bluuebunny/crossref_metadata_2025_split huggingface dataset:
Data-Driven Strain Design Using Aggregated Adaptive Laboratory Evolution Mutational Data
Authors: Phaneuf Patrick V. , Zielinski Daniel C. , Yurkovich James T. , Johnsen Josefin , Szubin Richard , Yang Lei , Kim Se Hyeuk , Schulz Sebastian , Wu Muyao , Dalldorf Christopher , Ozdemir Emre , Palsson Bernhard O. , Feist Adam M. 
Published: July 2021

AbstractMicrobes are being engineered for an increasingly large and diverse set of applications. However, the designing of microbial genomes remains challenging due to the general complexity of biological system. Adaptive Laboratory Evolution (ALE) leverages nature’s problem-solving processes to generate optimized genotypes currently inaccessible to rational methods. The large amount of public ALE data now represents a new opportunity for data-driven strain design. This study presents a novel and first of its kind meta-analysis workflow to derive data-driven strain designs from aggregate ALE mutational data using rich mutation annotations, statistical and structural biology methods. The mutational dataset consolidated and utilized in this study contained 63 Escherichia coli K-12 MG1655 based ALE experiments, described by 93 unique environmental conditions, 357 independent evolutions, and 13,957 observed mutations. High-level trends across the entire dataset were established and revealed that ALE-derived strain designs will largely be gene-centric, as opposed to non-coding, and a relatively small number of variants (approx. 4) can significantly alter cellular states and provide benefits which range from an increase in fitness to a complete necessity for survival. Three novel experimentally validated designs relevant to metabolic engineering applications are presented as use cases for the workflow. Specifically, these designs increased growth rates with glycerol as a carbon source through a point mutation to glpK and a truncation to cyaA or increased tolerance to toxic levels of isobutyric acid through a pykF truncation. These results demonstrate how strain designs can be extracted from aggregated ALE data to enhance strain design efforts.Abstract Figure
CRISPR screens for host factors critical for infection by SARS-CoV-2 variants of concern identify GATA6 as a central modulator of ACE2
Authors: Israeli Ma’ayan , Finkel Yaara , Yahalom-Ronen Yfat , Paran Nir , Chitlaru Theodor , Israeli Ofir , Cohen-Gihon Inbar , Aftalion Moshe , Falach Reut , Elia Uri , Nemet Ital , Kliker Limor , Mandelboim Michal , Beth-Din Adi , Israely Tomer , Cohen Ofer , Stern-Ginossar Noam , Bercovich-Kinori Adi 
Published: July 2021

AbstractThe global spread of SARS-CoV-2 led to the most challenging pandemic in this century, posing major economic and health challenges worldwide. Revealing host genes essential for infection by multiple variants of SASR-CoV-2 can provide insights into the virus pathogenesis, and facilitates the development of novel broad-spectrum host-directed therapeutics. Here, employing genome-scale CRISPR screens, we provide a comprehensive data-set of cellular factors that are exploited by WT-SARS-CoV-2 as well as two additional recently emerged variants of concerns (VOCs), Alpha and Beta. These screens identified known and novel host factors critical for SARS-CoV-2 infection, including various components belonging to the Clathrin-dependent transport pathway, ubiquitination and Heparan sulfate biogenesis. In addition, the host phosphatidylglycerol biosynthesis processes appeared to have major anti-viral functions. Comparative analysis of the different VOCs revealed the host factors KREMEN2 and SETDB1 as potential unique candidates required only to the Alpha variant, providing a possible explanation for the increased infectivity of this variant. Furthermore, the analysis identified GATA6, a zinc finger transcription factor, as an essential pro-viral gene for all variants inspected. We revealed that GATA6 directly regulates ACE2 transcription and accordingly, is critical for SARS-CoV-2 cell entry. Analysis of clinical samples collected from SARS-CoV-2 infected individuals showed an elevated level of GATA6, indicating the important role GATA6 may be playing in COVID-19 pathogenesis. Finally, pharmacological inhibition of GATA6 resulted in down-modulation of ACE2 and consequently to inhibition of the viral infectivity. Overall, we show GATA6 represents a target for the development of anti-SARS-CoV-2 therapeutic strategies and reaffirm the value of the CRISPR loss-of-function screens in providing a list of potential new targets for therapeutic interventions.
Intramembrane protease SPP defines a cholesterol-regulated abundance control of the mevalonate pathway enzyme SQS
Authors: Avci Dönem , Heidasch Ronny , Costa Martina , Lüchtenborg Christian , Kale Dipali , Brügger Britta , Lemberg Marius K. 
Published: July 2021

AbstractIntramembrane proteolysis regulates important processes such as signaling and transcriptional and posttranslational abundance control of proteins with key functions in metabolic pathways. This includes transcriptional control of mevalonate pathway genes, thereby ensuring balanced biosynthesis of cholesterol and other isoprenoids. Our work shows that, at high cholesterol levels, signal peptide peptidase (SPP) cleaves squalene synthase (SQS), an enzyme that defines the branching point for allocation of isoprenoids to the sterol and non-sterol arms of the mevalonate pathway. This intramembrane cleavage releases SQS from the membrane and targets it for proteasomal degradation. Regulation of this mechanism is achieved by the E3 ubiquitin ligase TRC8 that, in addition to ubiquitinating SQS in response to cholesterol levels, acts as an allosteric activator of SPP-catalyzed intramembrane cleavage of SQS. Cellular cholesterol levels increase in the absence of SPP activity. Hence, SPP-TRC8 mediated abundance control of SQS acts as a regulation step within the mevalonate pathway.
A dynamic and combinatorial histone code drives malaria parasite asexual and sexual development
Authors: von Grüning Hilde , Coradin Mariel , Mendoza Mariel R. , Reader Janette , Sidoli Simone , Garcia Benjamin A. , Birkholtz Lyn-Marie 
Published: July 2021

AbstractA ‘histone code’ defines system-level crosstalk between histone post-translational modifications (PTMs) to induce specific biological outcomes. Proteome-scale information of co-existing PTM across the entire chromatin landscape of the malaria parasite, Plasmodium falciparum, was lacking. Here, we used advanced quantitative middle-down proteomics to identify combinations of PTMs in both the proliferative, asexual stages and transmissible, sexual gametocyte stages of P. falciparum. We provide an updated, high-resolution compendium of 72 PTMs on H3 and H3.3, of which 30 are novel to the parasite. Co-existing PTMs with unique stage distinction was identified, indicating a dynamic and complex histone code with increased connectivity of novel PTMs seen in gametocytes. Chromatin proteomics of a gametocyte-specific combination, H3R17me2K18acK23ac, identified a SAGA-like effector complex (including the transcription factor AP2-G2) tied to this combination to regulate gene expression in mature gametocytes. Ultimately, this study unveils previously undiscovered histone PTMs and their functional relationship with co-existing partners. These results highlight that investigating chromatin regulation in the parasite using single histone PTM assays might overlook higher order gene regulation for distinct proliferation and differentiation processes.
Inference of polyploid origin and inheritance mode from population genomic data
Authors: Scott Alison Dawn , Van de Velde Jozefien D. , Novikova Polina Yu. 
Published: July 2021

Summary/AbstractWhole-genome duplications yield varied chromosomal pairing patterns, ranging from strictly bivalent to multivalent, resulting in disomic and polysomic inheritance modes. In the bivalent case, homeologous chromosomes form pairs, where in a multivalent pattern all copies are homologous and are therefore free to pair and recombine. As sufficient sequencing data is more readily available than high-quality cytological assessments of meiotic behavior or population genetic assessment of allelic segregation, especially for non-model organisms, here we describe two bioinformatics approaches to infer origins and inheritance modes of polyploids using short-read sequencing data. The first approach is based on distributions of allelic read depth at the heterozygous sites within an individual, as the expectations of such distributions are different for disomic and polysomic inheritance modes. The second approach is more laborious and based on a phylogenetic assessment of partially phased haplotypes of a polyploid in comparison to the closest diploid relatives. We discuss the sources of deviations from expected inheritance patterns, advantages and pitfalls of both methods, effects of mating types on the performance of the methods, and possible future developments.
Phytoene synthase 2 in tomato fruits remains functional and contributes to abscisic acid formation
Authors: Gupta Prateek , Rodriguez-Franco Marta , Bodanapu Reddaiah , Sreelakshmi Yellamaraju , Sharma Rameshwar 
Published: July 2021

AbstractIn ripening tomato fruits, the leaf-specific carotenoids biosynthesis mediated by phytoene synthase 2 (PSY2) is replaced by a fruit-specific pathway by the expression of two chromoplast-specific genes: phytoene synthase 1 (PSY1) and lycopene-β-cyclase (CYCB). Though both PSY1 and PSY2 genes express in tomato fruits, the functional role of PSY2 is not known. To decipher whether PSY2-mediated carotenogenesis operates in ripening fruits, we blocked the in vivo activity of lycopene-β-cyclases in fruits of several carotenoids and ripening mutants by CPTA (2-(4-Chlorophenylthio)triethylamine hydrochloride), an inhibitor of lycopene-β-cyclases. The CPTA-treatment induced accumulation of lycopene in leaves, immature-green and ripening fruits. Even, in psy1 mutants V7 and r that are deficient in fruit-specific carotenoid biosynthesis, CPTA triggered lycopene accumulation but lowered the abscisic acid level. Differing from fruit-specific carotenogenesis, CPTA-treated V7 and r mutant fruits accumulated lycopene but not phytoene and phytofluene. The lack of phytoene and phytofluene accumulation was reminiscent of PSY2-mediated leaf-like carotenogenesis, where phytoene and phytofluene accumulation is never seen. The lycopene accumulation was associated with the partial transformation of chloroplasts to chromoplasts bearing thread-like crystalline structures. Our study uncovers the operation of a parallel carotenogenesis pathway mediated by PSY2 that provides precursors for abscisic acid biosynthesis in ripening tomato fruits.Significance statementIt is believed that in ripening tomato fruits phytoene synthase 2 that drives carotenoid biosynthesis in leaves is redundant. Contrary to this, we show that in phytoene synthase 1 mutant fruit that is bereft of lycopene, the chemical inhibition of lycopene β-cyclases triggers lycopene accumulation. Our results uncover that phytoene synthase 2 remains functional in ripening fruits and provides precursors for abscisic acid formation in fruits.
Single-cell RNA Sequencing Reveals the Temporal Diversity and Dynamics of Cardiac Immunity after Myocardial Infarction
Authors: Jin Kaiyu , Gao Shan , Yang Penghui , Guo Rongfang , Li Dan , Zhang Yunsha , Lu Xiaoyan , Fan Guanwei , Fan Xiaohui 
Published: July 2021

AbstractMyocardial infarction (MI) is strongly associated with the temporal regulation of cardiac immunity. However, a variety of current clinical trials have failed because of the lack of post-MI immunomodulating/anti-inflammatory targets. We performed single-cell RNA sequencing analysis of cardiacCd45+immune cell at 0, 3, 7, and 14 days after injury in a mouse left anterior descending coronary artery ligation model. Major immune cell populations, distinct subsets, and dynamic changes were identified. Macrophages (Mø)/monocytes were most abundant, peaking at 3 days after infarction. Mø-5 and Mø-6 were the predominant infiltrated subsets at this time point, with strong expression of inflammatory factors. Further analysis demonstrated that suppressing these sets attenuated pathological MI progression by preventing subsequent leukocyte extravasation and adverse remodeling. We also detected abundant apoptotic neutrophils and a profibrotic macrophage subset on days 7 and 14 respectively. These results provide a basis for developing cell type- and time-specific interventions in MI.Graphic abstractTemporal regulation of cardiac immunity is strongly associated with the onset, progression, and outcomes of MI. Our study of time-series scRNA-seq on the whole cardiac immune cells isolated from the LAD ligation mice and the tanshinone IIA treated mice shed light on the underlying pathology of MI.
Typical and disrupted brain circuitry for conscious awareness in full-term and preterm infants
Authors: Hu Huiqing , Cusack Rhodri , Naci Lorina 
Published: July 2021

AbstractOne of the great frontiers of consciousness science is understanding how early consciousness arises in the development of the human infant. The reciprocal relationship between the default mode network (DMN) and frontoparietal networks — the dorsal attention network (DAN) and executive control network (ECN) — is thought to facilitate integration of information across the brain and its availability for conscious access to a wide set of mental operations. It remains unknown whether the brain mechanism of conscious awareness is instated in infants from birth. To address this gap, we asked what the impact of prematurity and neonate age is on the development the default mode and fronto-parietal networks, and of their reciprocal relationship. To address these questions, we used the Developing Human Connectome Project (dHCP), a unique Open Science project which provides a large sample of neonatal functional Magnetic Resonance Imaging (fMRI) data with high temporal and spatial resolution. Resting state fMRI data for full-term neonates (N = 282, age 41.2 w ± 12 d), and preterm neonates scanned at term-equivalent age (TEA) (N = 73, 40.9 w ± 14.5 d), or before TEA (N = 73, 34.6 w ± 13.4 d) were obtained from the dHCP, and for a reference adult group (N = 176, 22 – 36 years), from the Human Connectome Project. For the first time, we show that the reciprocal relationship between the DMN and DAN was present at full-term birth or TEA. Although different from the adult networks, the DMN, DAN and ECN were present as distinct networks at full-term birth or TEA, but premature birth disrupted network development. By contrast, neonates before TEA showed dramatic underdevelopment of high-order networks. Only the DAN was present as a distinct network and the reciprocal network relationship was not yet formed. Our results suggest that, at full-term birth or by term-equivalent age, infants possess key features of the neural circuitry that enables integration of information across diverse sensory and high-order functional modules, giving rise to conscious access. Conversely, they suggest that this brain infrastructure is not present before infants reach term-equivalent age. These findings improve understanding of the ontogeny of high-order network dynamics that support conscious awareness, and of their disruption by premature birth.
CHOmpact: a reduced metabolic model of Chinese hamster ovary cells with enhanced interpretability
Authors: Jiménez del Val Ioscani , Kyriakopoulos Sarantos , Albrecht Simone , Stockmann Henning , Rudd Pauline M , Polizzi Karen M , Kontoravdi Cleo 
Published: July 2021

AbstractMetabolic modelling has emerged as a key tool for the characterisation of biopharmaceutical cell culture processes. Metabolic models have also been instrumental in identifying genetic engineering targets and developing feeding strategies that optimise the growth and productivity of Chinese hamster ovary (CHO) cells. Despite their success, metabolic models of CHO cells still present considerable challenges. Genome scale metabolic models (GeMs) of CHO cells are very large (>6000 reactions) and are, therefore, difficult to constrain to yield physiologically consistent flux distributions. The large scale of GeMs also makes interpretation of their outputs difficult. To address these challenges, we have developed CHOmpact, a reduced metabolic network that encompasses 101 metabolites linked through 144 reactions. Our compact reaction network allows us to deploy multi-objective optimisation and ensure that the computed flux distributions are physiologically consistent. Furthermore, our CHOmpact model delivers enhanced interpretability of simulation results and has allowed us to identify the mechanisms governing shifts in the anaplerotic consumption of asparagine and glutamate as well as an important mechanism of ammonia detoxification within mitochondria. CHOmpact, thus, addresses key challenges of large-scale metabolic models and, with further development, will serve as a platform to develop dynamic metabolic models for the control and optimisation of biopharmaceutical cell culture processes.
SOX4 facilitates PGR protein stability and FOXO1 expression conducive for human endometrial decidualization
Authors: Huang Pinxiu , Deng Wenbo , Bao Haili , Lin Zhong , Liu Mengying , Wu Jinxiang , Zhou Xiaobo , Qiao Manting , Yang Yihua , Cai Han , Rao Faiza , Chen Jingsi , Chen Dunjin , Lu Jinhua , Wang Haibin , Qin Aiping , Kong Shuangbo 
Published: July 2021

AbstractThe establishment of receptive endometrium in human necessitates appropriate decidualization of stromal cells, which involves steroids regulated periodic transformation of endometrial stromal cells during menstrual cycle. Insufficient decidualization of endometrium contributes to not only the failure of embryo implantation and unexplained infertility, but also the occurrence of recurrent spontaneous abortion, intrauterine growth retardation, preeclampsia, and other clinical gynecological diseases. However, the potential molecular regulatory mechanism underlying the initiation and maintenance of decidualization in humans is yet to be fully elucidated. In this investigation, we document that SOX4 is a key regulator of human endometrial stromal cells (hESCs) decidualization by directly regulating PRL and FOXO1 expression as revealed by whole genomic binding of SOX4 assay and RNA-Seq. Besides, our immunoprecipitation and mass spectrometry results unravel that SOX4 modulates progesterone receptor (PGR) stability through repressing E3 ubiquitin ligase HERC4 mediated degradation. More importantly, we provide evidence that dysregulated SOX4-HERC4-PGR axis is a potential cause of defective decidualization and recurrent implantation failure (RIF) in IVF patients. In summary, this study evidences that SOX4 is a new and critical regulator for human endometrial decidualization, and provides insightful information for the pathology of decidualization-related infertility and will pave the way for pregnancy improvement.
Genetic basis of enhanced stress resistance in long-lived mutants highlights key role of innate immunity in determining longevity
Authors: Soo Sonja K. , Rudich Paige D. , Mistry Meeta , Van Raamsdonk Jeremy M. 
Published: July 2021

ABSTRACTMutations that extend lifespan are associated with enhanced resistance to stress. To better understand the molecular mechanisms underlying this relationship, we studied nine long-lived C. elegans mutants representative of different pathways of lifespan extension. We directly compared the magnitude of their lifespan extension and their ability to resist various external stressors (heat, oxidative stress, bacterial pathogens, osmotic stress, and anoxia). Furthermore, we analysed gene expression in each of these mutants to identify genes and pathways responsible for the enhanced resistance to stress. All of the examined long-lived mutants have increased resistance to one or more type of stress. Resistance to each of the examined types of stress had a significant, positive correlation with lifespan, with bacterial pathogen resistance showing the strongest relationship. All of the examined long-lived mutants have significant upregulation of multiple stress response pathways but differ in which stress response pathway has the greatest enrichment of genes. We used RNA sequencing data to identify which genes are most highly correlated with each type of stress resistance. There was a highly significant overlap between genes highly correlated with stress resistance, and genes highly correlated with longevity, suggesting that the same genetic pathways drive both phenotypes. This was especially true for genes correlated with bacterial pathogen resistance, which showed an 84% overlap with genes correlated with lifespan. Overall, our results demonstrate a strong correlation between stress resistance and longevity that results from the high degree of overlap in genes contributing to each phenotype.SIGNIFICANCE STATEMENTWhile increased resistance to stress has been correlated with longevity, the genetic basis for this relationship is incompletely understood. To advance our understanding of the relationship between stress resistance and lifespan, we measured lifespan, stress resistance and gene expression in a panel of nine long-lived mutants in C. elegans. All of the long-lived mutants exhibit enhanced resistance to at least one external stressor resulting from significant upregulation of multiple stress response pathways. Importantly, our data indicates that the same genetic pathways control stress resistance and lifespan, thereby accounting for the strong correlation between these two phenotypes. This work demonstrates the importance of innate immune signaling and other stress response pathways in determining longevity.
Strategies of tolerance reflected in two North American maple genomes
Authors: McEvoy Susan L. , Sezen U. Uzay , Trouern-Trend Alexander , McMahon Sean M. , Schaberg Paul G. , Yang Jie , Wegrzyn Jill L. , Swenson Nathan G. 
Published: July 2021

AbstractMaples (the genus Acer) represent important and beloved forest, urban, and ornamental trees distributed throughout the Northern hemisphere. They exist in a diverse array of native ranges and distributions, across spectrums of tolerance or decline, and have varying levels of susceptibility to biotic and abiotic stress. Among Acer species, several stand out in their importance to economic interest. Here we report the first two chromosome-scale genomes for North American species, Acer negundo and Acer saccharum. Both assembled genomes contain scaffolds corresponding to 13 chromosomes, with A. negundo at a length of 442 Mb, N50 of 32 Mb and 30,491 genes, and A. saccharum at 626 Mb, N50 of 46 Mb, and 40,074 genes. No recent whole genome duplications were detected, though A. saccharum has local gene duplication and more recent bursts of transposable elements, as well as a large-scale translocation between two chromosomes. Genomic comparison revealed that A. negundo has a smaller genome with recent gene family evolution that is predominantly contracted and expansions that are potentially related to invasive tendencies and tolerance to abiotic stress. Examination of expression from RNA-Seq obtained from A. saccharum grown in long-term aluminum and calcium soil treatments at the Hubbard Brook Experimental Forest, provided insights into genes involved in aluminum stress response at the systemic level, as well as signs of compromised processes upon calcium deficiency, a condition contributing to maple decline.Significance statementThe first chromosome-scale assemblies for North American members of the Acer genus, sugar maple (Acer saccharum) and boxelder (Acer negundo), as well as transcriptomic evaluation of abiotic stress response in A. saccharum. This integrated study describes in-depth aspects contributing to each species’ approach to tolerance and applies current knowledge in many areas of plant genome biology with Acer physiology to help convey the genomic complexities underlying tolerance in broadleaf tree species.