Evolution + Development

A team of scientists from Whitehead Institute and the University of Texas Southwestern Medical Center has added markedly to the job description of prions as agents of change, identifying a prion capable of triggering a transition in yeast from its conventional single-celled form to a cooperative, multicellular structure. This change, which appears to improve yeast’s chances for survival in the face of hostile environmental conditions, is an epigenetic phenomenon—a heritable alteration brought about without any change to the organism’s underlying genome.

One enzyme, RagA, has been found to regulate the mechanistic target of rapamycin complex 1 (mTORC1) pathway in cells according to glucose and amino acid availability. When this regulation breaks down in fasting newborn mice, the animals suffer a nutritional crisis and die.

Whitehead Institute researchers have created a complete catalog of genes active in the planarian eye. Several identified genes are known to have versions that play a role in the vertebrate eye, including genes involved in eye development and others associated with age-related macular degeneration and Usher syndrome, a disorder that causes progressive retinal degradation.

A team of Whitehead Institute and MIT scientists has shown that zebrafish can be a useful tool for studying the genes that contribute to such disorders.

Despite their unassuming appearance, the planarian flatworms in Whitehead Institute Member Peter Reddien's lab are revealing powerful new insights into the biology of stem cells—insights that may eventually help such cells deliver on a promising role in regenerative medicine.

Whitehead Institute scientists report that the growing fruit fly brain instructs subperineurial glia (SPG) cells that form the blood-brain barrier to enlarge by creating multiple copies of their genomes in a process known as polyploidization.

Whitehead Institute scientists have identified conserved, long intervening non-coding RNAs (lincRNAs) that play key roles during brain development in zebrafish, and went on to show that the human versions of these RNAs can substitute for the zebrafish lincRNAs.