all Department of Molecular and Cellular Biology stories

Driven:

404132862 — Tue, 26 Aug 2008 14:29:50 -0400

When the baby vomited again, Gail Melton knew something was seriously wrong with her second child, a son she and her husband, Doug Melton, had named Sam.

Harvard Stem Cell Institute researchers turn one form of adult mouse cell directly into another

404132862 — Sun, 10 Aug 2008 16:40:13 -0400

In a feat of biological prestidigitation likely to turn the field of regenerative medicine on its head, Harvard Stem Cell Institute (HSCI) co-director Doug Melton and post doctoral fellow Qiao "Joe" Zhou report having achieved what has long been a dream and ultimate goal of developmental biologists – directly turning one type of fully formed adult cell into another type of adult cell.

Astrocytes are rising stars (ScienceNews)

404132862 — Thu, 17 Jul 2008 15:05:33 -0400

Newly discovered class of mouse retinal cells detect upward motion

404132862 — Mon, 31 Mar 2008 12:10:06 -0400

Harvard researchers have discovered a previously unknown type of retinal cell that plays an exclusive and unusual role in mice: detecting upward motion. The cells reflect their function in the physical arrangement of their dendrites, branch-like structures on neuronal cells that form a communicative network with other dendrites and neurons in the brain.

The work, led by neuroscientists Joshua R. Sanes and Markus Meister, is described in a letter in the journal Nature.

President Faust testifies for increase in NIH funding

404132862 — Tue, 11 Mar 2008 15:02:07 -0400

With the careers of a generation of young researchers threatened by five years of flat National Institutes of Health (NIH) funding, Harvard President Drew Faust and leaders of six other major research institutions were in Washington today (March 11) calling on Congress to repair the “Broken Pipeline” through which breakthroughs in the biomedical sciences should be flowing.

Massive decoding effort reveals fruit fly DNA

404132862 — Wed, 07 Nov 2007 12:13:51 -0500

An enormous effort to decode the DNA of one of the most important laboratory animals — the fruit fly — ended in success this week as a collaboration of researchers from 16 nations announced the sequencing of 10 fly species’ genomes.

The research allows the extraordinary side-by-side comparison of the DNA of 12 species of fruit flies — two had already been decoded — as scientists search to understand the workings of individual genes and how those genes translate into specific physical characteristics.

Researchers create colorful "Brainbow" images of the nervous system

404132862 — Wed, 31 Oct 2007 14:07:16 -0400

By activating multiple fluorescent proteins in neurons, neuroscientists at Harvard University are imaging the brain and nervous system as never before, rendering their cells in a riotous spray of colors dubbed a "Brainbow."

Basic understanding of biological clock advances

404132862 — Tue, 16 Oct 2007 20:54:53 -0400

Writing this week in the journal Science, researchers at Harvard describe what causes a trio of proteins, if placed in a test tube with the common biochemical fuel ATP as a source of phosphate, to function as a minimalist biological clock of sorts, maintaining an accurate circadian rhythm for long periods of time.

The new Harvard work builds upon research reported in 2005 by biologist Takao Kondo and colleagues at Nagoya University in Japan. That team initially reported that a circadian clock could be reconstituted in a test tube solely with three proteins and ATP.

Nine Harvard faculty members win NIH’s Pioneer, Innovator Awards

404132862 — Thu, 20 Sep 2007 16:16:46 -0400

Nine Harvard researchers "well-positioned to make significant - and potentially transformative - discoveries in a variety of areas," ranging from brain development to reprogramming stem cells, have been awarded special funding by the National Institutes of Health (NIH).

The grants, announced Tuesday (Sept. 18), total $15 million over the next five years. They will be distributed through two NIH grant programs, both overseen by NIH Director Elias Zerhouni. One, the NIH Director's Pioneer Award, funds established researchers with $2.5 million each. The second, the Director's New Innovator Award, gives $1.5 million each to young, promising investigators.

Sensory organ differentiates male/female behavior in some mammals

50443248 — Mon, 01 Oct 2007 16:50:40 -0400

For years, scientists have searched in vain for slivers of the brain that might drive the dramatic differences between male and female behavior. Now biologists at Harvard University say these efforts may have fallen flat because such differences may not arise in the brain at all.

Rather, they say, the epicenter of sex-specific behavior in many species may be a small sensory organ found in the noses of all terrestrial vertebrates except higher primates. Their work, appearing this week in the journal Nature, indicates that defects in this organ, known as the vomeronasal organ, lead female mice to adopt male behaviors such as mounting and pelvic thrusting while abandoning female behaviors such as nesting and nursing.

Accelerating science with innovative computing

50443248 — Tue, 02 Oct 2007 16:31:17 -0400

How daunting a task is it, in an age when it is possible to visualize structures and to see them at magnifications not even dreamed of a short time ago, to produce a "wiring diagram" of the human brain?

It is an extreme challenge when one considers that the amount of information that needs to be gathered, manipulated, and analyzed is "equal to all the written materials in all the libraries in the world," Jeff Lichtman, professor of molecular and cellular biology in the Faculty of Arts and Sciences, explained to those attending the inaugural symposium of Harvard's new Initiative in Innovative Computing.

MacArthur Foundation honors Harvard faculty members, Radcliffe fellow

70652986 — Mon, 26 Mar 2007 06:28:04 -0400

Harvard faculty members and a Radcliffe fellow probing the mysteries of stem cells, the early universe, the modern practice of surgery, and the significance of public sights and modern ruins were honored Sept. 19 with the John D. and Catherine T. MacArthur Foundation's $500,000, no-strings-attached "genius grants."

The four are Assistant Professor of Molecular and Cellular Biology Kevin Eggan, Assistant Professor of Health Policy and Management and Assistant Professor of Surgery Atul Gawande, Professor of Astronomy and of Physics Matias Zaldarriaga, and Radcliffe fellow Anna Schuleit.

The four join 21 other MacArthur Foundation fellows engaged in a broad spectrum of endeavors - from deep sea exploring to journalism to sculpting - who have in common creativity and originality.

RNA sequence restrains fatal encephalitis

70652986 — Mon, 26 Mar 2007 06:25:17 -0400

One short sequence of RNA protected mice from deadly brain inflammation caused by West Nile virus and Japanese encephalitis virus, report Priti Kumar, Manjunath Swamy, and Premlata Shankar. The findings, which appear online and in the April 2006 PLoS Medicine, underscore the therapeutic potential of the fast-moving field of RNA interference. It has only been four years since scientists first showed that RNA interference, which protects plants, flies, and worms from viral infections, also works in mammalian cells. Now, at least two experimental siRNA therapies already have advanced to phase I safety trials in people. Short interfering RNA (siRNA) silences genes most commonly by triggering the destruction of RNA before proteins can be made.

Protein underlies brain's response to activity

70652986 — Mon, 26 Mar 2007 06:25:00 -0400

Experience helps shape the brain, but how that happens - how synapses are remodeled in response to activity - is one of neurobiology's biggest mysteries. Though axons and dendrites can be easily spotted waxing and waning under the microscope, the molecular middlemen working inside the cell to shape the neuron's sinewy processes have been much more elusive.

Two independent teams of Harvard Medical School (HMS) researchers report that they have found a protein that either pares down or promotes a neuron's synapses, depending on whether or not the neuron is being activated. Rather than work at the far reaches of the cell, in the axon or dendrite, the protein myocyte enhancer factor 2 (MEF2) resides in the nucleus, where it turns on and off genes that control dendritic remodeling. In fact, the researchers have identified some of MEF2's targets. In addition, one of the teams has identified how MEF2 switches from one program to the other, that is, from dendrite- promoting to dendrite-pruning. The discoveries are reported in back-to-back papers in the Feb. 17, 2006 Science.

The uncovering of the MEF2 pathway and its genetic switch helps fill in a theoretical blank in neurobiology, but what excites the researchers are the potential implications for the clinic. "Changes in the morphology of synapses could turn out to be very important in a whole host of diseases including neurodegenerative as well as psychiatric disorders," said Azad Bonni, HMS associate professor of pathology, who, with research fellow Aryaman Shalizi, HST medical student Brice Gaudilliére, and colleagues, authored one of the papers. Graduate student Steven Flavell and Michael Greenberg, HMS professor of neurology at Children's Hospital Boston, who led the other team, believe that the MEF2 pathway could play a role in autism and other neurodevelopmental diseases.

Long-term memory controlled by molecular pathway at synapses

70652986 — Mon, 26 Mar 2007 06:23:41 -0400

Even for a fruit fly, learning and memory are important adaptive tools that facilitate survival in the environment. A fly can learn to avoid what may do it harm, such as a flyswatter, or in the laboratory, an electric shock that happens when it smells a certain odor.

Now Harvard University biologists have identified a molecular pathway active in neurons that interacts with RNA to regulate the formation of long-term memory in fruit flies. The same pathway is also found at mammalian synapses, and could eventually present a target for new therapeutics to treat human memory loss.

"It has been known for some time that learning and long-term memory require synthesis of new proteins, but exactly how protein synthesis activity relates to memory creation and storage has not been clear," says Sam Kunes, professor of molecular and cellular biology in Harvard's Faculty of Arts and Sciences. "We have been able to monitor, for the first time, the synthesis of protein at the synapses between neurons as an animal learns, and we found a biochemical pathway that determines if and where this protein synthesis happens. This pathway, called RISC, interacts with RNA at synapses to facilitate the protein synthesis associated with forming a stable memory. In fruit flies, at least, this process makes the difference between remembering something for an hour and remembering it for a day or more."

Together with lead author Shovon Ashraf, a postdoctoral researcher in Harvard's Department of Molecular and Cellular Biology, and Anna McLoon '04 and Sarah Sclarsic '06, Kunes found that messenger RNA (mRNA) - a genetic photocopy that conveys information from DNA to a cell's translation machinery - is transported to synapses as a memory begins to form. This mRNA transport, and the protein synthesis that follows, are facilitated by components of the RISC pathway, which use very short RNA molecules called microRNAs to guide their activity. One of these RISC proteins, called Armitage, appears to be a critical regulatory molecule in long-lasting memory formation, and has to be destroyed at particular synapses in order for protein synthesis to occur there.

The findings were presented on the Web site of the journal Cell.