0000000000422401
AUTHOR
Christoph Hahn
Poly(ethylene glycol) with Multiple Aldehyde Functionalities Opens up a Rich and Versatile Post-Polymerization Chemistry
Two novel epoxide monomers 3,3-dimethoxy-propanyl glycidyl ether (DMPGE) and 3,3-dimethoxy-2,2-dimethylpropanyl glycidyl ether (DDPGE) were developed for the introduction of multiple aldehyde functionalities into the poly(ethylene glycol) (PEG) backbone. The acetal protecting group for the aldehyde functionality is stable against the harsh, basic conditions of the anionic ring-opening polymerization. Both monomers could be homopolymerized as well as copolymerized randomly with ethylene oxide (EO) in a controlled fashion. Copolymers with molecular weights (Mn) in the range of 4500–20100 g/mol and low dispersity (Mw/Mn) between 1.06 and 1.14 were obtained. The polymers were characterized by s…
Genomic signatures of local adaptation to the degree of environmental predictability in rotifers
AbstractEnvironmental fluctuations are ubiquitous and thus essential for the study of adaptation. Despite this, genome evolution in response to environmental fluctuations —and more specifically to the degree of environmental predictability– is still unknown. Saline lakes in the Mediterranean region are remarkably diverse in their ecological conditions, which can lead to divergent local adaptation patterns in the inhabiting aquatic organisms. The facultatively sexual rotifer Brachionus plicatilis shows diverging local adaptation in its life-history traits in relation to estimated environmental predictability in its habitats. Here, we used an integrative approach —combining environmental, phe…
Ecological genomics of adaptation to unpredictability in experimental rotifer populations
AbstractElucidating the genetic basis of phenotypic variation in response to different environments is key to understanding how populations evolve. Facultatively sexual rotifers can develop adaptive responses to fluctuating environments. In a previous evolution experiment, diapause-related traits changed rapidly in response to two selective regimes (predictable vs unpredictable) in laboratory populations of the rotifer Brachionus plicatilis. Here, we investigate the genomic basis of adaptation to environmental unpredictability in these experimental populations. We identified and genotyped genome-wide polymorphisms in 169 clones from both selective regimes after seven cycles of selection usi…