Tortulomyces thailandicus gen. et sp. nov. and Nitschkia siamensis sp. nov. (Coronophorales,Ascomycota) from northern Thailand

Two new species collected in northern Thailand are herein described and discussed. Tortulomyces thailandicus is the type of a new genus characterized by a combination of such features as a dense subiculum, non-ostiolate ascomata, two kinds of paraphyses (filiform and bead-like), and 1-septate, brown ascospores. Nitschkia siamensis has non-ostiolate, turbinate and stalked ascomata and hyaline, often slightly curved, 1-septate ascospores.     

Electrophysiological Heterogeneity of Fast-Spiking Interneurons: Chandelier versus Basket Cells

In the prefrontal cortex, parvalbumin-positive inhibitory neurons play a prominent role in the neural circuitry that subserves working memory, and alterations in these neurons contribute to the pathophysiology of schizophrenia. Two morphologically distinct classes of parvalbumin neurons that target the perisomatic region of pyramidal neurons, chandelier cells (ChCs) and basket cells (BCs), are generally thought to have the same “fast-spiking” phenotype, which is characterized by a short action potential and high frequency firing without adaptation. However, findings from studies in different species suggest that certain electrophysiological membrane properties might differ between these two cell classes. In this study, we assessed the physiological heterogeneity of fast-spiking interneurons as a function of two factors: species (macaque monkey vs. rat) and morphology (chandelier vs. basket). We showed previously that electrophysiological membrane properties of BCs differ between these two species. Here, for the first time, we report differences in ChCs membrane properties between monkey and rat. We also found that a number of membrane properties differentiate ChCs from BCs. Some of these differences were species-independent (e.g., fast and medium afterhyperpolarization, firing frequency, and depolarizing sag), whereas the differences in the first spike latency between ChCs and BCs were species-specific. Our findings indicate that different combinations of electrophysiological membrane properties distinguish ChCs from BCs in rodents and primates. Such electrophysiological differences between ChCs and BCs likely contribute to their distinctive roles in cortical circuitry in each species.     

The antioxidant enzymes activity in leaves of inter-varietal substitution lines of wheat (Triticum aestivum L.) with different tolerance to soil water deficit

Understanding of the genetic basis of physiological properties, which are most relevant to water-deficit tolerance would be helpful for genomic-assisted improvement of bread wheat. A set of bread wheat inter-varietal single chromosome substitution lines (ISCSLs) of variety ‘Janetzkis Probat’ (JP) in the genetic background of ‘Saratovskaya’ 29 (S29) were used to reveal the critical chromosomes in wheat genome controlling tolerance to water deficit. The same lines were involved in the identification of chromosomes associated with the activity of antioxidant enzymes that are closely related to the detoxification of H₂O₂ [catalase (CAT), ascorbate peroxidase, dehydroascorbate reductase and glutathione reductase (GR)]. The recipient cultivar S29 was highly drought tolerant while the donor JP was sensitive. Using non-metric multidimensional scaling of yield components and indices of drought tolerance/susceptibility chromosomes 2A and 4D, substitution in the genetic background of S29 was found to lead to a critical decrease of water-deficit tolerance. The drop of tolerance correlated with a sharp decline of cumulative activity of the catalase and the enzymes of ascorbate–glutathione cycle in wheat leaves. Clear evidence was obtained for the involvement of genes present on the homoeologous group 2 chromosomes in the control of GR and CAT activity. Substitution of the chromosome 4D had a significant reducing impact on the CAT activity level.     

Comparative Proteomic Analysis of Streptomyces lividans Wild-Type and ppk Mutant Strains Reveals the Importance of Storage Lipids for Antibiotic Biosynthesis

Streptomyces lividans TK24 is a strain that naturally produces antibiotics at low levels, but dramatic overproduction of antibiotics occurs upon interruption of the ppk gene. However, the role of the Ppk enzyme in relation to the regulation of antibiotic biosynthesis remains poorly understood. In order to gain a better understanding of the phenotype of the ppk mutant, the proteomes of the wild-type (wt) and ppk mutant strains, grown for 96 h on R2YE medium limited in phosphate, were analyzed. Intracellular proteins were separated on two-dimensional (2D) gels, spots were quantified, and those showing a 3-fold variation or more were identified by mass spectrometry. The expression of 12 proteins increased and that of 29 decreased in the ppk mutant strain. Our results suggested that storage lipid degradation rather than hexose catabolism was taking place in the mutant. In order to validate this hypothesis, the triacylglycerol contents of the wt and ppk mutant strains of S. lividans as well as that of Streptomyces coelicolor M145, a strain that produces antibiotics at high levels and is closely related to S. lividans, were assessed using electron microscopy and thin-layer chromatography. These studies highlighted the large difference in triacylglycerol contents of the three strains and confirmed the hypothetical link between storage lipid metabolism and antibiotic biosynthesis in Streptomyces.     

Late‐life time‐restricted feeding and exercise differentially alter healthspan in obesity

Aging and obesity increase multimorbidity and disability risk, and determining interventions for reversing healthspan decline is a critical public health priority. Exercise and time‐restricted feeding (TRF) benefit multiple health parameters when initiated in early life, but their efficacy and safety when initiated at older ages are uncertain. Here, we tested the effects of exercise versus TRF in diet‐induced obese, aged mice from 20 to 24 months of age. We characterized healthspan across key domains: body composition, physical, metabolic, and cardiovascular function, activity of daily living (ADL) behavior, and pathology. We demonstrate that both exercise and TRF improved aspects of body composition. Exercise uniquely benefited physical function, and TRF uniquely benefited metabolism, ADL behavior, and circulating indicators of liver pathology. No adverse outcomes were observed in exercised mice, but in contrast, lean mass and cardiovascular maladaptations were observed following TRF. Through a composite index of benefits and risks, we conclude the net healthspan benefits afforded by exercise are more favorable than those of TRF. Extrapolating to obese older adults, exercise is a safe and effective option for healthspan improvement, but additional comprehensive studies are warranted before recommending TRF.     

The cis-Regulatory Atlas of the Mouse Immune System

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Bioinformatical assay of human gene morbidity

Only a fraction of eukaryotic genes affect the phenotype drastically. We compared 18 parameters in 1273 human morbid genes, known to cause diseases, and in the remaining 16 580 unambiguous human genes. Morbid genes evolve more slowly, have wider phylogenetic distributions, are more similar to essential genes of Drosophila melanogaster, code for longer proteins containing more alanine and glycine and less histidine, lysine and methionine, possess larger numbers of longer introns with more accurate splicing signals and have higher and broader expressions. These differences make it possible to classify as non-morbid 34% of human genes with unknown morbidity, when only 5% of known morbid genes are incorrectly classified as non-morbid. This classification can help to identify disease-causing genes among multiple candidates.