In Nature this week, a team from Uppsala University presents genetic data suggesting that tooth enamel may have originated in fish. While enamel is unique to vertebrates, fossils and certain primitive species of fish alive today have an enamel-like tissue called ganoine on their scales. They use genetic data to show the equivalence of enamel and ganoine and presented fossil evidence that certain fish from around 400 million years ago had enamel-coated scales but lacked the tissue on their teeth. The group suggested that enamel originated on fish scales and later extended to dermal bones and, eventually, teeth. GenomeWeb has more on this study, here.
In Nature Genetics, an international group of researchers reports the results of a genome-wide association study that revealed new genetic loci that influence blood pressure and point to the involvement of DNA methylation. By carrying out the study in more than 320,000 individuals of East Asian, European, and South Asian ancestry, the team identified 12 loci affecting blood pressure phenotypes, including ones already linked to cardiovascular and metabolic phenotypes. They also discovered that certain SNPs affecting blood pressure are associated with methylation at multiple CpHG sites and that DNA methylation is associated with blood pressure regulation. GenomeWeb also covers this study here.
And in Nature Communications, a multi-institute research group publishes a study finding similarities between gut microbiota of baleen whales, which survive on fish and crustaceans, and terrestrial herbivores, suggesting an evolutionary role for the microbes living in the guts of mammals. The investigators found that the whales' overall microbiota composition and functional capacity resembles those of land-dwelling herbivore relatives, although certain microbial metabolic pathways were more similar to terrestrial carnivores. Overall, the findings point to an interplay between genetics and environment in the composition of gut microbiota. And there's more on this one, too, at GenomeWeb.