Precise spatiotemporal control of optogenetic activation using an acousto-optic device

Light activation and inactivation of neurons by optogenetic techniques has emerged as an important tool for studying neural circuit function. To achieve a high resolution, new methods are being developed to selectively manipulate the activity of individual neurons. Here, we report that the combination of an acousto-optic device (AOD) and single-photon laser was used to achieve rapid and precise spatiotemporal control of light stimulation at multiple points in a neural circuit with millisecond time resolution. The performance of this system in activating ChIEF expressed on HEK 293 cells as well as cultured neurons was first evaluated, and the laser stimulation patterns were optimized. Next, the spatiotemporally selective manipulation of multiple neurons was achieved in a precise manner. Finally, we demonstrated the versatility of this high-resolution method in dissecting neural circuits both in the mouse cortical slice and the Drosophila brain in vivo. Taken together, our results show that the combination of AOD-assisted laser stimulation and optogenetic tools provides a flexible solution for manipulating neuronal activity at high efficiency and with high temporal precision.     

Selection of aquatic plants for phytoremediation of heavy metal in electroplate wastewater

The remediation of heavy metal-contaminated sites using plants is a promising alternative to current methodologies. In this study, small-scale wetlands were constructed to search for new plant species that are suitable and hold potential for phytoremediation of heavy metal-contaminated wastewater originating from an electroplating plant. Ten macrophyte species [Phragmites australis (Cav.) Trin., Typha orientalis Presl, Lythrum salicaria Linn., Arundo donax Linn. var. versicolor Stokes, Typha minima Funk, Juncus effusus L., Pontederia cordata L., Cyperus alternifolius Linn. subsp. flabelliformis (Rottb.) Kükenth., Acorus calamus Linn., and Iris pseudacorus Linn.] were investigated and compared for their shapes, biomass, roots, and ability to accumulate heavy metals. Acorus calamus Linn., T. orientalis Presl, P. australis (Cav.) Trin., T. minima Funk, and L. salicaria Linn. exhibited the highest levels of metal tolerance, whereas P. cordata L., I. pseudacorus Linn., and C. alternifolius Linn. subsp. flabelliformis (Rottb.) Kükenth. had the lowest. Some plants accumulated higher concentrations of metals in the tissues compared with other species such as T. minima Funk, P. australis (Cav.) Trin., L. salicaria Linn., A. donax Linn. var. versicolor Stokes, P. cordata L., and A. calamus Linn., whereas T. orientalis Presl and C. alternifolius Linn. subsp. flabelliformis (Rottb.) Kükenth. had poor capacity to accumulate heavy metals. The results showed that, of the 10 species, P. australis (Cav.) Trin., A. calamus Linn., T. minima Funk, and L. salicaria Linn. are the most suitable and promising plant materials for phytoremediation of heavy metal-contaminated wastewater.     

Antimicrobial ergosteroids and pyrrole derivatives from halotolerant Aspergillus flocculosus PT05-1 cultured in a hypersaline medium

In order to obtain more structurally novel and bioactive lead compounds for subsequent drug discovery, we have shifted the focus of our study from traditional microbial resources to ‘extremophiles’. In this study, a halotolerant fungus Aspergillus flocculosus PT05-1 was isolated from the sediment of Putian saltern of Fujian Province of China in a hypersaline medium. Two new compounds, (22R,23S)-epoxy-3β,11α,14β,16β-tetrahydroxyergosta-5,7-dien-12-one (1) and 6-(1H-pyrrol-2-yl)hexa-1,3,5-trienyl-4-methoxy-2H-pyran-2-one (5) (existed as a pair of epimers with the configuration of 1E,3Z,5E and 1E,3E,5E separately), along with nine known compounds were isolated and identified from the fermentation broth of A. flocculosus PT05-1 grown at a 10 % saline medium. New ergosteroid 1 together with 7-nor-ergosterolide (2) and 3β-hydroxyergosta-8,24(28)-dien-7-one (3) showed cytotoxicity against HL-60 and BEL-7402 cells with IC₅₀ values of 12–18 μM, and antimicrobial activity against Enterobacter aerogenes, Pseudomonas aeruginosa, and Candida albicans with MIC values of 1.6–15 μM, respectively. New compound 5 exhibited antibacterial effect on E. aerogenes with MIC value of 3.7 μM. This study also showed great prospects in developing medicinal resources from extremophiles.     

Association of gene polymorphisms in MYH11 and TGF-β signaling with the susceptibility and clinical outcomes of DeBakey type III aortic dissection

To investigate the association of myosin heavy chain protein 11 (MYH11) and transforming growth factor β signaling-related gene polymorphisms with the susceptibility of DeBakey type III aortic dissection (AD) and its clinical outcomes. Four single-nucleotide polymorphism (SNPs) (MYH11 rs115364997, rs117593370, TGFB1 rs1800469, and TGFBR1 rs1626340) were analyzed in patients with DeBakey III AD (173) and healthy participants (335). Gene–gene and gene–environment interactions were evaluated using generalized multifactor dimensionality reduction. The patients were followed up for a median of 55.7 months. MYH11 rs115364997 G or TGFBR1 rs1626340 A carriers had an increased risk of DeBakey type III AD. MYH11, TGFB1, TGFBR1, and environment interactions contributed to the risk of DeBakey type III AD (cross-validation consistency?=?10/10, P?=?0.001). Dominant models of MYH11 rs115364997 AG?+?GG genotype (HR?=?2.443; 95%CI: 1.096–5.445, P?=?0.029), TGFB1 rs1800469 AG?+?GG (HR?=?2.303; 95%CI: 1.069–4.96, P?=?0.033) were associated with an increased risk of mortality in DeBakey type III AD. The dominant model of TGFB1 rs1800469 AG?+?GG genotype was associated with an increased risk of recurrence of chest pain in DeBakey type III AD (HR?=?1.566; 95%CI: 1.018–2.378, P?=?0.041). In conclusions, G carriers of MYH11 rs115364997 or TGFB1 rs1800469 may be the poor prognostic indicators of mortality and recurrent chest pain in DeBakey type III AD. The interactions of gene–gene and gene–environment are associated with the risk of DeBakey type III AD.

     

接种AMF对弱光环境及盐胁迫下甜瓜光合特性的影响

以甜瓜(Cucumis melo L.)品种"中蜜3号"为试材,摩西球囊霉菌(Glmous mosseae,GM)为供试菌种,采用温室盆栽试验研究了丛枝菌根真菌(Arbuscular Mycorrhizal Fungi,AMF)对弱光及盐胁迫下甜瓜幼苗叶绿素含量、光合气体交换参数、叶绿素荧光参数和光响应曲线的影响。结果表明:弱光及盐胁迫下接种AMF可显著增强甜瓜幼苗叶绿素含量、净光合速率(P_n)、光合电子传递速率(ETR)、水分利用率(WUE)和气孔限制因子(L_s);气孔导度(G_s)、蒸腾速率(T_r)、胞间CO_2浓度(C_i)则随胁迫时间延长不断增强;光化学猝灭系数(qP)与实际光化学效率(Φ_(PSⅡ))变化趋势基本一致且均显著高于未接菌处理;接种AMF显著增强了最大光化学效率(F_v/F_m),但处理之间差异不显著;并进一步提高了宿主的最大羧化速率(A_(max))、光饱和点(LSP)和表观量子效率(AQE),降低了光补偿点(LCP)和暗呼吸速率(R_d)。研究发现,AMF可通过改善叶绿素荧光、气体交换参数和光响应参数来减轻弱光及盐胁迫对植株造成的伤害,从而提高甜瓜对弱光及盐胁迫的耐性。     

Enantioselective Degradation of (2RS,3RS)‐Paclobutrazol in Peach and Mandarin Under Field Conditions

In this study we investigated the enantioselective degradation of (2RS,3RS)‐paclobutrazol in peach and mandarin fruits under field conditions after foliar treatment at 500 mg active ingredient/L using a Lux Cellulose‐1 chiral column on a reverse‐phase liquid chromatography–tandem mass spectrometry system. Degradations of paclobutrazol in both fruits followed first‐order kinetics, with half‐lives of about 9 days. Initial deposits were 1.63 mg/kg on peach and 1.99 mg/kg on mandarin; terminal concentrations were lower than 0.05 mg/kg, which was acceptable in most cases. As anticipated, paclobutrazol levels in peels of mature mandarin were about 6.3 times higher than in pulp, indicating the potential risk of peel consumption. We also observed that paclobutrazol degradation in mature mandarin was relatively slow, indicating it might not be efficient enough to hold mandarin fruits on trees for lowering paclobutrazol concentrations. Significant enantioselectivity was observed: the (2R,3R)‐enantiomer was preferentially degraded in mandarin (whole fruit, peels, and pulp) but enriched in peach. Because of its more rapid degradation in mandarin and the lower levels observed in pulp compared with peels, potential endocrine‐related side effects due to the (2R,3R)‐enantiomer pose less of a risk in mandarin than in peach. Chirality 26:400–404, 2014. © 2014 Wiley Periodicals, Inc.     

Multiplex CRISPR/Cas9‐mediated metabolic engineering increases soya bean isoflavone content and resistance to soya bean mosaic virus

Isoflavonoids, which include a variety of secondary metabolites, are derived from the phenylpropanoid pathway and are distributed predominantly in leguminous plants. These compounds play a critical role in plant–environment interactions and are beneficial to human health. Isoflavone synthase (IFS) is a key enzyme in isoflavonoid synthesis and shares a common substrate with flavanone‐3‐hydroxylase (F3H) and flavone synthase II (FNS II). In this study, CRISPR/Cas9‐mediated multiplex gene‐editing technology was employed to simultaneously target GmF3H1, GmF3H2 and GmFNSII‐1 in soya bean hairy roots and plants. Various mutation types and frequencies were observed in hairy roots. Higher mutation efficiencies were found in the T₀ transgenic plants, with a triple gene mutation efficiency of 44.44%, and these results of targeted mutagenesis were stably inherited in the progeny. Metabolomic analysis of T₀ triple‐mutants leaves revealed significant improvement in isoflavone content. Compared with the wild type, the T₃ generation homozygous triple mutants had approximately twice the leaf isoflavone content, and the soya bean mosaic virus (SMV) coat protein content was significantly reduced by one‐third after infection with strain SC7, suggesting that increased isoflavone content enhanced the leaf resistance to SMV. The isoflavone content in the seeds of T₂ triple mutants was also significantly increased. This study provides not only materials for the improvement of soya bean isoflavone content and resistance to SMV but also a simple system to generate multiplex mutations in soya bean, which may be beneficial for further breeding and metabolic engineering.