Epigenetics is a very interesting area, and I expect it to increase in importance following the ENCODE project that just came out.
The NYTimes article is a bit strange, though, trying to politicize epigenetics through the "mommy wars". The article also muddles the difference between genetic issues due to aging fathers and epigenetic issues. The recent Icelandic study links mutations in sperm from aging fathers to autism and schizophrenia, which is genetic (the mutations show up in genome sequencing), so it's basically irrelevant to the article's epigenetic thesis. The NYTimes article mentions a theory that maybe epigenetic regulation is reducing DNA repair and causing mutations, but that's a pretty tenuous connection.
It's silly to turn this into a "blame game", but it is interesting that males and females contribute different types of genetic errors: females typically introduce chromosome errors, while males introduce DNA mutations. 20% of human eggs have the wrong number of chromosomes, compared with 3-4% of sperm. A cell has to split the chromosomes twice in meiosis to form a gamete, which is a difficult process where a lot can go wrong. Eggs sit around potentially for decades and then need to twice split properly, and this becomes much more error-prone with age. The first split happens at ovulation, and the second at fertilization (which is much later than I'd expect). These errors in chromosome separation are the leading cause of miscarriage and mental retardation. On the other hand, males are the main source of DNA mutations, since sperm are constantly being created, and each round of DNA replication has a chance to introduce errors. [Reference: Molecular Biology of the Cell, chapter 21, which is an interesting book]
The NYTimes article is a bit strange, though, trying to politicize epigenetics through the "mommy wars". The article also muddles the difference between genetic issues due to aging fathers and epigenetic issues. The recent Icelandic study links mutations in sperm from aging fathers to autism and schizophrenia, which is genetic (the mutations show up in genome sequencing), so it's basically irrelevant to the article's epigenetic thesis. The NYTimes article mentions a theory that maybe epigenetic regulation is reducing DNA repair and causing mutations, but that's a pretty tenuous connection.
It's silly to turn this into a "blame game", but it is interesting that males and females contribute different types of genetic errors: females typically introduce chromosome errors, while males introduce DNA mutations. 20% of human eggs have the wrong number of chromosomes, compared with 3-4% of sperm. A cell has to split the chromosomes twice in meiosis to form a gamete, which is a difficult process where a lot can go wrong. Eggs sit around potentially for decades and then need to twice split properly, and this becomes much more error-prone with age. The first split happens at ovulation, and the second at fertilization (which is much later than I'd expect). These errors in chromosome separation are the leading cause of miscarriage and mental retardation. On the other hand, males are the main source of DNA mutations, since sperm are constantly being created, and each round of DNA replication has a chance to introduce errors. [Reference: Molecular Biology of the Cell, chapter 21, which is an interesting book]
Last week I read the book "The Epigenetics Revolution", which I recommend as it gives a good description of epigenetics. http://www.amazon.com/The-Epigenetics-Revolution-Understandi... (non-affiliate link)