Genetics + Genomics

The human Y chromosome has over the course of millions of years of evolution managed to preserve a small set of genes that has ensured not only its own survival but also the survival of men. Moreover, the vast majority of these tenacious genes appear to have little if any role in sex determination or sperm production. Taken together, these remarkable finding suggest that because these Y-linked genes are active across the body, they may actually be contributing to differences in disease susceptibility and severity observed between men and women.

Mitochondria, long known as “cellular power plants” for their generation of the key energy source adenosine triphosphate (ATP), are essential for proper cellular functions. Mitochondrial defects are often observed in a variety of diseases, including cancer, Alzheimer’s disease, and Parkinson’s disease, and are the hallmarks of a number of untreatable genetic mitochondrial disorders whose manifestations range from muscle weakness to organ failure. Whitehead Institute scientists have identified a protein whose inhibition could hold the key to alleviating suffering caused by such disorders.

Scientists at Whitehead Institute have pinpointed a major mitochondrial pathway that imbues cancer cells with the ability to survive in low-glucose environments. By identifying cancer cells with defects in this pathway or with impaired glucose utilization, the scientists can predict which tumors will be sensitive to these anti-diabetic drugs known to inhibit this pathway.

The most common fungal pathogen in humans, Candida albicans, rarely develops resistance to the antifungal drug amphotericin B (AmB).  This has been puzzling as the drug has been in clinical use for over 50 years. Whitehead Institute scientists have now discovered why.  The genetic mutations that enable certain strains of C. albicans to resist AmB simultaneously render it highly susceptible to environmental stressors and disarm its virulence factors.

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.