Two feature articles in Nature this week on work by Emory scientists.
One is from Virginia Hughes (Phenomena/SFARI/MATTER), delving into Kerry Ressler’s and Brian Dias’ surprising discovery in mice that sensitivity to a smell can be inherited, apparently epigenetically. Coincidentally, Ressler will be giving next week’s Dean’s Distinguished Faculty lecture (March 12, 5:30 pm at the School of Medicine).
Another is from Seattle global health writer Tom Paulson, on immunologist Bali Pulendran and using systems biology to unlock new insights into vaccine design.
Peng Jin and collaborators led by Da-Hua Chen from the Institute of Zoology, Chinese Academy of Sciences have a new paper in Stem Cell Reports. They describe a souped-up method for producing iPS cells (induced pluripotent stem cells).
Production of iPS cells in the laboratory is becoming more widespread. Many investigators, including those at Emory, are using the technology to establish â€œdisease in a dishâ€ models and derive iPS cells from patient donations, turning them into tools for personalized medicine research.
This intriguing research has received plenty of attention, Â both when it was presented at the Society of Neuroscience meeting in the fall and then when the results were published in Nature Neuroscience.
The short summary is: researchers at Yerkes National Primate Research Center found that when a mouse learns to become afraid of a certain odor, his or her pups will be more Gafas Ray Ban Baratas sensitive to that odor, even though the pups have never encountered it.Â Both the parent mouse and pups have more space in the smell-processing part of their brains, called the olfactory bulb, devoted to the odor to which they are sensitive.
[Note: a feature on a similar phenomenon, transgenerational inheritance of the effects of chemical exposure, appeared in Science this week]
Somehow information about the parent’s experiences is being inherited. But how? Brian Dias and Kerry Ressler are now pursuing followup experiments to firmly establish what’s going on. They discuss their research in this video:
The 2012 Nobel Prize in Medicine was awarded to Shinya Yamanaka and John Gurdon for the discovery that differentiated cells in the body can be reprogrammed. This finding led to the development of â€œinduced pluripotent stem cells.â€
These cells were once skin or blood cells. Through a process of artificial reprogramming in the lab, scientists wipe these cellsâ€™ slates clean and return them to a state very similar to that of embryonic stem cells.Â But not exactly the same.
It has become clear that iPS cells can retain some memories of their previous state. This can make it easier to change an iPS cell that used to be a blood cell (for example) back into a blood cell, compared to turning it into another type of cell. The finding raised questions about iPS cellsâ€™ stability and whether http://www.troakley.com/ iPS cell generation â€“ still a relatively new technique â€“ would need some revamping for eventual clinical use.
Chromosomal hotspots where iPS cells differ from ES cells
It turns out that iPS cells and embryonic stem cells have differing patterns of methylation, a modification of DNA that can alter how genes behave even if the underlying DNA sequence remains the same. Some of these differences are the same in all iPS cells and some are unique for each batch of reprogrammed cells.
Move over, A, G, C and T. The alphabet of epigenetic DNA modifications keeps getting longer.
A year ago, we described research on previously unseen information in the genetic code using this metaphor:
Imagine reading an entire book, but then realizing that your glasses did not allow you to distinguish â€œgâ€ from â€œq.â€ What details did you miss?
Geneticists faced a similar problem with the recent discovery of a â€œsixth nucleotideâ€ in the DNA alphabet. Two modifications of cytosine, one of the four bases http://www.raybani.com/ that make up DNA, look almost the same but mean different things. But scientists lacked a way of reading DNA, letter by letter, and detecting precisely where these modifications are found in particular tissues or cell types.
Now, a teamâ€¦ has developed and tested a technique to accomplish this task.
Well, Emory geneticist Peng Jin and his collaborator Chuan He at the University of Chicago are at it again.
Every time scientists identify genetic risk factors for a human disease or a personality trait, it seems like more weight accumulates on the “nature” side of the grand balance between nature and nurture.
That’s why it’s important to remember how much prenatal and childhood experiences such as education, nutrition, environmental exposures and stress influence later development.
At the Emory/Georgia Tech Predictive Health Symposium in December, biologist Victor Corces outlined this concept using a particularly evocative example: bees. A queen bee and a worker bee share the same DNA, so the only thing that determines whether an insect will become the next queen is whether she consumes royal jelly.
Posted on January 14, 2010