Evolutionary Patterns and Coevolutionary Consequences of MIRNA Genes and MicroRNA Targets Triggered by Multiple Mechanisms of Genomic Duplications in Soybean

The evolutionary dynamics of duplicated protein-encoding genes (PEGs) is well documented. However, the evolutionary patterns and consequences of duplicated MIRNAs and the potential influence on the evolution of their PEG targets are poorly understood. Here, we demonstrate the evolution of plant MIRNAs subsequent to a recent whole-genome duplication. Overall, the retention of MIRNA duplicates was correlated to the retention of adjacent PEG duplicates, and the retained MIRNA duplicates exhibited a higher level of interspecific preservation of orthologs than singletons, suggesting that the retention of MIRNA duplicates is related to their functional constraints and local genomic stability. Nevertheless, duplication status, rather than local genic collinearity, was the primary determinant of levels of nucleotide divergence of MIRNAs. In addition, the retention of duplicated MIRNAs appears to be associated with the retention of their corresponding duplicated PEG targets. Furthermore, we characterized the evolutionary novelty of a legume-specific microRNA (miRNA) family, which resulted from rounds of genomic duplication, and consequent dynamic evolution of its NB-LRR targets, an important gene family with primary roles in plant-pathogen interactions. Together, these observations depict evolutionary patterns and novelty of MIRNAs in the context of genomic duplication and evolutionary interplay between MIRNAs and their PEG targets mediated by miRNAs.     

Lignin‐modifying processes in the rhizosphere of arid land grasses

Genes associated with elevated oxidative enzyme activities in arid systems have not been well characterized. To link measured oxidative activities with specific enzymes, we assembled protein‐coding reads from the rhizospheres (RHZ) of two arid land grasses. Targeted gene scans for open reading frames, encoding genes potentially involved in lignin modification, resulted in 127 distinct assembly products. The putative genes included those significantly similar to Class II secretory fungal peroxidases. These genes are expressed at sufficiently high levels for assembly, annotation and differentiation across experimental conditions, and they demonstrate the interplay of root systems, environment and plant microbiomes. The genes assembled also included copper‐dependent lytic polysaccharide monooxygenases. We detail the enzymes in the host grass RHZs and present a preliminary taxonomic microhabitat characterization. Our findings provide support for biologically mediated Fenton chemistry in the root zones of desert grasses, and provide insight into arid land carbon flow. These results also demonstrate a hyperdiverse microbial community. Both ribosomal RNA and messenger RNA sequences were dominated by bacteria, followed by fungal sequence abundance. Among the notable fungal sequences were those from the members of the arbuscular mycorrhizal fungi (Glomeromycota), which though abundant in this study, we rarely observed in previous PCR‐based surveys.     

Aquatic macroinvertebrate community responses to wetland mitigation in the Greater Yellowstone Ecosystem

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Synthesis, characterization, spectroscopic and electrochemical properties of trans,trans,trans-bis(triphenyl phosphine) bis(aroyl hydrazonato)ruthenium(II) complexes

Four ruthenium (II) complexes of general formula Ru(PPh₃)₂(L)₂ have been synthesized and characterized. The spectroscopic and cyclic voltammetric studies of these complexes are also reported. X-ray crystal structure determination of two of the complexes reveal that Ru(II) occupies trans,trans,trans-(t,t,t) N₂O₂P₂ centrosymmetric octahedral environments, with the ligand pair occupying the equatorial plane. ³¹P NMR confirms the presence of two trans-PPh₃ groups in all the complexes. The transformation of the complexes in dichloromethane solution is studied by spectrophotometry and ³¹P NMR spectroscopy.     

Brain activity accompanying perception of implied motion in abstract paintings

Early 20th century artists including Duchamp and Balla tried to portray moving objects on a static canvas by superimposing objects in successive portrayals of an action. We investigated whether implied motion in those paintings is associated with activation of motion-sensitive area MT+. In Experiment 1, we found that observers rated these kinds of paintings higher in portraying motion than they did other abstract paintings in which motion is not intended. We also found that observers who had previously experienced abstract paintings with implied motion tended to give higher motion ratings to that class of paintings. In Experiment 2, we used functional magnetic resonance imaging (fMRI) to measure brain activity of observers while viewing abstract paintings receiving the highest and the lowest motion rating scores in Experiment 1. We found MT+, but not primary visual cortex (V1), showed greater BOLD responses to abstract paintings with implied motion than to abstract paintings with little motion impression, but only in observers with prior experience viewing those kinds of paintings. These results imply that the neural machinery ordinarily engaged during perception of real visual motion is activated when people view paintings explicitly designed to convey a sense of visual motion. Experience, however, is necessary to achieve this sense of motion.     

Basal muscle intracellular amino acid kinetics in women and men

Sexual dimorphism in skeletal muscle mass is apparent, with men having more muscle mass and larger individual muscle cells. However, no sex-based differences have been detected in blood forearm phenylalanine turnover, although whole body leucine oxidation has been reported to be greater in men than in women. We hypothesized that sex differences in intracellular amino acid turnover may account for these discrepancies, with men having a higher intracellular turnover than women. We studied young, healthy women (women, n = 8) and men (men, n = 10) following an overnight fast. Phenylalanine, leucine, and alanine muscle intracellular kinetics were assessed using stable isotope methodologies, femoral arteriovenous blood sampling, and muscle biopsies. Muscle intracellular amino acid kinetics were reported relative to both leg volume and lean leg mass because of sex differences in leg volume and in muscle and fat distribution. When expressed per leg volume (nmol.min(-1).100 ml leg volume(-1)), phenylalanine net balance (women: -16 +/- 4, men: -31 +/- 5), release from proteolysis in the blood (women: 46 +/- 9, men: 75 +/- 10) and intracellular availability (women: 149 +/- 23, men: 241 +/- 35), and alanine production, utilization, and intracellular availability were higher in men (P < 0.05). However, when the kinetic parameters were normalized per unit of lean leg mass, all differences disappeared. Muscle fractional synthetic rate was also not different between women and men. We conclude that there are no sex-based differences in basal muscle intracellular amino acid turnover when the data are normalized by lean mass. It remains to be determined if there are sex differences in intracellular amino acid metabolism following anabolic or catabolic stimuli.     

Use of multiple endpoints to assess the impact of captivity on gut flora diversity in Long Island Sound Fundulus heteroclitus

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