Rapid CRISPR-Cas13a genetic identification enables new opportunities for listed Chinook salmon management.

Accurate taxonomic identification is foundational for effective species monitoring and management. When visual identifications are infeasible or inaccurate, genetic approaches provide a reliable alternative. However, these approaches are sometimes less viable (e.

Does the bowfin gas bladder represent an intermediate stage during the lung-to-gas bladder evolutionary transition?

Whether phenotypic evolution occurs gradually through time has prompted the search for intermediate forms between the ancestral and derived states of morphological features, especially when there appears to be a discontinuous origin. The gas bladder, a derived character of the Actinopteri, is a modification of lungs, which characterize the common ancestor of bony vertebrates. While gas bladders and lungs are similar in many ways, the key morphological difference between these organs is the direction of budding from the foregut during development; essentially, the gas bladder buds dorsally and the lungs bud ventrally from the foregut.

Changes in Nkx2.1, Sox2, Bmp4, and Bmp16 expression underlying the lung-to-gas bladder evolutionary transition in ray-finned fishes.

The key to understanding the evolutionary origin and modification of phenotypic traits is revealing the responsible underlying developmental genetic mechanisms. An important organismal trait of ray-finned fishes is the gas bladder, an air-filled organ that, in most fishes, functions for buoyancy control, and is homologous to the lungs of lobe-finned fishes. The critical morphological difference between lungs and gas bladders, which otherwise share many characteristics, is the general direction of budding during development.