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1.
Int J Mol Sci ; 25(6)2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38542304

ABSTRACT

Male sterility is a valuable trait for hybrid seed production in tomato (Solanum lycopersicum). The mutants male sterile-30 (ms-30) and ms-33 of tomato exhibit twisted stamens, exposed stigmas, and complete male sterility, thus holding potential for application in hybrid seed production. In this study, the ms-30 and ms-33 loci were fine-mapped to 53.3 kb and 111.2 kb intervals, respectively. Tomato PISTILLATA (TPI, syn. SlGLO2), a B-class MADS-box transcription factor gene, was identified as the most likely candidate gene for both loci. TPI is also the candidate gene of tomato male sterile mutant 7B-1 and sl-2. Allelism tests revealed that ms-30, ms-33, 7B-1, and sl-2 were allelic. Sequencing analysis showed sequence alterations in the TPI gene in all these mutants, with ms-30 exhibiting a transversion (G to T) that resulted in a missense mutation (S to I); ms-33 showing a transition (A to T) that led to alternative splicing, resulting in a loss of 46 amino acids in protein; and 7B-1 and sl-2 mutants showing the insertion of an approximately 4.8 kb retrotransposon. On the basis of these sequence alterations, a Kompetitive Allele Specific PCR marker, a sequencing marker, and an Insertion/Deletion marker were developed. Phenotypic analysis of the TPI gene-edited mutants and allelism tests indicated that the gene TPI is responsible for ms-30 and its alleles. Transcriptome analysis of ms-30 and quantitative RT-PCR revealed some differentially expressed genes associated with stamen and carpel development. These findings will aid in the marker-assisted selection for ms-30 and its alleles in tomato breeding and support the functional analysis of the TPI gene.


Subject(s)
Infertility, Male , Solanum lycopersicum , Humans , Male , Solanum lycopersicum/genetics , Alleles , Plant Breeding , Gene Expression Profiling , Infertility, Male/genetics , Genetic Association Studies
2.
Eur J Nutr ; 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38446227

ABSTRACT

BACKGROUND: We aim to report the latest pooled analyses to evaluate the additive efficacy and safety of probiotics in the treatment of ulcerative colitis (UC). METHODS: We systematically searched the relevant literature investigating the efficacy and/or safety of probiotics in patients with UC from PubMed, Embase and Web of Science up to January 2023. Two researchers independently screened the literature, extracted data, and evaluated the quality of the included studies according to the inclusion and exclusion criteria. Any discrepancies throughout these processes were solved by consensus. All statistical analyses were performed by Review Manager version 5.4 and Stata version 15.0. RESULTS: A total of 13 articles were included in the pooled analyses, and the studies were all randomized controlled trials with a total of 930 patients. There were no significant differences between the probiotics and placebo groups concerning demographic and baseline characteristics. For patients with active UC, the probiotic group boosted the remission rate by 87% compared to the placebo group, but failed to reach a statistical difference (OR: 1.87; 95% CI 0.98, 3.57; P = 0.06, I2 = 67%); furthermore, there were no statistical differences in maintenance of clinical remission, clinical response, change in UCDAI scores, or mucosal healing outcomes in the probiotic group compared to the placebo group. For patients in clinical remission, the clinical relapse rates were significantly lower in the probiotic group than in the placebo group (OR: 0.34; 95% CI 0.14, 0.79; P = 0.01). Moreover, this study did not observe a significant difference between the two groups for general adverse events rate (OR: 1.98; 95% CI 0.69, 5.68; P = 0.20). CONCLUSION: Probiotic-assisted therapy may be effective in inhibiting UC recurrence in patients in clinical remission without increasing the risk of treatment-related adverse events; furthermore, probiotics may increase the rate of clinical remission in patients with active UC. However, caution is needed when interpreting the clinical efficacy of probiotics in improving the clinical outcome of patients with active UC.

3.
Nat Commun ; 14(1): 6680, 2023 10 21.
Article in English | MEDLINE | ID: mdl-37865661

ABSTRACT

Biosensors are powerful tools for detecting, real-time imaging, and quantifying molecules, but rapidly constructing diverse genetically encoded biosensors remains challenging. Here, we report a method to rapidly convert enzymes into genetically encoded circularly permuted fluorescent protein-based indicators to detect organic acids (GECFINDER). ANL superfamily enzymes undergo hinge-mediated ligand-coupling domain movement during catalysis. We introduce a circularly permuted fluorescent protein into enzymes hinges, converting ligand-induced conformational changes into significant fluorescence signal changes. We obtain 11 GECFINDERs for detecting phenylalanine, glutamic acid and other acids. GECFINDER-Phe3 and GECFINDER-Glu can efficiently and accurately quantify target molecules in biological samples in vitro. This method simplifies amino acid quantification without requiring complex equipment, potentially serving as point-of-care testing tools for clinical applications in low-resource environments. We also develop a GECFINDER-enabled droplet-based microfluidic high-throughput screening method for obtaining high-yield industrial strains. Our method provides a foundation for using enzymes as untapped blueprint resources for biosensor design, creation, and application.


Subject(s)
Amino Acids , Biosensing Techniques , Ligands , Proteins/chemistry , Phenylalanine , Biosensing Techniques/methods
4.
Plants (Basel) ; 12(11)2023 May 23.
Article in English | MEDLINE | ID: mdl-37299049

ABSTRACT

Tomato (Solanum lycopersicum) is a widely consumed vegetable, and the tomato fruit weight is a key yield component. Many quantitative trait loci (QTLs) controlling tomato fruit weight have been identified, and six of them have been fine-mapped and cloned. Here, four loci controlling tomato fruit weight were identified in an F2 population through QTL seq.; fruit weight 6.3 (fw6.3) was a major-effect QTL and its percentage of variation explanation (R2) was 0.118. This QTL was fine-mapped to a 62.6 kb interval on chromosome 6. According to the annotated tomato genome (version SL4.0, annotation ITAG4.0), this interval contained seven genes, including Solyc06g074350 (the SELF-PRUNING gene), which was likely the candidate gene underlying variation in fruit weight. The SELF-PRUNING gene contained a single-nucleotide polymorphism that resulted in an amino acid substitution in the protein sequence. The large-fruit allele of fw6.3 (fw6.3HG) was overdominant to the small-fruit allele fw6.3RG. The soluble solids content was also increased by fw6.3HG. These findings provide valuable information that will aid the cloning of the FW6.3 gene and ongoing efforts to breed tomato plants with higher yield and quality via molecular marker-assisted selection.

5.
ACS Synth Biol ; 12(6): 1761-1771, 2023 06 16.
Article in English | MEDLINE | ID: mdl-37198736

ABSTRACT

Genetically encoded biosensors are powerful tools for product-driven high-throughput screening in synthetic biology and metabolic engineering. However, most biosensors can only properly function in a limited concentration cutoff, and the incompatible performance characteristics of biosensors will lead to false positives or failure in screening. The transcription factor (TF)-based biosensors are usually organized in modular architecture and function in a regulator-depended manner, whose performance properties can be fine-tuned by modifying the expression level of the TF. In this study, we modulated the performance characteristics, including sensitivity and operating range, of an MphR-based erythromycin biosensor by fine-adjusting regulator expression levels via ribosome-binding site (RBS) engineering and obtained a panel of biosensors with varied sensitivities by iterative fluorescence-assisted cell sorting (FACS) in Escherichia coli to accommodate different screening purposes. To exemplify their application potential, two engineered biosensors with 10-fold different sensitivities were employed in the precise high-throughput screening by microfluidic-based fluorescence-activated droplet sorting (FADS) of Saccharopolyspora erythraea mutant libraries with different starting erythromycin productions, and mutants representing as high as 6.8 folds and over 100% of production improvements were obtained starting from the wild-type strain and the high-producing industrial strain, respectively. This work demonstrated a simple strategy to engineer biosensor performance properties, which was significant to stepwise strain engineering and production improvement.


Subject(s)
Biosensing Techniques , Erythromycin , High-Throughput Screening Assays , Transcription Factors/metabolism , Escherichia coli/genetics , Escherichia coli/metabolism
6.
BMC Psychiatry ; 23(1): 166, 2023 03 15.
Article in English | MEDLINE | ID: mdl-36922763

ABSTRACT

BACKGROUND: Ziprasidone mesylate injection is an atypical antipsychotic drug which is recently approved in China. In combination with its oral formulation, sequential therapy with ziprasidone brings new interventions to patients with agitation in the acute phase of schizophrenia. The purpose of this 7-day multicenter study conducted in China was to evaluate the efficacy and safety of ziprasidone sequential treatment through intramuscular/oral routes in agitated patients with schizophrenia. METHODS: A total of 95 patients were enrolled from three centers in this study. The study duration was 7 days. In the first 3 days, subjects were administered an intramuscular injection of ziprasidone 10-40 mg daily and started sequentially with oral ziprasidone 40-80 mg at dinner (or lunch) from the day of the last intramuscular injection. In the following 4 days, according to the severity of the symptoms and the drug response, 120-160 mg of ziprasidone was orally administered daily. In total, six visits were scheduled to assess the Positive and Negative Syndrome Scale (PANSS), the Behavioral Activity Rating Scale (BARS), the Clinical Global Impression of Severity (CGI-S), and Improvement (CGI-I) scores throughout the procedure. Lastly, adverse events were recorded during treatment. RESULTS: Out of the 95 patients that were enrolled, 83 cases were effectively completed. Visits 3, 4, 6, PANSS, and PANSS-excited component (PANSS-EC) subscale points, and Visit 2-Visit 6 viewpoints, BARS scale points, and baseline scores denote a progressive downward trend (P < 0.001). In this study, 62 adverse events were reported. The most common adverse events were extrapyramidal symptoms (EPS) (23 cases) and excessive sedation(10 cases), and 13 cases of prolonged QTc interval were reported. CONCLUSIONS: Ziprasidone IM demonstrated significant and rapid reduction in agitation, and sequential oral formulation keep stability and continuation of the treatment can further ensure efficacy. Ziprasidone sequential therapy may provide a new approach to acute agitation in schizophrenic patients. TRIAL REGISTRATION: The Chinese Clinical Trials Registry; URL: https://www.chictr.org.cn : ChiCTR-OIC-16007970.


Subject(s)
Antipsychotic Agents , Schizophrenia , Humans , Schizophrenia/diagnosis , Antipsychotic Agents/adverse effects , Piperazines/adverse effects , Thiazoles/adverse effects , Injections, Intramuscular , Treatment Outcome , Psychiatric Status Rating Scales
7.
Sci Adv ; 8(35): eabq2157, 2022 09 02.
Article in English | MEDLINE | ID: mdl-36044571

ABSTRACT

Genome-scale functional screening accelerates comprehensive assessment of gene function in cells. Here, we have established a genome-scale loss-of-function screening strategy that combined a cytosine base editor with approximately 12,000 parallel sgRNAs targeting 98.1% of total genes in Corynebacterium glutamicum ATCC 13032. Unlike previous data processing methods developed in yeast or mammalian cells, we developed a new data processing procedure to locate candidate genes by statistical sgRNA enrichment analysis. Known and novel functional genes related to 5-fluorouracil resistance, 5-fluoroorotate resistance, oxidative stress tolerance, or furfural tolerance have been identified. In particular, purU and serA were proven to be related to the furfural tolerance in C. glutamicum. A cloud platform named FSsgRNA-Analyzer was provided to accelerate sequencing data processing for CRISPR-based functional screening. Our method would be broadly useful to functional genomics study and strain engineering in other microorganisms.


Subject(s)
Corynebacterium glutamicum , Corynebacterium glutamicum/genetics , Furaldehyde , Gene Editing/methods , Genomics/methods , Phenotype
8.
Front Bioeng Biotechnol ; 10: 913077, 2022.
Article in English | MEDLINE | ID: mdl-35646853

ABSTRACT

Bioelectrochemical systems (BESs) based on Shewanella oneidensis MR-1 offer great promise for sustainable energy/chemical production, but the low rate of electron generation remains a crucial bottleneck preventing their industrial application. Here, we reconstructed a genome-scale metabolic model of MR-1 to provide a strong theoretical basis for novel BES applications. The model iLJ1162, comprising 1,162 genes, 1,818 metabolites and 2,084 reactions, accurately predicted cellular growth using a variety of substrates with 86.9% agreement with experimental results, which is significantly higher than the previously published models iMR1_799 and iSO783. The simulation of microbial fuel cells indicated that expanding the substrate spectrum of MR-1 to highly reduced feedstocks, such as glucose and glycerol, would be beneficial for electron generation. In addition, 31 metabolic engineering targets were predicted to improve electricity production, three of which have been experimentally demonstrated, while the remainder are potential targets for modification. Two potential electron transfer pathways were identified, which could be new engineering targets for increasing the electricity production capacity of MR-1. Finally, the iLJ1162 model was used to simulate the optimal biosynthetic pathways for six platform chemicals based on the MR-1 chassis in microbial electrosynthesis systems. These results offer guidance for rational design of novel BESs.

9.
ChemSusChem ; 15(16): e202200793, 2022 Aug 19.
Article in English | MEDLINE | ID: mdl-35674682

ABSTRACT

All-inorganic metal halide perovskite quantum dots (QDs) have attracted attention from researchers with their fascinating optoelectronic properties. However, blue-emitting perovskite QDs typically have low photoluminescence quantum yield (PLQY). For potential commercial applications, it is preferable to replace Pb with an element having low toxicity. Here, Pb-free Cs3 Bi2 Br9 @BiOBr perovskite QDs were anchored on the surface of NHx -rich monodisperse silica (A-SiO2 ) via N-Bi chemical bonding to isolate QDs from each other, thus enhancing efficient surface passivation and suppressing optical decay. Compared to unanchored QDs, Cs3 Bi2 Br9 @BiOBr QDs/A-SiO2 composites exhibited significantly enhanced blue emission performance, the PLQY of which increased from 16.62 % to 77.26 %, in addition to good water and environmental stability. Finally, the novel composites as photocatalysts were used to drive the oxidation of toluene, a template reaction of C(sp3 )-H bond activation and demonstrated astonishing conversion rates (4317 µmol g-1  h-1 ) with high selectivity (around 87 %).

10.
Front Pediatr ; 10: 811819, 2022.
Article in English | MEDLINE | ID: mdl-35573969

ABSTRACT

Objective: To investigate the epidemiology and the effectiveness of resuscitation from cardiopulmonary arrest (CPA) among critically ill children and adolescents during pediatric intensive care unit (PICU) stay across China. Methods: A prospective multicenter study was conducted in 11 PICUs in tertiary hospitals. Consecutively hospitalized critically ill children, from 29-day old to 18-year old, who had suffered from CPA and required cardiopulmonary resuscitation (CPR) in the PICU were enrolled (December 2017-October 2018). Data were collected and analyzed using the "in-hospital Utstein style." Neurological outcome was assessed with the Pediatric Cerebral Performance Category (PCPC) scale among children who had survived. Factors associated with the return of spontaneous circulation (ROSC) and survival at discharge were evaluated using multivariate logistic regression. Results: Among 11,599 admissions to PICU, 372 children (3.2%) had CPA during their stay; 281 (75.5%) received CPR, and 91 (24.5%) did not (due to an order of "Do Not Resuscitate" requested by their guardians). Cardiopulmonary disease was the most common reason for CPA (28.1% respiratory and 19.6% circulatory). The most frequent initial dysrhythmia was bradycardia (79%). In total, 170 (60.3%) of the total children had an ROSC, 91 had (37.4%) survived till hospital discharge, 28 (11.5%) had survived 6 months, and 19 (7.8%) had survived for 1 year after discharge. Among the 91 children who were viable at discharge, 47.2% (43/91) received a good PCPC score (1-3). The regression analysis results revealed that the duration of CPR and the dose of epinephrine were significantly associated with ROSC, while the duration of CPR, number of CPR attempts, ventricular tachycardia/ventricular fibrillation (VT/VF), and the dose of epinephrine were significantly associated with survival at discharge. Conclusion: The prevalence of CPA in critically ill children and adolescents is relatively high in China. The duration of CPR and the dose of epinephrine are associated with ROSC. The long-term prognosis of children who had survived after CPR needs further improvement.

11.
Molecules ; 27(10)2022 May 18.
Article in English | MEDLINE | ID: mdl-35630714

ABSTRACT

Jujube cores are fiber-rich industrial waste. Dewaxing, alkali treatment, bleaching, and sulfuric acid hydrolysis were used to generate cellulose nanocrystals (CNCs) from the jujube cores in this study. The morphological, structural, crystallinity, and thermal properties of the fibers were investigated using FE-SEM, TEM, AFM, FT-IR, XRD, and TGA under various processes. CNCs' zeta (ζ) potential and water contact angle (WAC) were also investigated. The findings demonstrate that non-fibrous components were effectively removed, and the fiber particles shrunk over time because of many activities. CNCs had a rod-like shape, with a length of 205.7 ± 52.4 nm and a 20.5 aspect ratio. The crystal structure of cellulose Iß was preserved by the CNCs, and the crystallinity was 72.36%. The temperature of the fibers' thermal degradation lowered during the operations, although CNCs still had outstanding thermal stability (>200 °C). Aside from the CNCs, the aqueous suspension of CNCs was slightly agglomerated; thus, the zeta (ζ) potential of the CNCs' suspension was −23.72 ± 1.7 mV, and the powder had high hydrophilicity. This research will be valuable to individuals who want to explore the possibility for CNCs made of jujube cores.


Subject(s)
Nanoparticles , Ziziphus , Cellulose/chemistry , Humans , Nanoparticles/chemistry , Spectroscopy, Fourier Transform Infrared , Water/chemistry
12.
Biotechnol Bioeng ; 119(7): 1926-1937, 2022 07.
Article in English | MEDLINE | ID: mdl-35257374

ABSTRACT

Myceliophthora thermophila, a thermophilic fungus that can degrade and utilize all major polysaccharides in plant biomass, has great potential in biotechnological industries. Here, the first manually curated genome-scale metabolic model iDL1450 for M. thermophila was reconstructed using an autogenerating pipeline with thorough manual curation. The model contains 1450 genes, 2592 reactions, and 1784 unique metabolites. High accuracy was shown in predictions related to carbon and nitrogen source utilization based on data obtained from Biolog experiments. Besides, metabolism profiles were analyzed using iDL1450 integrated with transcriptomics data of M. thermophila at various growth temperatures. The refined model provides new insights into thermophilic fungi metabolism and sheds light on model-driven strain design to improve biotechnological applications of this thermophilic lignocellulosic fungus.


Subject(s)
Sordariales , Biomass , Biotechnology , Plants/metabolism , Sordariales/genetics
13.
Health Sci Rep ; 5(1): e477, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35229043

ABSTRACT

The use of wearable photoplethysmography (PPG) technology for estimating heart rate (HR) and HR variability (HRV) in the health care system is gaining attention in recent years. However, the performance of these devices remains questionable in their ability to collect data in real working conditions for long-term monitoring. The present study aimed to examine the data collected from nurses during working hours by PPG and electrocardiography (ECG) devices. Twenty-two nurses underwent a 60-minute work protocol during the normal working conditions while wearing a PPG device and an ECG device. HR, low-frequency component (LF) and high-frequency component (HF), LF/HF ratio, and percent LF distribution in total spectral power, and steps were examined. Pearson's correlation analysis and Bland-Altman method was performed to examine the relationships between the two devices based on HR and HRV indices. The results found strong positive correlations between HR estimates of both devices, and moderate correlations between LF/HF ratio and percent LF indices estimates, respectively. Moreover, the Bland-Altman analysis showed a small mean bias in general between the captured data of both devices. This pilot study suggested that the PPG device appears to demonstrate good overall reliability in measuring HR, LF/HF ratio, and percent LF. A further large-scale study is required to investigate the feasibility and practicality for HR and HRV analysis in nurses during real working conditions using PPG devices.

14.
Food Chem ; 381: 132282, 2022 Jul 01.
Article in English | MEDLINE | ID: mdl-35176684

ABSTRACT

An efficient colorimetric detection platform based on multi-enzyme cascade has been developed for detection of organophosphorus. Firstly, the dual-enzyme platform was prepared and applied for sensitive glucose detection (detection limit 0.32 µM). And then three enzymes, including acetylcholinesterase, horseradish peroxidase and choline oxidase were encapsulated in cruciate flower-like zeolitic imidazolate framework-8 (CF-ZIF-8) through one-step co-precipitation to construct detection platform with acetylcholine chloride as substrate. The acephate inhibited the activity of acetylcholinesterase, obstructed the cascade reaction and reduced the production of H2O2, resulting in the changes of color intensity for the colorimetric detection. With suitable size and porous structure, CF-ZIF-8 provided a good microenvironment for guaranteeing the activity and spatial proximity of enzymes. The multi-enzyme platform displayed great performances with the detection limit of 0.23 nM for acephate. It was applied to the detection of acephate in Chinese cabbage and romaine, verifying the practicability of this platform.


Subject(s)
Biosensing Techniques , Metal-Organic Frameworks , Acetylcholinesterase , Biosensing Techniques/methods , Colorimetry , Glucose , Hydrogen Peroxide/chemistry , Metal-Organic Frameworks/chemistry
15.
Nat Commun ; 13(1): 891, 2022 02 16.
Article in English | MEDLINE | ID: mdl-35173152

ABSTRACT

Development of hyperproducing strains is important for biomanufacturing of biochemicals and biofuels but requires extensive efforts to engineer cellular metabolism and discover functional components. Herein, we optimize and use the CRISPR-assisted editing and CRISPRi screening methods to convert a wild-type Corynebacterium glutamicum to a hyperproducer of L-proline, an amino acid with medicine, feed, and food applications. To facilitate L-proline production, feedback-deregulated variants of key biosynthetic enzyme γ-glutamyl kinase are screened using CRISPR-assisted single-stranded DNA recombineering. To increase the carbon flux towards L-proline biosynthesis, flux-control genes predicted by in silico analysis are fine-tuned using tailored promoter libraries. Finally, an arrayed CRISPRi library targeting all 397 transporters is constructed to discover an L-proline exporter Cgl2622. The final plasmid-, antibiotic-, and inducer-free strain produces L-proline at the level of 142.4 g/L, 2.90 g/L/h, and 0.31 g/g. The CRISPR-assisted strain development strategy can be used for engineering industrial-strength strains for efficient biomanufacturing.


Subject(s)
Bioengineering/methods , Bioreactors/microbiology , Corynebacterium glutamicum/genetics , Corynebacterium glutamicum/metabolism , Proline/biosynthesis , Base Sequence , CRISPR-Cas Systems/genetics , Carrier Proteins/genetics , Gene Editing/methods , Phosphotransferases (Carboxyl Group Acceptor)/genetics , Protein Transport/genetics
16.
Int J Psychiatry Clin Pract ; 26(4): 337-342, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35023429

ABSTRACT

BACKGROUND: This study is the first to assess the safety and therapeutic efficacy of vagus nerve stimulation (VNS) as an adjunctive treatment for Chinese patients suffering from treatment-resistant depression (TRD). METHODS: A total of seven patients with TRD underwent surgical implantation of a VNS device were followed over a 9-month period. The 24-item Hamilton Rating Scale for Depression (HAMD-24) and the 14-item Hamilton Anxiety Scale (HAMA) were used to assess depressive and anxiety symptoms, respectively. Neurocognitive function was measured with the Wechsler Adult Intelligence Scale (WAIS) and the Wechsler Memory Scale (WMS). RESULTS: After 3 months of treatment with VNS, the antidepressant response and remission rates were 42.9% and 28.6%, respectively. After 9 months of treatment with VNS, the response and remission rates increased to 85.7% and 57.1%, respectively. Significant time main effects were identified for HAMD-24 scores, HAMA scores, the WMS memory quotient, and the full intelligence quotients measured with the WAIS (all ps < 0.05). The most frequent adverse effects of VNS treatment were voice alteration (100%) and cough frequency increase (71.4%). CONCLUSION: This preliminary study indicated that adjunctive VNS was effective and safe in treating Chinese patients who were suffering from TRD, and its efficacy increased with time.Key pointsThere is positive evidence to support the role of VNS as an adjunctive treatment in Chinese patients with TRD.The antidepressant efficacy of adjunctive VNS for Chinese patients with TRD increased with time.The most frequent adverse effects of VNS treatment were voice alteration and cough frequency increase.


Subject(s)
Vagus Nerve Stimulation , Adult , Humans , Vagus Nerve Stimulation/adverse effects , Depression , Cough/drug therapy , Treatment Outcome , Antidepressive Agents/therapeutic use
17.
Parasit Vectors ; 15(1): 13, 2022 Jan 11.
Article in English | MEDLINE | ID: mdl-35012619

ABSTRACT

BACKGROUND: Data on the genus Sarcocystis in insectivores are limited. The Asian gray shrew Crocidura attenuata is one of the most common species of the insectivore family Soricidae in South Asia and Southeast Asia. To our knowledge, species of Sarcocystis have never been recorded previously in this host. METHODS: Tissues were obtained from 42 Asian gray shrews caught in 2017 and 2018 in China. Sarcocysts were observed using light microscopy (LM) and transmission electron microscopy (TEM). To describe the parasite life cycle, muscle tissues of the host infected with sarcocysts were force-fed to two beauty rat snakes Elaphe taeniura. Individual sarcocysts from different Asian gray shrews, and oocysts/sporocysts isolated from the small intestines and feces of the experimental snakes, were selected for DNA extraction, and seven genetic markers, namely, two nuclear loci [18S ribosomal DNA (18S rDNA) and internal transcribed spacer region 1 (ITS1)], three mitochondrial genes [cytochrome oxidase subunit 1 (cox1), cox3 and cytochrome b], and two apicoplast genes (RNA polymerase beta subunit and caseinolytic protease C), were amplified, sequenced and analyzed. RESULTS: Sarcocysts were found in 17 of the 42 (40.5%) Asian gray shrews. Under LM, the microscopic sarcocysts showed saw- or tooth-like protrusions measuring 3.3-4.5 µm. Ultrastructurally, the sarcocyst wall contained numerous lancet- or leaf-like villous protrusions, similar to those described for type 9h of the common cyst wall classification. The experimental beauty rat snakes shed oocysts/sporocysts measuring 11.9-16.7 × 9.2-10.6 µm with a prepatent period of 10-11 days. Comparison of the newly obtained sequences with those previously deposited in GenBank revealed that those of 18S rDNA and cox1 were most similar to those of Sarcocystis scandentiborneensis recorded in the tree shrews Tupaia minor and Tupaia tana (i.e., 97.6-98.3% and 100% identity, respectively). Phylogenetic analysis based on 18S rDNA or ITS1 sequences placed this parasite close to Sarcocystis spp. that utilize small animals as intermediate hosts and snakes as the known or presumed definitive host. On the basis of morphological and molecular characteristics and host specificity, the parasite was proposed as a new species, named Sarcocystis attenuati. CONCLUSIONS: Sarcocysts were recorded in Asian gray shrews, to our knowledge for the first time. Based on morphological and molecular characterization, a new species of parasite is proposed: Sarcocystis attenuati. According to the LM and TEM results, S. attenuati sarcocysts are distinct from those of Sarcocystis spp. in other insectivores and those of S. scandentiborneensis in tree shrews. The 18S rDNA or cox1 sequences of Sarcocystis attenuati shared high similarity with those of Sarcocystis scandentiborneensis, Sarcocystis zuoi, Sarcocystis cf. zuoi in the Malayan field rat, and Sarcocystis sp. in the greater white-toothed shrew. Therefore, we suggest that more research on the relationships of these closely related taxa should be undertaken in the future.


Subject(s)
Sarcocystis/classification , Sarcocystosis/veterinary , Shrews/parasitology , Animals , China , Cyclooxygenase 1/genetics , DNA, Protozoan/chemistry , DNA, Ribosomal/chemistry , Phylogeny , Polymerase Chain Reaction , RNA, Ribosomal, 18S/genetics , Sarcocystis/genetics , Sarcocystis/isolation & purification , Sarcocystis/ultrastructure , Sarcocystosis/parasitology
18.
J Exp Bot ; 73(1): 123-138, 2022 01 05.
Article in English | MEDLINE | ID: mdl-34490889

ABSTRACT

The formation of locule gel is an important process in tomato and is a typical characteristic of berry fruit. In this study, we examined a natural tomato mutant that produces all-flesh fruit (AFF) in which the locule tissue remains in a solid state during fruit development. We constructed different genetic populations to fine-map the causal gene for this trait and identified SlMBP3 as the locus conferring the locule gel formation, which we rename as AFF. We determined the causal mutation as a 416-bp deletion in the promoter region of AFF, which reduces its expression dosage. Generally, this sequence is highly conserved among Solanaceae, as well as within the tomato germplasm. Using BC6 near-isogenic lines, we determined that the reduced expression dosage of AFF did not affect the normal development of seeds, whilst producing unique, non-liquefied locule tissue that was distinct from that of normal tomatoes in terms of metabolic components. Combined analysis using mRNA-seq and metabolomics indicated the importance of AFF in locule tissue liquefaction. Our findings provide insights into fruit-type differentiation in Solanaceae crops and also present the basis for future applications of AFF in tomato breeding programs.


Subject(s)
Solanum lycopersicum , Fruit/genetics , Solanum lycopersicum/genetics , Mutation , Plant Breeding , Promoter Regions, Genetic
19.
ChemSusChem ; 15(3): e202102334, 2022 Feb 08.
Article in English | MEDLINE | ID: mdl-34898013

ABSTRACT

Lead halide perovskite nanocrystals (NCs) have been regarded as a promising potential photocatalyst, owing to their high molar extinction coefficient, low economic cost, adjustable light absorption range, and ample surface active sites. However, the toxicity of lead and its inherent instability in water and polar solvents could hinder their wide application in the field of photocatalysis. Herein, with α-alkylation of aldehydes as a model reaction, C-C bond-forming is demonstrated in high yield by using lead-free double perovskite Cs2 AgSbCl6 NCs under visible light irradiation. Moreover, the photocatalytic performance is simply improved by rational control of the surface ligands and a reaction mechanism involving a radical intermediate is proposed. Although the stability requires further amelioration, the results indicate the enormous potential of lead-free double perovskite NC photocatalysts for organic synthesis and chemical transformations.

20.
Dalton Trans ; 50(48): 17960-17966, 2021 Dec 14.
Article in English | MEDLINE | ID: mdl-34854449

ABSTRACT

It was thought that the organic-inorganic hybrid perovskite MAPbI3 could be used to collect visible light for the photocatalytic hydrogen evolution reaction (HER). However, its ability to generate H2 is limited. Herein, we synthesized amorphous NiCoB through a redox method and coupled it with MAPbI3 to form the NiCoB/MAPbI3 composite photocatalyst by electrostatic self-assembly. 30% NiCoB/MAPbI3 exhibited the maximum H2 generation yield of 2625.57 µmol g-1 h-1, which was approximately 114 fold that of pristine MAPbI3 and much better than that of Pt/MAPbI3. In addition to the excellent photocatalytic HER capability, NiCoB/MAPbI3 maintained good stability in the 24 h cycling hydrogen evolution experiment. The photoelectric analysis showed that NiCoB as a cocatalyst could realize rapid charge separation. This work can offer a reference for the construction of efficient photocatalysts based on lead halide perovskites.

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