Monday, September 18, 2006

noncoding (mRNA-like) RNA under selection in humans

The publication of "An RNA gene expressed during cortical development evolved rapidly in humans" by Pollard et al. (Nature, PubMed) is significant for several reasons. HAR1F appears to be one of those genes under selection in humans (see "From HapMap to Selection Map," May 12, 2006). Such genes, the methods for finding them, and their roles in human development, are all important. For me, however, there is special excitement because this study points to an important role for a spliced ("mRNA like") noncoding RNA. I have long been a fan of noncoding RNAs in general. I like to emphasize that not all exons are coding (see "Things that are not Exons," June 30, 2005) and that not all non-coding RNAs are of the class that associates with the RISC complex. This result does both.

Tuesday, September 05, 2006

Paternal Age and Autism Risk

The Washington Post describes a new study by Abraham Reichenberg and colleagues showing a significant effect of paternal age on autism rates (link). The author, Shankar Vedantam, ends with this:
While the link between older fathers and autistic children is likely to be genetic, the researchers who conducted the new study also acknowledged the possibility that unknown other factors could simultaneously be causing men to delay parenthood while independently increasing autism rates.
It seems to me that, paradoxically, this is backwards. If paternal age itself somehow leads to autism, then the cause is less likely to be genetic (a father's genes don't change as he ages, but epigenetic factors could play a role). On the other hand, if there are factors that simultaneously delay parenthood and induce autism, those factors could be genetic. Under this hypothesis, fathers with certain alleles are more likely to be fathers late in life, and those same alleles, inherited by the child, could cause a predisposition towards autism.

Monday, September 04, 2006

News on Genetics

Yes, I'm starting yet another blog! This one is devoted to quick comments on genetics news. I have developed the habit of bookmarking articles on Connotea. This blog a place where I can put my brief comments on news that interests me, and provide links to related sites of interest.