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 Tracing the evolution of vision
23.08.2019 | University of Göttingen

nachricht Caffeine does not influence stingless bees
23.08.2019 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Hamburg and Kiel researchers observe spontaneous occurrence of skyrmions in atomically thin cobalt films

Since their experimental discovery, magnetic skyrmions - tiny magnetic knots - have moved into the focus of research. Scientists from Hamburg and Kiel have now been able to show that individual magnetic skyrmions with a diameter of only a few nanometres can be stabilised in magnetic metal films even without an external magnetic field. They report on their discovery in the journal Nature Communications.

The existence of magnetic skyrmions as particle-like objects was predicted 30 years ago by theoretical physicists, but could only be proven experimentally in...

Im Focus: Physicists create world's smallest engine

Theoretical physicists at Trinity College Dublin are among an international collaboration that has built the world's smallest engine - which, as a single calcium ion, is approximately ten billion times smaller than a car engine.

Work performed by Professor John Goold's QuSys group in Trinity's School of Physics describes the science behind this tiny motor.

Im Focus: Quantum computers to become portable

Together with the University of Innsbruck, the ETH Zurich and Interactive Fully Electrical Vehicles SRL, Infineon Austria is researching specific questions on the commercial use of quantum computers. With new innovations in design and manufacturing, the partners from universities and industry want to develop affordable components for quantum computers.

Ion traps have proven to be a very successful technology for the control and manipulation of quantum particles. Today, they form the heart of the first...

Im Focus: Towards an 'orrery' for quantum gauge theory

Experimental progress towards engineering quantized gauge fields coupled to ultracold matter promises a versatile platform to tackle problems ranging from condensed-matter to high-energy physics

The interaction between fields and matter is a recurring theme throughout physics. Classical cases such as the trajectories of one celestial body moving in the...

Im Focus: A miniature stretchable pump for the next generation of soft robots

Soft robots have a distinct advantage over their rigid forebears: they can adapt to complex environments, handle fragile objects and interact safely with humans. Made from silicone, rubber or other stretchable polymers, they are ideal for use in rehabilitation exoskeletons and robotic clothing. Soft bio-inspired robots could one day be deployed to explore remote or dangerous environments.

Most soft robots are actuated by rigid, noisy pumps that push fluids into the machines' moving parts. Because they are connected to these bulky pumps by tubes,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The power of thought – the key to success: CYBATHLON BCI Series 2019

16.08.2019 | Event News

4th Hybrid Materials and Structures 2020 28 - 29 April 2020, Karlsruhe, Germany

14.08.2019 | Event News

What will the digital city of the future look like? City Science Summit on 1st and 2nd October 2019 in Hamburg

12.08.2019 | Event News

 
Latest News

Making small intestine endoscopy faster with a pill-sized high-tech camera

23.08.2019 | Medical Engineering

More reliable operation offshore wind farms

23.08.2019 | Power and Electrical Engineering

Tracing the evolution of vision

23.08.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>