Name: Multiple origins of green coloration in frogs mediated by a novel biliverdin-binding serpin
Brand: pnas.org
SKU: pnas-org-128
Availability: OnlineOnly

critic

Multiple origins of green coloration in frogs mediated by a novel biliverdin-binding serpin

preview

Edited by David M. Hillis, The University of Texas at Austin, Austin, TX, and approved June 5, 2020 (received for review April 16, 2020)This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.Green coloration of vertebrates is normally attributed to pigments and structural components inside skin chromatophores cells. However, these components do not account for the vivid blue-green colors of hundreds of species of frogs with sparse chromatophores. Our study shows that green coloration originates in proteins of the serpin superfamily that bind the pigment biliverdin, modulating its absorbance properties. Using a South American treefrog, we demonstrated that these serpins have a clear ecological role in modulating the reflectance properties and rendering animals cryptic in the foliage even in the near-infrared portion of the spectrum. These findings open up exciting research perspectives both in biochemistry and evolution of serpins, as well as in the study of extracellular protein-mediated coloration in vertebrates.Many vertebrates have distinctive blue-green bones and other tissues due to unusually high biliverdin concentrations—a phenomenon called chlorosis. Despite its prevalence, the biochemical basis, biology, and evolution of chlorosis are poorly understood. In this study, we show that the occurrence of high biliverdin in anurans (frogs and toads) has evolved multiple times during their evolutionary history, and relies on the same mechanism—the presence of a class of serpin family proteins that bind biliverdin. Using a diverse combination of techniques, we purified these serpins from several species of nonmodel treefrogs and developed a pipeline that allowed us to assemble their complete amino acid and nucleotide sequences. The described proteins, hereafter named biliverdin-binding serpins (BBS), have absorption spectra that mimic those of phytochromes and bacteriophytochromes. Our models showed that physiological concentration of BBSs fine-tune the color of the animals, providing the physiological basis for crypsis in green foliage even under near-infrared light. Additionally, we found that these BBSs are most similar to human glycoprotein alpha-1-antitrypsin, but with a remarkable functional diversification. Our results present molecular and functional evidence of recurrent evolution of chlorosis, describe a biliverdin-binding protein in vertebrates, and introduce a function for a member of the serpin superfamily, the largest and most ubiquitous group of protease inhibitors.Published under the .You may purchase access to this article. This will require you to if you don't already have one.Subscribers, for more details, please visit our .Please click to log into the PNAS submission website.Multiple origins of green coloration in frogs mediated by a novel biliverdin-binding serpinMultiple origins of green coloration in frogs mediated by a novel biliverdin-binding serpinDerek Moulton explains the mathematics behind bivalve shell design.Researchers need safe return-to-work programs coupled with an infusion of stimulus funds and appropriate testing.Image credit: Wikimedia Commons/National Institutes of Health.Image credit: Ifremer/Victor6000/Momarsat 2017.Watercourts were used to store live surplus fish in ancient Florida, a study suggests.Image credit: Zachary S. Randall (Florida Museum of Natural History, Gainesville, FL).Models to predict six life outcomes based on data collected over 15 years suggest that the use of predictive models in criminal and social systems may need to be reevaluated, along with the assumption that life trajectories can be predicted.Image credit: iStock/DNY59.

Edited by David M. Hillis, The University of Texas at Austin, Austin, TX, and approved June 5, 2020 (received for review April 16, 2020)This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.Green coloration of vertebrates is normally attributed to pigments and structural components inside skin chromatophores cells. However, these components do not account for the vivid blue-green colors of hundreds of species of frogs with sparse chromatophores. Our study shows...

Multiple origins of green coloration in frogs mediated by a novel biliverdin-binding serpin

No article scores yet.

CRITIC REVIEWS

PUBLIC REVIEWS