September 16th, 2006

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Molecular motors cooperate in moving cellular cargo

Researchers using an extremely fast and accurate imaging technique have shed light on the tiny movements of molecular motors that shuttle material within living cells. The motors cooperate in a delicate choreography of steps, rather than engaging in the brute-force tug of war many scientists had imagined.
When measured outside the cell, kinesin moved about 0.5 microns per second. Inside the cell, the speed increased to 12 microns per second.

“There must be a mechanism that allows the peroxisomes to move by multiple motors much faster than independent, uncoupled kinesins and dyneins,” Paul Selvin said. “It appears that motors are somehow regulated, being turned on or off in a fashion that prevents them from simultaneously dragging the peroxisome.”

University of Illinois press release (Apr. 2005)

Science, Apr. 2005
Kinesin and Dynein Move a Peroxisome in Vivo: A Tug-of-War or Coordinated Movement? 




Single Molecule Studies of Molecular Motors, Both in vitro & in vivo
-- talk by Dr. Paul Selvin, University Illinois (Apr. 2006)

см. также
http://nature-wonder.livejournal.com/11371.html


Hongyun Wang's Research on Molecular Motors

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the vole - маленький пушистый зверек... но очень странный, генетически.


• Voles are evolving 60-100 times faster than the average vertebrate in terms of creating different species.

•Within the genus, the number of chromosomes in voles ranges from 17-64.

•In one species, the X chromosome contains about 20 percent of the entire genome. Sex chromosomes normally contain much less genetic information.

•In another species, females possess large portions of the Y (male) chromosome.

•In yet another species, males and females have different chromosome numbers, which is uncommon in animals.


A final "counterintuitive oddity" is that despite genetic variation, all voles look alike. "All voles look very similar, and many species are completely indistinguishable," DeWoody said.
Nevertheless, voles are perfectly adept at recognizing those of their own species.

Rodent's bizarre traits deepen mystery of genetics, evolution


Genetica, Sept. 2006
Accelerated molecular evolution in Microtus (Rodentia) as assessed via complete mitochondrial genome sequences -- PDF