Navigation Links
Slicing mitotic spindle with lasers, nanosurgeons unravel old pole-to-pole theory
Date:4/26/2012

Cambridge, Mass. - April 26, 2012 - The mitotic spindle, an apparatus that segregates chromosomes during cell division, may be more complex than the standard textbook picture suggests, according to researchers at the Harvard School of Engineering and Applied Sciences (SEAS).

The findings, which result from quantitative measurements of the mitotic spindle, will appear tomorrow in the journal Cell.

The researchers used a femtosecond laser to slice through the strands of the organelle and then performed a mathematical analysis to infer the microscopic structure of the spindle from its response to this damage.

"We've been using this nanosurgery technique to understand the architecture and assembly of the spindle in a way that was never possible before," says Eric Mazur, Balkanski Professor of Physics and Applied Physics at Harvard, who co-authored the study. "It's very exciting."

The spindle, which is made of protein strands called microtubules, forms during cell division and segregates chromosomes into the daughter cells. It was previously unclear how microtubules are organized in the spindles of animal cells, and it was often assumed that the microtubules stretch along the length of the entire structure, pole to pole.

Mazur and his colleagues demonstrated that the microtubules can begin to form throughout the spindle. They also vary in length, with the shortest ones close to the poles.

"We wondered whether this size difference might result from a gradient of microtubule stabilization across the spindle, but it actually results from transport," says lead author Jan Brugus, a postdoctoral fellow at SEAS. "The microtubules generally nucleate and grow from the center of the spindle, from which point they are transported towards the poles. They disassemble over the course of their lifespan, resulting in long, young microtubules close to the midline and older, short microtubules closer to the poles."

"This research provides concrete evidence for something that we've only been able to estimate until now," Brugus adds.

Mazur and Brugus worked with Daniel Needleman, Assistant Professor of Applied Physics and Molecular and Cellular Biology at Harvard, and Valeria Nuzzo, a former postdoctoral fellow in Mazur's lab at SEAS, to bring the tools of applied physics to bear on a biological question.

The team used a femtosecond laser to make two small slices perpendicular to the plane of growth of the spindle apparatus in egg extracts of the frog species Xenopus laevis.

They were then able to collect quantitative data on the reconstruction of the spindle following this disruption and precisely determine the length and polarity of individual microtubules. Observing the speed and extent of depolymerization (unraveling) of the spindle, the team worked backwards to compile a complete picture of the beginning and end points of each microtubule. Finally, additional experiments and a numerical model confirmed the role of transport.

"The laser allowed us to make precise cuts and perform experiments that simply were not possible using previous techniques," says Mazur.

With further inquiries into spindle architecture, the researchers hope that scientists will one day have a complete understanding, and possibly even control over, the formation of the spindle.

"Understanding the spindle means understanding cell division," notes Brugus. "With a better understanding of how the spindle is supposed to operate, we have more hope of tackling the range of conditionsfrom cancer to birth defectsthat result from disruptions to the cell cycle or from improper chromosomal segregation."


'/>"/>
Contact: Caroline Perry
cperry@seas.harvard.edu
617-496-1351
Harvard University
Source:Eurekalert  

Related medicine news :

1. Colorful brains, cooling lasers, disease-detecting lights and more
2. Sanford-Burnham scientists unravel cancer drugs secret to resistance
3. Researchers discover method to unravel malarias genetic secrets
4. Moffitt Cancer Center researchers unravel biochemical factor important in tumor metastasis
5. Unraveling the complex signaling that helps cells know when to grow, when to sit tight
6. Study Unravels Link Between Stress and Chronic Health Issues
7. New tool for cell research may help unravel secrets of disease
8. Scientists Unravel Secrets of Sound Sleep
9. Scientists unravel human-ecosystem interactions
10. Scientists Unravel Secret of HIV Resistance
11. Scientists Unravel Mysteries of Intelligence
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Slicing mitotic spindle with lasers, nanosurgeons unravel old pole-to-pole theory
(Date:5/27/2017)... Los Angeles, California (PRWEB) , ... May 26, 2017 , ... ... Canadian senior citizens who visit a doctor for colds or respiratory issues that are ... note that excessive time pressure on doctors may be largely responsible for the problem ...
(Date:5/27/2017)... Rosa, CA (PRWEB) , ... May 27, 2017 , ... ... cause for concern, but a new study from the Osteoarthritis Initiative shows ... to developing knee osteoarthritis. Knowing this in advance may give doctors the opportunity to ...
(Date:5/26/2017)... Fairfax, VA (PRWEB) , ... May 26, 2017 ... ... is pleased to announce a new educational seminar to focus on current legislative ... Regulatory News(LEARN) seminar will begin at 1 p.m. Sunday, Sept. 10, and will ...
(Date:5/26/2017)... ... 26, 2017 , ... Boar’s Head Brand®, one of the ... Day entertaining that are sure to satisfy your guests’ flavor cravings, while adding ... cheeses featured in these refreshingly balanced recipes are packed with flavor, creating the ...
(Date:5/26/2017)... ... May 26, 2017 , ... Yisrayl Hawkins, Pastor and Overseer at The House ... focusing on the Peace Agreements being discussed by President Donald Trump and the rest ... to try to speed up peace talks in the continuous battle between Israel and ...
Breaking Medicine News(10 mins):
(Date:5/8/2017)... May 8, 2017  Diplomat Pharmacy, Inc. (NYSE: DPLO)., ... ("WRB"), a health care service center company based ... WRB specializes in relationship management programs for leading pharmaceutical ... WRB will join Envoy Health ... services for manufacturers, biotech firms, and other service companies. ...
(Date:5/4/2017)... Tenn. , May 4, 2017  A ... Infection Control, Ultraviolet-C light as a ... Tru-D SmartUVC,s ability to reduce bioburden on anesthesia ... bioburden reduction on high-touch, complex medical equipment surfaces ... surgical infections. "This study further validates ...
(Date:5/4/2017)...   BioLife Solutions , Inc. (NASDAQ: ... proprietary clinical grade hypothermic storage and ... announced that the Company,s first quarter 2017 financial results ... 11, 2017, and that the Company will host a ... that afternoon. Management will provide an overview of the ...
Breaking Medicine Technology: