Combined Photoredox/Enzymatic C-H Benzylic Hydroxylations.

Chemical transformations that install heteroatoms into C-H bonds are of significant interest because they streamline the construction of value-added small molecules. Direct C-H oxyfunctionalization, or the one step conversion of a C-H bond to a C-O bond, could be a highly enabling transformation due to the prevalence of the resulting enantioenriched alcohols in pharmaceuticals and natural products,. Here we report a single-flask photoredox/enzymatic process for direct C-H hydroxylation that proceeds with broad reactivity, chemoselectivity and enantioselectivity. This unified strategy advances general photoredox and enzymatic catalysis synergy and enables chemoenzymatic processes for powerful and selective oxidative transformations.

Comparative Genomics Reveals Accelerated Evolution in Conserved Pathways during the Diversification of Anole Lizards.

Squamates include all lizards and snakes, and display some of the most diverse and extreme morphological adaptations among vertebrates. However, compared with birds and mammals, relatively few resources exist for comparative genomic analyses of squamates, hampering efforts to understand the molecular bases of phenotypic diversification in such a speciose clade. In particular, the ∼400 species of anole lizard represent an extensive squamate radiation. Here, we sequence and assemble the draft genomes of three anole species-Anolis frenatus, Anolis auratus, and Anolis apletophallus-for comparison with the available reference genome of Anolis carolinensis. Comparative analyses reveal a rapid background rate of molecular evolution consistent with a model of punctuated equilibrium, and strong purifying selection on functional genomic elements in anoles. We find evidence for accelerated evolution in genes involved in behavior, sensory perception, and reproduction, as well as in genes regulating limb bud development and hindlimb specification. Morphometric analyses of anole fore and hindlimbs corroborated these findings. We detect signatures of positive selection across several genes related to the development and regulation of the forebrain, hormones, and the iguanian lizard dewlap, suggesting molecular changes underlying behavioral adaptations known to reinforce species boundaries were a key component in the diversification of anole lizards.

A large-scale view of the evolution of amniote development: insights from somitogenesis in reptiles.

Uncovering the genetic and developmental changes that generate morphological diversity is one of the longstanding challenges in biology. The developmental process generating the spine, one of the defining features of vertebrates, constitutes one of these core questions. The vertebral column is patterned in early development through the formation of segments, called somites, regulated by gene networks collectively called the segmentation clock. While previous studies of somite development in amniotes have focused almost exclusively on the mouse and chick model systems, the growing availability of genomic sequences in other taxa has opened up the possibility of comparative developmental studies in nontraditional reptilian models, such as the anole lizard, alligator, and snake. These studies have identified conserved features of the segmentation clock, but they have also challenged previous assumptions and identified divergence in the genetic networks. Ongoing work will help to elucidate which of these morphological changes may be explained by divergences in development in amniote evolution.