Researchers at the National Institute of Aging and Stanford University have used gene arrays to identify genes whose activity changes with age in 16 different mouse tissues. The study, published November 30 in PLoS Genetics, uses a newly available database called AGEMAP to document the process of aging in mice at the molecular level. The work describes how aging affects different tissues in mice, and ultimately could help explain why lifespan is limited to just two years in mice.
As an organism ages, most tissues change their structure (for example, muscle tissues become weaker and have slow twitch rather than fast twitch fibers), and all tissues are subject to cellular damage that accumulates with age. Both changes in tissues and cellular damage lead to changes in gene expression, and thus probing which genes change expression in old age can lead to insights about the process of aging itself.
Previous studies have studied gene expression changes during aging in just one tissue. The new work stands out because it is much larger and more complete, including aging data for 16 different tissues and containing over 5.5 million expression measurements.
One noteworthy result is that some tissues (such as the thymus, eyes and lung) show large changes in which genes are active in old age whereas other tissues (such as liver and cerebrum) show little or none, suggesting that different tissues may degenerate to different degrees in old mice.
Another insight is that there are three distinct patterns of aging, and that tissues can be grouped according to which aging pathway they take. This result indicates that there are three different clocks for aging that may or may not change synchronously, and that an old animal may be a mixture of tissues affected by each of the different aging clocks.
Finally, the report compares aging in mice to aging in humans. Several aging pathways were found to be the same, and these could be interesting because they are relevant to human aging and can also be scientifically studied in mice.
CITATION: Zahn JM, Poosala S, Owen AB, Ingram DK, Lustig A, et al. (2007) AGEMAP: A gene expression database for aging in mice. PLoS Genet 3(11): e201. doi:10.1371/journal.pgen.0030201
CONTACT:
Dr. Stuart Kim
Stanford University Medical Center
+1-650-725-7612
kim@cmgm.stanford.edu
Disclaimer
This press release refers to an upcoming article in PLoS Genetics. The release is provided by the article authors. Any opinions expressed in this release or article are the personal views of the journal staff and/or article contributors, and do not necessarily represent the views or policies of PLoS. PLoS expressly disclaims any and all warranties and liability in connection with the information found in the releases and articles and your use of such information.
About PLoS Genetics
PLoS Genetics (http://www.plosgenetics.org) reflects the full breadth and interdisciplinary nature of genetics and genomics research by publishing outstanding original contributions in all areas of biology. All works published in PLoS Genetics are open access. Everything is immediately and freely available online throughout the world subject only to the condition that the original authorship and source are properly attributed. Copyright is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.
About the Public Library of Science
The Public Library of Science (PLoS) is a non-profit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource. For more information, visit http://www.plos.org.
PLEASE MENTION THE OPEN-ACCESS JOURNAL PLoS GENETICS (www.plosgenetics.org) AS THE SOURCE FOR THIS ARTICLE AND PROVIDE A LINK TO THE FREELY AVAILABLE TEXT. THANK YOU.
PLoS Genetics is an open-access, peer-reviewed journal published weekly by the Public Library of Science (PLoS).
Journal
PLOS Genetics