Commentary: What We Know About Stemflow's Infiltration Area

[No abstract available

Residual laminin-binding activity and enhanced dystroglycan glycosylation by LARGE in novel model mice to dystroglycanopathy

Hypoglycosylation and reduced laminin-binding activity of α-dystroglycan are common characteristics of dystroglycanopathy, which is a group of congenital and limb-girdle muscular dystrophies. Fukuyama-type congenital muscular dystrophy (FCMD), caused by a mutation in the fukutin gene, is a severe form of dystroglycanopathy. A retrotransposal insertion in fukutin is seen in almost all cases of FCMD. To better understand the molecular pathogenesis of dystroglycanopathies and to explore therapeutic strategies, we generated knock-in mice carrying the retrotransposal insertion in the mouse fukutin ortholog. Knock-in mice exhibited hypoglycosylated α-dystroglycan; however, no signs of muscular dystrophy were observed. More sensitive methods detected minor levels of intact α-dystroglycan, and solid-phase assays determined laminin binding levels to be ∼50% of normal. In contrast, intact α-dystroglycan is undetectable in the dystrophic Largemyd mouse, and laminin-binding activity is markedly reduced. These data indicate that a small amount of intact α-dystroglycan is sufficient to maintain muscle cell integrity in knock-in mice, suggesting that the treatment of dystroglycanopathies might not require the full recovery of glycosylation. To examine whether glycosylation defects can be restored in vivo, we performed mouse gene transfer experiments. Transfer of fukutin into knock-in mice restored glycosylation of α-dystroglycan. In addition, transfer of LARGE produced laminin-binding forms of α-dystroglycan in both knock-in mice and the POMGnT1 mutant mouse, which is another model of dystroglycanopathy. Overall, these data suggest that even partial restoration of α-dystroglycan glycosylation and laminin-binding activity by replacing or augmenting glycosylation-related genes might effectively deter dystroglycanopathy progression and thus provide therapeutic benefits

High field effect on ultrafast pump-probe excitation of compound semiconductors

The pump–probe excitation of compound semiconductors in the presence of high electric fields is studied with a model of the non-interacting photo-excited electron–hole system theoretically. Coherent excitation of the interband polarization produces an oscillatory structure in the carrier density and the differential transmission spectrum (DTS) above the band gap. The DTS profile is altered by the effect of a high electric field on both the pump excitation and the probe excitation. Our analysis reveals that the pump excitation with relatively longer pulse (100 fs) induces the oscillatory structure in the DTS while the probe excitation with short pulse (20 fs) gives rise to a peak shift towards the lower energy side due to the field assisted generation. The oscillation period in the DTS depends on the electric field to the two-third power, which corresponds to the Franz–Keldysh oscillation

Loss of RNA-Binding Protein Sfpq Causes Long-Gene Transcriptopathy in Skeletal Muscle and Severe Muscle Mass Reduction with Metabolic Myopathy

Summary: Growing evidences are suggesting that extra-long genes in mammals are vulnerable for full-gene length transcription and dysregulation of long genes is a mechanism underlying human genetic disorders. How long-distance transcription is achieved is a fundamental question to be elucidated. In previous study, we had discovered that RNA-binding protein SFPQ preferentially binds to long pre-mRNAs and specifically regulates the cluster of neuronal genes >100 kbp. Here we investigated the roles of SFPQ for long gene expression, target specificities, and also physiological functions in skeletal muscle. Loss of Sfpq selectively downregulated genes >100 kbp including Dystrophin, which is 2.26 Mbp in length. Sfpq knockout (KO) mice showed progressive muscle mass reduction and metabolic myopathy characterized by glycogen accumulation and decreased abundance of mitochondrial oxidative phosphorylation complexes. Functional clustering analysis identified energy metabolism pathway genes as SFPQ's targets. These findings indicate target gene specificities and tissue-specific physiological functions of SFPQ in skeletal muscle. : Molecular Biology; Molecular Mechanism of Gene Regulation; Pathophysiology Subject Areas: Molecular Biology, Molecular Mechanism of Gene Regulation, Pathophysiolog

Characterization of differential throughfall drop size distributions beneath European beech and Norway spruce

Forest canopies present irregular surfaces that alter both the quantity and spatiotemporal variability of precipitation inputs. The drop size distribution (DSD) of rainfall varies with rainfall event characteristics and is altered substantially by the forest stand properties. Yet, the influence of two major European tree species, European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) H. karst), on throughfall DSD is largely unknown. In order to assess the impact of these two species with differing canopy structures on throughfall DSD, two optical disdrometers, one above and one below the canopy of each European beech and Norway spruce, measured DSD of both incident rainfall and throughfall over 2 months at a 10-s resolution. Fractions of different throughfall categories were analysed for single-precipitation events of different intensities. While penetrating the canopies, clear shifts in drop size and temporal distributions of incoming rainfall were observed. Beech and spruce, however, had different DSD, behaved differently in their effect on diameter volume percentiles as well as width of drop spectrum. The maximum drop sizes under beech were higher than under spruce. The mean ± standard deviation of the median volume drops size (D50) over all rain events was 2.7 ± 0.28 mm for beech and 0.80 ± 0.04 mm for spruce, respectively. In general, there was a high-DSD variability within events indicating varying amounts of the different throughfall fractions. These findings help to better understand the effects of different tree species on rainfall partitioning processes and small-scale variations in subcanopy rainfall inputs, thereby demonstrating the need for further research in high-resolution spatial and temporal properties of rainfall and throughfall