Excessive Branching Research Articles

Pathological oligodendrocyte precursor cells revealed in human schizophrenic brains and trigger schizophrenia-like behaviors and synaptic defects in genetic animal model

Although the link of white matter to pathophysiology of schizophrenia is documented, loss of myelin is not detected in patients at the early stages of the disease, suggesting that pathological evolution of schizophrenia may occur before significant myelin loss. Disrupted-in-schizophrenia-1 (DISC1) protein is highly expressed in oligodendrocyte precursor cells (OPCs) and regulates their maturation. Recently, DISC1-Δ3, a major DISC1 variant that lacks exon 3, has been identified in schizophrenia patients, although its pathological significance remains unknown. In this study, we detected in schizophrenia patients a previously unidentified pathological phenotype of OPCs exhibiting excessive branching. We replicated this phenotype by generating a mouse strain expressing DISC1-Δ3 gene in OPCs. We further demonstrated that pathological OPCs, rather than myelin defects, drive the onset of schizophrenic phenotype by hyperactivating OPCs’ Wnt/β-catenin pathway, which consequently upregulates Wnt Inhibitory Factor 1 (Wif1), leading to the aberrant synaptic formation and neuronal activity. Suppressing Wif1 in OPCs rescues synaptic loss and behavioral disorders in DISC1-Δ3 mice. Our findings reveal the pathogenetic role of OPC-specific DISC1-Δ3 variant in the onset of schizophrenia and highlight the therapeutic potential of Wif1 as an alternative target for the treatment of this disease.

Investigation of LED Light Qualities for Peppermint (Mentha x Piperita L.) Cultivation Focusing on Plant Quality and Consumer Safety Aspects

To understand how peppermint responds to different LED light qualities during the early vegetative phase, peppermints were illuminated with three different LED light conditions (RB = Red/Blue, RGB = Red/Green/Blue, SUN = artificial sunlight closely resembling the terrestrial sunlight spectrum between 380 and 780 nm) in an automated vertical cultivation system. RB resulted in compact growth, whereas both green-containing lighting conditions induced excessive stem and side branch elongations and significant leaf expansions. Although peppermint plants achieved marketable appearances regardless of lighting condition, essential oil (EO) compositions with highly elevated amounts of pulegone and menthofuran did not meet consumer safety requirements. Both artificial SUN and RB spectra showed lower concentrations of pulegone in the EO at 41 and 43%, respectively, than detected under RGB at more than 49%. Reasons for this undesirable EO composition are discussed as a result of the lighting conditions applied and the early harvest time, leading to an incomplete reduction of pulegone to menthone during biosynthesis. Based on these findings, aromatic peppermint cultivation under LEDs can be improved to meet regulatory requirements and highlights the need for analytical quality controls regarding consumer safety to evaluate the applicability of LED lighting for fresh herb productions.

Multi-Label Classification Using Binary Tree of Classifiers

This article proposes a binary tree of classifiers for multi-label classification that preserves label dependencies and handles class imbalance. At each node, the input data is strategically split into two subsets for its subsequent child nodes, keeping the label correlations intact. A novel approach of partitioning the data based on label-set proximity has also been proposed. Various data appropriate classifiers are trained to learn the binary partition at every internal node. The tree of classifiers grows iteratively depending on two parameters – multi-label entropy and sample cardinality, computed on the data at the current node. During training, the decision at any node is based on these parameters and the branching out is restricted, if deemed unnecessary. Specific classifiers at the leaf nodes perform the final classification task and assign appropriate label-sets to the unlabelled data. The proposed system aims to appropriately split the data and build the hierarchical structure such that the training and classification tasks become simpler. Also, the problem of class imbalance leads to the irregular splitting of data and excessive branching out of the tree which is handled through the novel use of suitable classifiers and parameters at the intermediate and leaf nodes. The proposed method has shown significant performance improvement on fourteen datasets against fourteen existing multi-label classifiers. Two-tailed Wilcoxon signed rank test statistics show that for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$T_{Wilcoxon}(14,0.2)=31$</tex-math></inline-formula> the proposed method outperforms all the other comparison models.

TUBA1A tubulinopathy mutants disrupt neuron morphogenesis and override XMAP215/Stu2 regulation of microtubule dynamics.

Heterozygous, missense mutations in α- or β-tubulin genes are associated with a wide range of human brain malformations, known as tubulinopathies. We seek to understand whether a mutation's impact at the molecular and cellular levels scale with the severity of brain malformation. Here, we focus on two mutations at the valine 409 residue of TUBA1A, V409I, and V409A, identified in patients with pachygyria or lissencephaly, respectively. We find that ectopic expression of TUBA1A-V409I/A mutants disrupt neuronal migration in mice and promote excessive neurite branching and a decrease in the number of neurite retraction events in primary rat neuronal cultures. These neuronal phenotypes are accompanied by increased microtubule acetylation and polymerization rates. To determine the molecular mechanisms, we modeled the V409I/A mutants in budding yeast and found that they promote intrinsically faster microtubule polymerization rates in cells and in reconstitution experiments with purified tubulin. In addition, V409I/A mutants decrease the recruitment of XMAP215/Stu2 to plus ends in budding yeast and ablate tubulin binding to TOG (tumor overexpressed gene) domains. In each assay tested, the TUBA1A-V409I mutant exhibits an intermediate phenotype between wild type and the more severe TUBA1A-V409A, reflecting the severity observed in brain malformations. Together, our data support a model in which the V409I/A mutations disrupt microtubule regulation typically conferred by XMAP215 proteins during neuronal morphogenesis and migration, and this impact on tubulin activity at the molecular level scales with the impact at the cellular and tissue levels.

Increased branching independent of strigolactone in cytokinin oxidase 2-overexpressing tomato is mediated by reduced auxin transport

Tomato production is influenced by shoot branching, which is controlled by different hormones. Here we produced tomato plants overexpressing the cytokinin-deactivating gene CYTOKININ OXYDASE 2 (CKX2). CKX2-overexpressing (CKX2-OE) plants showed an excessive growth of axillary shoots, the opposite phenotype expected for plants with reduced cytokinin content, as evidenced by LC-MS analysis and ARR5-GUS staining. The TCP transcription factor SlBRC1b was downregulated in the axillary buds of CKX2-OE and its excessive branching was dependent on a functional version of the GRAS-family gene LATERAL SUPPRESSOR (LS). Grafting experiments indicated that increased branching in CKX2-OE plants is unlikely to be mediated by root-derived signals. Crossing CKX2-OE plants with transgenic antisense plants for the strigolactone biosynthesis gene CAROTENOID CLEAVAGE DIOXYGENASE (CCD7-AS) produced an additive phenotype, indicating independent effects of cytokinin and strigolactones on increased branching. On the other hand, CKX2-OE plants showed reduced polar auxin transport and their bud outgrowth was reduced when combined with auxin mutants. Accordingly, CKX2-OE basal buds did not respond to auxin applied in the decapitated apex. Our results suggest that tomato shoot branching depends on a fine-tuning of different hormonal balances and that perturbations in the auxin status could compensate for the reduced cytokinin levels in CKX2-OE plants.

Fungal endophytes in Fraxinus excelsior petioles and their in vitro antagonistic potential against the ash dieback pathogen Hymenoscyphus fraxineus.

Fungal endophytes were isolated from 250 asymptomatic leaf petioles of Fraxinus excelsior collected from trees showing symptoms of ash dieback in five forest sites in southern Poland. Fungal isolations yielded 1646 colonies representing 97 taxa, including 92 Ascomycota and 5 Basidiomycota species. The most common Ascomycota comprised Nemania serpens (38.0 % of colonized petioles), Diaporthe eres (33.6 %), Venturia fraxini (26.4 %), Diaporthe sp. 1 (20.4 %), Alternaria sp. 1 (14.8 %), Colletotrichum acutatum (14.8 %), Nemania diffusa (14.0 %), Colletotrichum gloeosporioides (12.4 %) and Colletotrichum sp. (12.4 %). The occurrence of all these taxa except Alternaria sp. 1 was significantly different between the studied forest sites. Two yeast species, Vishniacozyma foliicola (4.8 %) and Cystobasidium pinicola (2.8 %), dominated among the Basidiomycota endophytes detected. All the fungal endophytes were tested in dual culture antagonistic assays against two strains of Hymenoscyphus fraxineus, resulting in the development of four interaction types. The interactions included the physical contact of co-partners' mycelia (41.8 %), development of an inhibition zone (47.4 %), growth of endophyte mycelia over H. fraxineus colonies (9.3 %) and growth of H. fraxineus mycelia over endophyte colonies (1.5 %). The strongest antibiotic activity against H. fraxineus, measured by the width of the inhibition zone, was observed for Cytospora pruinosa, Fusarium lateritium, Phoma sp. 2, Pleosporales sp. 2 and Thielavia basicola. A variety of morphophysiological deformations of H. fraxineus hyphae were observed under endophyte pressure: spiral twist of the hyphae, formation of cytoplasmic extrusions, development of torulose hyphae and excessive lateral branching of the hyphae. The strongest antagonistic effects, coupled with the potential to overgrow H. fraxineus colonies, was shown by Clonostachys rosea, Nemania diffusa, N. serpens, Peniophora cinerea, Rosellinia corticium and Xylaria polymorpha. Some of these species were able to attack H. fraxineus hyphae in a mycoparasitic manner. The antagonistic activities included the physical penetration of H. fraxineus hyphae, dissolution of hyphal cell walls, disappearance of pigmentation, disintegration of hyphae and degradation of other fungal structures. In contrast, one of the most commonly detected endophytes in ash leaves, Venturia fraxini, did not show in vitro antagonistic potential against H. fraxineus. Finally, we discuss the potential of the detected fungal endophytes to combat H. fraxineus invasion, the cause of ash decline in Europe.

Primary Mode of Action of the Novel Sulfonamide Fungicide against Botrytis cinerea and Field Control Effect on Tomato Gray Mold.

Botrytis cinerea is considered an important plant pathogen and is responsible for significant crop yield losses. With the frequent application of commercial fungicides, B. cinerea has developed resistance to many frequently used fungicides. Therefore, it is necessary to develop new kinds of fungicides with high activity and new modes of action to solve the increasingly serious problem of resistance. During our screening of fungicide candidates, one novel sulfonamide compound, N-(2-trifluoromethyl-4-chlorphenyl)-2-oxocyclohexyl sulfonamide (L13), has been found to exhibit good fungicidal activity against B. cinerea. In this work, the mode of action of L13 against B. cinerea and the field control effect on tomato gray mold was studied. L13 had good control against B. cinerea resistant to carbendazim, diethofencarb, and iprodione commercial fungicides in the pot culture experiments. SEM and TEM observations revealed that L13 could cause obvious morphological and cytological changes to B. cinerea, including excessive branching, irregular ramification or abnormal configuration, and the decomposition of cell wall and vacuole. L13 induced more significant electrolyte leakage from hyphae than procymidone as a positive control. L13 had only a minor effect on the oxygen consumption of intact mycelia, with 2.15% inhibition at 50 μg/mL. In two locations over 2 years, the field control effect of L13 against tomato gray mold reached 83% at a rate of 450 g ai ha−1, better than the commercial fungicide of iprodione. Moreover, toxicological tests demonstrated the low toxicological effect of L13. This research seeks to provide technical support and theoretical guidance for L13 to become a real commercial fungicide.

Perspective on automated in vivo drug screening using the chodl mutant zebrafish line.

Perspective on automated in vivo drug screening using the chodl mutant zebrafish line.

Citrus Huanglongbing (HLB) and the Brazilian Efforts to Overcome the Disease

Recorded in Brazil since 2004, Huanglongbing (HLB), or simply Greening, is the most impacting disease in citrus production worldwide. It induces qualitative and quantitative losses in production, but also can be lethal to the infected citrus plant. The disease is caused by phloem-limited bacteria with three identified species, Candidatus Liberibacter asiaticus (CLas), Ca. L. africanus (CLaf), and Ca. L. americanus (CLam). CLas and CLam are reported in Brazil, being vectored by the Asian citrus psyllid Diaphorina citri. HLB-infected citrus exhibit blotchy mottling with green islands on leaves, and small and lopsided fruits. As the infection progresses, excessive fruit drop and dead branches are frequently observed, shortening the trees' lifespan and reducing fruit yield and quality. HLB occurrence is restricted to the States of São Paulo, Minas Gerais, Mato Grosso do Sul and Paraná, which corresponds to more than 85% of citrus production in Brazil. Although citrus production is concentrated in these states, commercial citrus groves are present in 85% of the microregions of Brazil, reinforcing the economic and social importance of citrus for the country. Thus, in addition to the economic damage already caused to the national citrus industry, the spread of HLB to other regions of Brazil represents a great risk to the economic and food security of these non-affected regions. For this reason, the management of HLB is supported by legislative force, both at the federal and state levels. In 2008, based on scientific knowledge at the time, the Brazilian Ministry of Agriculture published a Normative Instruction 53 (IN53) which established criteria related to HLB surveillance and control, imposing the obligation to carry out periodic phytosanitary inspections, eradication of symptomatic hosts and planting HLB-free nursery trees. The implementation of IN53 has already resulted in the eradication of 55.5 million HLB-infected citrus plants in the State of São Paulo alone in the period from 2007 to 2019. In May 2021, IN53 was revoked and Portaria 317 was published. This new policy establishes the National Programme for HLB Prevention and Control. It addresses the problem according to the HLB status in each State, with or without the disease, and sets the general guidelines for local control actions.&lt;br/&gt; In view of the economic importance and complexity of this pathosystem, the disease has required concerted mobilization of the research community and inter-institutional cooperation, which has been working intensively to understand all the components directly and indirectly involved with the pathosystem. Also, a major cooperation effort is needed to gather all the information to develop and/or improve technologies and cultural practices to fight the disease better and reduce its impacts as much as possible. Here we present some of these efforts which are being carried out to develop short, medium and long term solutions for HLB control and management in areas of occurrence, as well as for surveillance and risk mitigation in non-affected areas.

Unique Path Method of the Pinch-Out Profile Based on Unified Stratigraphic Sequence

Pinch-outs refers to the gradual thinning of the thickness of the sedimentary layer laterally until there is no deposition and are a major topic of modern research on the automated drawing of geological profiles. The rapid development of smart geological systems imposed an urgent need for high-speed, accurate methods to plot pinch-outs. However, because of their complexity, excessive number of branch paths, low rendering speed, and poor reliability in the case of large-scale data, the existing pinch-out drawing methods are inadequate and cannot satisfy the modeling needs of large-scale geological projects. To resolve these problems, based on unified stratigraphic sequences, this paper proposes a unique path method for drawing pinch-out profiles by converting the principle of plotting of pinch-outs into controlling the appearance of stratigraphic boundaries, and a high-speed and reliable method for drawing pinch-out in digital profiles is also proposed. The proposed method is successfully applied to drawing geological profiles for an urban geological project in East China, and greatly reduces the complexity of the method without reducing the drawing accuracy. Compared with those of other methods, the speed and reliability are significantly improved. Therefore, the unique path method for drawing pinch-out profiles based on a unified stratigraphic sequence proposed in the writers’ previous paper effectively avoids the excessive branch paths, slow speed, and insufficient reliability of the existing methods and provides effective and reliable support for the rapid drawing of profiles in smart geological systems.

Screen Oilseed Rape (Brassica napus) Suitable for Low-Loss Mechanized Harvesting

The main reason for the massive loss of rapeseed in mechanized harvesting is the mismatch between the harvester requirements and the pod shatter resistance and plant branching characteristics. Low pod resistance, entanglement caused by excessive branches, and inconsistent pod maturity are primary mismatch problems. However, studies on rape characteristics by integrating agricultural machinery and agronomy are limited. A total of 15 varieties were planted for research from 2016 to 2018. In this paper, the Two-Degree-of-Freedom (2-DOF) collision method was adopted to evaluate the pod shatter resistance taken from the field, and the plant agronomic characteristics and their correlation were investigated. In 2020, a screened variety of C6009 with higher shatter resistance and suitable plant features for mechanized harvesting was planted in large areas and harvested by machines for verification. The test results demonstrated that the compact plant varieties with high branches might be more favorable for yield and shatter resistance. The field harvest loss of the screened variety was significantly less than that of the control group. It provides a reliable reference for agronomic experts in terms of rape variety improvement and agricultural machinery experts regarding the optimization of rape harvesters.

R-Ras Deficiency in Pericytes Causes Frequent Microphthalmia and Perturbs Retinal Vascular Development

Purpose: The retinal vasculature is heavily invested by pericytes. Small GTPase R-Ras is highly expressed in endothelial cells and pericytes, suggesting importance of this Ras homolog for the regulation of the blood vessel wall. We investigated the specific contribution of pericyte-expressed R-Ras to the development of the retinal vasculature. Methods: The effect of R-Ras deficiency in pericytes was analyzed in pericyte-targeted conditional Rras knockout mice at birth and during the capillary plexus formation in the neonatal retina. Results: The offspring of these mice frequently exhibited unilateral microphthalmia. Analyses of the developing retinal vasculature in the eyes without microphthalmia revealed excessive endothelial cell proliferation, sprouting, and branching of the capillary plexus in these animals. These vessels were structurally defective with diminished pericyte coverage and basement membrane formation. Furthermore, these vessels showed reduced VE-cadherin staining and significantly elevated plasma leakage indicating the breakdown of the blood-retinal barrier. This defect was associated with considerable macrophage infiltration in the retina. Conclusions: The normal retinal vascular development is dependent on R-Ras expression in pericytes, and the absence of it leads to unattenuated angiogenesis and significantly weakens the blood-retinal barrier. Our findings underscore the importance of R-Ras for pericyte function during the normal eye development.

First report of a Jujube witches’‐broom phytoplasma (16SrV) strain associated with witches’‐broom and little leaf disease of Solanum melongena in India

Solanum melongena (aubergine or brinjal; family Solanaceae) is a popular vegetable grown extensively in India, Bangladesh, Pakistan, China, Japan, Philippines, Egypt, France, Italy, and the United States (Chadha et al., 1993). Brinjal's cultivation is hampered by the Brinjal little leaf (BLL) phytoplasma. A phytoplasma survey was conducted in various brinjal production areas of Hoshangabad in Central India (Figure 1) during May 2019. Phytoplasma-like symptoms such as proliferation of axillary shoots, witches’- broom, excessive branching, little leaf and the absence of flowers and fruits when compared to symptomless brinjal plants were observed (Figure 2). For molecular detection of phytoplasma, total DNA was isolated from diseased and symptomless leaf samples (100 mg). The phytoplasma 16S rRNA gene was amplified by direct PCR using P1/P6 primers (Deng & Hiruki, 1991) and nested PCR with universal primers R16F2n/R16R2 (Gundersen & Lee, 1996), producing amplicons of the expected size (c. 1.2 kb) for the diseased (4/4) samples but not from the symptomless plant tested. Two nested PCR amplicons were purified (Wizard SV gel extraction kit; Promega, USA) and sequenced bidirectionally (Bioinovations Pvt. Ltd., India). The consensus partial 16S rRNA gene sequences were identical and the sequence data was submitted to GenBank, Accession Nos. MW025971 (BR01) and MW025257 (BR02). BLASTn analysis showed that the sequence shared 99% sequence identity with the 16S rRNA gene sequence of Jujube witches'-broom phytoplasma (MH972556, MH972553, MH972548) and ‘Candidatus Phytoplama balanitae’ (HG937644, LT558785, MH819290), Periwinkle yellows phytoplasma (EU375835) and the Elm yellows group (16SrV). Phylogenetic analysis (MEGA v 7.1) showed the closest relationships with strains of Jujube witches'-broom phytoplasma (MH972556, H744152 and MH972548) and ‘Ca. P. balanitae’ (LT558785), a member the group 16SrV, ‘Ca. P. ulmi’ (Figure 3). Six phytoplasma ribosomal groups (16SrI, 16SrII, 16SrIII, 16SrVI, 16SrIX, 16SrXII) have been associated with S. melongena globally. BLL phytoplasmas were first reported in India in 1995 (Schneider et al., 1995). In India and Japan, a BLL phytoplasma was identified as a member of the group 16SrI, ‘Ca. P. asteris’ (Kumar et al., 2012). The group 16SrVI, ‘Ca. Phytoplasma trifolii’ was also associated with BLL symptoms in India (Yadav et al., 2015). However, this is the first report of a ‘Ca. P. ulmi’ strain (group 16SrV), associated with a witches'-broom disease of brinjal in India. This finding has a significant impact for future epidemiological studies since brinjal could be an alternative host for 16SrV phytoplasma strain which affect several other important vegetable crops cultivated in Hoshangabad, Central India. The authors would like to thank to the Head of the Department of Microbiology and Vice Chancellor, Barkatullah University, Bhopal for support and encouragement.

Control of grey mould disease on strawberry using the effective agent, Bacillus amyloliquefaciens Y1

ABSTRACT This study was conducted to investigate the effect of Bacillus amyloliquefaciens Y1 on the control of grey mould disease caused by Botrytis cinerea and subsequent growth promotion of strawberry. Strain Y1 strongly inhibited mycelial growth of B. cinerea on different media with the highest inhibition of 61.22% on V8 juice agar medium. The higher the bacterial culture filtrate (BCF) concentration of strain Y1 blended in the PDA medium, the stronger the rate of inhibition on mycelial growth of B. cinerea. Microscopic observation revealed that the hyphal structure of the fungal pathogen was severely affected by the BCF indicating abnormal growth with excessive branching and swelling. Strain Y1 showed the promising ability to suppress grey mould disease under in vivo conditions and significantly lessened disease severity on flowers and fruits leading to an increase in disease control value when compared to fungicide treatment. Moreover, application of strain Y1 resulted in a significant promotion of strawberry plants with higher values in most growth characteristics compared to other treatments. The detection of higher levels of the defence-related enzyme, β-1,3-glucanase in the Y1-treated plants indicated that induction of resistance by this strain was at least partly involved in disease suppression. Even though there were reductions in the overall numbers of the soil bacterial population in the Y1-treated plants, no significant impact on the growth of strawberry was observed. Based on our results, strain Y1 is a promising candidate for environment-friendly disease control strategies.

Relationship between crack length, wedge-shaped cutter geometry, and salt rocks viscosity in a cross-cutting scheme

Introduction. Existing publications lack studies on the relationship between salt rocks physical properties, cutters geometry, cutting force, and intergranular fracture of rock under the cutter. By analyzing the system of cracks formed by the cutters between the cutting lines, it is possible to estimate the effi ciency of fracture and design the nature and conditions of cutting. Research aim is to obtain an analytical dependence that links cracks size, cutter geometry, and salt rocks crack resistance; calculate the cutting force; experimentally determine sylvine, halite and carnallite fracture toughness coeffi cients necessary for the calculation. And fi nally, based on the obtained data, the research aimed to build 3D graphs of crack length dependence on cutter geometry for a cross-cutting scheme. Methodology. Sylvine, halite and carnallite crack resistance coeffi cients were obtained by indentation. The coeffi cient values were used in the formula for calculating the size of cracks between the cutting lines in these rocks. The formula was corrected after D6.22 cutter indentation test in salt rocks. Light microscopy technique was used to study fl uid inclusions in salt rocks. Results. Analytical dependence, values of crack resistance coeffi cients were obtained. 3D graphs for halite, sylvine and carnallite were constructed for the cross-cutting scheme. The type, size and concentration of fl uid inclusions along the grain boundaries are given that accelerate intergranular fracture under the cutter. Conclusions. The resulting formula relates cutter geometry (cutting rim width and cutting angle) to the cutting force and viscosity of rocks. The formula was used to build the 3D graphs for sylvine, halite and carnallite for the cross-cutting scheme. The size of cracks under the cutter is connected with the presence of fl uid inclusions. The obtained analytical dependence allows to model the spatial distribution and size of microfractures in salt rocks under the action of the cutting tool. Excessive branching of cracks, energy intensity, and the number of small fractions decrease, when the trajectory of the cutter partially passes through the “technogenic” cracks of the previous bed. This is implemented in the cross-cutting scheme, where this group of cracks plays the role of “starting” ones. Their length in actual practice is important for justifying the optimal cutting parameters and estimating the cutter’s effi ciency.

Effect of Regulated Deficit Irrigation on Potato under-Mulched Drip Irrigation

In order to study the effects of water deficit on potato under-mulched drip irrigation, the paper interpreted the effects of water deficit at different growth stages on growth characteristics, yield, quality and the water use of potato under-mulched drip irrigation. The results showed that mild water deficit treatment in potato tuber forming period can effectively reduce excessive plant branches and contribute to the increase of crop yield. Meanwhile, the total sugar content, protein and starch content can be improved, and the content of organic acids was significantly reduced, which is conducive to the improvement of potato quality. Tuber growth period is a period with large water demand for crops, so that enough moisture should be guaranteed during this period. Finally, the current problems in potato planting were analysed, and the future research directions were prospected.

Excess Neuronal Branching Allows for Local Innervation of Specific Dendritic Compartments in Mature Cortex.

The connectivity of cortical microcircuits is a major determinant of brain function; defining how activity propagates between different cell types is key to scaling our understanding of individual neuronal behavior to encompass functional networks. Furthermore, the integration of synaptic currents within a dendrite depends on the spatial organization of inputs, both excitatory and inhibitory. We identify a simple equation to estimate the number of potential anatomical contacts between neurons; finding a linear increase in potential connectivity with cable length and maximum spine length, and a decrease with overlapping volume. This enables us to predict the mean number of candidate synapses for reconstructed cells, including those realistically arranged. We identify an excess of potential local connections in mature cortical data, with densities of neurite higher than is necessary to reliably ensure the possible implementation of any given axo-dendritic connection. We show that the number of local potential contacts allows specific innervation of distinct dendritic compartments.

Nonmuscle myosin 2 regulates cortical stability during sprouting angiogenesis.

Among the three nonmuscle myosin 2 (NM2) paralogs, NM 2A and 2B, but not 2C, are detected in endothelial cells. To study the role of NM2 in vascular formation, we ablate NM2 in endothelial cells in mice. Ablating NM2A, but not NM2B, results in reduced blood vessel coverage and increased vascular branching in the developing mouse skin and coronary vasculature. NM2B becomes essential for vascular formation when NM2A expression is limited. Mice ablated for NM2B and one allele of NM2A develop vascular abnormalities similar to those in NM2A ablated mice. Using the embryoid body angiogenic sprouting assay in collagen gels reveals that NM2A is required for persistent angiogenic sprouting by stabilizing the endothelial cell cortex, and thereby preventing excessive branching and ensuring persistent migration of the endothelial sprouts. Mechanistically, NM2 promotes focal adhesion formation and cortical protrusion retraction during angiogenic sprouting. Further studies demonstrate the critical role of Rho kinase–activated NM2 signaling in the regulation of angiogenic sprouting in vitro and in vivo.

Zfp36l1b protects angiogenesis through Notch1b/Dll4 and Vegfa regulation in zebrafish

Background and aimsAngiogenesis is a key process for establishing functional vasculature during embryogenesis and involves different signaling mechanisms. The RNA binding protein Zfp36l1 was reported to be involved in various diseases in different species, including cardiovascular diseases. However, whether Zfp36l1b, one of the 2 paralogs of Zfp36l1 in zebrafish, works like mammalian Zfp36l1, and if the molecular mechanisms are different remains unclear. Here, we show that Zfp36l1b plays a crucial protective role in angiogenesis of zebrafish embryos. MethodsWe used transparent transgenic and wild-type zebrafish larvae to dynamically investigate the early stage of angiogenesis with confocal in vivo, after the knockdown of Zfp36l1b by morpholinos (MOs). In situ hybridization and fluorescence-activated cell sorting were performed to detect Zfp36l1b expression. mRNA rescue and CRISPR/Cas9 knockdown, and luciferase reporter experiments were performed to further explore the role of Zfp36l1b in angiogenesis. ResultsWe found that knockdown of Zfp36l1b led to defected angiogenesis in intersomitic vessels and sub-intestinal veins (SIVs), which could be rescued by the addition of Zfp36l1b mRNA. Moreover, knockdown of Zfp36l1b suppressed Notch1b expression, while knockdown of Notch1b resulted in a partial relief of angiogenesis defects induced by Zfp36l1b down-regulation. Besides, Zfp36l1b knockdown alleviated the excessive branch of SIVs caused by Vegfa over-expression. ConclusionsOur results show that Zfp36l1b is responsible for establishing normal vessel circuits by affecting the extension of endothelial tip cells filopodia and the proliferation of endothelial cells partly through Notch1b/Fll4 suppression and synergistic function with Vegfa.

Ultrahigh Branching of Main‐Chain‐Functionalized Polyethylenes by Inverted Insertion Selectivity

AbstractBranched polyolefin microstructures resulting from so‐called “chain walking” are a fascinating feature of late transition metal catalysts; however, to date it has not been demonstrated how desirable branched polyolefin microstructures can be generated thereby. We demonstrate how highly branched polyethylenes with methyl branches (220 Me/1000 C) exclusively and very high molecular weights (ca. 106 g mol−1), reaching the branch density and microstructure of commercial ethylene–propylene elastomers, can be generated from ethylene alone. At the same time, polar groups on the main chain can be generated by in‐chain incorporation of methyl acrylate. Key to this strategy is a novel rigid environment in an α‐diimine PdII catalyst with a steric constraint that allows for excessive chain walking and branching, but restricts branch formation to methyl branches, hinders chain transfer to afford a living polymerization, and inverts the regioselectivity of acrylate insertion to a 1,2‐mode.