Are phylogenetic and evolutionary patterns in microbial carotenoid biosynthesis revealed by comparative genomics?
Comparative genomics analyses of microbial carotenoid biosynthetic proteins indicate a much greater taxonomic diversity then that identified based on structural and biosynthetic data, and divides microbial carotenoid biosynthesis into several, well-supported phylogenetic lineages not evident previously. This phylogenetic framework is applicable to understanding the evolution of specific carotenoid biosynthetic proteins or the unique characteristics of carotenoid biosynthetic evolution in a specific phylogenetic lineage. Together, these analyses suggest a "bramble" model for microbial carotenoid biosynthesis whereby later biosynthetic steps exhibit greater evolutionary plasticity and reticulation compared to those closer to the biosynthetic "root". Structural diversification may be constrained ("trimmed") where selection is strong, but less so where selection is weaker. These analyses also highlight likely productive avenues for future research and bioprospecting by identifying both gaps in current knowledge and taxa which may particularly facilitate carotenoid diversification.
In our study, the circulating TGF-β1 levels were not statistically different in the fetal hydronephrosis group when compared to the controls. According to our study, TGF-β1 is not useful in the detection and follow-up of fetal hydronephrosis. We therefore require further studies involving larger groups with moderate or severe fetal hydronephrosis to detect the usefulness of the serum levels of TGF-β1 in pregnant women with fetal hydronephrosis.