COOL! What happens to your DNA after a year in space?



Mukherjee’s controversial piece on epigenetics #Drama

The scientific community is in uproar over Siddhartha Mukherjee’s latest piece for the New Yorker titled: Same but Different (you may know him from his novel Emperor of all maladies: a biography of cancer). His article highlights the study of epigenetics, and how recent findings may blur the line between nature and nurture. So why is the scientific community outraged? Vox explains:


Here’s the beef scientists have with Mukherjee and the New Yorker

The article is the type of piece the New Yorker usually is very good at: diving deep into a crevice of science and connecting it to veins of either history, politics, or the poetry of everyday life.

Mukherjee starts off with a personal tale. His mother and aunt are identical twins, and he muses on how their life experiences made them different people later on. He then connects this personal mystery with other mysteries in nature: Why are two ants genetically near identical but one is a worker and one is a boss?

In the story, what links these mysteries is the science of epigenetics, which, basically, explores how the environment can leave a lasting mark1 on how our genes work.

DNA is the instruction manual for life. So epigenetics may determine how likely those instructions are to be read. Understanding epigenetics is important because it could help us understand how we become more susceptible to disease (or not) over our lifetimes. And there’s some not-yet-conclusive evidence that epigenetic information is inheritable. As Vox’s Susannah Locke has explained, epigenetics means a person may pass on genes as well as experiences to a child.

But the article seems to have hit a nerve with some researchers who feel “epigenetics” has become a buzzword that’s distorting the science.

What Mukherjee (mainly) gets wrong, according to the scientists, is his explanation of how this process is thought to work. Mukherjee’s explanation is anchored in a discussion of histones, which are tiny proteins that act as a kind of a scaffolding for DNA. He leans heavily on the work of David Allis, a researcher at Rockefeller University, who has foundthese histones open and close specific sections of DNA, which he says changes the output of the genes.

“The coils of DNA seemed to open and close in response to histone modifications — inhaling, exhaling, inhaling, like life,” Mukherjee writes.

Next, Mukherjee notes (more vaguely) that scientists have found “other systems, too, that could scratch different kinds of code on the genome.”

There are two main points the scientists are clamoring over.

One is that they say Allis’s theory that histones actually change the output of genes is far from proven. In a second post on Coyne’s blog, Greally and Mark Ptashne, a biologist at Sloan Kettering, write, “there is no evidence that coiling and uncoiling of DNA has a causal effect on gene activity.”

The second is the critics say those glossed-over “other systems” are actually the prevailing theory on how it all works, and should be at least discussed at greater length.

The big, overarching, concept Mukherjee missed is “transcription factors,” which are proteins that can turn specific genes on and off. It’s these factors that scientists say should be the main focus of the explanation of how our genes are differentiated. And despite decades of research on them, transcription factors are hardly mentioned at all in the piece.

Steve Henikoff, a molecular biologist, writes on Coyne’s blog:

Mukherjee seemed not to realize that transcription factors occupy the top of the hierarchy of epigenetic information, that this has been widely accepted in the broader chromatin [i.e. DNA] field, and that histone modifications at most act as cogs in the machinery that enforces the often complex programs specified by the binding of transcription factors.

(To note: The scientists have other concerns with the piece. You can read more about those here.)

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FDA approves the first genetically engineered animal: Salmon!

GMO‘s are not unusual in today’s grocery stores (nor are they harmful…), but now for the first time, the FDA has approved a genetically engineered animal– salmon. From The Washington Post:

After years of review and endless controversy, the Food and Drug Administration on Thursday approved the nation’s first genetically altered animal — a salmon engineered to grow twice as fast as its natural counterpart.

AquAdvantage, produced by Massachusetts-based AquaBounty, is an Atlantic salmon that contains a growth hormone from a Chinook salmon and has been given a gene from the ocean pout, an eel-like fish. The result is a fish that is large enough for consumption in about a year and a half, rather than the typical three years.

Food-safety activists, environmental groups and the salmon fishing industry, not to mention lawmakers from Alaska, have long opposed the approval of the fish — which they derisively refer to as “Frankenfish” — and have argued that its existence could open the door to a broad range of potentially unsafe genetically modified animal foods. Knowing an FDA approval was likely, critics have in recent years won commitments from some of the nation’s most recognizable chains — including Whole FoodsTrader Joe’s and Target — to not sell the fish.

The FDA said Thursday that its decision was “based on sound science and a comprehensive review,” and that regulators are confident that the genetically altered fish is as safe to eat as a normal Atlantic salmon, with no discernible difference in its nutritional value. Officials noted that the agency held meetings, combed through thousands of public comments and conducted scientific and environmental assessments about the AquaBounty fish before finally approving it.

Supporters argue that this fish will prevent overfishing of wild salmon and will also help protect the ocean and marine habitats.

Awesome @radiolab episode on CRISPR and Cas9 DNA editing!! #science

Check out this podcast episode from Radiolab focusing on CRISPR and its potential applications.


Out drinking with a few biologists, Jad finds out about something called CRISPR. No, it’s not a robot or the latest dating app, it’s a method for genetic manipulation that is rewriting the way we change DNA. Scientists say they’ll someday be able to use CRISPR to fight cancer and maybe even bring animals back from the dead. Or, pretty much do whatever you want. Jad and Robert delve into how CRISPR does what it does, and consider whether we should be worried about a future full of flying pigs, or the simple fact that scientists have now used CRISPR to tweak the genes of human embryos.

Cool Nature Video explains the Epigenome with music!! #science

Epigenome: The symphony in your cells

Almost every cell in your body has the same DNA sequence. So how come a heart cell is different from a brain cell? Cells use their DNA code in different ways, depending on their jobs. Just like orchestras can perform one piece of music in many different ways. A cell’s combined set of changes in gene expression is called its epigenome. This week Nature publishes a slew of new data on the epigenomic landscape in lots of different cells. Learn how epigenomics works in this video.