Navigation Links
Study of cell division sheds light on special mechanism in egg cells
Date:8/22/2010

In a study of egg cells using time-lapse microscopy, researchers at the University of California, San Diego School of Medicine and the Ludwig Institute for Cancer Research have discovered an unusual property of meiosis cell division that produces reproductive cells in sexually reproducing organisms. The discovery of an "inside out" mechanism by which egg cell chromosomes separate from each other may shed light on mistakes made in chromosome distribution that can lead to Down syndrome, high miscarriage rates in humans, and the age-related decrease in fertility in human females. Their findings are reported in the September issue of Nature Cell Biology.

Sexual reproduction relies on the merger of chromosomes present in the sperm and egg at fertilization. Formation of sperm and egg cells requires the process of meiosis, which halves the chromosome number of each parent, so that the sperm-egg merger regenerates a cell with two copies of each chromosome. The reduction of chromosome number in meiosis is accomplished through two divisions without an intervening duplication of the genome.

Both meiotic and mitotic divisions require specialized protein polymers called microtubules. These polymers are organized into a football-shaped spindle with the polymer ends embedded in a special organelle called the centrosome at each end of the football. Egg cells, however, are unusual in that they lack centrosomes, and instead use a spindle that is self-organized from microtubules. Egg cells, especially in humans, are prone to mistakes in dividing the chromosomes during meiosis; mistakes which result in reproductive problems in humans such as Down syndrome, infertility and miscarriages.

Researchers led by Arshad Desai, PhD, professor of Cellular and Molecular Medicine and investigator with the Ludwig Institute at UC San Diego, used the roundworm C. elegans, as a model to study egg cell division. Julien Dumont, a postdoctoral fellow in the Desai lab, developed time lapse microscopy methods to observe egg cell meiosis with high precision.

Prior to this study, dividing cell chromosomes were thought to move apart by pulling on the microtubule polymers and moving into the ends of the spindle, like a person pulling himself up on a rope. But the UCSD researchers discovered that, in C. elegans egg cells, chromosome move apart by being pushed in the middle most likely caused by the growth of microtubule polymers between the chromosome halves.

"This finding suggests that egg cells use a special mechanism for meiotic chromosome separation," said Desai. "Since defects in egg cell meiosis underlie infertility in humans, it will be important for future research to address whether such a mechanism is also operating in human females."


'/>"/>

Contact: Debra Kain
ddkain@ucsd.edu
619-543-6163
University of California - San Diego
Source:Eurekalert

Related medicine news :

1. Pay-for-performance programs improve radiology report turnaround times, study suggests
2. Study Finds Even a Little Cigarette Smoke Harms Airway
3. Virtual colonoscopies help identify additional cancers outside of the colon, study suggests
4. Breast cancer survivors dont need to be afraid of air travel: U of A study
5. New study finds new connection between yoga and mood
6. Study identifies factors which predict alcohol use after liver transplantation
7. Study to examine new treatment for West Nile virus
8. When Doctors Admit Mistakes, Fewer Malpractice Suits Result, Study Says
9. MRSA policies differ among hospitals, study shows
10. Study examines risks, rewards of energy drinks
11. Berkeley study shows ozone and nicotine a bad combination for asthma
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/8/2016)... ... December 08, 2016 , ... CURE Media Group, the nation’s leading ... has aligned with Upstage Lung Cancer in efforts to combat lung cancer, announced CURE ... Hennessy, Jr said, “CURE Media Group is honored to team up with Upstage Lung ...
(Date:12/8/2016)... , ... December 08, 2016 ... ... Suite 10.2 version gives development continuity to its innovative Unified Instance Manager ... management capacity. In addition, this new version optimizes the unattended auto-dialing system ...
(Date:12/8/2016)... ... December 08, 2016 , ... Today’s patients are encouraged to ... mind, SIGVARIS has created a new line of anti-embolism stockings to help prevent ... the benefits of graduated compression when transitioning from recovery to early rehabilitation. , ...
(Date:12/8/2016)... ... December 08, 2016 , ... ... from offices headquartered in Jefferson County, is announcing the launch of a charity ... , The number of homeless women and children in Birmingham has grown steadily ...
(Date:12/8/2016)... ... December 08, 2016 , ... Bill Mull Agencies, a Wichita-based ... and around central Kansas, is joining the Youth Horizons organization for a charity ... Headquartered in Wichita, Youth Horizons works to empower area children from unstable, troubled, ...
Breaking Medicine News(10 mins):
(Date:12/8/2016)... A Small Business Innovative Research (SBIR) grant ... (NIH) to Phoenix -based NeuroEM Therapeutics, ... grant will seek to determine an optimal set of ... waves to treat Alzheimer,s Disease. The grant will also ... treat other neurologic disorders such as Parkinson,s Disease and ...
(Date:12/8/2016)... -- Economic growth in the United States will continue in ... in their December 2016 Semiannual Economic Forecast. Expectations are ... in mid-2009, as indicated in the monthly ISM ® ... manufacturing sector is optimistic about growth in 2017, with ... the non-manufacturing sector indicates that 14 of its industries ...
(Date:12/8/2016)... LOS ANGELES , Dec. 8, 2016 /PRNewswire/ ... and manufacturing of dissolution testing and diffusion testing ... has been acquired by Teledyne Instruments, Inc. ("Teledyne"). ... Hanson,s long-proven line of precision testing instruments, as ... while accelerating development of new products and services. ...
Breaking Medicine Technology: