Genetics + Genomics

Having recently discovered a set of powerful gene regulators that control cell identity in a few mouse and human cell types, Whitehead Institute scientists are now showing that these regulators—which they named “super-enhancers”—act across a vast array of human cell types and are enriched in mutated regions of the genome that are closely associated with a broad spectrum of diseases.

Whitehead Institute researchers have discovered that the protein product of the gene MECP2, which is mutated in about 95% of Rett syndrome patients, is a global activator of neuronal gene expression. Mutations in the protein can cause decreased gene transcription, reduced protein synthesis, and severe defects in the AKT/mTOR signaling pathway.

Whitehead Institute researchers have used the gene regulation system CRISPR/Cas (for “clustered regularly interspaced short palindromic repeat/CRISPR-associated) to engineer mouse genomes containing reporter and conditional alleles in one step. Animals containing such sophisticated engineered alleles can now be made in a matter of weeks rather than years and could be used to model diseases and study gene function.

Painstaking new analysis of the genetic sequence of the X chromosome—long perceived as the “female” counterpart to the male-associated Y chromosome—reveals that large portions of the X have evolved to play a specialized role in sperm production.

Whitehead Institute researchers have determined that in basal breast cancer cells a transcription factor known as ZEB1 is held in a poised state, ready to increase the cells’ aggressiveness and enable them to transform into cancer stem cells capable of seeding new tumors throughout the body. Intriguingly, luminal breast cancer cells, which are associated with a much better clinical prognosis, carry this gene in a state in which it seems to be permanently shut down.

Researchers at Whitehead Institute have identified a key target protein of glucocorticoids, the drugs that are used to increase red blood cell production in patients with certain types of anemia, including those resulting from trauma, sepsis, malaria, kidney dialysis, and chemotherapy.

In a surprising finding that helps explain fundamental behaviors of normal and diseased cells, Whitehead Institute scientists have discovered a set of powerful gene regulators dubbed “super-enhancers” that control cell state and identity.