cell biology
purepedantry | November 24, 2006If you remember back from when I was at the Society for Neuroscience, I saw a talk by Bruce Appel where he showed videos of oligodendrocytes migrating and myelinating in the zebrafish.
Oligodendrocytes are the myelin forming cell in the central nervous system of vertebrates -- the cells that coat axons in a sheet of fat called myelin that helps the axons conduct action potentials more quickly. At a point in oligodendrocyte development the oligodendrocyte precursor cells (OPCs) have to migrate out from the ventral part of the spine to cover the axons in the spinal cord. However, this…
purepedantry | October 13, 2006Scientists have discovered a bacteria the survives with an incredibly small number of genes:
The tiniest genomes ever found belong to two types of bacteria that live inside insects, researchers have announced.
One of these types of bacteria, Carsonella ruddii, is so small that it could perhaps be considered an organelle within the cells of the bugs. But both microbe species face the threat of extinction because of their small genome size, experts say.
C. ruddii has the fewest genes of any cell known in the world - a mere 182, according to the new results. Humans, by comparison boast…
purepedantry | October 2, 2006Andrew Fire and Craig Mello have won the Nobel Prize in Medicine for the discovery of RNA interference:
Americans Andrew Z. Fire and Craig C. Mello won the Nobel Prize in physiology or medicine Monday for discovering a powerful way to turn off the effect of specific genes, opening a new avenue for disease treatment.
''RNA interference'' is already being widely used in basic science as a method to study the function of genes and it is being studied as a treatment for infections such as the AIDS and hepatitis viruses and for other conditions, including heart disease and cancer.
Fire, 47, of…
purepedantry | September 4, 2006Check out this awesome molecular biology animation by XVIVO. My favorite is the depiction of actin and microtubule assembly and the movement of a kinesin molecule tethered to a vesicle.
Apparently, Harvard has contracted out with this company to provide this animations to students. If that is true, that would be lovely. Anything that helps students understand better is a good idea in my book.
However, I am skeptical about the validity of this:
XVIVO's animation plays an instrumental role in the BioVisions at Harvard program established by Dr. Lue. "Furthermore, preliminary evaluation…
purepedantry | August 3, 2006Neurodegenerative diseases, including Parkinson's, were for many years regarded as exclusively diseases of molecular crud. You would look at brains of patients with Alzheimer's and Parkinson's patients and notice that there were all these aggregates of protein crud forming in specific locations. This led scientists to conclude that the crud must be causing the neurons to do die through a mechanism that was not at the time clear.
The reality we are learning is far more complicated.
There is a form of inherited Parkinson's disease that is caused by loss-of-function mutations in the gene…
purepedantry | June 21, 2006I remember for a couple years, it was "lipid rafts this" and "lipid rafts that." The idea of the lipid rafts -- for the uninitiated -- was that there were microdomains in the plasma membranes of cells defined by their more hydrophobic composition. You can definitely separate these fractions from the fractions of plasma membrane (I know because I have done it), and under some circumstances proteins migrate from one compartment to another.
A paper in the latest Cell by Douglass and Vale contests the notion that the hydrophobicity of the membrane is responsible for recruiting proteins into the…