Complete Plastome Sequences of Equisetum arvense and Isoetes flaccida: Implications for Phylogeny and Plastid Genome Evolution of Early Land Plant Lineages

Background Despite considerable progress in our understanding of land plant phylogeny, several nodes in the green tree of life remain poorly resolved. Furthermore, the bulk of currently available data come from only a subset of major land plant clades. Here we examine early land plant evolution using complete plastome sequences including two previously unexamined and phylogenetically critical lineages. To better understand the evolution of land plants and their plastomes, we examined aligned nucleotide sequences, indels, gene and nucleotide composition, inversions, and gene order at the boundaries of the inverted repeats. Results We present the plastome sequences of Equisetum arvense, a horsetail, and of Isoetes flaccida, a heterosporous lycophyte. Phylogenetic analysis of aligned nucleotides from 49 plastome genes from 43 taxa supported monophyly for the following clades: embryophytes (land plants), lycophytes, monilophytes (leptosporangiate ferns + Angiopteris evecta + Psilotum nudum + Equisetum arvense), and seed plants. Resolution among the four monilophyte lineages remained moderate, although nucleotide analyses suggested that P. nudum and E. arvense form a clade sister to A. evecta + leptosporangiate ferns. Results from phylogenetic analyses of nucleotides were consistent with the distribution of plastome gene rearrangements and with analysis of sequence gaps resulting from insertions and deletions (indels). We found one new indel and an inversion of a block of genes that unites the monilophytes. Conclusions Monophyly of monilophytes has been disputed on the basis of morphological and fossil evidence. In the context of a broad sampling of land plant data we find several new pieces of evidence for monilophyte monophyly. Results from this study demonstrate resolution among the four monilophytes lineages, albeit with moderate support; we posit a clade consisting of Equisetaceae and Psilotaceae that is sister to the true ferns, including Marattiaceae

Chloroplast Genome Sequence of the Moss Torula ruralis: Gene Content, Polymorphism, and Structural Arrangement Relative to Other Green Plant Chloroplast Genomes

Background Tortula ruralis, a widely distributed species in the moss family Pottiaceae, is increasingly used as a model organism for the study of desiccation tolerance and mechanisms of cellular repair. In this paper, we present the chloroplast genome sequence of T. ruralis, only the second published chloroplast genome for a moss, and the first for a vegetatively desiccation-tolerant plant. Results The Tortula chloroplast genome is ~123,500 bp, and differs in a number of ways from that of Physcomitrella patens, the first published moss chloroplast genome. For example, Tortula lacks the ~71 kb inversion found in the large single copy region of the Physcomitrella genome and other members of the Funariales. Also, the Tortula chloroplast genome lacks petN, a gene found in all known land plant plastid genomes. In addition, an unusual case of nucleotide polymorphism was discovered. Conclusions Although the chloroplast genome of Tortula ruralis differs from that of the only other sequenced moss, Physcomitrella patens, we have yet to determine the biological significance of the differences. The polymorphisms we have uncovered in the sequencing of the genome offer a rare possibility (for mosses) of the generation of DNA markers for fine-level phylogenetic studies, or to investigate individual variation within population

Cerium Oxide Nanoparticles Protect Cardiac Progenitor Cells from Oxidative Stress

Cardiac progenitor cells (CPCs) are a promising autologous source of cells for cardiac regenerative medicine. However, CPC culture in vitro requires the presence of microenvironmental conditions (a complex array of bioactive substance concentration, mechanostructural factors, and physicochemical factors) closely mimicking the natural cell surrounding in vivo, including the capability to uphold reactive oxygen species (ROS) within physiological levels in vitro. Cerium oxide nanoparticles (nanoceria) are redox-active and could represent a potent tool to control the oxidative stress in isolated CPCs. Here, we report that 24 h exposure to 5, 10, and 50 !g/mL of nanoceria did not a!ect cell growth and function in cardiac progenitor cells, while being able to protect CPCs from H2O2-induced cytotoxicity for at least 7 days, indicating that nanoceria in an e!ective antioxidant. Therefore, these "ndings con"rm the great potential of nanoceria for controlling ROS-induced cell damage

Speckle tracking evaluation in endurance athletes: the “optimal” myocardial work

To analyze left ventricular myocardial deformation and contractile reserve in endurance athletes at rest and during exercise, and their possible correlations with functional capacity. The athlete’s heart in endurance training is characterized by physiologic eccentric remodeling, with left ventricle adaptation at rest and echocardiographic parameters at low end of normality. Assessment of left ventricle systolic function and contractile reserve has an important role in the decision-making and in differential diagnosis with cardiomyopathies. Standard echo, lung ultrasound, left ventricle 2D speckle-tracking strain and myocardial work were performed at rest and during exercise in endurance athletes and in age- and sex-comparable healthy controls. 350 endurance athletes (male sex 58.5%; 31.6 ± 4.2 years) and 150 healthy controls were enrolled. Left ventricular ejection fraction at baseline was comparable between the two groups. Resting left ventricular global longitudinal strain was reduced in endurance athletes (− 18.4 ± 2.6% vs. − 22.4 ± 3.3% in controls; p < 0.01). Myocardial work efficiency did not show significative difference between the two groups. At peak exertion during exercise stress echocardiography, endurance athletes showed better exercise capacity and peak VO2 consumption (58.6 ± 10.2 ml/kg/min vs 38.6 ± 3.3 ml/kg/min in controls, p < 0.0001), associated with a preserved contractile reserve and augmented pulmonary artery systolic pressure. By multivariable analysis myocardial work efficiency at rest was closely related to maximal watts (p < 0.0001), peak VO2, (p < 0.0001), left ventricular E/eʹ (p < 0.001) and number of B-lines (p < 0.001), all measured at peak effort. Myocardial work efficiency shows less load-dependency than global longitudinal strain. Normal resting values of myocardial work efficiency in endurance athletes suggest a physiological remodeling, associated with a better exercise capacity and preserved contractile reserve during physical effort. © 2020, Springer Nature B.V

Aml1-eto collaborates with the homeobox genes meis1 and meis2 in inducing aml

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