Scientists probe mechanism of asymmetry in meiotic cell division

Oct 07, 2008

The Stowers Institute's Rong Li Lab has characterized a mechanism that allows for asymmetrical cell division during meiosis in oocytes. By tracking chromosome movement in live mouse oocytes, the team discovered that chromosomes can recruit to their vicinity a protein called formin-2. This protein allows the oocyte to retain the majority of the cytoplasm – a requirement for embryonic development after fertilization – while the other daughter cell (called a polar body) resulting from the asymmetric division gets only a minimal amount and subsequently dies.

The work was published this week in the advance online publication of Nature Cell Biology.

Formin-2 is an actin-nucleating protein that can promote the formation of actin filaments around the chromosomes. Actin filaments undergo dynamic elongation and shortening and, in the process, push the chromosomes towards the outer edge of the oocyte. After the chromosomes reach the periphery, the actin filaments orient the cell division plane so that most of the cytoplasm required to sustain the earliest stages of development stays with the daughter cell that retains the identy of the oocyte.

"This work revealed the general mechanism by which the actin cytoskeleton drives chromosome movement in mammalian meiotic oocytes," said Hongbin Li, Ph.D., Senior Research Associate and lead author on the publication. "Our findings will enable us to carry out even more detailed dissection of the molecular components and mechanisms."

"Infertility and birth defects are often related to problems during oocyte meiotic cell divisions," said Rong Li, Ph.D., Investigator and senior author on the paper. "Failure in the chromosome movement will lead to failed oocyte maturation and infertility. These findings provide an important step toward a better understanding of the process of meiotic divisions and how actin generates the force to power intra-cellular movements."

Source: Stowers Institute for Medical Research

Explore further: Researchers discover new mechanism of DNA repair

Related Stories

The determining factors of cell shape examined

Oct 04, 2012

A European team is investigating the role of the bacterial cell wall and the cytoskeleton in mediating cell shape. Results are expected to have broader implications for cell biology.

Cell division, minus the cells

Oct 30, 2014

(Phys.org) —The process of cell division is central to life. The last stage, when two daughter cells split from each other, has fascinated scientists since the dawn of cell biology in the Victorian era. ...

Recommended for you

Researchers discover new mechanism of DNA repair

Jul 03, 2015

The DNA molecule is chemically unstable giving rise to DNA lesions of different nature. That is why DNA damage detection, signaling and repair, collectively known as the DNA damage response, are needed.

The math of shark skin

Jul 03, 2015

"Sharks are almost perfectly evolved animals. We can learn a lot from studying them," says Emory mathematician Alessandro Veneziani.

Cuban, US scientists bond over big sharks

Jul 03, 2015

Somewhere in the North Atlantic right now, a longfin mako shark—a cousin of the storied great white—is cruising around, oblivious to the yellow satellite tag on its dorsal fin.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.