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Grain protein content (GPC) is an indicator of cereal nutritional quality. Identification of genes involved in the regulation of GPC provides targets for molecular breeding for crop protein quality. We characterized a maize gene encoding the putative amino acid transporter ZmAAP6, a gene expressed mainly in immature seeds, especially in the basal endosperm transfer layer. Total protein and zein contents were decreased in ZmAAP6 null mutants and increased in ZmAAP6 overexpression (OE) lines, consistent with their changed in the size of protein bodies. Metabolic and transcriptomic analysis supported the regulatory role of ZmAAP6 in amino acid transportation. These results suggest that ZmAAP6 functions as a positive regulator of GPC in maize, shedding new light on the genetic basis of GPC regulation. [ABSTRACT FROM AUTHOR]

High temperatures interfere with meiotic recombination and the subsequent progression of meiosis in plants, but few genes involved in meiotic thermotolerance have been characterized. Here, we characterize a maize (Zea mays) classic dominant male-sterile mutant Ms42, which has defects in pairing and synapsis of homologous chromosomes and DNA doublestrand break (DSB) repair. Ms42 encodes a member of the heat shock protein family, HSP101, which accumulates in pollen mother cells. Analysis of the dominant Ms42 mutant and hsp101 null mutants reveals that HSP101 functions in RADIATION SENSITIVE 51 loading, DSB repair, and subsequent meiosis. Consistent with these functions, overexpression of Hsp101 in anthers results in robust microspores with enhanced heat tolerance. These results demonstrate that HSP101 mediates thermotolerance during microsporogenesis, shedding light on the genetic basis underlying the adaptation of male meiocytes to high temperatures. [ABSTRACT FROM AUTHOR]

In view of the problem that collapse column and associated fault are generally developed which seriously affects mine safety production, this paper proposed that collapse columns and associated faults should be regarded as a geological structure consortium which was named collapse column-fault composite structure. Based on a large number of gas geological data in Lijialou Mine Field, the development causes and distribution laws of collapse column-fault composite structure were summarized in depth, and combining with field gas parameter test, the influence of composite structure on gas occurrence was explored. The results showed that the distribution of collapse column-fault composite structure in Lijialou Mine Field was controlled by regional structure. The exposed composite structure generally developed in the axis of the Yingnanfeng syncline, and its associated faults were small in scale with a fragmented upper wall. The gas occurrence around the composite structure was abnormal, and the closer it is to the composite structure, the higher the gas content and gas desorption index of drill cuttings are, and the more the composite structure controls the gas in the local area.

In the three-dimensional extracellular matrix of the insect cuticle, horizontally aligned microfibrils composed of the polysaccharide chitin and associated proteins are stacked either parallel to each other or helicoidally. The underlying molecular mechanisms that implement differential chitin organization are largely unknown. To learn more about cuticle organization, we sought to study the role of chitin deacetylases (CDA) in this process. In the body cuticle of nymphs of the migratory locust Locusta migratoria, helicoidal chitin organization is changed to an organization with unidirectional microfibril orientation when LmCDA2 expression is knocked down by RNA interference. In addition, the LmCDA2-deficient cuticle is less compact suggesting that LmCDA2 is needed for chitin packaging. Animals with reduced LmCDA2 activity die at molting, underlining that correct chitin organization is essential for survival. Interestingly, we find thatLmCDA2localizes only to the initially produced chitin microfibrils that constitute the apical site of the chitin stack. Based on our data, we hypothesize that LmCDA2- mediated chitin deacetylation at the beginning of chitin production is a decisive reaction that triggers helicoidal arrangement of subsequently assembled chitin-protein microfibrils. [ABSTRACT FROM AUTHOR]

High-resolution sampling of more than 10,000 microfossils from seven Late Permian-Middle Triassic paleoequatorial sections in south China refutes claims for a 5 m.y. recovery delay after the end-Permian mass extinction. We show that level-bottom seafloor diversity began to recover in the early Smithian, little more than 1 m.y. after the mass extinction, while recovery of reef-building metazoans began 4 m.y. later, in the Anisian. A further mass extinction in the late Smithian, identified in the pelagic fossil record, is weakly manifest as a temporary pause in diversification among benthic communities. In the Early Triassic of south China, the offshore diversity increase began before then, in shallower settings. The recovery from the end-Permian mass extinction in south China was therefore significantly more rapid and environmentally more complex than hitherto known. [ABSTRACT FROM AUTHOR]

The development of bioaffinity chromatography columns that are based on the entrapment of biomolecules within the pores of sol-gel-derived monolithic silica is reported. Monolithic nanoflow columns are formed by mixing the protein-compatible silica precursor diglycerylsilane with a buffered aqueous solution containing poly(ethylene oxide) (PEO, MW 10 000) and the protein of interest and then loading this mixture into a fused-silica capillary (150-250-μm i.d.). Spinodal decomposition of the PEO-doped sol into two distinct phases prior to the gelation of the silica results in a bimodal pore distribution that produces large macropores (>0.1 μm), to allow good flow of eluent with minimal back pressure, and mesopores (∼3-5-nm diameter) that retain a significant fraction of the entrapped protein. Addition of low levels of (3-aminopropyl)triethoxysilane is shown to minimize non-selective interactions of analytes with the column material, resulting in a column that is able to retain small molecules by virtue of theft interaction with the entrapped biomolecules. Such columns are shown to be suitable for pressure-driven liquid chromatography and can be operated at relatively high flow rates (up to 500 μL·min-1' or with low back pressures (<100 psi) when used at flow rates of 5-10 μL·min-1. The clinically relevant enzyme dihydrofolate reductase was entrapped within the bio-affinity columns and was used to screen mixtures of small molecules using frontal affinity chromatography with mass spectrometric detection. Inhibitors present in compound mixtures were retained via bioaffinity interactions, with the retention lime being dependent on both the ligand concentration and the affinity of the ligand for the protein. The results suggest that such columns may find use in high-throughput screening of compound mixtures. [ABSTRACT FROM AUTHOR]

Autophagic/lysosomal dysfunction was a critical pathogenesis of neuronal death after an ischemic stroke, but what drove the impairment of autophagic flux remained elusive. Studies indicated that histone H4 lysine 16 acetylation (H4K16ac) drastically modulated the autophagic/lysosomal signaling pathway. Herein, we investigated whether the autophagic/lysosomal dysfunction in neurons could be restored by altering H4K16ac levels after cerebral ischemia. The rat model of ischemic stroke and the cell ischemia model in HT22 neurons were prepared by middle cerebral artery occlusion (MCAO) and oxygen-glucose deprivation (OGD), respectively. The result showed that H4K16ac could be effectively reduced by intracerebroventricular administration with MG149 (a H4K16ac inhibitor) after an ischemic stroke. Moreover, attenuated H4K16ac greatly alleviated the autophagic/lysosomal dysfunction in penumbral neurons, as indicated by decreased autophagic substrates of LC3-II, insoluble SQSTM1, and ubiquitinated proteins, accompanied by increased lysosomal cathepsin D. Conversely, treatment with trichostatin A (TSA, a H4K16ac facilitator) aggravated the impairment of autophagic flux. This regulative machinery of H4K16ac on the autophagic/lysosomal signaling pathway was also manifested in the OGD model of HT22 neurons. Furthermore, H4K16ac attenuation-ameliorated autophagic flux significantly alleviated stroke brain injury, as reflected by decreased infarct size, neuron loss, and neurological deficits. Similarly, the H4K16ac inhibition-mitigated autophagic/lysosomal dysfunction markedly promoted neuron survival and cell viability in OGD HT22 neurons. However, H4K16ac downregulation-ameliorated autophagic flux in neurons and thereby induced neuroprotection could be greatly counteracted by the lysosomal inhibitor bafilomycin A1 (Baf-A1). Our data indicate that cerebral ischemia-elevated H4K16ac creates the autophagic/lysosomal dysfunction due to lysosomal inefficiency, suggesting that H4K16ac attenuation benefits poststroke neuroprotection by resuming lysosomal functions in neurons.

Objectives: Ginkgo biloba leaf extract (EGb-761) injection has been widely used as adjuvant therapy for cerebral stroke in China. However, its underlying pharmacological mechanism is not completely understood. The present study aimed to investigate whether the therapeutic effects of EGb-761 are exerted by modulating autophagy flux., Materials and Methods: Ischemic cerebral stroke was prepared in male Sprague-Dawley rats by middle cerebral artery occlusion (MCAO) followed by reperfusion. The MCAO/reperfusion rats were then treated with EGb-761 injection once daily for 7 days. Thereafter, the brain tissues in the ischemic penumbra were obtained to detect the key proteins in the autophagic/lysosomal pathway with Beclin1, LC3, (SQSTM1)/p62, ubiquitin, LAMP-1, cathepsin B, and cathepsin D antibodies by western blot and immunofluorescence. Meanwhile, the infarct volume, neurological deficits, and neuronal apoptosis were assessed to evaluate the therapeutic outcomes., Results: The results illustrated that EGb-761 treatment was not only able to promote the autophagic activities of Beclin1 and LC3-II in neurons, but also could enhance the autophagic clearance, as indicated by reinforced lysosomal activities of LAMP-1, cathepsin B, and cathepsin D, as well as alleviating autophagic accumulation of ubiquitin and insoluble p62 in the MCAO+EGb-761 group, compared with those in the MCAO+saline group. Meanwhile, cerebral ischemia-induced neurological deficits, infarct volume, and neuronal apoptosis were significantly attenuated by 7 days of EGb-761 therapy., Conclusion: Our data suggest that EGb-761 injection can elicit a neuroprotective efficacy against MCAO/reperfusion injury, and this neuroprotection may be exerted by enhancement of autophagy flux in neurons in the ischemic penumbra., Competing Interests: The authors declare that they have no conflicts of interest.