what it originally meant. Now I feel like the definition is transforming into the definition you gave. However the author of the smithsonian article is confusing the two usages, because in several places the article alludes to the heritability.