The links between genotype and phenotype, along with the advances that have improved our understanding of the factors that impact the human phenotype, are discussed in four reviews appearing in Science this week. The first examines the sources of genotype-phenotype associations, and looks at the progress being made in interpreting these associations in humans. The second review discusses how translational genomics is driving precision medicine, including the development of biomarkers for diagnosis, disease monitoring, and treatment targeting. The third review highlights data linking gut microbiota and host phenotypic expression, health, and disease, while the last one focuses on the use of single-cell genomics to map human cellular phenotypes to genotypes.
A number of the genes that became inactivated as whales and dolphins transitioned from life on land to life in water millions of years ago may be responsible for allowing the cetaceans to survive in the open ocean, according to a new study in Science Advances. A team of scientists screened for protein-coding genes that were inactivated in the ancestral cetacean lineage, finding 85 gene losses. According to the investigators, a number of these gene inactivations are likely beneficial to the animals, with some reducing the risk of blood clots during deep dives and others eliminating melatonin synthesis, which may play a role in cetaceans' ability to maintain activity in one part of the brain during sleep so that they can resurface and generate heat as needed.