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Abstract: Nectogaline shrews are a major component of the small mammalian fauna of Europe and Asia, and are notable for their diverse ecology, including utilization of aquatic habitats. So far, molecular phylogenetic analyses including nectogaline species have been unable to infer a well-resolved, well-supported phylogeny, thus limiting the power of comparative evolutionary and ecological analyses of the group. Here, we employ Bayesian phylogenetic analyses of eight mitochondrial and three nuclear genes to infer the phylogenetic relationships of nectogaline shrews. We subsequently use this phylogeny to assess the genetic diversity within the genus Episoriculus, and determine whether adaptation to aquatic habitats evolved independently multiple times. Moreover, we both analyze the fossil record and employ Bayesian relaxed clock divergence dating analyses of DNA to assess the impact of historical global climate change on the biogeography of Nectogalini. We infer strong support for the polyphyly of the genus Episoriculus. We also find strong evidence that the ability to heavily utilize aquatic habitats evolved independently in both Neomys and Chimarrogale + Nectogale lineages. Our Bayesian molecular divergence analysis suggests that the early history of Nectogalini is characterized by a rapid radiation at the Miocene/Pliocene boundary, thus potentially explaining the lack of resolution at the base of the tree. Finally, we find evidence that nectogalines once inhabited northern latitudes, but the global cooling and desiccating events at the Miocene/Pliocene and Pliocene/Pleistocene boundaries and Pleistocene glaciation resulted in the migration of most Nectogalini lineages to their present day southern distribution. [Copyright &y& Elsevier]

Sir2 family proteins are highly conserved and catalyze Nicotinamide Adenine Dinucleotide (NAD + )-dependent protein deacetylation reaction that regulates multiple cellular processes. Little is known about Sir2 family proteins in Giardia . In this research, Sir2 homologs of Giardia were Phylogenetically analyzed. GL50803_10707 (GlSIR2.2) showed strong homology to SIRT1 and was the only parasite SIRT1 homolog being reported to date. Recombinant GlSIR2.2 (rGlSIR2.2) was expressed and purified. The renaturied recombinant protein showed a typical NAD-dependent protein deacetylase activity that could be inhibited by nicotinamide, with IC 50 of 4.47 mM rGlSIR2.2 displayed deacetylase activity under varied NAD + , with K m , k cat and k cat /K m values of 31.71 μM, 1.4 × 10 −3 s −1 , and 4.42 × 10 −5 μM −1 s −1 . Similarly, the steady-state kinetic parameters with varied ZMAL, yielded K m , k cat and k cat /K m values of 96.89 μM, 4.7 × 10 −3 s −1 , and 4.85 × 10 −5 μM −1 s −1 . Anti-rGlSIR2.2 serum was used to probe subcellular localization of GlSIR2.2 and strong staining was found predominantly in the nucleus. So we demonstrated that GlSIR2.2 was a SIRT1-like, nuclear-located, NAD + -dependent deacetylase. This is the first report of deacetylase activity of Sir2 family protein in Giardia . [ABSTRACT FROM AUTHOR]

Highlights: [•] We develop a microfluidic device for G. lamblia culture in toxicity testing. [•] We validated G. lamblia culture in microfluidics. [•] Using the device, G. lamblia were successfully stressed on-chip. [•] Dose–response experiment can be performed in a simple and reagent-saving way. [Copyright &y& Elsevier]