Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Checkered History of Mother and Daughter Cells Explains Cell Cycle Differences

21.10.2009
When mother and daughter cells are created each time a cell divides, they are not exactly alike. They have the same set of genes, but differ in the way they regulate them.

New research now reveals that these regulatory differences between mother and daughter cells are directly linked to how they prepare for their next split. The work, a collaboration between scientists at Rockefeller University and the State University of New York, Stony Brook, may ultimately lead to a better understanding of how cell division goes awry in different types of cancer. The findings are reported in this week’s PLoS Biology.

“You can basically think of mother and daughter cells as different cells just like you would a neuron and liver cell but on a much subtler level,” says first author Stefano Di Talia, who received his Ph.D. from Rockefeller in 2009. “We found that their differences in gene expression are also what makes the mother and daughter cells start their cell cycles differently.”

When a mature cell divides, it produces a mother and a daughter cell, the daughter being smaller than the mother, explains Di Talia, who is now a postdoc at Princeton University. Since the 1970s, it was thought that both mother and daughter cells use the same gears and levers to prepare for cell division. The only difference was that the daughter cell would take longer to start dividing on account of its size.

This tidy explanation now gives way to a more nuanced version, the seeds of which can be traced to research from the University of Wisconsin in 2003. It was then proposed that the size of the daughter cell has no bearing on whether it is ready to divide. What matters is that the daughter cell, and not the mother cell, receives a protein called Ace2 at the time the two cells are born. “This model was against the accepted dogma and against our own previous findings. Our work was an attempt to resolve the debate,” says Di Talia.

Di Talia and Frederick R. Cross, head of Rockefeller’s Laboratory of Yeast Molecular Genetics and a researcher who, like the Wisconsin group, works with budding yeast, seem to have reconciled the two theories and in the process nailed down new details.

The researchers found that both mothers and daughters do control and sense their size before committing to divide but the levers and gears that they use to make that commitment are different. The reason: Daughters, but not mothers, receive the protein Ace2 as well as a never-before-implicated protein called Ash1, which, like Ace2, controls the levers that crank genes into gear.

In their work, Di Talia and Cross studied a phase of the cell cycle known as G1, during which cells determine whether they are healthy enough to enter another grueling phase of division. G1 is considered critical because mistakes in this process can lead to cancer.

Di Talia and Cross, with colleagues Bruce Futcher and Hongyin Wang at SUNY Stony Brook, found that daughter cells, which normally have Ace2 and Ash1, interpret their size as 20 percent smaller than their birth twin. The researchers show that, without these proteins, daughter cells begin dividing as if they were mother cells, even at a size that would normally be deemed too small. When Ace2 and Ash1 were genetically manipulated to localize into mothers as well, the opposite happened: they unnecessarily continued to grow and began dividing as if they were daughters.

This critical finding showed that the direct target of these two proteins is a gene called CLN3, which scientists have long suspected is the ultimate green light for cells to start dividing. The reason daughter cells spend a longer time preparing for cell division is because both Ace2 and Ash1 lower the expression of CLN3. To make sure daughter cells do not start dividing before they are ready, and as backup, Ace2 also turns on production of Ash1.

“This work builds on our previous findings very nicely,” says Di Talia. “That CLN3 is the central regulator of this cell cycle phase and that it is controlled very precisely shows that even small changes can result in big differences.”

Thania Benios | Newswise Science News
Further information:
http://www.rockefeller.edu

More articles from Life Sciences:

nachricht A new 'cool' blue
17.01.2020 | American Chemical Society

nachricht Neuromuscular organoid: It’s contracting!
17.01.2020 | Max-Delbrück-Centrum für Molekulare Medizin in der Helmholtz-Gemeinschaft

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Miniature double glazing: Material developed which is heat-insulating and heat-conducting at the same time

Styrofoam or copper - both materials have very different properties with regard to their ability to conduct heat. Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz and the University of Bayreuth have now jointly developed and characterized a novel, extremely thin and transparent material that has different thermal conduction properties depending on the direction. While it can conduct heat extremely well in one direction, it shows good thermal insulation in the other direction.

Thermal insulation and thermal conduction play a crucial role in our everyday lives - from computer processors, where it is important to dissipate heat as...

Im Focus: Fraunhofer IAF establishes an application laboratory for quantum sensors

In order to advance the transfer of research developments from the field of quantum sensor technology into industrial applications, an application laboratory is being established at Fraunhofer IAF. This will enable interested companies and especially regional SMEs and start-ups to evaluate the innovation potential of quantum sensors for their specific requirements. Both the state of Baden-Württemberg and the Fraunhofer-Gesellschaft are supporting the four-year project with one million euros each.

The application laboratory is being set up as part of the Fraunhofer lighthouse project »QMag«, short for quantum magnetometry. In this project, researchers...

Im Focus: How Cells Assemble Their Skeleton

Researchers study the formation of microtubules

Microtubules, filamentous structures within the cell, are required for many important processes, including cell division and intracellular transport. A...

Im Focus: World Premiere in Zurich: Machine keeps human livers alive for one week outside of the body

Researchers from the University Hospital Zurich, ETH Zurich, Wyss Zurich and the University of Zurich have developed a machine that repairs injured human livers and keep them alive outside the body for one week. This breakthrough may increase the number of available organs for transplantation saving many lives of patients with severe liver diseases or cancer.

Until now, livers could be stored safely outside the body for only a few hours. With the novel perfusion technology, livers - and even injured livers - can now...

Im Focus: SuperTIGER on its second prowl -- 130,000 feet above Antarctica

A balloon-borne scientific instrument designed to study the origin of cosmic rays is taking its second turn high above the continent of Antarctica three and a half weeks after its launch.

SuperTIGER (Super Trans-Iron Galactic Element Recorder) is designed to measure the rare, heavy elements in cosmic rays that hold clues about their origins...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

„Advanced Battery Power“- Conference, Contributions are welcome!

07.01.2020 | Event News

 
Latest News

A new 'cool' blue

17.01.2020 | Life Sciences

EU-project SONAR: Better batteries for electricity from renewable energy sources

17.01.2020 | Power and Electrical Engineering

Neuromuscular organoid: It’s contracting!

17.01.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>