Ptashne again cuts through epic epigenetic confusion of transcription factors versus histone marks, cause versus effect.
“The Chemistry of Regulation of Genes and Other Things”:
As I have described, where the activated gene encodes the activator itself, we have memory: a self-perpetuating state of gene expression transmitted by regulatory proteins distributed to daughter cells as cells divide.
These now obvious ideas seem to be hard to accept for some. Ignoring the specificity problem and in the search for some alternative solution to the memory problem, they have created an incoherent and counterfactual world, one in which chromatin structure determines the activity of transcription factors (recruiters) rather than the other way around. Chromatin structure is usually meant to imply histone modifications, which somehow have acquired the name epigenetic modifications. The literature is replete with studies of histone modifications presented as studies of “epigenetics,”… Continue reading
This week Science for the People is exploring the limits of science exploration in both fictional and fact. We’re joined by “lifelong space nerd” Andy Weir, to talk about his debut novel The Martian (and soon to be film, trailer below), that pits human invenitveness and ingenuity against the unforgiving environment of the red planet. And astrophysicist and science blogger Ethan Siegel returns to explore so-called “impossible space engines“, and what news stories about them can teach us about journalism and science literacy.
*Josh provides research & social media help to Science for the People and is, therefore, completely biased.
Posted in Curiosities of Nature
Tagged Andy Weir, Books, Ethan Siegel, Journalism, Mars, Podcast, sciart, science for the people, science literacy, Space, Space exploration, the martian
It sounds like exciting science: the hunt for the genes that make us human. But are we learning all that much about our biology by tracking down those parts of our genome that are unique to us?
In my Pacific Standard column this week, I argue no – at least not yet. The search for human specific genes, or those parts of our genome that show signs of rapid evolution, called “human accelerated regions” hasn’t really yielded much insight into what makes us different from other species, particularly our closest relatives. For the most part, we’ve discovered genes and regulatory elements that are somehow associated with brain function, but we can’t say much more than that. Continue reading