In this week's Science, a multi-institute team of scientists reports a genomic study of pigmentation, providing details about the evolution of the range of skin tones found among humans. The researchers sequenced the genomes of more than 2,000 Africans living in Ethiopia, Tanzania, and Botswana, pinpointing a number of variants significantly associated with skin pigmentation. One, near the SCL24A5 gene locus, appears to have been introduced into East Africa by gene flow from non-Africans. Other variants associated with dark pigmentation in Africans were found to be identical by descent in southern Asian and Australo-Melanesian populations. The authors say that additional research in larger numbers of ethnically diverse Africans is needed to gain deeper insight into the evolutionary history and adaptive significance of skin pigmentation in humans. GenomeWeb has more on this study, here.
And in Science Translational Medicine, a group of investigators from industry and academia describe adapting two gene-editing platforms to treat severe combined immunodeficiency — a condition characterized by improper immune cell maturation — in a mouse model. The team created the model by introducing the mutant gene responsible for SCID, called IL2RG, then optimized CRISPR-Cas9 and zinc-finger nuclease genome-editing protocols to introduce functional copies of IL2RG into blood stem cells. By transplanting the cells into the mice, the scientists were able to repopulate T and B cells in the animals, enabling antiviral responses. The work, the researchers write, provides a framework for developing gene correction for SCID and other diseases.