Elevated auxin and reduced cytokinin contents in rootstocks improve their performance and grafting success

Plant grafting is an important technique for horticultural and silvicultural production. However, many rootstock plants suffer from undesirable lateral bud outgrowth, low grafting success rates or poor rooting. Here, we used a root‐predominant gene promoter (SbUGT) to drive the expression of a tryptophan‐2‐monooxygenase gene (iaaM) from Agrobacterium tumefaciens to increase auxin levels in tobacco. The transgenic plants, when used as a rootstock, displayed inhibited lateral bud outgrowth, enhanced grafting success rate and improved root initiation. However, root elongation and biomass of SbUGT::iaaM transgenic plants were reduced compared to those of wild‐type plants. In contrast, when we used this same promoter to drive CKX (a cytokinin degradation gene) expression, the transgenic tobacco plants displayed enhanced root elongation and biomass. We then made crosses between the SbUGT::CKX and SbUGT::iaaM transgenic plants. We observed that overexpression of the CKX gene neutralized the negative effects of auxin overproduction on root elongation. Also, the simultaneous expression of both the iaaM and CKX genes in rootstock did not disrupt normal growth and developmental patterns in wild‐type scions. Our results demonstrate that expression of both the iaaM and CKX genes predominantly in roots of rootstock inhibits lateral bud release from rootstock, improves grafting success rates and enhances root initiation and biomass.     

Effect of JGK-263 as a new glycogen synthase kinase-3β inhibitor on extrinsic apoptosis pathway in motor neuronal cells

Glycogen synthase kinase-3β (GSK-3β) has been identified as one of the important pathogenic mechanisms in motor neuronal death. GSK-3β inhibitor has been investigated as a modulator of apoptosis and has been shown to confer significant protective effects on cell death in neurodegenerative diseases. However, GSK-3β is known to have paradoxical effects on apoptosis subtypes, i.e., pro-apoptotic in mitochondrial-associated intrinsic apoptosis, but anti-apoptotic in death receptor-related extrinsic apoptosis. In this study, we evaluated the effect of a new GSK-3β inhibitor (JGK-263) on motor neuron cell survival and apoptosis, by using low to high doses of JGK-263 after 48 h of serum withdrawal, and monitoring changes in extrinsic apoptosis pathway components, including Fas, FasL, cleaved caspase-8, p38α, and the Fas–Daxx interaction. Cell survival peaked after treatment of serum-deprived cells with 50 μM JGK-263. The present study showed that treatment with JGK-263 reduced serum-deprivation-induced motor neuronal apoptosis by inactivating not only the intrinsic, but also the extrinsic apoptosis pathway. These results suggest that JGK-263 has a neuroprotective effect through effective modulation of the extrinsic apoptosis pathway in motor neuron degeneration.     

双眼和单眼视觉剥夺猫外膝体细胞的图形适应

为测定丘脑外膝体细胞的图形适应是否依赖于早期视觉经验,在细胞外记录了双眼和单眼缝合的猫外膝体中断细胞对手工时间运动光栅刺激的反应。在双眼剥夺猫,占６８％的记录到的细胞在３０ｓ内反应下降到稳定值,其平均反应值下降３３％,适应程度较正常猫显著。在单眼剥夺猫,记录到的剥夺眼驱动的和非剥夺眼驱动的细胞中,分别有占５３％和４４％的细胞显示图形适应,两者差别不大。研究表明,早期视剥夺能增强或保持图形适应,提示     

Circulating tumor microemboli: Progress in molecular understanding and enrichment technologies

Circulating tumor cells (CTCs) and their clusters, also known as circulating tumor microemboli (CTM), have emerged as valuable tool that can provide mechanistic insights into the tumor heterogeneity, clonal evolution, and stochastic events within the metastatic cascade. However, recent investigations have hinted that CTM may not be mere aggregates of tumor cells but cells comprising CTM exhibit distinct phenotypic and molecular characteristics in comparison to single CTCs. Moreover, in many cases CTM demonstrated higher metastatic potential and resistance to apoptosis as compared to their single cell counterparts. Thus, their evaluation and enumeration may provide a new dimension to our understanding of cancer biology and metastatic cancer spread as well as offer novel theranostic biomarkers. Most of the existing technologies for isolation of hematogenous tumor cells largely favor single CTCs, hence there is a need to devise new approaches, or re-configure the existing ones, for specific and efficient CTM isolation. Here we review existing knowledge and insights on CTM biology. Furthermore, a critical commentary on current and emerging trends in CTM enrichment and characterization along with recently developed ex-vivo CTC expansion methodologies is presented with the aim to facilitate researchers to identify further avenues of research and development.     

白杨派杂种无性系生根特性研究

通过对采用杂交育种方法选育出的白杨无性系生根性状进行研究。结果表明,新无性系在最早生根时间、主侧根总数量、主侧根总长度等指标上均存在极显著差异,说明各无性系的生根能力具有显著差异。主根平均根数和侧根平均根数两个性状的遗传方差均大于环境方差,其重复力分别可达95％和87％。进一步分析结果表明易生根的无性系根原基数量最多,平均每段插穗约14．7～7．3个．而较难生根的无性系平均每段插穗约5．5～6．8个,难生根的毛白杨根原基数量最少,平均每段插穗约3．3个。通过层次分析法(AHP)对各无性系生根特性的综合评价结果表明：9606、9603、9608、9607、9614、9610、9602等7个无性系生根能力均优于其亲本和毛白杨。     

Sensory pathways and their modulation in the control of locomotion

Recent experiments have extended our understanding of how sensory information in premotor networks controlling motor output is processed during locomotion, and at what level the efficacy of specific sensory—motor pathways is determined. Phasic presynaptic inhibition of sensory transmission combined with postsynaptic alterations of excitatory and inhibitory synaptic transmission from interneurons of the premotor networks contribute to the modulation of reflex pathways and to the generation of reflex reversal. These mechanisms play an important role in adapting the operation of central networks to external demands and thus help optimize sensory—motor integration.     

Information-Theoretic Analysis of Neural Coding

We describe an approach to analyzing single- and multiunit (ensemble) discharge patterns based on information-theoretic distance measures and on empirical theories derived from work in universal signal processing. In this approach, we quantify the difference between response patterns, whether time-varying or not, using information-theoretic distance measures. We apply these techniques to single- and multiple-unit processing of sound amplitude and sound location. These examples illustrate that neurons can simultaneously represent at least two kinds of information with different levels of fidelity. The fidelity can persist through a transient and a subsequent steady-state response, indicating that it is possible for an evolving neural code to represent information with constant fidelity.     

Lateral line scale types and review of their taxonomic distribution

The trunk canal of fishes is contained within a series of lateral line (LL) scales. To categorise LL scale structural types, and determine their distribution, an analysis of original data was undertaken using light and scanning electron microscopy in combination with a literature survey from over 1,000 species representative of most orders of bony fishes. Our categorisation of LL scales is based on the relationship between the tube, or ossified trunk canal segment, and associated scale. Tubular‐Scalar LL scales consist of a distinguishable tube and elasmoid scale in scale pockets. Four types occur only in species with elasmoid scales. Integrated LL scales do not develop in scale pockets, and their tube is enclosed or extended by a non‐elasmoid scale or spines. Integrated 1 and 2 LL scales co‐occur with ganoid and calcidermoid scales, and Integrated 3 LL scales occur when common scales are absent or elasmoid. Tubular LL scales are tubes only, occurring mainly in scaleless species or with calcidermoid and elasmoid scales. Non‐Tubular LL scales are composed only of a scale, co‐occurring mainly with cycloid scales. There is consistency of LL scale type in many orders, families and genera and the presence of different types within taxa can be meaningful.     

平均亮度对猫外膝体瞬变细胞和持续细胞时间调谐曲线的影响

用正弦波调制的光点刺激麻痹的清醒猫外膝体神经元感受野中心,当平均亮度改变时,瞬变细胞的时间频率调谐曲线的形状和敏感频率没有或很少变化,与此相应,这些细胞的自发发放也不随未调制的光照水平而改变。持续细胞的调谐曲线的调幅大体随对未调制光照的平均发放水平的升降而增大或减小,但敏感峰不变。衰减平均亮度1—2对数单位,可使多数呈双峰的调谐曲线的高调频峰消失,对产生此变化的原因,曾加以讨论。