In Science this week, investigators from Nagoya University report data suggesting that it was modification, rather than loss, that resulted in modern day insects lacking wings on certain body regions. Insects today have wings exclusively on the second and third thoracic segments, yet insect fossil records show wing-like pads on other segments. Using RNA interference to silence genes responsible for specific body segment identities, the researchers found that the mealworm beetle was capable of growing wing-like structures on the first thoracic region. The findings indicate that insects did not lose their ability to grow wings in other areas of their bodies, but that modification "provided an additional diversifying mechanism of insect body plan," the researchers write.
Also in Science, a multi-institute team led by Harvard University researchers show that the accumulation of multiple mutations associated with a single gene, as opposed to a single mutation with widespread effects, are responsible for the coat colors of deer mice. When studying a gene known to influence hair color, the scientists found that a variety of genetic variants associated with light coloration were under selection, suggesting that local adaptation results from "independent selection on many mutations within a single locus, each with a specific effect on an adaptive phenotype, thereby minimizing pleiotropic consequences."
Meanwhile, in Science Translational Medicine, a group of scientists and healthcare experts write that while molecular diagnostics are expected to improve healthcare by enabling providers to optimize treatment selection, regulatory and reimbursement challenges threaten to hinder their development and integration into the healthcare system. They propose a variety of changes to existing statutory and regulatory policies and strategies that may help overcome these hurdles.