Featured Research

from universities, journals, and other organizations

'Parent' cells reset cell division clock

Date:
May 8, 2014
Source:
Walter and Eliza Hall Institute
Summary:
A 40-year-old theory on when and how cells divide has been overturned by a study that shows that 'parent' cells program a cell division time for their offspring that is different from their own. Scientists have shown that both phases of the cell cycle contribute to the overall change in division time rather than one staying fixed in duration as previously thought. They have developed these findings into a new model that helps scientists predict how a population of cells has divided.

Professor Phil Hodgkin (L), Dr John Markham and colleagues from the institute have developed a new model of predicting how cells have divided over time.
Credit: Image courtesy of Walter and Eliza Hall Institute

Melbourne researchers have overturned a 40-year-old theory on when and how cells divide, showing that 'parent' cells program a cell division time for their offspring that is different from their own.

Scientists from the Walter and Eliza Hall Institute have shown that both phases of the cell cycle contribute to the overall change in division time rather than one staying fixed in duration as previously thought. They have developed these findings into a new model that helps scientists predict how a population of cells has divided.

Their research could impact our understanding of cell replication, such as occurs during the immune response to infection or in cancer development and progression. The study was published in the journal Proceedings of the National Academy of Sciences.

Institute scientists Professor Phil Hodgkin, Dr Mark Dowling, Dr John Markham, Dr Andrey Kan and colleagues made the discovery while studying how immune cells called B and T cells divided over time. Using time-lapse microscopy, the research group followed individual cells, observing each phase of the cell cycle as the cell divided into two new 'daughter' cells and recording how long each phase took.

The cell cycle can be broken into two phases. In the first phase, cells grow in size and make the proteins required to copy their DNA. In the second stage, the DNA is copied and final preparations are made to split the cell in half in a final stage known as mitosis. Since 1973, scientists have predicted cell division using a model that captures the overall length of the cell cycle, but does not explain how long each phase may last.

Dr Markham, who completed the research while at National Information and Communication Technologies Australia (NICTA), said the study found the time taken for each stage of the cell division cycle varied from cell to cell. "The old model of cell cycle times didn't fit our observations, so we developed a new model that more accurately predicts how a population of cells has divided," Dr Markham said.

"Imagine the cell cycle as an elastic band, representing the time a cell takes to divide. Each phase of the cell cycle is in a fixed place on the elastic band, but the band itself can stretch or shrink, effectively elongating or shortening the time taken for each phase of the cycle."

Professor Hodgkin said the study not only provided a better model for how cells divided, it also provided clues as to why there was variability in cell cycle times across a group of the same cell type. "The old model assumed the second phase of cell division took a fixed amount of time, with all the variability coming from the first phase," he said. "It used a concept called 'transition probability' to predict how a population of cells may behave, but it couldn't be applied individual cells.

"Our study revealed that when a cell divides, its two 'daughter' cells share the same division time as each other, but this time is different from their 'parent'. From this we can conclude that cell division times are programmed by the parent cell when preparing to divide, but that time is not carried across generations. While we don't yet understand exactly how it is set, this internal timing mechanism has replaced the external 'transition probability' used in the old model."

Professor Hodgkin said although the study provided a better understanding of fundamental science, it would also have practical applications, for example in investigating how immune cells responded to infections. "Our model will allow researchers to take fewer, simpler measurements to complete the picture of how B cells and T cells have divided," Professor Hodgkin said. "However more work is still needed to determine whether these mechanisms are the same in other types of cells in the body, such as cancer cells."


Story Source:

The above story is based on materials provided by Walter and Eliza Hall Institute. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. R. Dowling, A. Kan, S. Heinzel, J. H. S. Zhou, J. M. Marchingo, C. J. Wellard, J. F. Markham, P. D. Hodgkin. Stretched cell cycle model for proliferating lymphocytes. Proceedings of the National Academy of Sciences, 2014; 111 (17): 6377 DOI: 10.1073/pnas.1322420111

Cite This Page:

Walter and Eliza Hall Institute. "'Parent' cells reset cell division clock." ScienceDaily. ScienceDaily, 8 May 2014. <www.sciencedaily.com/releases/2014/05/140508095828.htm>.
Walter and Eliza Hall Institute. (2014, May 8). 'Parent' cells reset cell division clock. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2014/05/140508095828.htm
Walter and Eliza Hall Institute. "'Parent' cells reset cell division clock." ScienceDaily. www.sciencedaily.com/releases/2014/05/140508095828.htm (accessed September 22, 2014).

Share This



More Plants & Animals News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins