shape

形状
  • 文章类型: Journal Article
    神经元树突的分支结构是神经元如何形成有序网络的关键因素,并不断发现蛋白质和蛋白质-蛋白质相互作用,这些蛋白质和蛋白质相互作用指导或执行树突的分支和延伸。我们先前的工作表明,分子支架Pdlim5和delta-catenin,在结合中,是两种蛋白质,有助于调节培养的海马神经元中树突的分支和伸长,并通过上游谷氨酸信号触发的磷酸化依赖性机制实现。在本报告中,我们重点介绍了Pdlim5的多个支架域,以及每个支架域如何有助于枝晶分支。Pdlim5中的三个识别区域是PDZ,DUF,和三个LIM域;然而,未解决的是Pdlim5的分子内构象以及哪些结构域对于调节树突分支至关重要。我们通过单独检查每个结构域的作用并在全长蛋白质的背景下使用缺失突变体来解决Pdlim5的结构和功能。使用原代海马神经元的结果表明,Pdlim5DUF结构域在增加树突分支中起主导作用。PDZ域和LIM域都不单独支持增加的分支。在全长Pdlim5的情况下使用缺失突变体证实了DUF结构域的中心作用。在分子建模的指导下,其他域映射研究表明,C端LIM域与N端PDZ域形成稳定的相互作用,我们确定了这种相互作用所需的每个结构域界面的关键氨基酸残基。我们认为,Pdlim5的中央DUF结构域可能在全长蛋白的情况下受到N端PDZ和C端LIM结构域之间的分子内相互作用的调节。总的来说,我们的研究揭示了调节Pdlim5在调节神经元分支中的功能的新机制,并强调了DUF域在介导这些作用中的关键作用。
    The branched architecture of neuronal dendrites is a key factor in how neurons form ordered networks and discoveries continue to be made identifying proteins and protein-protein interactions that direct or execute the branching and extension of dendrites. Our prior work showed that the molecular scaffold Pdlim5 and delta-catenin, in conjunction, are two proteins that help regulate the branching and elongation of dendrites in cultured hippocampal neurons and do so through a phosphorylation-dependent mechanism triggered by upstream glutamate signaling. In this report we have focused on Pdlim5\'s multiple scaffolding domains and how each contributes to dendrite branching. The three identified regions within Pdlim5 are the PDZ, DUF, and a trio of LIM domains; however, unresolved is the intra-molecular conformation of Pdlim5 as well as which domains are essential to regulate dendritic branching. We address Pdlim5\'s structure and function by examining the role of each of the domains individually and using deletion mutants in the context of the full-length protein. Results using primary hippocampal neurons reveal that the Pdlim5 DUF domain plays a dominant role in increasing dendritic branching. Neither the PDZ domain nor the LIM domains alone support increased branching. The central role of the DUF domain was confirmed using deletion mutants in the context of full-length Pdlim5. Guided by molecular modeling, additional domain mapping studies showed that the C-terminal LIM domain forms a stable interaction with the N-terminal PDZ domain, and we identified key amino acid residues at the interface of each domain that are needed for this interaction. We posit that the central DUF domain of Pdlim5 may be subject to modulation in the context of the full-length protein by the intra-molecular interaction between the N-terminal PDZ and C-terminal LIM domains. Overall, our studies reveal a novel mechanism for the regulation of Pdlim5\'s function in the regulation of neuronal branching and highlight the critical role of the DUF domain in mediating these effects.
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  • 文章类型: Journal Article
    二级和三级RNA结构在单链正义RNA病毒的基因组复制中起关键作用。复杂,功能结构在小核糖核酸病毒的非翻译区中特别丰富,他们参与翻译的启动,启动新链合成和基因组环化。口蹄疫病毒(FMDV)的5'UTR预计包括一个c。360核苷酸长的茎环,称为短(S)片段。这种结构是高度保守的,对于病毒复制是必不可少的,但精确的函数(S)是不清楚的。这里,我们使用通过引物延伸分析的选择性2'羟基乙酰化(SHAPE)来实验确定结构的各个方面,以及比较基因组分析,以确认来自广泛领域分离株的结构保守性。为了检查其在细胞培养中病毒复制中的作用,我们在茎环的远端和近端区域引入了一系列缺失。这些截短影响基因组复制的大小依赖性,在某些情况下,宿主细胞依赖性方式。此外,在从S片段茎环的近端区域掺入最大耐受缺失的病毒传代过程中,在病毒RNA依赖性RNA聚合酶中选择了一个额外的突变,3Dpol.这些数据表明S片段和3Dpol在FMDV复制复合物的形成中相互作用。
    Secondary and tertiary RNA structures play key roles in genome replication of single-stranded positive sense RNA viruses. Complex, functional structures are particularly abundant in the untranslated regions of picornaviruses, where they are involved in initiation of translation, priming of new strand synthesis and genome circularization. The 5\' UTR of foot-and-mouth disease virus (FMDV) is predicted to include a c. 360 nucleotide-long stem-loop, termed the short (S) fragment. This structure is highly conserved and essential for viral replication, but the precise function(s) are unclear. Here, we used selective 2\' hydroxyl acetylation analyzed by primer extension (SHAPE) to experimentally determine aspects of the structure, alongside comparative genomic analyses to confirm structure conservation from a wide range of field isolates. To examine its role in virus replication in cell culture, we introduced a series of deletions to the distal and proximal regions of the stem-loop. These truncations affected genome replication in a size-dependent and, in some cases, host cell-dependent manner. Furthermore, during the passage of viruses incorporating the largest tolerated deletion from the proximal region of the S fragment stem-loop, an additional mutation was selected in the viral RNA-dependent RNA polymerase, 3Dpol. These data suggest that the S fragment and 3Dpol interact in the formation of the FMDV replication complex.
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  • 文章类型: Journal Article
    根据协调局部细胞形态发生的空间和时间线索,在发育过程中形成(并在再生过程中重新形成)。尾鳍是大多数鱼类用于推进的主要附属物,并表现出一系列适应不同游泳策略的不同形态,然而,负责产生这些不同形状的分子机制仍然是未知的。在斑马鱼中,尾鳍呈叉形,外围有较长的支持性骨射线,中心有较短的射线。这里,我们证明了过早的,在晚期胚胎发育过程中,声波刺猬a(shha)过表达的瞬时脉冲会导致中央射线的过度增殖和生长,导致成年尾鳍长成三角形,截断形状。全球和区域异位shha过度表达都足以改变鳍的形状,叉形可以通过随后用规范Shh途径的拮抗剂进行治疗来挽救。诱导的截短鳍显示出减少的鳍射线数,并且无法形成通常将背侧和腹侧鳍叶分开的充膜舒张。当分叉的鳍再生其原始的分叉形态时,截断鳍再生截断,这表明,在胚胎发生过程中,通过短暂的治疗可以永久性地改变鳍状射线的位置记忆。射线鳍鱼已经进化出了广泛的尾鳍形态,从截断到分叉,当前的工作提供了对可能构成这种形状多样性的发展机制的见解。
    Appendage shape is formed during development (and re-formed during regeneration) according to spatial and temporal cues that orchestrate local cellular morphogenesis. The caudal fin is the primary appendage used for propulsion in most fish species, and exhibits a range of distinct morphologies adapted for different swimming strategies, however the molecular mechanisms responsible for generating these diverse shapes remain mostly unknown. In zebrafish, caudal fins display a forked shape, with longer supportive bony rays at the periphery and shortest rays at the center. Here, we show that a premature, transient pulse of sonic hedgehog a (shha) overexpression during late embryonic development results in excess proliferation and growth of the central rays, causing the adult caudal fin to grow into a triangular, truncate shape. Both global and regional ectopic shha overexpression are sufficient to alter fin shape, and forked shape may be rescued by subsequent treatment with an antagonist of the canonical Shh pathway. The induced truncate fins show a decreased fin ray number and fail to form the hypural diastema that normally separates the dorsal and ventral fin lobes. While forked fins regenerate their original forked morphology, truncate fins regenerate truncate, suggesting that positional memory of the fin rays can be permanently altered by a transient treatment during embryogenesis. Ray finned fish have evolved a wide spectrum of caudal fin morphologies, ranging from truncate to forked, and the current work offers insights into the developmental mechanisms that may underlie this shape diversity.
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  • 文章类型: Journal Article
    双歧杆菌SAM-VI核开关经历调节下游基因表达的动态构象变化。传统的结构方法,如晶体学以高分辨率捕获结合的构象,额外的努力将揭示动态过渡的细节。这里,我们揭示了两歧双歧杆菌SAM-VI核开关的转录依赖性构象模型。在这项研究中,我们结合了小角度X射线散射,化学探测,和等温滴定量热法揭示了双歧杆菌SAM-VI核开关及其变体的配体结合特性和构象变化。我们的结果表明,SAM-VI核糖开关包含一个预先组织的配体结合口袋,并在与SAM结合后稳定为结合的构象。P1茎是否形成和长度变化严重影响SAM-VI核开关的构象动力学。我们的研究通过操纵其外周序列而不修饰SAM结合核心,为人工工程化核糖开关提供了基础。
    The Bifidobacterium bifidum SAM-VI riboswitch undergoes dynamic conformational changes that modulate downstream gene expression. Traditional structural methods such as crystallography capture the bound conformation at high resolution, and additional efforts would reveal details from the dynamic transition. Here, we revealed a transcription-dependent conformation model for Bifidobacterium bifidum SAM-VI riboswitch. In this study, we combine small-angle X-ray scattering, chemical probing, and isothermal titration calorimetry to unveil the ligand-binding properties and conformational changes of the Bifidobacterium bifidum SAM-VI riboswitch and its variants. Our results suggest that the SAM-VI riboswitch contains a pre-organized ligand-binding pocket and stabilizes into the bound conformation upon binding to SAM. Whether the P1 stem formed and variations in length critically influence the conformational dynamics of the SAM-VI riboswitch. Our study provides the basis for artificially engineering the riboswitch by manipulating its peripheral sequences without modifying the SAM-binding core.
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  • 文章类型: Journal Article
    目的:面部裂痕是复杂的先天性异常,需要在彻底评估解剖结构的基础上进行综合治疗。本研究旨在使用几何形态计量学检查裂隙类型对颅面形态的影响。
    方法:我们评估了75例双侧唇腭裂患者的侧位头颅造影,63例单侧唇腭裂患者,和76例孤立性腭裂患者。在16个硬组织界标坐标上进行了广义Procrustes分析。用主成分分析研究了形状变异性。在风险模型方法中,前9个主成分(PC)用于检查裂隙类型的影响。
    结果:我们发现裂隙类型之间的平均形状存在统计学上的显着差异。双侧唇腭裂和孤立性腭裂之间的差异最大(平均0.026,P=0.0011)。裂隙类型之间的差异在PC4和PC5中最为明显(P=0.0001),它们一起占总形状变化的10%。PC4和PC5在上下表面的比例上显示出形状差异,下颌后高度,和下颌角。
    结论:裂隙型对非综合征性口面部裂隙患者颅面形态变异性有统计学意义,但影响较弱,主要是在垂直维度。
    结论:了解裂隙对颅面形态的影响对于为患者提供适合其特定需求的治疗至关重要。这项研究对文献有贡献,特别是由于我们的风险模型方法代替了预测模型。
    OBJECTIVE: Orofacial clefts are complex congenital anomalies that call for comprehensive treatment based on a thorough assessment of the anatomy. This study aims to examine the effect of cleft type on craniofacial morphology using geometric morphometrics.
    METHODS: We evaluated lateral cephalograms of 75 patients with bilateral cleft lip and palate, 63 patients with unilateral cleft lip and palate, and 76 patients with isolated cleft palate. Generalized Procrustes analysis was performed on 16 hard tissue landmark coordinates. Shape variability was studied with principal component analysis. In a risk model approach, the first nine principal components (PC) were used to examine the effect of cleft type.
    RESULTS: We found statistically significant differences in the mean shape between cleft types. The difference is greatest between bilateral cleft lip and palate and isolated cleft palate (distance of means 0.026, P = 0.0011). Differences between cleft types are most pronounced for PC4 and PC5 (P = 0.0001), which together account for 10% of the total shape variation. PC4 and PC5 show shape differences in the ratio of the upper to the lower face, the posterior mandibular height, and the mandibular angle.
    CONCLUSIONS: Cleft type has a statistically significant but weak effect on craniofacial morphological variability in patients with non-syndromic orofacial clefts, mainly in the vertical dimension.
    CONCLUSIONS: Understanding the effects of clefts on craniofacial morphology is essential to providing patients with treatment tailored to their specific needs. This study contributes to the literature particularly due to our risk model approach in lieu of a prediction model.
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  • 文章类型: Journal Article
    髓母细胞瘤(MB)是儿童中最常见的恶性脑肿瘤,具有广泛的异质性,导致不同的临床结局。最近,MB分为四个分子亚组,WNT,SHH,第3组和第4组。虽然SHH和第4组因其中间预后而闻名,研究报告了这些亚组中患者结局的巨大差异.这项研究旨在创建一个放射学的预后标志,髓母细胞瘤影像组学风险(mRRisk),为了识别SHH和第4组子组内的风险水平,个别,用于可靠的风险分层。我们的假设是,这种特征可以全面捕获肿瘤特征,从而能够准确识别风险水平。总的来说,从三个机构回顾性地策划了70项MB研究(48项第4组和22项SHH)。对于每个子组,232个手工制作的功能,捕获熵,表面变化,提取肿瘤的轮廓特征。将特征连接并输入到风险分层的回归模型中。与Chang分层相比,Chang分层在亚组内没有产生任何显着差异,在第4组(p=0.04,一致性指数(CI)=0.82)的两个风险组之间观察到囊性核和非增强肿瘤的显着差异,SHH(p=0.03,CI=0.74)对肿瘤的增强作用。我们的结果表明,影像组学可以作为改善MB风险分层的预后工具,改善患者护理。
    Medulloblastoma (MB) is the most frequent malignant brain tumor in children with extensive heterogeneity that results in varied clinical outcomes. Recently, MB was categorized into four molecular subgroups, WNT, SHH, Group 3, and Group 4. While SHH and Group 4 are known for their intermediate prognosis, studies have reported wide disparities in patient outcomes within these subgroups. This study aims to create a radiomic prognostic signature, medulloblastoma radiomics risk (mRRisk), to identify the risk levels within the SHH and Group 4 subgroups, individually, for reliable risk stratification. Our hypothesis is that this signature can comprehensively capture tumor characteristics that enable the accurate identification of the risk level. In total, 70 MB studies (48 Group 4, and 22 SHH) were retrospectively curated from three institutions. For each subgroup, 232 hand-crafted features that capture the entropy, surface changes, and contour characteristics of the tumor were extracted. Features were concatenated and fed into regression models for risk stratification. Contrasted with Chang stratification that did not yield any significant differences within subgroups, significant differences were observed between two risk groups in Group 4 (p = 0.04, Concordance Index (CI) = 0.82) on the cystic core and non-enhancing tumor, and SHH (p = 0.03, CI = 0.74) on the enhancing tumor. Our results indicate that radiomics may serve as a prognostic tool for refining MB risk stratification, towards improved patient care.
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  • 文章类型: Journal Article
    中央沟将许多类人猿大脑中的初级运动和体感皮质分开。与其他灵长类动物相比,大猿和人类沿背腹平面的中央沟的表面积和深度存在差异。在人类物种中,他们的手运动区域的深度和方面有变化,或旋钮,在中央前回内。在这项研究中,我们使用磁共振图像的后图像分析来表征人类的中央沟形状,黑猩猩,大猩猩(大猩猩),和猩猩(Pongopygmaeus和Pongoabelii)。利用这些数据,我们检查了人类中央沟的形态变异性,专注于手区域,人类进化的重大变化。我们表明,大猿物种之间的中央沟形状不同,但所有的手旋钮的位置都显示出类似的变化。然而,沿着背腹侧平面和偏侧的旋钮位置的患病率在物种之间有所不同,并且第二个腹侧运动旋钮的存在似乎是人类独有的。人类和猩猩表现出最相似和最复杂的中央沟形状。然而,它们的相似性可能反映了与选择不同位置和习惯性运动功能有关的不同进化过程。
    The central sulcus divides the primary motor and somatosensory cortices in many anthropoid primate brains. Differences exist in the surface area and depth of the central sulcus along the dorso-ventral plane in great apes and humans compared to other primate species. Within hominid species, there are variations in the depth and aspect of their hand motor area, or knob, within the precentral gyrus. In this study, we used post-image analyses on magnetic resonance images to characterize the central sulcus shape of humans, chimpanzees (Pan troglodytes), gorillas (Gorilla gorilla), and orangutans (Pongo pygmaeus and Pongo abelii). Using these data, we examined the morphological variability of central sulcus in hominids, focusing on the hand region, a significant change in human evolution. We show that the central sulcus shape differs between great ape species, but all show similar variations in the location of their hand knob. However, the prevalence of the knob location along the dorso-ventral plane and lateralization differs between species and the presence of a second ventral motor knob seems to be unique to humans. Humans and orangutans exhibit the most similar and complex central sulcus shapes. However, their similarities may reflect divergent evolutionary processes related to selection for different positional and habitual locomotor functions.
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  • 文章类型: Journal Article
    最近的fMRI实验揭示了在不同类型的2D视觉刺激中相似的神经表现;然而,提供动作的真实3D对象相对于2D对象不同地影响神经激活和行为结果。在单感官期间招募多个感觉区域(视觉,触觉,和听觉)对象形状任务表明形状表示可能是模态不变的。这篇迷你评论探讨了对象形状表示中涉及的重叠神经区域,跨2D,3D,视觉,和触觉实验。
    Recent functional magnetic resonance imaging (fMRI) experiments revealed similar neural representations across different types of two-dimensional (2-D) visual stimuli; however, real three-dimensional (3-D) objects affording action differentially affect neural activation and behavioral results relative to 2-D objects. Recruitment of multiple sensory regions during unisensory (visual, haptic, and auditory) object shape tasks suggests that shape representation may be modality invariant. This mini-review explores the overlapping neural regions involved in object shape representation, across 2-D, 3-D, visual, and haptic experiments.
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  • 文章类型: Journal Article
    感知涉及对有关世界的内容或信息的处理。这种内容以什么形式表示?我认为感知是广泛的组成。感知系统代表许多刺激特征(包括形状,定位,和运动)就其他特征(如形状部分、倾斜和倾斜,公共和残差运动矢量)。但是组合性可以采取多种形式。感性表征的构成方式与句子或思想的构成方式明显不同。我认为,感知是构成的论点本身并不是具有特定预测的具体假设;相反,它为开发和评估有关感知表示的形式和内容的特定经验假设提供了一个富有成效的框架。问题不仅仅是感知是否构成,但如何。回答后一个问题可以提供对感知的基本见解。本文分为:哲学>表征哲学>认知科学心理学的基础>感知与心理物理学。
    Perception involves the processing of content or information about the world. In what form is this content represented? I argue that perception is widely compositional. The perceptual system represents many stimulus features (including shape, orientation, and motion) in terms of combinations of other features (such as shape parts, slant and tilt, common and residual motion vectors). But compositionality can take a variety of forms. The ways in which perceptual representations compose are markedly different from the ways in which sentences or thoughts are thought to be composed. I suggest that the thesis that perception is compositional is not itself a concrete hypothesis with specific predictions; rather it affords a productive framework for developing and evaluating specific empirical hypotheses about the form and content of perceptual representations. The question is not just whether perception is compositional, but how. Answering this latter question can provide fundamental insights into perception. This article is categorized under: Philosophy > Representation Philosophy > Foundations of Cognitive Science Psychology > Perception and Psychophysics.
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  • 文章类型: Journal Article
    射线鳍鱼的尺度可用于多种用途。除了其他特定的结构和元素组成外,它们还可用于年龄确定和食物网研究。此外,只是他们的存在,缺席,形状,location,或者数字可以提供可靠的分类信息。鱼鳞也表现出显著的大小变化,这些特征为淡水鱼的环境需求提供了可靠的信息。但是到目前为止,在没有足够大和详细的数据库的情况下,这些信息是不可解释和可比的。在这项研究中,我们提供了一个数据库,可以促进进一步复杂的比较研究。我们的数据集包括2954张比例照片,描述了193种淡水鱼。所有照片都有一个唯一的识别码,准确显示了该鳞片所属的物种。除了照片,我们的数据库包括一张表格,显示所研究物种的确切分类,平均身体轮廓指数,和相对比例大小,以及每个物种的生态(流量和摄食栖息地偏好)和生命战略特征(摄食和繁殖公会成员)。采样的物种有不同的起源,覆盖五个生物地理区域。从每个物种中平均选择五个成虫进行采样。从背鳍和侧线之间的身体前部收集三到四个鳞片。清除除去的鳞片并准备成显微镜载玻片,在这个过程之后,他们被拍照或扫描。我们的数据库可用于研究和教育目的。分配物种的大量比例照片可以是创建自动物种识别系统的机会。此外,通过使用人工智能分析数据库,可以消除形态测量中的主观性。
    Scales of the ray finned fishes can be used for multiple purposes. Beside others by their specific structure and elemental composition they are usable for age determination and food-web researches. Additionally, just their presence, absence, shape, location, or numbers could provide a reliable taxonomic information. The fish scales show remarkable size variation also, which characteristics provide reliable information about the environmental needs of freshwater fish. But till now this information was not interpretable and comparable in the absence of a sufficiently large and detailed database. In this study we provide a database which can facilitate the further complex comparative studies. Our dataset consists of 2954 scale photos characterising 193 freshwater fish species. All photos have a uniquely identification code showing exactly which species the scale belongs to. In addition to the photos, our database includes a table showing the exact taxonomic classification of the studied species, the average body profile-index, and the relative scale size, as well as the ecological (flow and feeding habitat preferences) and life strategic characteristics (feeding and breeding guild memberships) of each species. The sampled species have diverse origin, covering five biogeographical regions. An average of five adults from each species were selected for sampling. Three-to-four scales were collected from the anterior part of the body between the dorsal fin and the lateral line. The removed scales were cleaned and prepared to microscope slides, and after this process they were photographed or scanned. Our database can be used for both research and educational purposes. A large number of scale photos assigned of species can be an opportunity to create an automatic species identification system. Moreover, the subjectivity in morphometric measurements can be eliminated by analysing the database with artificial intelligence.
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