Biology & Genetics

Jul

2010

Longevity debate: Chips to blame?

The Scientist, July 13, 2010.

At the heart of a feverish debate over the validity of a recent genome-wide association study (GWAS) of centenarians is the authors’ possible misuse of gene chips in different testing groups, part of an ongoing issue affecting other GWAS research. How this variation might impact the validity of the longevity findings, however, including the 150 SNPs associated with extreme longevity, is unclear.

The initially heralded study, published in Science Express July 2, examined the genomes of about 1,000 centenarians, those rare humans that have reached the age of 100, and compared them to those of controls. However, the authors used two different gene chips to analyze their centenarian population, with one gathering about 10 percent of the data. Read More >

Jun

2010

Longevity’s secret code revealed

The Scientist (blog), June 30, 2010.

Extreme longevity is associated with a select group of genetic markers, according to a new study of centenarians, people living at least 100 years. Using these markers, researchers can predict a person’s ability to become a centenarian with 77 percent accuracy.

“Exceptional longevity is not this vacuous entity that no one can figure out,” said lead author Thomas Perls, the director of the New England Centenarian Study at Boston Medical Center. “I think we’ve made quite some inroads here in terms of demonstrating a pretty important genetic component to this wonderful trait.”

“This paper is an important breakthrough in the field,” agreed Jan Vijg, a gerontological geneticist at the Albert Einstein College of Medicine, who did not participate in the study. Read More >

Apr

2010

Gene Grows Worm Heads

WIRED Science blog, April 29th, 2010.

A worm named Schmidtea mediterranea has the unique ability to regenerate not just its body, but also its head and brain. Now, scientists studying the worm have discovered one of the genes that allows it to accomplish this amazing feat.

The gene, called “smed-prep,” regulates the location and structure of the flatworm’s brain during regeneration. When the gene is absent, the worm forms a stump with random junk from other parts of its body, but no brain. When it’s expressed in other areas of the body, heads can be made to sprout from anywhere.

“One of the main goals in the lab was to understand the mechanisms that allowed this worm to regenerate its head, brain and sensory organs,” said molecular biologist Aziz Aboobaker of the University of Nottingham, lead author of the paper published in PLoS GeneticsApril 22. “It’s a big problem because you have to make this all from the old tissue. The cells have to mobilize, migrate to the right place and differentiate.” Read More >

Dec

2009

Muscle cell infusion shown to strengthen sphincters in animals in Stanford study

Stanford University Medical Center, December 4th, 2009.

A new study shows that muscle cells grown in the lab can restore an intestine’s ability to squeeze shut properly. The work, performed in dogs and rats, might ultimately help treat patients with conditions such as gastric reflux and fecal incontinence.

This technique may be used to strengthen sphincters, which are the bands of muscle that separate the major sections of your intestinal tract. Weakness in these areas can cause gastrointestinal esophageal reflux disease, or GERD, which affects 25 million adults in the United States. It is also a cause of fecal incontinence, or loss of control of the bowels, which afflicts more than 5 percent of adults under 40, especially women after childbirth; its prevalence increases with age. Read More >