I’m quite pleased to host this month’s Mendel’s Garden – a blog carnival featuring the best genetics writing on the internets for the last month. Since it’s my party, I’ve picked out a few of my favorite topics to feature. But in the way of introduction for the neophytes in the crowd, let’s define our terms. The first question I ask my students on their first exam is “What is a gene and how is it regulated?”. I’m looking for them to talk about Mendel’s description of units of inheritance and the modern DNA based definition. Well, RPM of Evolgen thinks that it’s time to expand our definition or throw the word out entirely. He makes a solid argument, based on the fact that a lot of things that are transcribed in the genome wouldn’t be considered ‘genes’ by most of us. But if we trash the word, what would geneticists call themselves?
For a perfect example of the beautiful complexity of genetics illustrated, check out this father-son photo from Not Afraid To Use It. About says it all. Without further ado, a few of my favorite things genetical:
I found a couple of great posts about the genetics of autism. Now, to clarify, I’m not a big fan of autism per se, but I got embroiled (in a minor way) in the controversy with this post on the autism-MMR vaccine sham. Since then, I’ve followed the new research on autism with some interest. A post over at Highlight Health describes two genome-wide genetic analyses that identified five genetic loci that contribute to autism susceptibility, lending more support to the argument that autism is largely a heritable disorder. Kristina Chew, of AutismVox, thinks that geneticists sometimes go a bit far, however. Her response to a “sweeping” new theory that an evolutionary tug-of-war between parental genetic contributions is astutely skeptical. And of course, As is the case with any genetic disorder, there is an environmental component to consider. Reviewing an odd study out of Cornell, the Great Beyond details an assertion that autism rates are higher in rainy parts of the world. Take of it what you will, folks.
I’ve become increasingly fascinated with human evolution and in the genomic era research into our roots is just burgeoning. This month, Daniel McArthur at Genetic Future writes about one of the new tools available to evolutionary geneticists and gives an example of its use to look at positive selection at certain human genetic loci. One of the more interesting stories from this field is of the pair of skeletons found in a mass grave in Germany locked in an intimate embrace. The Great Beyond describes the DNA analysis that revealed that the 4600 year old remains were of a parent and child and appear, with fractured skulls and an arrowhead in the spine, to have been unfortunate victims of humanity’s penchant for genocide. Of course, none of this may matter according to UCL’s Steve Jones (as reported on Dick Dawkins dot net) who says that human evolution is done due to a dearth of older fathers. Jones argues that genetic variation comes, in part, from mutations that men accumulateas they get older. Don’t worry, Steve, I think there are plenty of toxins about to keep us mutating.
Speaking of junk science, there was some new junk on junk DNA released as a press release from the Genome Institute of Singapore. As Bayblab points out, this is a new and disturbing way of publishing your results – skip all the hassle of peer review and editing and just throw it out there to the mainstream press. Shame really, because this is my third topic of choice – epigenetics. Yann Klimentidis, on his blog, recounts some recent research looking at epigenetic changes in utero brought on by environmental stress. Zamp Bionews has more about epigenetic control of offspring fertility, which in this case is regulated by small RNAs apparently passed on maternally. Alex at The Daily Transcript has RNA, if not epigenetic, regulation in his post describing how each RNA binding protein in yeast tends to associate with mRNAs of a particular type. He hypothesizes that the expression of entire classes of genes may be subject to coordinated regulation at the level of mRNA metabolism.
And finally this month, a technical brief for those of you doing the hard work of science rather than just writing about it. Sandra, who blogs at Discovering Biology in a Digital World, tells us about a new BLAST feature that allows users to create a custom database. Sandra goes through a step-by-step tut and generates a viral phylogeny. For those Ph.D. students out there in the “Nothing Works Doldrums”, Nick at Bite Size Bio has some reassuring words for you – sometimes things just don’t work. That’s biology.