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141.
李翛然 (2024-09-27 21:35):
#paper doi:10.13345/j.cjb.220582 《工程菌种自动化高通量编辑与筛选研究进展》该论文主要讨论了合成生物学领域中工程菌种的自动化高通量编辑与筛选技术的研究进展。合成生物学通过标准化和模块化生物实验对象、方法、技术和流程,创建自动化与高通量的合成生物铸造模式。 这种模式结合了复杂生物过程与自动化设施,颠覆了传统的劳动密集型研究方式,提高了技术迭代能力,促进了合成生物学的发展和产业化应用。 研究进展: 自动化基因编辑: 论文回顾了天津工业生物技术研究所在自动化高通量编辑与筛选领域的工作进展。 讨论了基因克隆、基因组编辑、编辑序列设计的自动化实现。 介绍了CRISPR/Cas9系统等基因编辑技术在自动化操作中的应用。 高通量筛选技术: 论文分析了流式细胞、液滴微流控、全基因组规模扰动测序等高通量筛选技术。 讨论了这些技术在筛选工程菌株中的应用和效果。 最近在读博,高级制药工程需要读中文论文…………
142.
半面阳光 (2024-09-25 15:13):
#paper DOI: https://doi.org/10.1038/s41436-019-0634-7, Genetics in Medicine, 2020, Low-pass genome sequencing versus chromosomal microarray analysis: implementation in prenatal diagnosis. 这篇文章比较了 low-pass genome sequencing (GS)与chromosomal microarray analysis (CMA)两种方法在染色体异常的产前检测中的表现。征集了1023个产前诊断的样本,同时进行了低深度WGS和CMA来检测CNVs. 分析结果显示,低深度的WGS检测出124例的染色体数目异常和致病(p)或可能致病(lp)CNVs121例,同时还检测出17例其他临床相关的p/lpCNVs. 低深度WGS检测显著降低了需要进一步进行CMA检测的重复检测率(4.6%,47/1023),并且其所需DNA样本量更低(50ng)。文章认为,与CMA相比而言,低深度的WGS能够提供共临床有效信息,并且提升了检测的分辨率,增强了检测出嵌合性(mosaicism)异常的敏感性。这篇文献为低深度的WGS用于产前检测CNVs提供了证据支持。
143.
龙海晨 (2024-09-19 12:12):
#paper Zhu Q, Wan NB, Deng HW, Lu LL, Zhang Y, He X, Liu H, He Y. SEC14L3 plays a tumor-suppressive role in breast cancer through a Wnt/β-catenin-related way. Exp Cell Res. 2022 Aug 1;417(1):113161. doi: 10.1016/j.yexcr.2022.113161. Epub 2022 Apr 18. PMID: 35447102.这是一篇生物信息与分子生物学细胞生物学实验相结合的文章。文章先对TCGA-BRCA数据集进行挖掘,发现IL1F6、MRGPRX1、SEC14L3与乳腺癌患者总生存期显著相关。SEC14L3对乳腺癌的生存益处最大,选择SEC14L3进行后续研究(细胞生物学,分子生物层面)。在后续的研究重发现,SEC14L3 mRNA表达和蛋白表达情况,乳腺癌细胞系明显低于正常的乳腺上皮细胞。SEC14L3 过度表达可以抑制癌细胞迁移和侵袭的能力。SEC14L3 过表达降低了间质标志物的水平,而 SEC14L3 敲低则促进了乳腺癌细胞的恶性行为。SEC14L3 过表达还抑制了 Wnt/β-catenin 激活。乳腺癌细胞和组织中低表达的SEC14L3可能通过Wnt /β-catenin相关的方式发挥肿瘤抑制作用。
Abstract:
Breast cancer, the most prevalent malignancy in women, is also the leading cause of cancer-related deaths in women worldwide. The activation of the Wnt pathway plays a pivotal role in … >>>
Breast cancer, the most prevalent malignancy in women, is also the leading cause of cancer-related deaths in women worldwide. The activation of the Wnt pathway plays a pivotal role in the metastatic abilities of breast cancer. In this study, IL1F6, MRGPRX1, and SEC14L3 were significantly correlated to breast cancer patients'overall survival based on TCGA-BRCA dataset. Although IL1F6, MRGPRX1 and SEC14L3 high expression were associated with better survival in breast cancer patients, SEC14L3 had the biggest survival benefit for breast cancer; therefore, SEC14L3 was selected for the subsequent investigation. SEC14L3 mRNA expression and protein levels within breast cancer cell lines decreased compared with normal human breast epithelial cells. Overexpressing SEC14L3 in breast cancer cells inhibited the malignant phenotypes of cancer cells, including the capacity of cells to migrate and invade. SEC14L3 overexpression decreased the levels of mesenchymal markers, whereas SEC14L3 knockdown facilitated the malignant behaviors of breast cancer cells. SEC14L3 overexpression also inhibited Wnt/β-catenin activation. The Wnt agonist strengthened the malignant phenotypes of breast cancer cells; moreover, the anti-tumor effects of SEC14L3 overexpression were partially attenuated by the Wnt agonist. Conclusively, SEC14L3, which is underexpressed in breast cancer cells and tissues, could play a tumor-suppressive role in a Wnt/β-catenin-related way. <<<
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144.
DeDe宝 (2024-09-12 14:24):
#paper, DOI: 10.1073/pnas.0805414105 ,Neural basis of the cognitive map: Path integration does not require hippocampus or entorhinal cortex. 研究主要探讨了海马体和内嗅皮层在记忆功能和空间认知中的作用,尤其是它们在路径整合能力中的作用。路径整合是指利用自身运动线索来跟踪参考位置的能力。当被试被要求蒙上眼睛导航并指向起点位置,海马体或内嗅皮层受损的被试表现与对照组相似。在距离估计任务中,受损组和对照组的估计也相似。只有在延迟和分心条件下,受损组表现不如对照组,显示了他们在长期记忆任务上的困难。上述结果表明,虽然海马体和内嗅皮层对于长期记忆至关重要,但它们对于路径整合的空间计算并不是必需的。
Abstract:
The hippocampus and entorhinal cortex have been linked to both memory functions and to spatial cognition, but it has been unclear how these ideas relate to each other. An important … >>>
The hippocampus and entorhinal cortex have been linked to both memory functions and to spatial cognition, but it has been unclear how these ideas relate to each other. An important part of spatial cognition is the ability to keep track of a reference location using self-motion cues (sometimes referred to as path integration), and it has been suggested that the hippocampus or entorhinal cortex is essential for this ability. Patients with hippocampal lesions or larger lesions that also included entorhinal cortex were led on paths while blindfolded (up to 15 m in length) and were asked to actively maintain the path in mind. Patients pointed to and estimated their distance from the start location as accurately as controls. A rotation condition confirmed that performance was based on self-motion cues. When demands on long-term memory were increased, patients were impaired. Thus, in humans, the hippocampus and entorhinal cortex are not essential for path integration. <<<
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145.
惊鸿 (2024-09-11 14:53):
#paper Pub Date  : 2024-09-09 DOI : 10.1073/pnas.2403200121青春期是社会情感显着发展的时期,伴随着大脑结构和功能的巨大变化。由于 COVID-19 大流行而实施的封锁导致的社会隔离对青少年的心理健康产生了不利影响,其中女性的心理健康比男性受到的影响更大。我们评估了 COVID-19 大流行封锁对青少年大脑结构的影响,重点关注性别差异。我们纵向收集了大流行封锁前后青少年的 MRI 结构数据。新冠疫情前的数据用于创建典型青少年发育期间皮质厚度随年龄变化的规范模型。将新冠疫情后数据中的皮质厚度值与该规范模型进行了比较。分析显示,新冠疫情后大脑皮质加速变薄,这种现象在整个大脑中更为广泛,并且女性的程度比男性更大。当以同等发育年数来衡量时,女性的平均加速度为 4.2 岁,男性的平均加速度为 1.4 岁。发育过程中的慢性压力或逆境会导致大脑加速成熟,这一点已有充分记录。这些发现表明,与 COVID-19 大流行封锁相关的生活方式中断导致了大脑生物学的变化,并且对女性大脑的影响比男性大脑更严重。
Abstract:
Adolescence is a period of substantial social-emotional development, accompanied by dramatic changes to brain structure and function. Social isolation due to lockdowns that were imposed because of the COVID-19 pandemic … >>>
Adolescence is a period of substantial social-emotional development, accompanied by dramatic changes to brain structure and function. Social isolation due to lockdowns that were imposed because of the COVID-19 pandemic had a detrimental impact on adolescent mental health, with the mental health of females more affected than males. We assessed the impact of the COVID-19 pandemic lockdowns on adolescent brain structure with a focus on sex differences. We collected MRI structural data longitudinally from adolescents prior to and after the pandemic lockdowns. The pre-COVID data were used to create a normative model of cortical thickness change with age during typical adolescent development. Cortical thickness values in the post-COVID data were compared to this normative model. The analysis revealed accelerated cortical thinning in the post-COVID brain, which was more widespread throughout the brain and greater in magnitude in females than in males. When measured in terms of equivalent years of development, the mean acceleration was found to be 4.2 y in females and 1.4 y in males. Accelerated brain maturation as a result of chronic stress or adversity during development has been well documented. These findings suggest that the lifestyle disruptions associated with the COVID-19 pandemic lockdowns caused changes in brain biology and had a more severe impact on the female than the male brain. <<<
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146.
刘昊辰 (2024-09-06 09:51):
#paper arXiv:2012.11045v1 [cs.AI] 20 Dec 2020, Monte-Carlo Graph Search for AlphaZero. 这是一篇关于如何改进AlphaZero算法的研究论文。AlphaZero算法在棋类游戏中取得了显著成果,但传统的MCTS算法并不共享不同子树之间的信息,这限制了其效率。论文将AlphaZero的搜索树从有向树扩展到有向无环图,允许不同子树之间的信息流动,显著减少内存消耗;并提出了结合蒙特卡洛图搜索(MCGS)的一系列改进,包括 ϵ-greedy、改进的残局求解器和领域知识的整合作为约束条件。使用CrazyAra引擎在国际象棋和crazyhouse上进行评估,展示了这些改进为AlphaZero带来的显著提升。下载地址:https://arxiv.org/pdf/2012.11045
arXiv, 2020-12-20T22:51:38Z. DOI: 10.48550/arXiv.2012.11045
Abstract:
The AlphaZero algorithm has been successfully applied in a range of discretedomains, most notably board games. It utilizes a neural network, that learns avalue and policy function to guide the … >>>
The AlphaZero algorithm has been successfully applied in a range of discretedomains, most notably board games. It utilizes a neural network, that learns avalue and policy function to guide the exploration in a Monte-Carlo TreeSearch. Although many search improvements have been proposed for Monte-CarloTree Search in the past, most of them refer to an older variant of the UpperConfidence bounds for Trees algorithm that does not use a policy for planning.We introduce a new, improved search algorithm for AlphaZero which generalizesthe search tree to a directed acyclic graph. This enables information flowacross different subtrees and greatly reduces memory consumption. Along withMonte-Carlo Graph Search, we propose a number of further extensions, such asthe inclusion of Epsilon-greedy exploration, a revised terminal solver and theintegration of domain knowledge as constraints. In our evaluations, we use theCrazyAra engine on chess and crazyhouse as examples to show that these changesbring significant improvements to AlphaZero. <<<
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147.
林海onrush (2024-09-01 00:00):
#paper, DOI: 10.1088/1367-2630/ab8ab1 ,Randomized benchmarking for qudit Clifford gates,这篇论文研究了如何将随机基准测试(RB)技术从传统的量子比特(qubit)扩展到量子系统中的更高维度(qudit),即具有两个以上能级的量子系统。通过引入单位2-设计(U2D),作者开发了适用于qudit Clifford门的随机基准测试协议,并提供了详细的伪代码算法。这种方法允许有效地评估qudit门的平均保真度,进而为更复杂的量子计算系统提供了可靠的性能表征手段。 同时讨论为什么不能简单地将多量子比特的RB结果应用于qudit系统,特别强调qudit Clifford门的独特性及其不同于qubit的特点。研究为未来基于qudit的量子计算提供了实验测试的理论基础,特别是在利用光子实现的qudit量子计算中, 为高维量子系统的基准测试奠定了基础,有助于推动量子计算的扩展和容错能力的发展。
Abstract:
Abstract We introduce unitary-gate randomized benchmarking (URB) for qudit gates by extending single- and multi-qubit URB to single- and multi-qudit gates. Specifically, we develop a qudit URB procedure that exploits … >>>
Abstract We introduce unitary-gate randomized benchmarking (URB) for qudit gates by extending single- and multi-qubit URB to single- and multi-qudit gates. Specifically, we develop a qudit URB procedure that exploits unitary 2-designs. Furthermore, we show that our URB procedure is not simply extracted from the multi-qubit case by equating qudit URB to URB of the symmetric multi-qubit subspace. Our qudit URB is elucidated by using pseudocode, which facilitates incorporating into benchmarking applications. <<<
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<jats:title>摘要</jats:title> <jats:p>我们通过将单量子比特和多量子比特 URB 扩展到单量子比特门和多量子门,为 qudit 门引入了幺正门随机基准测试 (URB)。具体来说,我们开发了一个利用单一 2 设计的 qudit URB 程序。此外,我们表明,我们的 URB 过程不是通过将 qudit URB 等同于对称多量子比特子空间的 URB 来简单地从多量子比特情况中提取的。我们的 qudit URB 是使用伪代码来阐明的,这有助于整合到基准测试应用程序中。</jats:p>
148.
尹志 (2024-08-31 23:47):
#paper doi: 10.1038/s41586-019-1923-7, Nature volume 577, pages706–710 (2020), Improved protein structure prediction using potentials from deep learning, alphafold1的原始文献,在当时是一个非常重要的突破,让深度学习在生物领域开始大放光彩。后续各种围绕深度学习的改进,将AI+生物学推到了风口浪尖。虽然这篇alphafold1的工作现在来看,性能已经无法和当前的版本或者类似模型媲美,但创新性的引入深度学习,同时考虑蛋白质序列信息、二级结构、三维构象信息等多尺度信息建模的方式,都成为了后续的蛋白质折叠问题的研究的data driven的方法的基线模型。当然现在看来,使用potential of mean force这样比较物理的方式处理,可能是一种俘获问题的物理本质的有益尝试,对于data driven的方式的使用反而不是那么大胆。但对比后续越来越依靠大力出奇迹,我也更倾向于通过物理描述去俘获折叠问题的本质及动力学机制。
149.
muton (2024-08-31 23:32):
#paper Huang, Q., Xiao, Z., Yu, Q. et al. Replay-triggered brain-wide activation in humans. Nat Commun 15, 7185 (2024). https://doi.org/10.1038/s41467-024-51582-5 将零散的经历整合成一个连贯的故事可以塑造认知地图,为我们的经历提供有组织的认知表征。在这个过程中,过去的记忆会被激活并以顺序播放,促进海马体与皮质之间的对话。然而,记忆序列激活(或重播)同时在整个大脑范围内发生的协同作用仍尚未得到充分研究。在这项研究中,作者利用EEG-fMRI同时记录技术捕捉记忆重播的时空动态。我们发现,在心理模拟过程中,过去的记忆会以快速序列的形式通过EEG检测到。这些短暂的重播事件与海马体和前额叶皮质的增强fMRI活动有关。重播发生的频率会增强海马体与默认模式网络(一组对代表认知地图的关键脑区)之间的功能连接。另一方面,当受试者在学习后休息时,与任务相关的记忆重播强度高于学习前的休息时,并与海马体激活的增强和海马体与齿状回的连接增强有关。我们的研究结果共同表明,短暂的记忆重现与连续的重放过程与大脑广泛的区域性活动有关。
Abstract:
The consolidation of discrete experiences into a coherent narrative shapes the cognitive map, providing structured mental representations of our experiences. In this process, past memories are reactivated and replayed in … >>>
The consolidation of discrete experiences into a coherent narrative shapes the cognitive map, providing structured mental representations of our experiences. In this process, past memories are reactivated and replayed in sequence, fostering hippocampal-cortical dialogue. However, brain-wide engagement coinciding with sequential reactivation (or replay) of memories remains largely unexplored. In this study, employing simultaneous EEG-fMRI, we capture both the spatial and temporal dynamics of memory replay. We find that during mental simulation, past memories are replayed in fast sequences as detected via EEG. These transient replay events are associated with heightened fMRI activity in the hippocampus and medial prefrontal cortex. Replay occurrence strengthens functional connectivity between the hippocampus and the default mode network, a set of brain regions key to representing the cognitive map. On the other hand, when subjects are at rest following learning, memory reactivation of task-related items is stronger than that of pre-learning rest, and is also associated with heightened hippocampal activation and augmented hippocampal connectivity to the entorhinal cortex. Together, our findings highlight a distributed, brain-wide engagement associated with transient memory reactivation and its sequential replay. <<<
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150.
符毓 Yu (2024-08-31 23:18):
#paper doi: 10.1038/s41598-022-06214-7, Science Report, 2022, Low voltage optical fiber positioner robot based on minimum inductance hollow cup motors 新一代光纤定位机器人选用了相位电感最小的4 mm空心杯电机。由于光纤定位机器人负载为恒定值,电机转动惯量很小,因此提出了一种基于空间矢量脉冲宽度调制的开环定位控制方法,并通过相关实验策略直接整定具体的开环参数。从细分、基频、造波方式、峰值电流4个方面详细讨论了开环驱动方式的关键因素。基于实际光纤定位机器人,搭建了硬件驱动与考核平台。定位试验表明,所提方法实用有效,满足新一代光纤定位机器人的精密定位需求。
Abstract:
AbstractWith the further transformation of The Large Sky Area Multi-Object Fiber Spectroscopic Telescope, the new generation of fiber positioner robot chooses a 4 mm hollow cup motor with minimum phase … >>>
AbstractWith the further transformation of The Large Sky Area Multi-Object Fiber Spectroscopic Telescope, the new generation of fiber positioner robot chooses a 4 mm hollow cup motor with minimum phase inductance. Because the load of the fiber positioner robot is constant and the inertia of the motor is very small, an open loop positioning control method based on Space Vector Pulse Width Modulation is proposed, and the specific open loop parameters are directly tuned by relevant experimental strategies. The critical factors of the open loop driving mode are discussed in detail from four aspects: subdivision, fundamental frequency, wave generation mode and peak current. Based on the actual fiber positioner robot, the hardware driver and assessment platform are built. The positioning tests show that the method proposed is practical and effective, and meets the precision positioning demand of the new generation optical fiber positioner robot. <<<
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151.
白鸟 (2024-08-31 23:17):
#paper doi: 10.1038/s41586-024-07661-0 Interactions between immune cell types facilitate the evolution of immune traits 宏观上,作者想了解生物自然群体在与病原体做生存斗争,免疫系统是如何进化的?用群体遗传学方法GWAS研究免疫系统。 关键词:免疫,进化; 进化知识: 为了适应性-->基因型变异-->性状表型改变-->物种进化;免疫相关基因进化最快;免疫进化两个因素:个体免疫细胞类型存在差异,免疫进化是不同免疫细胞的相互作用; 整体设计:CC品系群体---GWAS分析;基因型(遗传多样性)<-->表型(免疫细胞丰度占比) 实验设计:8个创始品系骨髓(3个重复);30个重组近交系骨髓(2个重复) 群体:构造一个小型的小鼠自然群体(免疫相关的遗传差异大) 表型:复杂的免疫表型用个体免疫细胞占比表征,CyTOF分析测定9种免疫细胞群比例; 基因型:个体进行SNP芯片检测,芯片SNP只保留免疫相关基因; QTL分析:DOQTL-->获得免疫特征相关的基因位点;重点分析cyto-trans反式基因;
Abstract:
An essential prerequisite for evolution by natural selection is variation among individuals in traits that affect fitness. The ability of a system to produce selectable variation, known as evolvability, thus … >>>
An essential prerequisite for evolution by natural selection is variation among individuals in traits that affect fitness. The ability of a system to produce selectable variation, known as evolvability, thus markedly affects the rate of evolution. Although the immune system is among the fastest-evolving components in mammals, the sources of variation in immune traits remain largely unknown. Here we show that an important determinant of the immune system's evolvability is its organization into interacting modules represented by different immune cell types. By profiling immune cell variation in bone marrow of 54 genetically diverse mouse strains from the Collaborative Cross, we found that variation in immune cell frequencies is polygenic and that many associated genes are involved in homeostatic balance through cell-intrinsic functions of proliferation, migration and cell death. However, we also found genes associated with the frequency of a particular cell type that are expressed in a different cell type, exerting their effect in what we term cyto-trans. The vertebrate evolutionary record shows that genes associated in cyto-trans have faced weaker negative selection, thus increasing the robustness and hence evolvability of the immune system. This phenomenon is similarly observable in human blood. Our findings suggest that interactions between different components of the immune system provide a phenotypic space in which mutations can produce variation with little detriment, underscoring the role of modularity in the evolution of complex systems. <<<
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152.
盼盼 (2024-08-31 22:13):
#paper doi: 10.1038/s41586-024-07185-7. APOE4/4 is linked to damaging lipid droplets in Alzheimer’s disease microglia 美国斯坦福大学医学院的Tony 团队在Nature上发表题目为APOE4/4 is linked to damaging lipid droplets in Alzheimer’s disease microglia的文章,通过对AD患者死后脑组织的核RNA测序,发现一种表达由脂滴相关酶ACSL1的小胶质细胞状态,其中ACSL1阳性的小胶质细胞在APOE4/4基因型AD患者中最为丰富。在iMG中证实纤维状淀粉样蛋白-β(fAβ)可以以APOE依赖的方式诱导ACSL1表达和脂滴积累,并且含有脂滴积累的小胶质细胞的培养基可以APOE依赖的方式介导Tau磷酸化和神经毒性。这歌研究提示我们小胶质细胞代谢状态的改变,可能是神经退行性疾病进展因素,这为AD的治疗提供了新策略。
Abstract:
Several genetic risk factors for Alzheimer's disease implicate genes involved in lipid metabolism and many of these lipid genes are highly expressed in glial cells. However, the relationship between lipid … >>>
Several genetic risk factors for Alzheimer's disease implicate genes involved in lipid metabolism and many of these lipid genes are highly expressed in glial cells. However, the relationship between lipid metabolism in glia and Alzheimer's disease pathology remains poorly understood. Through single-nucleus RNA sequencing of brain tissue in Alzheimer's disease, we have identified a microglial state defined by the expression of the lipid droplet-associated enzyme ACSL1 with ACSL1-positive microglia being most abundant in patients with Alzheimer's disease having the APOE4/4 genotype. In human induced pluripotent stem cell-derived microglia, fibrillar Aβ induces ACSL1 expression, triglyceride synthesis and lipid droplet accumulation in an APOE-dependent manner. Additionally, conditioned media from lipid droplet-containing microglia lead to Tau phosphorylation and neurotoxicity in an APOE-dependent manner. Our findings suggest a link between genetic risk factors for Alzheimer's disease with microglial lipid droplet accumulation and neurotoxic microglia-derived factors, potentially providing therapeutic strategies for Alzheimer's disease. <<<
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153.
半面阳光 (2024-08-31 22:01):
#paper DOI:10.1038/nrg1767, Nature Review Genetics, 2006, Structural variation in the human genome. 发表在Nature review genetics上的一篇关于人类基因组结构变异的综述文章。文章中概括总结的信息主要有以下几点。 (1)人类基因组中的结构变异包括细胞遗传学上可检测到的和亚显微水平的缺失、重复、大片段的拷贝数变异、倒位和易位。 (2)直到近期(文章发表的时间)在技术层面才有能力在整个基因组范围内地较为稳定和准确地检测和描述 1kb ~ 3Mb 范围内的结构变异。 (3)新的基因组检测技术和计算学方法的发展,以及可获得的用于分析的参考序列推动了大量结构变异的发现。 (4)许多研究显示,人类基因组中结构变异的总量可能等于或超过 SNP。 (5)结构变异往往与低拷贝重复 DNA(也称为片段重复)相吻合,因为这些高度相关的序列更有可能发生非等位基因重组和随后的重排。 (6)基因组中的结构变异可通过不同机制直接或间接影响基因剂量,从而影响表型变异和疾病。 (7)对结构变异及其在人群中的频率进行编目,对于疾病图谱研究和正确解读临床诊断测试数据非常重要。 通过这篇综述可以系统地了解基因组结构变异的基本概念,以及基因组技术蓬勃发展和应用起来的这个时期,基因组结构变异这个分支领域的研究关注点。
154.
哪有情可长 (2024-08-31 22:00):
#paper Convergent selection of a WD40 protein that enhances grain yield in maize and rice DOI: 10.1126/science.abg798. 文章对玉米和水稻中控制籽粒行数的基因发现趋同进化。首先在玉米中利用RIL群体鉴定到了一个关于穗行数的基因,图位克隆发现一个KRN2基因,验证分子机理后。后续又在水稻同源鉴定该及验证该基因能够控制水稻的分支数。研究人员在多种环境中种植玉米KRN2和水稻OsKRN2基因敲除系进行产量测试。经过三种环境的田间试验表明,玉米和水稻的KRN2基因敲除系KRN增加使得产量增加,其他农艺性状没有明显改变。这些发现表明,KRN2/OsKRN2等位基因完全丧失功能可提高粮食产量,但对试验环境中其他农艺性状没有明显的负面影响。最后在水稻和玉米的全基因组上鉴定这些同源进化的基因,发现玉米和水稻中都经历了趋同选择的同源基因对,不同类型的淀粉合成相关酶功能高度保守,尽管它们在玉米和水稻中的拷贝数和同工酶数量不同。这些发现表明,一些同源基因在相同的代谢或调控途径中起作用,但它们在不同作物中的选择路径可能不同。通过趋同选择实现的遗传趋同程度与给定选择的基因网络的保守性和复杂性有关。
Science, 2022-3-25. DOI: 10.1126/science.abg7985
Abstract:
A better understanding of the extent of convergent selection among crops could greatly improve breeding programs. We found that the quantitative trait locus KRN2 in maize and its rice ortholog, … >>>
A better understanding of the extent of convergent selection among crops could greatly improve breeding programs. We found that the quantitative trait locus KRN2 in maize and its rice ortholog, OsKRN2 , experienced convergent selection. These orthologs encode WD40 proteins and interact with a gene of unknown function, DUF1644, to negatively regulate grain number in both crops. Knockout of KRN2 in maize or OsKRN2 in rice increased grain yield by ~10% and ~8%, respectively, with no apparent trade-offs in other agronomic traits. Furthermore, genome-wide scans identified 490 pairs of orthologous genes that underwent convergent selection during maize and rice evolution, and these were enriched for two shared molecular pathways. KRN2 , together with other convergently selected genes, provides an excellent target for future crop improvement. <<<
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155.
小年 (2024-08-31 21:29):
#paper The impact of HLA polymorphism on herpesvirus infection and disease DOI :10.1007/s00251-022-01288-z 文章探讨了 HLA 多态性对感染和疾病的影响。以疱疹病毒为切入口,讲述了HLA 的遗传变异与疱疹病毒感染和疾病的易感性密切相关。 文章通过对 HHV 的感染和疾病信息的总结,以及对 HLA 免疫功能的介绍,阐述了 HLA - HHV 协同进化的证据。通过 GWAS 和病例 - 对照研究,确定了与不同疱疹病毒相关的 HLA 等位基因,并探讨了 HLA 等位基因协调可变免疫反应的机制。文章发现,A * 01 和 A * 02 等位基因分别与疱疹病毒感染和疾病的易感性和抵抗力普遍相关,其他 HLA 等位基因与特定疱疹病毒或疾病的关联存在差异。文章强调了 HLA 在疱疹病毒免疫中的重要性,但也指出相关研究存在局限性,未来需要进一步深入研究。 这里这里有趣的是文章讲了疱疹病毒与人类有古老的共同进化关系,由此延伸,如果去找那先与人类关系紧密又比较“古老”的病毒和疾病,应该能发现更多类似的跟我们免疫系统有着共同进化关系的病毒和疾病,说不定能挖出来些东西。
Abstract:
AbstractHuman Leukocyte Antigens (HLA) are cell surface molecules, central in coordinating innate and adaptive immune responses, that are targets of strong diversifying natural selection by pathogens. Of these pathogens, human … >>>
AbstractHuman Leukocyte Antigens (HLA) are cell surface molecules, central in coordinating innate and adaptive immune responses, that are targets of strong diversifying natural selection by pathogens. Of these pathogens, human herpesviruses have a uniquely ancient relationship with our species, where coevolution likely has reciprocating impact on HLA and viral genomic diversity. Consistent with this notion, genetic variation at multiple HLA loci is strongly associated with modulating immunity to herpesvirus infection. Here, we synthesize published genetic associations of HLA with herpesvirus infection and disease, both from case/control and genome-wide association studies. We analyze genetic associations across the eight human herpesviruses and identify HLA alleles that are associated with diverse herpesvirus-related phenotypes. We find that whereas most HLA genetic associations are virus- or disease-specific, HLA-A*01 and HLA-A*02 allotypes may be more generally associated with immune susceptibility and control, respectively, across multiple herpesviruses. Connecting genetic association data with functional corroboration, we discuss mechanisms by which diverse HLA and cognate receptor allotypes direct variable immune responses during herpesvirus infection and pathogenesis. Together, this review examines the complexity of HLA-herpesvirus interactions driven by differential T cell and Natural Killer cell immune responses. <<<
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156.
庞庞 (2024-08-31 16:56):
#paper DOI: 10.1038/s41398-021-01524-2 Contributing factors to advanced brain aging in depression and anxiety disorders 这篇文章探讨了患有 MDD、焦虑症或两者兼有的患者的多变量大脑老化,并研究了哪些因素导致大脑看起来更老。多变量模型表明,躯体抑郁症症状严重程度和抗抑郁药物的使用 对大脑 脑龄 有独特的贡献。
Abstract:
AbstractDepression and anxiety are common and often comorbid mental health disorders that represent risk factors for aging-related conditions. Brain aging has shown to be more advanced in patients with major … >>>
AbstractDepression and anxiety are common and often comorbid mental health disorders that represent risk factors for aging-related conditions. Brain aging has shown to be more advanced in patients with major depressive disorder (MDD). Here, we extend prior work by investigating multivariate brain aging in patients with MDD, anxiety disorders, or both, and examine which factors contribute to older-appearing brains. Adults aged 18–57 years from the Netherlands Study of Depression and Anxiety underwent structural MRI. A pretrained brain-age prediction model based on >2000 samples from the ENIGMA consortium was applied to obtain brain-predicted age differences (brain PAD, predicted brain age minus chronological age) in 65 controls and 220 patients with current MDD and/or anxiety. Brain-PAD estimates were associated with clinical, somatic, lifestyle, and biological factors. After correcting for antidepressant use, brain PAD was significantly higher in MDD (+2.78 years, Cohen’sd = 0.25, 95% CI −0.10-0.60) and anxiety patients (+2.91 years, Cohen’sd = 0.27, 95% CI −0.08-0.61), compared with controls. There were no significant associations with lifestyle or biological stress systems. A multivariable model indicated unique contributions of higher severity of somatic depression symptoms (b = 4.21 years per unit increase on average sum score) and antidepressant use (−2.53 years) to brain PAD. Advanced brain aging in patients with MDD and anxiety was most strongly associated with somatic depressive symptomatology. We also present clinically relevant evidence for a potential neuroprotective antidepressant effect on the brain-PAD metric that requires follow-up in future research. <<<
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157.
李翛然 (2024-08-31 14:38):
#paper Development of Free Energy calculation methods for the study of monosaccharidesconformation in computer simulations Doi:10.3389/fmolb.2021.712085 六元环状单糖的褶皱构象开发新的计算工具来研究和描述在分子动力学模拟里碳水化合物的构象特性。 最重要的问题是力场选择问题,目前力场参数(GROMOS 45a4参数集),不能复现糖成分的偏好构象对葡萄糖构象的研究存在的困难: 无论从实验上(第二流行的构象极其少见的出现)和理论计算模拟上(构象由少数结构主导,导致非遍历性的性能瓶颈 因此加速采样方法比如 metadynamics其中集体变量(CV)和对应坐标系的选择很重要, 要考虑到分子环的非平面和褶皱构象 1. 采用了新的坐标系Cremer-Pole(θ,φ) 2. 采用了新的坐标系Strauss-Pickett(α1,α2,α3) 3. 采用了笛卡尔压缩的Cremer-Pole(qx,qy)
Abstract:
The grand challenge in structure-based drug design is achieving accurate prediction of binding free energies. Molecular dynamics (MD) simulations enable modeling of conformational changes critical to the binding process, leading … >>>
The grand challenge in structure-based drug design is achieving accurate prediction of binding free energies. Molecular dynamics (MD) simulations enable modeling of conformational changes critical to the binding process, leading to calculation of thermodynamic quantities involved in estimation of binding affinities. With recent advancements in computing capability and predictive accuracy, MD based virtual screening has progressed from the domain of theoretical attempts to real application in drug development. Approaches including the Molecular Mechanics Poisson Boltzmann Surface Area (MM-PBSA), Linear Interaction Energy (LIE), and alchemical methods have been broadly applied to model molecular recognition for drug discovery and lead optimization. Here we review the varied methodology of these approaches, developments enhancing simulation efficiency and reliability, remaining challenges hindering predictive performance, and applications to problems in the fields of medicine and biochemistry. <<<
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158.
前进 (2024-08-31 14:29):
#paper https://doi.org/10.15326/jcopdf.2023.0399 Chen, J., Xu, Z., Sun, L., Yu, K., Hersh, C. P., Boueiz, A., ... Batmanghelich, K. (2023). Deep learning integration of chest computed tomography and gene expression identifies novel aspects of COPD. Chronic Obstructive Pulmonary Diseases: Journal of the COPD Foundation, 10(4), 355-368. 这篇论文通过深度学习的方法,联合分析了慢性阻塞性肺病(COPD)患者的胸部CT扫描图像和血液RNA测序数据,以探索肺部结构变化与血液转录组模式之间的新型关系。研究识别出了两种图像-表达轴(IEAs),分别与肺气肿和气道疾病相关,揭示了它们与COPD的不同临床测量和健康预后的关联。此外,研究还通过生物信息学分析,确定了与这两种IEAs相关的生物学通路。这项研究为理解COPD的异质性提供了新的视角,并可能有助于开发针对性的治疗方法。
Abstract:
Rationale: Chronic obstructive pulmonary disease (COPD) is characterized by pathologic changes in the airways, lung parenchyma, and persistent inflammation, but the links between lung structural changes and blood transcriptome patterns … >>>
Rationale: Chronic obstructive pulmonary disease (COPD) is characterized by pathologic changes in the airways, lung parenchyma, and persistent inflammation, but the links between lung structural changes and blood transcriptome patterns have not been fully described.Objections: The objective of this study was to identify novel relationships between lung structural changes measured by chest computed tomography (CT) and blood transcriptome patterns measured by blood RNA sequencing (RNA-seq).Methods: CT scan images and blood RNA-seq gene expression from 1223 participants in the COPD Genetic Epidemiology (COPDGene®) study were jointly analyzed using deep learning to identify shared aspects of inflammation and lung structural changes that we labeled image-expression axes (IEAs). We related IEAs to COPD-related measurements and prospective health outcomes through regression and Cox proportional hazards models and tested them for biological pathway enrichment.Results: We identified 2 distinct IEAs: IEAemph which captures an emphysema-predominant process with a strong positive correlation to CT emphysema and a negative correlation to forced expiratory volume in 1 second and body mass index (BMI); and IEAairway which captures an airway-predominant process with a positive correlation to BMI and airway wall thickness and a negative correlation to emphysema. Pathway enrichment analysis identified 29 and 13 pathways significantly associated with IEAemph and IEAairway, respectively (adjusted p<0.001).Conclusions: Integration of CT scans and blood RNA-seq data identified 2 IEAs that capture distinct inflammatory processes associated with emphysema and airway-predominant COPD. <<<
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159.
钟鸣 (2024-08-30 20:53):
#paper doi:10.1371/journal.pbio.3002771 A taxon-restricted duplicate of Iroquois3 is required for patterning the spider waist 蜘蛛有极其纤细的腰,其形成机制在发育生物学中引人注目但仍未阐明,这里作者使用RNA测序的方法发现了一个此前没有被注意到的基因,无腰基因。作者选择了个体较大容易解剖的蜘蛛,狼蛛。在其不同的发育阶段,对不同部位进行了解剖并分别建库测序。随后分析在不同发育阶段和不同部位(前体后体)中表达趋势明显变化的基因。通过更换筛选策略并结合RNA沉默技术进行功能验证。最后还结合原位杂交技术,观察了沉默无腰基因后的胚胎的形态学变化。
Abstract:
The chelicerate body plan is distinguished from other arthropod groups by its division of segments into 2 tagmata: the anterior prosoma (“cephalothorax”) and the posterior opisthosoma (“abdomen”). Little is understood … >>>
The chelicerate body plan is distinguished from other arthropod groups by its division of segments into 2 tagmata: the anterior prosoma (“cephalothorax”) and the posterior opisthosoma (“abdomen”). Little is understood about the genetic mechanisms that establish the prosomal-opisthosomal (PO) boundary. To discover these mechanisms, we created high-quality genomic resources for the large-bodied spider Aphonopelma hentzi. We sequenced specific territories along the antero-posterior axis of developing embryos and applied differential gene expression analyses to identify putative regulators of regional identity. After bioinformatic screening for candidate genes that were consistently highly expressed in only 1 tagma (either the prosoma or the opisthosoma), we validated the function of highly ranked candidates in the tractable spider model Parasteatoda tepidariorum. Here, we show that an arthropod homolog of the Iroquois complex of homeobox genes is required for proper formation of the boundary between arachnid tagmata. The function of this homolog had not been previously characterized, because it was lost in the common ancestor of Pancrustacea, precluding its investigation in well-studied insect model organisms. Knockdown of the spider copy of this gene, which we designate as waist-less, in P. tepidariorum resulted in embryos with defects in the PO boundary, incurring discontinuous spider germ bands. We show that waist-less is required for proper specification of the segments that span the prosoma-opisthosoma boundary, which in adult spiders corresponds to the narrowed pedicel. Our results demonstrate the requirement of an ancient, taxon-restricted paralog for the establishment of the tagmatic boundary that defines Chelicerata. <<<
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160.
徐炳祥 (2024-08-25 15:03):
#paper doi: 10.1016/j.cell.2024.07.040 Cell, 2024, Spatiotemporal omics for biology and medicine。自从被提出以来,空间多组学技术就以其所具备的高时空分辨率在从系统学的角度理解生物过程中扮演核心角色,因而也成为组学、分子生物学、系统生物学等多个学科的前沿分支。这篇华大最近发表在Cell上的综述对当前空间多组学(尤其空间转录组学)的主流技术路线(基于成像和基于标记测序)的原理,每分支下的关键技术节点及其技术发展脉络、各技术的优势和不足。生物信息分析的主要过程和每个步骤中的常用工具,面临的主要问题及可能的解决方式。空间多组学技术在生命科学研究和临床医学中的成功应用及其挑战等进行了详细梳理。是空间多组学研究入门的良好参考,也可以帮助领域内研究者发现可能的研究目标。
Cell, 2024-Aug-22. DOI: 10.1016/j.cell.2024.07.040 PMID: 39178830
Abstract:
The completion of the Human Genome Project has provided a foundational blueprint for understanding human life. Nonetheless, understanding the intricate mechanisms through which our genetic blueprint is involved in disease … >>>
The completion of the Human Genome Project has provided a foundational blueprint for understanding human life. Nonetheless, understanding the intricate mechanisms through which our genetic blueprint is involved in disease or orchestrates development across temporal and spatial dimensions remains a profound scientific challenge. Recent breakthroughs in cellular omics technologies have paved new pathways for understanding the regulation of genomic elements and the relationship between gene expression, cellular functions, and cell fate determination. The advent of spatial omics technologies, encompassing both imaging and sequencing-based methodologies, has enabled a comprehensive understanding of biological processes from a cellular ecosystem perspective. This review offers an updated overview of how spatial omics has advanced our understanding of the translation of genetic information into cellular heterogeneity and tissue structural organization and their dynamic changes over time. It emphasizes the discovery of various biological phenomena, related to organ functionality, embryogenesis, species evolution, and the pathogenesis of diseases. <<<
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