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Non-typhoidal Salmonella enterica cause an estimated 1 million cases of gastroenteritis annually in the United States. These serovars use secreted protein effectors to mimic and reprogram host cellular functions. We previously discovered that the secreted effector SarA (Salmonella anti-inflammatory response activator; also known as SteE) was required for increased intracellular replication of S. Typhimurium and production of the anti-inflammatory cytokine interleukin-10 (IL-10). SarA facilitates phosphorylation of STAT3 through a region of homology with the host cytokine receptor gp130. Here, we demonstrate that a single amino acid difference between SarA and gp130 is critical for the anti-inflammatory bias of SarA-STAT3 signaling. An isoleucine at the pY+1 position of the YxxQ motif in SarA (which binds the SH2 domain in STAT3) causes increased STAT3 phosphorylation and expression of anti-inflammatory target genes. This isoleucine, completely conserved in ~4000 Salmonella isolates, renders SarA a better substrate for tyrosine phosphorylation by GSK-3. GSK-3 is canonically a serine/threonine kinase that nonetheless undergoes tyrosine autophosphorylation at a motif that has an invariant isoleucine at the pY+1 position. Our results provide a molecular basis for how a Salmonella secreted effector achieves supraphysiological levels of STAT3 activation to control host genes during infection.
RESUMEN
Objective To assess and correlate sleep quality and depressed mood symptoms in the late pregnancy and early postpartum periods. Study Design In a prospective pilot observational study, participants completed the Pittsburgh Sleep Quality Index (PSQI) and the Edinburgh Postnatal Depression Scale (EPDS) questionnaires at delivery, 1, and 2 months postpartum. Pearson's correlation coefficients and PROC MIXED function estimated overall correlation for repeated measures. Results Twenty-six women were enrolled with a mean gestational age at delivery of 38.4 (± 2.4) weeks. Sleep quality and mood data were available at the three time points for 24, 16, and 11 participants, respectively. Poor sleep scores were noted by 75.0, 87.5, and 72.7% of women at the three time points. An elevated EPDS score of 10 or higher was claimed by 20.8, 12.5, and 18.2% of women, respectively. Higher PSQI scores were positively associated with higher EPDS scores overall ( r = 0.71, p < 0.001) and at each of the individual time points ( r = 0.79, p < 0.0001; r = 0.52, p = 0.04; and r = 0.70, p = 0.016, respectively). None of the women reporting good sleep quality had elevated EPDS scores. Conclusion Poor sleep is commonly reported around delivery, and at 1 and 2 months postpartum, and there is an association between poor sleep and depression symptoms.
RESUMEN
The North American tiger salamander species complex, including its best-known species, the Mexican axolotl, has long been a source of biological fascination. The complex exhibits a wide range of variation in developmental life history strategies, including populations and individuals that undergo metamorphosis; those able to forego metamorphosis and retain a larval, aquatic lifestyle (i.e., paedomorphosis); and those that do both. The evolution of a paedomorphic life history state is thought to lead to increased population genetic differentiation and ultimately reproductive isolation and speciation, but the degree to which it has shaped population- and species-level divergence is poorly understood. Using a large multilocus dataset from hundreds of samples across North America, we identified genetic clusters across the geographic range of the tiger salamander complex. These clusters often contain a mixture of paedomorphic and metamorphic taxa, indicating that geographic isolation has played a larger role in lineage divergence than paedomorphosis in this system. This conclusion is bolstered by geography-informed analyses indicating no effect of life history strategy on population genetic differentiation and by model-based population genetic analyses demonstrating gene flow between adjacent metamorphic and paedomorphic populations. This fine-scale genetic perspective on life history variation establishes a framework for understanding how plasticity, local adaptation, and gene flow contribute to lineage divergence. Many members of the tiger salamander complex are endangered, and the Mexican axolotl is an important model system in regenerative and biomedical research. Our results chart a course for more informed use of these taxa in experimental, ecological, and conservation research.
