In Science this week, researchers from the University of New Mexico and Aarhus University present data showing that bird species with hemoglobin suited for high altitudes evolved this trait independently. The team analyzed genetic mutations in the hemoglobin of 28 species of birds that live in either high or low altitudes. They found that while the high-flying birds all had mutations resulting in hemoglobin with high affinity for oxygen, the molecular mechanisms underlying these mutations varied. Further, the researchers tested the effects of one such mutation — common to hummingbirds and one species of flowerpiercers — when it was introduced into the reconstructed hemoglobin of their respective ancestors and found that it had no effect. This suggests that there are other genetic differences in how the particular mutation is expressed, the researchers say.
And in Science Translational Medicine, a team from the University of Texas Southwestern Medical Center reports on the use of a high-throughput chemical screen to identify a potential new drug to specifically target colorectal cancer cells harboring a certain mutation. In testing, the compound killed cancer cells with mutations in the tumor suppressor adenomatous polyposis coli while sparing healthy and other cancer cells. Notably, about 80 percent of colorectal cancer patients have such mutations and there is currently no targeted treatments available for them.