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1.
Article in English | MEDLINE | ID: mdl-38335998

ABSTRACT

INTRODUCTION: Arthroscopy is a well-established diagnostic modality for various orthopaedic conditions in veterinary medicine. The aim of this study was to describe the relationship of canine shoulder arthroscopy portals to major muscular, ligamentous, and neurovascular structures for anatomical and safety considerations. MATERIALS AND METHODS: Arthroscopic exploration of 20 adult canine cadaver shoulders was performed. Each shoulder region was dissected layer by layer to the level of the joint. Musculotendinous, ligamentous, and cartilaginous lesions were documented. The distance was measured from each portal to neurovascular structures encountered. RESULTS: Muscular lesions included the deltoideus, cleidobrachialis, omotransversarius, supraspinatus, infraspinatus, and teres minor muscles. The neurovascular structures identified were the omobrachial vein, the caudal circumflex humeral artery, axillobrachial vein, and branches of the axillary nerve. Lesions to the lateral glenohumeral ligament were noted from the caudal instrument portal and the middle arthroscope portal. Iatrogenic articular cartilage injuries were identified on the caudal humeral head and the glenoid. CONCLUSION: This study supports the safety of lateral shoulder arthroscopy in dogs. Most local neurovascular structures are unaffected with traditional scope portal positions. Musculotendinous lesions are unavoidable due to the extensive muscling surrounding the shoulder but are unlikely to cause severe complications postoperatively.

2.
Plants (Basel) ; 12(12)2023 Jun 19.
Article in English | MEDLINE | ID: mdl-37375992

ABSTRACT

Soil salinity can impose substantial stress on plant growth and cause significant yield losses. Crop varieties tolerant to salinity stress are needed to sustain yields in saline soils. This requires effective genotyping and phenotyping of germplasm pools to identify novel genes and QTL conferring salt tolerance that can be utilised in crop breeding schemes. We investigated a globally diverse collection of 580 wheat accessions for their growth response to salinity using automated digital phenotyping performed under controlled environmental conditions. The results show that digitally collected plant traits, including digital shoot growth rate and digital senescence rate, can be used as proxy traits for selecting salinity-tolerant accessions. A haplotype-based genome-wide association study was conducted using 58,502 linkage disequilibrium-based haplotype blocks derived from 883,300 genome-wide SNPs and identified 95 QTL for salinity tolerance component traits, of which 54 were novel and 41 overlapped with previously reported QTL. Gene ontology analysis identified a suite of candidate genes for salinity tolerance, some of which are already known to play a role in stress tolerance in other plant species. This study identified wheat accessions that utilise different tolerance mechanisms and which can be used in future studies to investigate the genetic and genic basis of salinity tolerance. Our results suggest salinity tolerance has not arisen from or been bred into accessions from specific regions or groups. Rather, they suggest salinity tolerance is widespread, with small-effect genetic variants contributing to different levels of tolerance in diverse, locally adapted germplasm.

3.
BMC Womens Health ; 23(1): 251, 2023 05 10.
Article in English | MEDLINE | ID: mdl-37161466

ABSTRACT

BACKGROUND: The Billings Ovulation Method®(the Billings Method) is a fertility awareness-based method (FABM) of family planning that relies on the observation of patterns of fertility and infertility based on vulvar sensations and appearance of discharges. This allows people to choose when to have intercourse, depending on whether they want to avoid or achieve pregnancy. Few studies have documented user experiences with FABMs. METHODS: We conducted four virtual focus groups (FGs) in May and June 2021 with current adult women users of the Billings Method. We asked questions about users' reasons for selecting a FABM and the Billings Method, positive experiences and challenges learning and using the Billings Method, and suggestions for improving the user experience. We performed a content analysis of the transcribed FGs to explore key themes from the discussions. COREQ guidelines were followed. RESULTS: Twenty women between the ages of 23 and 43 participated in the FGs. Reasons women described choosing a FABM included to follow religious beliefs, to avoid side effects of hormonal contraception, and/or to learn more about their bodies. Reasons for selecting the Billings Method included perceiving it as more precise and easier to understand than other FABMs, having a scientific basis, and being recommended by family and friends. Experiences related to learning and using the Billings Method were mainly positive. They included finding the method easy to use and learn, successfully using it to either postpone or achieve a pregnancy and increasing their awareness of their bodies. Challenges for participants included the inherent learning curve for identifying sensations at the vulva and the required periods of abstinence. Participants provided suggestions and recommendations for improving users' experience, including raising awareness of the Billings Method among healthcare providers. CONCLUSIONS: Users of the Billings Method expressed an overall positive experience when learning and using it for family planning and body awareness. Some challenges were identified that offer opportunities to improve how the Billings Method is taught and delivered. These findings can also enhance healthcare providers' interactions with FABM users, including those of the Billings Method.


Subject(s)
Fertility , Infertility , Adult , Pregnancy , Humans , Female , Young Adult , Focus Groups , Family Planning Services , Ovulation
4.
Microorganisms ; 11(2)2023 Feb 14.
Article in English | MEDLINE | ID: mdl-36838441

ABSTRACT

Chagas disease is caused by infection with the protozoan parasite, Trypanosoma cruzi. The disease causes ~12,000 deaths annually and is one of the world's 20 neglected tropical diseases, as defined by the World Health Organisation. The drug discovery pipeline for Chagas disease currently has few new clinical candidates, with high attrition rates an ongoing issue. To determine if the Trypanosoma cruzi strain utilised to assess in vitro compound activity impacts activity, a comparison of laboratory-adapted T. cruzi strains from differing geographical locations was undertaken for a selection of compounds with anti-T. cruzi activity. To minimise the possible effect of differences in experimental methodology, the same host cell and multiplicity of infection were utilised. To determine whether the compound exposure time influenced results, activity was determined following exposure for 48 and 72 h of incubation. To ascertain whether replication rates affected outcomes, comparative rates of replication of the T. cruzi strains were investigated, using the nucleoside analogue, 5-ethynyl-2'-deoxyuridine. Minimal differences in the in vitro activity of compounds between strains were observed following 48 h incubation, whereas significant differences were observed following 72 h incubation, in particular for the cytochrome P450 inhibitors tested and the cell cycle inhibitor, camptothecin. Thus, the use of panels of laboratory adapted strains in vitro may be dependent on the speed of action that is prioritised. For the identification of fast-acting compounds, an initial shorter duration assay using a single strain may be used. A longer incubation to identify compound activity may alternatively require profiling of compounds against multiple T. cruzi strains.

5.
Conserv Physiol ; 11(1): coac081, 2023.
Article in English | MEDLINE | ID: mdl-36694596

ABSTRACT

Cortisol, the primary glucocorticoid in fishes, is secreted into the bloodstream in response to stress. Circulating cortisol accumulates in scales, a durable calcified structure that can be easily sampled from many fish species. As such, the use of scale cortisol concentration (SCC) is currently being explored as a means of chronic stress biomonitoring in wild fishes. Scales serve an important role in fish physiology and thus the number of scales required for reliable cortisol analysis is a limiting factor in the non-lethal collection of such samples. To date, scale cortisol quantification has also only been performed non-lethally in captive fishes and due to differences in stress responsiveness SCCs likely differ in wild species. As such, this study aimed to (1) apply our fish scale processing and analysis protocol to wild fish species and (2) apply it to five north temperate fish species to provide information useful to future non-lethal scale sampling regimes. Cortisol was successfully measured in scales collected from wild northern pike (Esox lucius), walleye (Sander vitreus), whitefish (Coregonus clupeaformis), white sucker (Catostomus commersonii) and captive rainbow trout (Oncorhynchus mykiss). SCCs were significantly different between species and thus the sample mass required for reliable cortisol analysis differed as well. In addition to the size of the fish and the mass of their scales this is an important consideration for future scale cortisol analyses as these factors could make SCC an attainable non-lethal sample matrix in some species of fish but impractical in others.

6.
Data Brief ; 46: 108787, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36506801

ABSTRACT

This article describes a dataset of high-resolution visible-spectrum images of safflower (Carthamus tinctorius L.) plants obtained from a LemnaTec Scanalyser automated phenomics platform along with the associated image analysis output and manually acquired biomass data. This series contains 1832 images of 200 diverse safflower genotypes, acquired at the Plant Phenomics Victoria, Horsham, Victoria, Australia. Two Prosilica GT RGB (red-green-blue) cameras were used to generate 6576 × 4384 pixel portable network graphic (PNG) images. Safflower genotypes were either subjected to a salt treatment (250 mM NaCl) or grown as a control (0 mM NaCl) and imaged daily from 15 to 36 days after sowing. Each snapshot consists of four images collected at a point in time; one of which is taken from above (top-view) and the remainder from the side at either 0°, 120° or 240°. The dataset also includes analysis output quantifying traits and describing phenotypes, as well as manually collected biomass and leaf ion content data. The usage of the dataset is already demonstrated in Thoday-Kennedy et al. (2021) [1]. This dataset describes the early growth differences of diverse safflower genotypes and identified genotypes tolerant or susceptible to salinity stress. This dataset provides detailed image analysis parameters for phenotyping a large population of safflower that can be used for the training of image-based trait identification pipelines for a wide range of crop species.

7.
Article in English | MEDLINE | ID: mdl-36427661

ABSTRACT

Fish scales have been reported to incorporate cortisol over long periods of time and thus provide a promising means of assessing long-term stress in many species of teleost fish. However, the quantification of other stress related hormones has only been accomplished in our previous study conducted in goldfish (Carassius auratus). DHEA is a precursory androgen with anti-stress effects used alongside cortisol to diagnose chronic stress via the cortisol:DHEA ratio in mammals. Included in DHEA's anti-stress mechanisms are changes in the metabolism of cortisol to its inactive metabolite cortisone suggesting the relationships between cortisol, DHEA and cortisone may be additionally informative in the assessment of long-term stress. Therefore, to further explore these concepts in a native fish species and generate more comprehensive comparisons between scale and serum hormone concentrations than was possible in our previous study we implemented a 14-day stress protocol in adult rainbow trout (Oncorhynchus mykiss) and quantified resulting scale and serum cortisol, cortisone and DHEA concentrations. As predicted, elevations in scale concentrations of all hormones were observed in stressed trout compared to controls but were not reflected in serum samples. Significant differences in the cortisol:DHEA and cortisone:cortisol ratios were also found between control and stressed group scales but not serum. These results suggest not only that scales provide a superior medium for the assessment of long-term stress but also that the addition of scale cortisone and DHEA may provide additional relevant information for such assessments.


Subject(s)
Cortisone , Oncorhynchus mykiss , Animals , Hydrocortisone , Oncorhynchus mykiss/physiology , Cortisone/metabolism , Androgens , Dehydroepiandrosterone/metabolism , Mammals
8.
Mol Microbiol ; 119(2): 174-190, 2023 02.
Article in English | MEDLINE | ID: mdl-36577696

ABSTRACT

Bordetella species cause lower respiratory tract infections in mammals. B. pertussis and B. bronchiseptica are the causative agents of whooping cough and kennel cough, respectively. The current acellular vaccine for B. pertussis protects against disease but does not prevent transmission or colonization. Cases of pertussis are on the rise even in areas of high vaccination. The PlrSR two-component system, is required for persistence in the mouse lung. A partial plrS deletion strain and a plrS H521Q strain cannot survive past 3 days in the lung, suggesting PlrSR works in a phosphorylation-dependent mechanism. We characterized the biochemistry of B. bronchiseptica PlrSR and found that both proteins function as a canonical two-component system. His521 was essential and Glu522 was critical for PlrS autophosphorylation. Asn525 was essential for phosphatase activity. The PAS domain was critical for both PlrS autophosphorylation and phosphatase activities. PlrS could both phosphotransfer to and exert phosphatase activity toward PlrR. Unexpectedly, PlrR formed a tetramer when unphosphorylated and a dimer upon phosphorylation. Finally, we demonstrated the importance of PlrS phosphatase activity for persistence within the murine lung. By characterizing PlrSR we hope to guide future in vivo investigation for development of new vaccines and therapeutics.


Subject(s)
Bordetella Infections , Bordetella bronchiseptica , Whooping Cough , Mice , Animals , Phosphorylation , Bordetella pertussis , Respiratory System/microbiology , Phosphoric Monoester Hydrolases , Bordetella Infections/microbiology , Mammals
9.
Biochem Soc Trans ; 50(6): 1847-1858, 2022 12 16.
Article in English | MEDLINE | ID: mdl-36416676

ABSTRACT

The rapid increase of '-omics' data warrants the reconsideration of experimental strategies to investigate general protein function. Studying individual members of a protein family is likely insufficient to provide a complete mechanistic understanding of family functions, especially for diverse families with thousands of known members. Strategies that exploit large amounts of available amino acid sequence data can inspire and guide biochemical experiments, generating broadly applicable insights into a given family. Here we review several methods that utilize abundant sequence data to focus experimental efforts and identify features truly representative of a protein family or domain. First, coevolutionary relationships between residues within primary sequences can be successfully exploited to identify structurally and/or functionally important positions for experimental investigation. Second, functionally important variable residue positions typically occupy a limited sequence space, a property useful for guiding biochemical characterization of the effects of the most physiologically and evolutionarily relevant amino acids. Third, amino acid sequence variation within domains shared between different protein families can be used to sort a particular domain into multiple subtypes, inspiring further experimental designs. Although generally applicable to any kind of protein domain because they depend solely on amino acid sequences, the second and third approaches are reviewed in detail because they appear to have been used infrequently and offer immediate opportunities for new advances. Finally, we speculate that future technologies capable of analyzing and manipulating conserved and variable aspects of the three-dimensional structures of a protein family could lead to broad insights not attainable by current methods.


Subject(s)
Amino Acids , Proteins , Amino Acid Sequence , Proteins/genetics , Proteins/chemistry , Amino Acids/genetics , Amino Acids/chemistry , Protein Domains
10.
Microorganisms ; 10(7)2022 Jun 25.
Article in English | MEDLINE | ID: mdl-35889006

ABSTRACT

Chagas disease caused by the protozoan Trypanosoma cruzi is endemic to 21 countries in the Americas, effects approximately 6 million people and on average results in 12,000 deaths annually. Human African Trypanosomiasis (HAT) is caused by the Trypanosoma brucei sub-species, endemic to 36 countries within sub-Saharan Africa. Treatment regimens for these parasitic diseases are complicated and not effective against all disease stages; thus, there is a need to find improved treatments. To identify new molecules for the drug discovery pipelines for these diseases, we have utilised in vitro assays to identify compounds with selective activity against both T. cruzi and T.b. brucei from the Medicines for Malaria Venture (MMV) Pathogen Box compound collection. To prioritise these molecules for further investigation, temporal and wash off assays were utilised to identify the speed of action and cidality of compounds. For translational relevance, compounds were tested against clinically relevant T.b. brucei subspecies. Compounds with activity against T. cruzi cytochrome P450 (TcCYP51) have not previously been successful in clinical trials for chronic Chagas disease; thus, to deprioritise compounds with this activity, they were tested against recombinant TcCYP51. Compounds with biological profiles warranting progression offer important tools for drug and target development against kinetoplastids.

11.
Contraception ; 114: 32-40, 2022 10.
Article in English | MEDLINE | ID: mdl-35716805

ABSTRACT

OBJECTIVES: To summarize the evidence on typical and perfect-use effectiveness of fertility awareness-based methods for avoiding pregnancy during the postpartum period, whether breastfeeding or not. STUDY DESIGN: We conducted a systematic review of studies published in English, Spanish, French, or German by November 2021 in MEDLINE, EMBASE, CINAHL, Web of Science, and ClinicalTrials.gov. Abstract and full text reviews were completed by 2 independent reviewers. Study inclusion: at least 50 subjects who enrolled prior to experiencing 3 cycles after childbirth and were using a specific fertility awareness-based method to avoid pregnancy; unintended pregnancy rate or probability calculated; postpartum amenorrheic and postpartum cycling individuals analyzed separately; and prospectively measured pregnancy intentions and outcomes. Outcomes were abstracted and study quality was systematically assessed by 2 independent investigators. RESULTS: Four studies provided effectiveness data for 1 specific fertility awareness-based method among postpartum individuals. Of these, there were zero high quality, 1 moderate quality, and 3 low quality for our question of interest. Typical-use pregnancy probability for the first 6 cycles postpartum for Marquette Method users was 12.0 per 100 women years (standard error [SE] not reported) and for Billings Ovulation Method users ranged from 9.1 (SE 3.9) for non-lactating women <30 years old to 26.8 (SE 4.6) for lactating women <30 years old. Typical-use pregnancy probabilities for the first 6 months post-first menses for the Postpartum Bridge to Standard Days Method users was 11.8 (95% confidence interval 6.01-17.16) and for Billings Ovulation Method users was 8.5 per 100 women (SE 1.7). CONCLUSION: The current evidence on the effectiveness of each fertility awareness-based method for postpartum persons is very limited and of mostly low quality. More high quality studies on the effectiveness of fertility awareness-based method in postpartum persons are needed to inform clinical counseling and patient-centered decision-making. IMPLICATIONS: Although postpartum individuals may desire to use fertility awareness-based methods to avoid pregnancy, the evidence of the effectiveness of fertility awareness-based methods in this population is limited. More high-quality studies are needed to inform shared decision-making.


Subject(s)
Fertility , Postpartum Period , Adult , Breast Feeding , Counseling , Female , Humans , Pregnancy , Pregnancy, Unplanned
12.
J Clin Microbiol ; 60(7): e0034222, 2022 07 20.
Article in English | MEDLINE | ID: mdl-35766514

ABSTRACT

The rapid emergence of SARS-CoV-2 variants raised public health questions concerning the capability of diagnostic tests to detect new strains, the efficacy of vaccines, and how to map the geographical distribution of variants to understand transmission patterns and loads on healthcare resources. Next-generation sequencing (NGS) is the primary method for detecting and tracing new variants, but it is expensive, and it can take weeks before sequence data are available in public repositories. This article describes a customizable reverse transcription PCR (RT-PCR)-based genotyping approach which is significantly less expensive, accelerates reporting, and can be implemented in any lab that performs RT-PCR. Specific single-nucleotide polymorphisms (SNPs) and indels were identified which had high positive-percent agreement (PPA) and negative-percent agreement (NPA) compared to NGS for the major genotypes that circulated through September 11, 2021. Using a 48-marker panel, testing on 1,031 retrospective SARS-CoV-2 positive samples yielded a PPA and NPA ranging from 96.3 to 100% and 99.2 to 100%, respectively, for the top 10 most prevalent World Health Organization (WHO) lineages during that time. The effect of reducing the quantity of panel markers was explored, and a 16-marker panel was determined to be nearly as effective as the 48-marker panel at lineage assignment. Responding to the emergence of Omicron, a genotyping panel was developed which distinguishes Delta and Omicron using four highly specific SNPs. The results demonstrate the utility of the condensed panel to rapidly track the growing prevalence of Omicron across the US in December 2021 and January 2022.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnosis , Humans , Nucleic Acid Amplification Techniques , Retrospective Studies , SARS-CoV-2/genetics
13.
J Bacteriol ; 204(2): e0052721, 2022 02 15.
Article in English | MEDLINE | ID: mdl-34843377

ABSTRACT

Azorhizobium caulinodans is a nitrogen-fixing bacterium that forms root nodules on its host legume, Sesbania rostrata. This agriculturally significant symbiotic relationship is important in lowland rice cultivation and allows nitrogen fixation under flood conditions. Chemotaxis plays an important role in bacterial colonization of the rhizosphere. Plant roots release chemical compounds that are sensed by bacteria, triggering chemotaxis along a concentration gradient toward the roots. This gives motile bacteria a significant competitive advantage during root surface colonization. Although plant-associated bacterial genomes often encode multiple chemotaxis systems, A. caulinodans appears to encode only one. The che cluster on the A. caulinodans genome contains cheA, cheW, cheY2, cheB, and cheR. Two other chemotaxis genes, cheY1 and cheZ, are located independently from the che operon. Both CheY1 and CheY2 are involved in chemotaxis, with CheY1 being the predominant signaling protein. A. caulinodans CheA contains an unusual set of C-terminal domains: a CheW-like/receiver pair (termed W2-Rec) follows the more common single CheW-like domain. W2-Rec impacts both chemotaxis and CheA function. We found a preference for transfer of phosphoryl groups from CheA to CheY2, rather than to W2-Rec or CheY1, which appears to be involved in flagellar motor binding. Furthermore, we observed increased phosphoryl group stabilities on CheY1 compared to CheY2 and W2-Rec. Finally, CheZ enhanced dephosphorylation of CheY2 substantially more than CheY1 but had no effect on the dephosphorylation rate of W2-Rec. This network of phosphotransfer reactions highlights a previously uncharacterized scheme for regulation of chemotactic responses. IMPORTANCE Chemotaxis allows bacteria to move toward nutrients and away from toxins in their environment. Chemotactic movement provides a competitive advantage over nonspecific motion. CheY is an essential mediator of the chemotactic response, with phosphorylated and unphosphorylated forms of CheY differentially interacting with the flagellar motor to change swimming behavior. Previously established schemes of CheY dephosphorylation include action of a phosphatase and/or transfer of the phosphoryl group to another receiver domain that acts as a sink. Here, we propose that A. caulinodans uses a concerted mechanism in which the Hpt domain of CheA, CheY2, and CheZ function together as a dual sink system to rapidly reset chemotactic signaling. To the best of our knowledge, this mechanism is unlike any that have previously been evaluated. Chemotaxis systems that utilize both receiver and Hpt domains as phosphate sinks likely occur in other bacterial species.


Subject(s)
Azorhizobium caulinodans/genetics , Azorhizobium caulinodans/physiology , Chemotaxis/genetics , Phosphates/metabolism , Chemotaxis/physiology , Phosphoric Monoester Hydrolases/metabolism , Phosphorylation
14.
Front Plant Sci ; 12: 662498, 2021.
Article in English | MEDLINE | ID: mdl-34220887

ABSTRACT

Salinity is a major contributing factor to the degradation of arable land, and reductions in crop growth and yield. To overcome these limitations, the breeding of crop varieties with improved salt tolerance is needed. This requires effective and high-throughput phenotyping to optimize germplasm enhancement. Safflower (Carthamus tinctorius L.), is an underappreciated but highly versatile oilseed crop, capable of growing in saline and arid environments. To develop an effective and rapid phenotyping protocol to differentiate salt responses in safflower genotypes, experiments were conducted in the automated imaging facility at Plant Phenomics Victoria, Horsham, focussing on digital phenotyping at early vegetative growth. The initial experiment, at 0, 125, 250, and 350 mM sodium chloride (NaCl), showed that 250 mM NaCl was optimum to differentiate salt sensitive and tolerant genotypes. Phenotyping of a diverse set of 200 safflower genotypes using the developed protocol defined four classes of salt tolerance or sensitivity, based on biomass and ion accumulation. Salt tolerance in safflower was dependent on the exclusion of Na+ from shoot tissue and the maintenance of K+ uptake. Salinity response identified in glasshouse experiments showed some consistency with the performance of representatively selected genotypes tested under sodic field conditions. Overall, our results suggest that digital phenotyping can be an effective high-throughput approach in identifying candidate genotypes for salt tolerance in safflower.

15.
PLoS One ; 16(7): e0254908, 2021.
Article in English | MEDLINE | ID: mdl-34297757

ABSTRACT

Drought is one of the most severe and unpredictable abiotic stresses, occurring at any growth stage and affecting crop yields worldwide. Therefore, it is essential to develop drought tolerant varieties to ensure sustainable crop production in an ever-changing climate. High-throughput digital phenotyping technologies in tandem with robust screening methods enable precise and faster selection of genotypes for breeding. To investigate the use of digital imaging to reliably phenotype for drought tolerance, a genetically diverse safflower population was screened under different drought stresses at Agriculture Victoria's high-throughput, automated phenotyping platform, Plant Phenomics Victoria, Horsham. In the first experiment, four treatments, control (90% field capacity; FC), 40% FC at initial branching, 40% FC at flowering and 50% FC at initial branching and flowering, were applied to assess the performance of four safflower genotypes. Based on these results, drought stress using 50% FC at initial branching and flowering stages was chosen to further screen 200 diverse safflower genotypes. Measured plant traits and dry biomass showed high correlations with derived digital traits including estimated shoot biomass, convex hull area, caliper length and minimum area rectangle, indicating the viability of using digital traits as proxy measures for plant growth. Estimated shoot biomass showed close association having moderately high correlation with drought indices yield index, stress tolerance index, geometric mean productivity, and mean productivity. Diverse genotypes were classified into four clusters of drought tolerance based on their performance (seed yield and digitally estimated shoot biomass) under stress. Overall, results show that rapid and precise image-based, high-throughput phenotyping in controlled environments can be used to effectively differentiate response to drought stress in a large numbers of safflower genotypes.


Subject(s)
Carthamus tinctorius/genetics , Droughts , Genotype , Phenomics/methods , Plant Breeding/methods , Stress, Physiological , Automation, Laboratory/methods , Biomass , Carthamus tinctorius/physiology , Phenotype
16.
Biochemistry ; 60(26): 2130-2151, 2021 07 06.
Article in English | MEDLINE | ID: mdl-34167303

ABSTRACT

Two-component signaling is a primary method by which microorganisms interact with their environments. A kinase detects stimuli and modulates autophosphorylation activity. The signal propagates by phosphotransfer from the kinase to a response regulator, eliciting a response. Response regulators operate over a range of time scales, corresponding to their related biological processes. Response regulator active site chemistry is highly conserved, but certain variable residues can influence phosphorylation kinetics. An Ala-to-Pro substitution (K+4, residue 113) in the Escherichia coli response regulator CheY triggers a constitutively active phenotype; however, the A113P substitution is too far from the active site to directly affect phosphochemistry. To better understand the activating mechanism(s) of the substitution, we analyzed receiver domain sequences to characterize the evolutionary role of the K+4 position. Although most featured Pro, Leu, Ile, and Val residues, chemotaxis-related proteins exhibited atypical Ala, Gly, Asp, and Glu residues at K+4. Structural and in silico analyses revealed that CheY A113P adopted a partially active configuration. Biochemical data showed that A113P shifted CheY toward a more activated state, enhancing autophosphorylation. By characterizing CheY variants, we determined that this functionality was transmitted through a hydrophobic network bounded by the ß5α5 loop and the α1 helix of CheY. This region also interacts with the phosphodonor CheAP1, suggesting that binding generates an activating perturbation similar to the A113P substitution. Atypical residues like Ala at the K+4 position likely serve two purposes. First, restricting autophosphorylation may minimize background noise generated by intracellular phosphodonors such as acetyl phosphate. Second, optimizing interactions with upstream partners may help prime the receiver domain for phosphorylation.


Subject(s)
Escherichia coli Proteins/chemistry , Methyl-Accepting Chemotaxis Proteins/chemistry , Allosteric Regulation/genetics , Amino Acid Sequence , Catalytic Domain , Escherichia coli/chemistry , Escherichia coli Proteins/genetics , Hydrophobic and Hydrophilic Interactions , Kinetics , Methyl-Accepting Chemotaxis Proteins/genetics , Molecular Dynamics Simulation , Mutagenesis, Site-Directed , Mutation , Phosphorylation/genetics , Protein Conformation , Protein Domains/genetics
17.
Molecules ; 26(11)2021 May 30.
Article in English | MEDLINE | ID: mdl-34070798

ABSTRACT

A series of novel quinoline-based tetracyclic ring-systems were synthesized and evaluated in vitro for their antiplasmodial, antiproliferative and antimicrobial activities. The novel hydroiodide salts 10 and 21 showed the most promising antiplasmodial inhibition, with compound 10 displaying higher selectivity than the employed standards. The antiproliferative assay revealed novel pyridophenanthridine 4b to be significantly more active against human prostate cancer (IC50 = 24 nM) than Puromycin (IC50 = 270 nM) and Doxorubicin (IC50 = 830 nM), which are used for clinical treatment. Pyridocarbazoles 9 was also moderately effective against all the employed cancer cell lines and moreover showed excellent biofilm inhibition (9a: MBIC = 100 µM; 9b: MBIC = 100 µM).


Subject(s)
Indole Alkaloids/pharmacology , Quinolines/chemical synthesis , Quinolines/pharmacology , Anti-Infective Agents/pharmacology , Antimalarials/pharmacology , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Indole Alkaloids/metabolism , Plasmodium falciparum/drug effects , Quinolines/metabolism , Structure-Activity Relationship
19.
Trends Microbiol ; 29(10): 883-893, 2021 10.
Article in English | MEDLINE | ID: mdl-33853736

ABSTRACT

Bacterial two-component regulatory systems (TCSs) mediate signal transduction by transferring phosphoryl groups between sensor kinase and response regulator proteins, sometimes using intermediary histidine-phosphotransferase (Hpt) domains to form multistep phosphorelays. Because (i) almost all known fungal sensor kinases exhibit a domain architecture characteristic of bacterial TCS phosphorelays, (ii) all known fungal Hpts are stand-alone proteins suited to shuttle between cytoplasm and nucleus, and (iii) the best-characterized fungal TCS is a canonical phosphorelay, it is widely assumed that most or all fungal TCSs function via phosphorelays. However, fungi generally encode more sensor kinases than Hpts or response regulators, leading to a disparity between putative phosphorelay inputs and outputs. The simplest resolution of this paradox is to hypothesize that most fungal sensor kinases do not participate in phosphorelays. Reimagining how fungal TCSs might function leads to multiple testable predictions.


Subject(s)
Fungal Proteins/metabolism , Fungi/metabolism , Gene Expression Regulation, Fungal , Fungal Proteins/genetics , Fungi/genetics , Histidine Kinase/genetics , Histidine Kinase/metabolism , Signal Transduction
20.
IEEE Open J Eng Med Biol ; 2: 286-290, 2021.
Article in English | MEDLINE | ID: mdl-35257097

ABSTRACT

Goal: Monitoring the genetic diversity and emerging mutations of SARS-CoV-2 is crucial for understanding the evolution of the virus and assuring the performance of diagnostic tests, vaccines, and therapies against COVID-19. SARS-CoV-2 is still adapting to humans and, as illustrated by B.1.1.7 (Alpha) and B.1.617.2 (Delta), lineage dynamics are fluid, and strain prevalence may change radically in a matter of months. The National Institutes of Health's Rapid Acceleration of Diagnostics (RADxSM) initiative created a Variant Task Force to assess the impact of emerging SARS-CoV-2 variants on in vitro diagnostic testing. Working in tandem with clinical laboratories, the FDA, and the CDC, the Variant Task Force uses both in silico modeling and in vitro testing to determine the effect of SARS-CoV-2 mutations on diagnostic molecular and antigen tests. Here, we offer an overview of the approach and activities of the RADx Variant Task Force to ensure test performance against emerging SARS-CoV-2 lineages.

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