Evolution + Development

The genes that are responsible for maintaining each cell type form DNA loops that link control elements for these genes. This surprising genome structure is generated and reinforced by two essential protein complexes that bridge the loops and contribute to proper gene regulation.

Normal vertebrate brain ventricle formation relies upon the stretchiness or “relaxation” of the neuroepithelium, which is regulated by the motor protein myosin. This process was discovered in zebrafish and may play a role in the proper expansion of tubes in other organs throughout development.

The first comprehensive comparison of Y chromosomes from two species sheds new light on Y chromosome evolution.  Contrary to a widely held scientific theory that the mammalian Y chromosome is slowly decaying or stagnating, new evidence suggests that in fact the Y is actually reinventing itself through continuous, wholesale renovation.

The unique mechanism behind the evolutionary survival of the human Y chromosome may also be responsible for a range of sex disorders, from failed sperm production to sex reversal to Turner Syndrome.

In yeast, a protein-misfolding mechanism can reveal hidden genetic variations and thus generate new phenotypes that may increase cell survival. Researchers now have demonstrated that when yeast cells are stressed, this mechanism is triggered much more often.

A previously undescribed molecular mechanism for changing the shape of cell sheets is demonstrated in the embryonic brain, using the zebrafish model. This process, termed "basal constriction", is likely to occur in different structures during development in all animals.

In the first mechanistic study of how a red blood cell loses its nucleus, the research sheds light on one of the most essential steps in mammalian evolution.

In the biological battle between the sexes, the Y chromosome has suffered defeat after defeat. The male-determining chromosome has seen its gene supply shrink from more than 1,000 genes when sex chromosomes first evolved, to what scientists once thought was only a handful of genes, a downward trend predicted to continue until the Y disappeared altogether.

For decades the human Y chromosome, the male sex chromosome, has been the Rodney Dangerfield of human genetics: "it don't get no respect." For long, the Y was considered to be little more than a smaller, less stable version of the X. Now, new evidence from Dr. Page and his collaborators at the Whitehead Institute, the Massachusetts Institute of Technology, and the University of Washington reveals that the Y chromosome has led an independent existence after all.