Cell Renewal

Stem cells can both renew themselves and give rise to cells that begin differentiating into specialized types. A new study led by Whitehead Institute researchers shows how some of those descendant cells retain the ability to become stem cells again and identifies the mechanisms that help determine whether a cell self-renews, differentiates, or reverts to a stem cell state.

Whitehead Institute Member Siniša Hrvatin and colleagues  show that inducing a prolonged state of dormancy in mice slows down progressive molecular changes associated with aging. The work also identifies decreased body temperature as a central regulator of this anti-aging effect.

Our latest Research Highlights video features three exciting new findings from Whitehead Institute: New work from the Jaenisch lab helps explain bats' impressive resistance to viruses; researchers in the Young lab identify a common denominator underlying chronic disease states; and researchers in the Cheeseman lab identify precise regulatory mechanisms controlling the production of protein variants during mitosis.

Whitehead Institute Member Iain Cheeseman and colleagues found that cells not only make many variants of known proteins, but that they switch between making different variants to tailor protein function during cell division.

In order for researchers to understand the biology of living organisms, they must consider what is happening across the size scale. Interactions between molecules drive interactions between cells that affect traits and behaviors. Experiences and decisions made by the organism can lead to changes at the cellular and molecular level. In order to understand the full picture, Whitehead Institute researchers study everything from molecules to cells to whole organisms.

Whitehead Institute Member David Bartel and colleagues uncovered how small changes in the molecular machines that carry out RNA interference can lead to big differences in the efficacy of gene silencing. Their findings have implications for the design of gene-silencing therapeutics.

Whitehead Institute Director and Member Ruth Lehmann and colleagues have found that membrane-less compartments, called condensates, within germ cells not only store but also play an active role in the translation of specific mRNAs. This finding uncovers the possibility that other RNA-protein condensates can actively regulate protein production.

Whitehead Institute Member Jonathan Weissman and colleagues used large-scale systematic genetic screens to identify the molecules and pathways that populate the mitochondrial surface with important and diverse signaling proteins. They deciphered the logic by which the cell ensures the proper delivery of these proteins. These findings may have important implications for understanding the impact on health and disease when these processes go awry.

Whitehead Institute Member Jonathan Weissman and collaborators developed a tool to reconstruct the family trees and individual states of cells in humans, revealing how blood cell production changes in old age.

Whitehead Institute Member Iain Cheeseman and colleagues found that the key factor in determining the assembly location of the kinetochore—a cellular machine that helps distribute chromosomes during cell division—is the local concentration of kinetochore proteins.