You are currently browsing the monthly archive for November 2008.
Representative microRNAs are differentially expressed in a 6-year-old (left), an 11-year-old (center) and a 13-year-old, all with autism and compared with age-matched controls. Up-regulated miRNAs are in red and down-regulated ones in green.
Some small fragments of RNA are expressed differently in people with autism than in controls, according to two new studies. The findings unveil another layer of complexity in the genetics of autism.
These pieces of single-stranded RNA — dubbed microRNAs or miRNAs — have wide-ranging, subtle effects on the production of many different proteins without affecting a cell’s underlying DNA code.
That may account for some of the widespread variation among people with autism, and even among family members who share genes, experts say.
Check out the inspiration for "Genes & Jazz": Drew Barry's animation of DNA coiling within a chromosome
Too often, I read about a great NYC event that’s already happened. This time it was “Genes & Jazz,” a lecture at the Guggenheim Museum on November 16. The featured speaker was president of Memorial Sloan-Kettering Cancer Center (and Obama’s likely pick for Science Advisor) Harold Varmus. He talked about basic biology and evolution while his son, Jacob Varmus, led an accompanying jazz quintet.
“We both felt that there were unexplored similarities between jazz and science,” Jacob said to the New Yorker‘s Paul Goldberger. “They both involve investigating patterns and structures and how things work. Science and jazz are also both fringe communities in this country, and so we figured we could tell a parallel story.”
The duo decided to use music to explain the double helix and the rest of a cell’s basic structure. But, like a typical father and son, they disagreed on just how to do that. Happily, Drew Barry’s fantastic computer animations of cell biology came to the rescue. Go read the whole story.
Happy Turkey Day!
I’m in Michigan this week, enjoying my mom’s fantastic holiday feast: butternut squash bisque, prime rib (she has an aversion to making turkey), mashed potatoes, scalloped corn, green bean casserole, broccoli and cheese casserole, chocolate peanut butter pie, egg nog pie, coconut cream pie…
The menu choices are classically Midwestern and, unsurprisingly, not organic: the nearest Whole Foods is 70 miles east of my house.
I’d like to think that, if available, I’d always choose the organic option. But I was shocked to find out just how much that costs: 75 percent more (!), according to a recent post on Tara Parker-Pope’s blog, Well. Here’s how she breaks down the price differences (organic versus non-organic) of the typical parts of a Thanksgiving meal:
Three weeks ago, less than a year after the release of the complete genomes of two people of European descent—Craig Venter and James Watson—Nature published two additional genomes, one of a Yoruba African and another from a Han Chinese. Just before that, George Church and nine other prominent Harvard scientists announced that they, too, would volunteer their genomic sequences to science. And the 1,000 Genomes Project aims to sequence 1,000 complete genomes from people of various ethnicities in the next few years.
These whole-genome sequencing projects have been big news because they’re so complicated and expensive. Right now, it costs at least $350,000 to sequence one complete (or near-complete) genome.
But Helicos BioSciences claims that within the next few years, its technology will be able to read the entire human genome for less than $1,000. To quote my favorite 17-year-old friend, that’s really effing cool. If you want to know why, check out Dan MacArthur’s many ridiculously clear and insightful blog posts on the subject. Or, if you don’t like reading, then watch this short video explaining how it works, produced by Helicos:
(Hat tip: Aaron)
Percentage of guests who have been on Comedy Central’s Colbert Report to discuss science: 17.5%
Odds that said guest is a woman: 1 in 16
Odds that said guest is Craig Venter: 1 in 16
(Colbert to Venter: “Now, when you decoded your genome, was there any marker that proved you were some sort of narcissistic egomaniac?”)
…Check out more fantastic data—from an “elastic list” of Nobel Laureates to drawings of “typical scientists” made by adults in Madison Square Park—in Seed‘s newly released “State of Science” feature
A child’s language ability correlates with the volume of his or her amygdala — the small, deep brain region that is strongly associated with emotional processing — according to an unpublished five-year longitudinal study presented Wednesday afternoon at the Society for Neuroscience meeting.
Analyzing brain imaging data collected from 24 infants at 6 months of age, researchers at Rutgers University found that the larger the volume of the right amygdala, the lower the babies score on language tests given at 2, 3, and 4 years of age. The researchers found the inverse to be true of the left amygdala, but not to statistical significance.
Based on these results and previous studies, the researchers speculate that during early development, neuronal connections are strengthened between the amygdala and known language processing centers in the brain. Because children with autism have impaired social interaction, these connections may be disrupted, the researchers say.
I’m recouperating now after five intense days covering autism research for SFARI at the Society for Neuroscience meeting in Washington, D.C.
This will be my last post about the meeting, I swear. Just wanted to share a cool technology that was on display in the exhibition hall. It’s called “Optotrak Smart Markers,” and made by the Northern Digital company. Basically, it allows scientists to track (and view) very rapid motions, such as the eye-tracking experiments done on children with autism by Warren Jones and Ami Klin at Yale.
In their exhibit booth, a man was playing the piano with gloves that had been fitted with electronic sensors at each knuckle (see first photo). As he played, his super-fast finger motions were relayed (in real time!) as little red dots on a screen projection on the wall (see second photo). Pretty cool, ja?
Micro effects: Some microRNAs are under expressed in schizophrenia and bipolar disorder.
(As published today at SFARI)
Some small fragments of RNA, called microRNAs, are under-expressed in people with schizophrenia and bipolar disorder compared with controls, according to unpublished research based on postmortem brain tissue presented this morning at the Society for Neuroscience meeting.
Schizophrenia and bipolar disorder each affect about one percent of the population, and recent genetic studies have shown some similarities between the two disorders.
For both disorders, studies have identified large ‘linkage peaks’ — relatively large regions of the genome that are similar in individuals with that disorder, but different compared with controls. However, scientists have had trouble pinpointing genes within those regions that are strongly associated with disease.
“That got us thinking whether we need to start looking at other types of genetic elements, things like microRNAs,” said Linda Brzustowicz, professor of genetics at Rutgers University.
Dense dendrites: Lithium decreases the length and density of dendritic spines in a mouse model of fragile X.
(As published last night on SFARI)
Lithium treatment reverses some of the behavioral and brain-cell abnormalities in mouse models of fragile X syndrome — an inherited form of mental retardation that includes learning deficits, aggressiveness, and social withdrawal — according to research presented today at the Society for Neuroscience meeting.
Doctors have for about 50 years prescribed lithium salts for mood problems, such as bipolar disorder. Three years ago, scientists found that lithium reduces memory deficits and repairs neuronal defects in a Drosophila model of fragile X.
In August, an open-label clinical trial of two months of lithium treatment of 15 people with fragile X found that the chemical alleviates irritability, inappropriate speech and aggressive behavior.
The results presented at the conference are the first to investigate the effect on brain cells of mouse models of the disorder, according to Zhong-Hua Liu, a postdoctoral fellow at the National Institute of Mental Health who presented the data.
Single source: Stem cells derived from the skin can form nerve cells and be used to study autism.
(As published earlier today on SFARI)
A team of scientists is reprogramming adult stem cells generated from tiny skin samples of people with autism to form nerve cells, creating a powerful research tool for the disorder.
Exposed to the correct transcription proteins, skin cells can transform into pluripotent stem cells — which, in turn, can be prompted to differentiate into any kind of cell in the body, including neurons.
Working with the nerve cells may help scientists study various aspects of the disorder, including potential imbalances in excitatory and inhibitory signaling, defects in synapse formation or any problems with cell division.
“We’re starting with the idea that there are a limited set of cellular processes that are altered in kids with autism,” says lead investigator Ricardo Dolmetsch, an assistant professor of molecular pharmacology at Stanford University. “All of that we can study in a dish.”
