BackgroundAs the importance of beneficial bacteria is better recognized, understanding the dynamics of symbioses becomes increasingly crucial. In many gut symbioses, it is essential to understand whether changes in host diet play a role in the persistence of the bacterial gut community. In this study, termites were fed six dietary sources and the microbial community was monitored over a 49-day period using 16S rRNA gene sequencing. A deep backpropagation artificial neural network (ANN) was used to learn how the six different lignocellulose food sources affected the temporal composition of the hindgut microbiota of the termite as well as taxon-taxon and taxon-substrate interactions.ResultsShifts in the termite gut microbiota after diet change in each colony were observed using 16S rRNA gene sequencing and beta diversity analyses. The artificial neural network accurately predicted the relative abundances of taxa at random points in the temporal study and showed that low-abundant taxa maintain community driving correlations in the hindgut.ConclusionsThis combinatorial approach utilizing 16S rRNA gene sequencing and deep learning revealed that low-abundant bacteria that often do not belong to the core community are drivers of the termite hindgut bacterial community composition.Electronic supplementary materialThe online version of this article (10.1186/s40168-018-0469-5) contains supplementary material, which is available to authorized users.
In filamentous fungi, an important kinase responsible for adaptation to changes in available nutrients is cyclic AMP (cAMP)-dependent protein kinase (protein kinase A [PKA]). This kinase has been well characterized at a molecular level, but its systemic action and direct/indirect targets are generally not well understood in filamentous fungi. In this work, we used a pkaA deletion strain (ΔpkaA) to identify Aspergillus nidulans proteins for which phosphorylation is dependent (either directly or indirectly) on PKA. A combination of phosphoproteomic and transcriptomic analyses revealed both direct and indirect targets of PKA and provided a global perspective on its function. One of these targets was the transcription factor CreA, the main repressor responsible for carbon catabolite repression (CCR). In the ΔpkaA strain, we identified a previously unreported phosphosite in CreA, S319, which (based on motif analysis) appears to be a direct target of Stk22 kinase (AN5728). Upon replacement of CreA S319 with an alanine (i.e., phosphonull mutant), the dynamics of CreA import to the nucleus are affected. Collectively, this work provides a global overview of PKA function while also providing novel insight regarding significance of a specific PKA-mediated phosphorylation event.
IMPORTANCE The cyclic AMP (cAMP)-dependent protein kinase A (PKA) signaling pathway is well conserved across eukaryotes, and previous work has shown that it plays an important role in regulating development, growth, and virulence in a number of fungi. PKA is activated in response to extracellular nutrients and acts to regulate metabolism and growth. While a number of components in the PKA pathway have been defined in filamentous fungi, current understanding does not provide a global perspective on PKA function. Thus, this work is significant in that it comprehensively identifies proteins and functional pathways regulated by PKA in a model filamentous fungus. This information enhances our understanding of PKA action and may provide information on how to manipulate it for specific purposes.
The preemptive administration of bupivacaine before laparoscopy results in decreased postoperative pain and should allow a more rapid return to normal activities. The popular practice of infiltrating bupivacaine at time of incision closure does not offer any benefit in the control of pain after laparoscopy.
The present study investigated 1) whether extra- and intramyometrial arteries contain hCG/human LH receptor messenger ribonucleic acid (mRNA) and receptor protein, 2) whether hCG can bind to its vascular receptors and regulate the formation of vasoactive eicosanoids, and 3) whether hCG administration for ovulation induction can affect the vascular resistance in uterine arteries. The uterine arteries contain multiple hCG/LH receptor mRNA transcripts in endothelial and smooth muscle cells. The uterine arteries also contain an 80-kilodalton immunoreactive receptor protein in endothelial and smooth muscle cells. The extra- and intramyometrial arteries and an 80-kilodalton receptor protein bind [125I]hCG, which is inhibited by excess unlabeled hCG. The receptor mRNA, receptor protein, and ligand binding are higher in smaller intramyometrial arteries than in larger extramyometrial arteries. Incubation of uterine arteries with highly purified hCG resulted in a dose-dependent increase in immunoreactive cyclooxygenase-1, cyclooxygenase-2, prostacyclin synthase, and 6-keto-prostaglandin-F1 alpha and a decrease in prostaglandin-E2, thromboxane-A2 synthase, and thromboxane-B2. There was a significant decrease in the resistance index in uterine arteries, but not in common carotid arteries, by 16 h after the administration of 10,000 IU hCG for ovulation induction in women. This decrease is positively correlated with serum hCG levels, but not with progesterone or estradiol levels. In summary, these data, demonstrating the expression of functional hCG/LH receptors in human uterine arteries, are novel and may have important implications for physiological uterine blood flow regulation, reproductive failure, and obstetrical hemorrhage.
The fungal cell-wall integrity signaling (CWIS) pathway regulates cellular response to environmental stress to enable wall repair and resumption of normal growth. This complex, interconnected, pathway has been only partially characterized in filamentous fungi. To better understand the dynamic cellular response to wall perturbation, a β-glucan synthase inhibitor (micafungin) was added to a growing A. nidulans shake-flask culture. From this flask, transcriptomic and phosphoproteomic data were acquired over 10 and 120 minutes, respectively. To differentiate statistically-significant dynamic behavior from noise, a multivariate adaptive regression splines (MARS) model was applied to both data sets. Over 1800 genes were dynamically expressed and 430 phosphorylation sites had changing phosphorylation levels upon micafungin exposure. Twelve kinases had altered phosphorylation and phenotypic profiling of all non-essential kinase deletion mutants revealed putative connections between PrkA, Hk-8-4, and Stk19 and the CWIS pathway. Our collective data implicate actin regulation, endocytosis, and septum formation as critical cellular processes responding to activation of the CWIS pathway, and connections between CWIS and calcium, HOG, and SIN signaling pathways.
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