bluuebunny/crossref_metadata_2025_split huggingface dataset:
SOL3D: Soft-lithography on 3D vat polymerised moulds for fast, versatile, and accessible high-resolution fabrication of customised multiscale cell culture devices with complex designs
Authors: Hagemann Cathleen , Bailey Matthew C. D. , Carraro Eugenia , Lionello Valentina Maria , Khokhar Noreen , Suklai Pacharaporn , Moreno-Gonzalez Carmen , O’Toole Kelly , Konstantinou George , Joshi Sudeep , Giagnorio Eleonora , Bergholt Mads , Imbert Albane , Tedesco Francesco Saverio , Serio Andrea 
Published: February 2022

AbstractCell culture devices, such as microwells and microfluidic chips, are designed to increase the complexity of cell-based models whilst retaining control over culture conditions and have become indispensable platforms for biological systems modelling. From microtopography, microwells, plating devices and microfluidic systems to larger constructs for specific applications such as live imaging chamber slides, a wide variety of culture devices with different geometries have become indispensable in biology laboratories. However, while their application in biological projects is increasing exponentially, due to a combination of the techniques and tools required for their manufacture, and the physical science background sometimes needed, the design and fabrication of such devices directly by biological labs remains a relatively high investment in terms of costs, use of facilities, needed collaborations and time. Whilst commercially available systems are available, these are also often costly, and importantly lack the potential for customisation by each single lab. This combination of factors still limits widespread application of microfabricated custom devices in most biological wet labs.Capitalising on recent important advancements in the fields of bioengineering and microfabrication, and taking advantage of low-cost, high-resolution desktop resin 3D printers combined with PDMS soft lithography, we have developed an optimised low-cost and highly reproducible microfabrication pipeline, capable of generating a wide variety of customisable devices for cell culture and tissue engineering in an easy, fast reproducible way for a fraction of the cost of conventional microfabrication or commercial alternatives. This protocol is designed specifically to be a resource for biological labs with little to none prior exposure to these fields technique and enables the manufacture of complex devices across the µm to cm scale.We provide a ready-to-go pipeline for the efficient treatment of resin-based 3D printed constructs for PDMS curing, using a combination of curing steps, washes and surface treatments. Together with the extensive characterisation of the fabrication pipeline, we show the utilization of this system to a variety of applications and use cases relevant to biological experiments, ranging from micro topographies for cell alignments to complex multi-part hydrogel culturing systems.This methodology can be easily adopted by any wet lab, irrespective of prior expertise or resource availability and will enable the wide adoption of tailored microfabricated devices across many fields of biology.
Spatiotemporal growth pattern during plant nutation implies fast dynamics for cell wall mechanics and chemistry: a multiscale study in Averrhoa carambola
Authors: Rivière Mathieu , Peaucelle Alexis , Derr Julien , Douady Stéphane 
Published: February 2022

Nutation is the most striking and ubiquitous example of the rhythmic nature of plant development. Although there is a consensus that this wide oscillatory motion is driven by growth, its internal mechanisms have not been fully elucidated yet. In this work, we study the specific case of nutation in compound leaves in the archetypal Averrhoa carambola plant. We quantify the macroscopic growth kinematics with time lapse imaging, image analysis and kinematics modeling. We further characterize the mechanical and chemical properties of the cell wall with atomic force microscopy and immunolabelling. Our data first reveal that the differential growth driving nutation is localized and peaks where the average growth drops. We then show this specific spatiotemporal growth profile is compatible with local contraction events. At the cell wall level, differential growth is further colocalized with an asymmetry of the cell wall elastic modulus, and with an asymmetric distribution of homogalacturonans (HG). Our results not only back up the hypothesis of HG being involved in plant growth, but also build up on it by suggesting a dynamic nature for this process.Significance StatementNutation is an oscillatory motion displayed by many organs of growing plants. Most works on nutation focus on its relation to external stimuli attempting to explain its origins. By contrast, its internal physiological mechanisms remain to be fully explored. Here we propose an experimental and multiscale characterization of undisturbed nutation. We determine the macroscopic growth profile and show it is compatible with cell expansion but also local contractions in the tissues. At the microscopic level, we reveal that both the rigidity and composition of the cell wall are asymmetrically distributed where nutation occurs. The combination of results on both scales brings contributions to the understanding of interplay between global movement, local growth, cell wall mechanics and cell wall biochemistry.
A SARS-CoV-2 peptide vaccine which elicits T-cell responses in mice but does not protect against infection or disease
Authors: Baxter Victoria K. , Anderson Elizabeth J. , Taft-Benz Sharon A. , Olsen Kelly , Sambade Maria , Gentry Kaylee M. , Beck Wolfgang , Garness Jason , Woods Allison , Fini Misha , Carpenter Brandon , Smith Christof C. , Heise Mark T. , Vincent Benjamin , Rubinsteyn Alex 
Published: February 2022

AbstractWe vaccinated BALB/c mice with peptides derived from the SARS-CoV-2 proteome selectedin silicoto elicit T-cell responses and/or B-cell responses against linear epitopes. These peptides were administered in combination with either of two adjuvants, poly(I:C) and the STING agonist BI-1387466. Antibody responses against predicted linear epitopes were not observed but both adjuvants consistently elicited T-cell responses to the same peptides, which were primarily from the set chosen for predicted T-cell immunogenicity. The magnitude of T-cell responses was significantly higher with BI-1387466 compared with poly(I:C). Neither adjuvant group, however, provided any protection against infection with the murine adapted virus SARS-CoV-2-MA10 or from disease following infection. In light of more recent evidence for protection from severe disease mediated by CD8+ T-cells, we suspect that the epitopes selected for vaccination were not presented by infected murine cells.
Single-cell analysis reveals the range of transcriptional states of circulating human neutrophils
Authors: Wigerblad Gustaf , Cao Qilin , Brooks Stephen , Naz Faiza , Gadkari Manasi , Jiang Kan , Gupta Sarthak , O’Neil Liam , Dell’Orso Stefania , Kaplan Mariana J. , Franco Luis M. 
Published: February 2022

AbstractNeutrophils are the most abundant leukocytes in human blood and are essential components of innate immunity. Until recently, neutrophils were considered homogeneous and transcriptionally inactive cells, but both concepts are being challenged. To date, neutrophils have been characterized based on discrete parameters including cell-surface markers, buoyancy, maturation status, or tissue localization. Single-cell RNA sequencing (scRNA-seq) offers an unbiased view of cells along a continuum of transcriptional states. However, the use of scRNA-seq to characterize neutrophils has proven technically difficult, explaining in part the paucity of published single-cell data on neutrophils. We have found that modifications to the data analysis pipeline, rather than to the existing scRNA-seq chemistries, can significantly increase the detection of human neutrophils in scRNA-seq. We have then applied a modified pipeline to the study of human peripheral blood neutrophils. Our findings indicate that circulating human neutrophils are transcriptionally heterogeneous cells, which can be classified into one of four transcriptional clusters that are reproducible among healthy human subjects. We demonstrate that peripheral blood neutrophils shift from relatively immature (Nh0) cells, through a transitional phenotype (Nh1), into one of two endpoints defined by either relative transcriptional inactivity (Nh2) or high expression of type I interferon-inducible genes (Nh3). Transitions among states are characterized by the expression of specific transcription factors. By simultaneously measuring surface proteins and intracellular transcripts at the single-cell level, we show that these transcriptional subsets are independent of the canonical surface proteins that are commonly used to define and characterize human neutrophils. These findings provide a new view of human neutrophil heterogeneity, with potential implications for the characterization of neutrophils in health and disease.
Novel and Reported Compensatory Mutations in rpoABC Associate Specifically with Predominant Mycobacterium tuberculosis Rifampicin Resistance Marker rpoB:S450L
Authors: Conkle-Gutierrez D , Ramirez-Busby SM , Gorman BM , Elghraoui A , Hoffner S , Elmaraachli W , Valafar F 
Published: February 2022

AbstractBackgroundRifampicin (RIF) is a key first-line drug used to treat tuberculosis, a pulmonary disease caused by Mycobacterium tuberculosis. However antibiotic resistance to RIF is prevalent despite an apparent fitness cost. RIF resistance is primarily caused by mutations in the RIF resistance determining region in the rpoB gene, at the cost of slower growth in rich media. Compensatory mutations in the genes rpoA and rpoC have been shown to alleviate this fitness cost. These compensatory mutations may explain how RIF resistant strains have spread so rapidly. However, the effect of compensation on transmission is still unclear, partly because of uncertainty over which rpoABC mutations compensate for which RIF resistance markers.ObjectivesWe performed an association study on a globally representative set of 4309 whole genome sequenced clinical M. tuberculosis isolates to identify novel putative compensatory mutations, determine the prevalence of known and previously reported putative compensatory mutations, and determine which RIF resistance markers associate with these compensatory mutations.Results and ConclusionsOnly 20.0% (216/1079) of RIF resistant isolates carried previously reported high-probability compensatory mutations, suggesting existence of other compensatory mutations. Using a strict phylogenetic approach, we identified 18 novel putative compensatory mutations in rpoC, rpoB, and rpoA. Novel and previously reported compensatory mutations were strongly associated with the RIFR marker rpoB:S450L, suggesting compensation may be specific to particular RIFR markers. These findings will aid identification of RIF-resistant M. tuberculosis strains with restored fitness. Such strains pose a greater risk of causing resistant outbreaks.
Trunk neural crest migratory position and asymmetric division predict terminal differentiation
Authors: Alhashem Zain , Camargo-Sosa Karen , Kelsh Robert N , Linker Claudia 
Published: February 2022

AbstractThe generation of complex structures during embryogenesis requires the controlled migration and differentiation of cells from distant origins. How migration and differentiation are coordinated and impact each other to form functional structures is not fully understood. Neural crest cells migrate extensively giving rise to many cell types. In the trunk, neural crest migrate collectively forming chains comprised of cells with distinct migratory identities: one leader cell at the front of the group directs migration, while followers track the leader forming the body of the chain. Herein we analysed the relationship between trunk neural crest migratory identity and terminal differentiation. We found that trunk neural crest migration and fate allocation is coherent. Leader cells that initiate movement give rise to the most distal derivativities. Interestingly, the asymmetric division of leaders separates migratory identity and fate. The distal daughter cell retains the leader identity and clonally forms the Sympathetic Ganglia. The proximal sibling migrates as a follower and gives rise to Schwann cells. The sympathetic neuron transcription factor phox2bb is strongly expressed by leaders from early stages of migration, suggesting that specification and migration occur concomitantly and in coordination. Followers divide symmetrically and their fate correlates with their position in the chain.
PERK Signaling Promotes Mitochondrial Elongation By Remodeling Membrane Phosphatidic Acid
Authors: Perea Valerie , Cole Christian , Lebeau Justine , Dolina Vivian , Baron Kelsey R. , Madhavan Aparajita , Kelly Jeffery W. , Grotjahn Danielle A. , Wiseman R. Luke 
Published: February 2022

SUMMARYEndoplasmic reticulum (ER) stress and mitochondrial dysfunction are linked in the onset and pathogenesis of numerous diseases. This has led to considerable interest in defining the mechanisms responsible for regulating mitochondria during ER stress. The PERK signaling arm of the unfolded protein response (UPR) has emerged as a prominent ER stress-responsive signaling pathway that regulates diverse aspects of mitochondrial biology. Here, we show that PERK activity also promotes adaptive remodeling of mitochondrial membrane phosphatidic acid (PA) to induce protective mitochondrial elongation during ER stress. We find that PERK activity is required for ER stress-dependent increases in both cellular PA and YME1L-dependent degradation of the intramitochondrial PA transporter PRELID1. Together, these processes lead to the accumulation of PA on the outer mitochondrial membrane where it induces mitochondrial elongation by inhibiting mitochondrial fission. Our results establish a new role for PERK in the adaptive remodeling of mitochondrial phospholipids and demonstrate that PERK-dependent PA regulation functions to adapt organellar shape in response to ER stress.
Functional stemness-related genes revealed by single-cell profiling of naïve and stimulated human CD34+ cells from CB and mPB
Authors: Dong Guoyi , Xu Xiaojing , Li Yue , Ouyang Wenjie , Zhao Weihua , Gu Ying , Li Jie , Liu Tianbin , Zeng Xinru , Zou Huilin , Wang Shuguang , Liu Sixi , Sun Hai-Xi , Liu Chao 
Published: February 2022

AbstractHematopoietic stem cells (HSCs) from different sources show varied repopulating capacity, and HSCs lose their stemness after long-time ex vivo culture. However, the underlying mechanisms of the stemness differences because of the cell sources and the culture stimulation are not fully understood. Here, we applied single-cell RNA-seq (scRNA-seq) to analyze the naïve and stimulated human CD34+ cells from cord blood (CB) and mobilized peripheral blood (mPB). We collected over 16,000 single-cell data to construct a comprehensive trajectory inference map and characterized the HSCs population on the hierarchy top, which is under quiescent state. Then we compared HSCs in CB to those in mPB and HSCs of naïve samples to those of cultured samples, and identified stemness-related genes (SRGs) associated with culture time (CT-SRGs) and cell source (CS-SRGs), respectively. Interestingly, CT-SRGs and CS-SRGs share genes enriched in the signaling pathways such as mRNA catabolic process, Translational initiation, Ribonucleoprotein complex biogenesis and Cotranslational protein targeting to membrane, suggesting dynamic protein translation and processing may be a common requirement for stemness maintenance. Meanwhile, CT-SRGs are enriched in pathways involved in glucocorticoid and corticosteroid response that affect HSCs homing and engraftment. In contrast, CS-SRGs specifically contain genes related purine and ATP metabolic process which is important to initiate hematopoiesis. Finally, we presented an application through a small-scale drug screening using Connectivity Map (CMap) against CT-SRGs and found a small molecule cucurbitacin I, targeting STAT3/JAK2, can efficiently expand HSCs ex vivo while maintaining its stemness. These results indicate SRGs revealed by scRNA-seq can provide helpful insights to understand the stemness differences under diverse circumstances, and CT-SRGs can be a valuable database to identify candidates enhancing functional HSCs expansion during ex vivo culture.
Maternal and/or direct supplementation with a combination of a casein hydrolysate and yeast β-glucan on post-weaning performance and intestinal health in the pig
Authors: Conway Eadaoin , O’Doherty John V. , Mukhopadhya Anindya , Dowley Alison , Vigors Stafford , Maher Shane , Ryan Marion T. , Sweeney Torres 
Published: February 2022

AbstractA 2 × 2 factorial experiment was conducted to investigate the effect of maternal supplementation from day 83 of gestation and/or direct supplementation from weaning of a bovine casein hydrolysate plus a yeast β-glucan (CH-YBG) on pig performance and intestinal health on day ten post-weaning. Twenty cross bred gilts (Large White × Landrace) were randomly assigned to one of two dietary groups (n = 10 gilts/group): basal diet (basal sows) and basal diet supplemented with CH-YBG (supplemented sows) from day 83 of gestation until weaning (2g/sow/day). At weaning, 120 pigs (6 pigs/sow) were selected. The two dam groups were further divided, resulting in four experimental groups (10 replicates/group; 3 pigs/pen) as follows: 1) BB (basal sows + basal pigs); 2) BS (basal sows + supplemented pigs); 3) SB (supplemented sows + basal pigs); 4) SS (supplemented sows + supplemented pigs). Supplemented pigs were offered 0.5g CH-YBG/kg of feed for 10 days post-weaning. On day 10 post-weaning, 1 pig/pen was humanely sacrificed and samples were taken from the gastrointestinal tract for analysis. Pigs weaned from supplemented sows (SS, SB) had reduced faecal scores and incidence of diarrhoea (P<0.05) compared to pigs weaned from basal sows (BB, BS), with SS pigs not displaying the transient rise in faecal scores seen in the other three groups from day 3 to day 10 post-weaning (P<0.05). Pigs weaned from supplemented sows had reduced feed intake (P<0.05), improved feed efficiency (P<0.05), increased butyrate concentrations (P<0.05), increased abundance of Lactobacillus (P<0.05) and decreased abundance of Enterobacteriaceae and Campylobacteraceae (P<0.05) compared to pigs weaned from basal sows. In conclusion, a combination of both maternal and direct supplementation with CH-YBG is the desirable feeding strategy to ameliorate the post-weaning challenge in pig production systems.
Coursing hyenas and stalking lions: the potential for inter- and intraspecific interactions
Authors: Barker Nancy A. , Joubert Francois G. , Kasaona Marthin , Shatumbu Gabriel , Stowbunenko Vincent , Alexander Kathleen A. , Slotow Rob , Getz Wayne M. 
Published: February 2022

AbstractResource partitioning promotes coexistence among guild members, and carnivores reduce interference competition through behavioural mechanisms that promote spatio-temporal separation. We analyzed sympatric lion and spotted hyena movements and activity patterns to ascertain the mechanisms facilitating their coexistence within semi-arid and wetland ecosystems. We identified recurrent high-use (revisitation) and extended stay (duration) areas within home ranges, and correlated environmental variables with movement-derived measures of inter- and intraspecific interactions. Spatial overlaps among lions and hyenas occurred at edges of home ranges, around water-points, along pathways between patches of high-use areas, and expanded during the wet season. Lions shared more of their home ranges with spotted hyenas in arid ecosystems, but shared more of their ranges with conspecifics in mesic environments. Despite shared space use, we found evidence for subtle temporal differences in the nocturnal movement and activity patterns between the two predators, suggesting a fine localized-scale avoidance strategy. Revisitation frequency and duration within home ranges were influenced by interspecific interactions, subsequent to land cover categories and diel cycles. Intraspecific interactions were also important for lions and, for hyenas, moon illumination and ungulates attracted to former anthrax carcass sites in Etosha, with distance to water in Chobe/Linyanti. Recursion and duration according to locales of competitor probabilities were similar among female lions and both sexes of hyenas, but different for male lions. Our results suggest that lions and spotted hyenas mediate the potential for interference competition through subtle differences in temporal activity, fine-scale habitat use differentiation, and localized reactive-avoidance behaviours. These findings enhance our understanding of the potential effects of interspecific interactions among large carnivore space-use patterns within an apex predator system, and show adaptability across heterogeneous and homogeneous environments. Future conservation plans should emphasize the importance of inter- and intraspecific competition within large carnivore communities, particularly moderating such effects within increasingly fragmented landscapes.
Quantifying the phenotypic information in mRNA abundance
Authors: Maltz Evan , Wollman Roy 
Published: February 2022

AbstractQuantifying the dependency between mRNA abundance and downstream cellular phenotypes is a fundamental open problem in biology. Advances in multimodal single cell measurement technologies provide an opportunity to apply new computational frameworks to dissect the contribution of individual genes and gene combinations to a given phenotype. Using an information theory approach, we analyzed multimodal data of the expression of 83 genes in the Ca2+signaling network and the dynamic Ca2+response in the same cell. We found that the overall expression levels of these 83 genes explain approximately 60% of Ca2+signal entropy. The average contribution of each single gene was 16%, revealing a large degree of redundancy between genes. Using different heuristics we estimated the dependency between the size of a gene set and its information content, revealing that on average a set of 53 genes contains 90% of the information about Ca2+signaling within the cellular transcriptional state. Our results provide the first direct quantification of information content about complex cellular phenotype that exists in mRNA abundance measurements.
Complex effects of chytrid parasites on the growth of the cyanobacteriumPlanktothrix rubescensacross interacting temperature and light gradients
Authors: Wierenga Joren , Thomas Mridul K. , Ranjan Ravi , Ibelings Bas W. 
Published: February 2022

AbstractChytrids are important drivers of aquatic ecosystems as phytoplankton parasites. The interaction between these parasites and their hosts are shaped by abiotic factors such as temperature and light. Here, we performed a full-factorial experiment to study how temperature and light interact to affect the dynamics of the bloom-forming toxic cyanobacteriumPlanktothrix rubescensand its chytrid parasite. We used a dynamic host-parasite model to explore how temperature and light affect long term dynamics. At low temperatures, chytrids do not survive. Higher light and temperature levels stimulated both phytoplankton and chytrid growth, with complex effects on their dynamics. Model exploration indicates that increasing temperature and light shifts equilibrium outcomes fromP. rubescenspersisting alone to stable coexistence and then to limit cycles. This provides an alternative biological explanation for whyP. rubescensis mainly found in the relatively cold and dark lake metalimnion – it may enable avoidance of its parasite. Our study emphasizes the importance of investigating how abiotic factors interact with biotic interactions to drive complex outcomes.