Journal of Biosciences最新文献

Rice production is severely affected by various diseases such as bacterial leaf blight (BLB), brown spot (BS), false smut (FS), foot rot (FR), rice blast (RB), and sheath blight (SB). In recent years, several quantitative trait loci (QTLs) studies involving different populations have been carried out, resulting in the identification of hundreds of resistance QTLs for each disease. These QTLs can be integrated and analyzed using meta-QTL (MQTL) analysis for better understanding of the genetic architecture underlying multiple disease resistance (MDR). This study involved an MQTL analysis on 661 QTLs (378, 161, 21, 41, 44, and 16 QTLs for SB, RB, BLB, BS, FS, and FR, respectively) retrieved from 50 individual studies published from 1995 to 2021. Of these, 503 QTLs were projected finally onto the consensus map saturated with 6,275 markers, resulting in 73 MQTLs, including 27 MDR-MQTLs conferring resistance to three or more diseases. Forty-seven MQTLs were validated using marker-trait associations identified in published genome-wide association studies. A total of 3,310 genes, including both R and defense genes, were also identified within some selected high-confidence MQTL regions that were investigated further for the syntenic relationship with barley, wheat, and maize genomes. Thirty-nine high-confidence candidate genes were selected based on their expression patterns and recommended for future studies involving functional validation, genetic engineering, and gene editing. Nineteen MQTLs were co-localized with 39 known R genes for BLB and RB diseases. These results could pave the way to utilize candidate genes in a marker-assisted breeding program for MDR in rice.

Trehalose serves as a primary circulatory sugar in insects which is crucial in energy metabolism and stress recovery. It is hydrolyzed into two glucose molecules by trehalase. Silencing or inhibiting trehalase results in reduced fitness, developmental defects, and insect mortality. Despite its importance, the molecular response of insects to trehalase inhibition is not known. Here, we performed transcriptomic analyses of Helicoverpa armigera treated with validamycin A (VA), a trehalase inhibitor. VA ingestion resulted in increased mortality, developmental delay, and reduced ex vivo trehalase activity. Pathway enrichment and gene ontology analyses suggest that key genes involved in carbohydrate, protein, fatty acid, and mitochondria-related metabolisms are deregulated. The activation of protein and fat degradation may be necessary to fulfil energy requirements, evidenced by the dysregulated expression of critical genes in these metabolisms. Co-expression analysis supports the notion that trehalase inhibition leads to putative interaction with key regulators of other pathways. Metabolomics correlates with transcriptomics to show reduced levels of key energy metabolites. VA generates an energy-deficient condition, and insects activate alternate pathways to facilitate the energy demand. Overall, this study provides insights into the molecular mechanisms underlying the response of insects to trehalase inhibition and highlights potential targets for insect control.

The Kunming–Montreal Global Biodiversity Framework (GBF) is a recently signed protocol by the conference of the parties (COP 15) with an aim to protect biodiversity from risks imposed by biological threats such as invasive alien species (IAS). The present work is an effort to meet target 6 of GBF which directly deals with IAS by assessing the current and future distribution of Ageratum species in regions of the Eastern Ghats of India. Prediction of Ageratum distribution was done based on greenhouse gas emission levels, namely RCP 4.5, 6.0 and 8.5 for the climatic years 2030, 2050 and 2080. Of a total of 23 environmental parameters (19 bioclimatic, 1 land use land cover (LULC) and 3 topographic) seven were selected for species distribution modeling (SDM) considering value inflation factor (VIF) scores <3 by using maximum entropy. In the current climatic scenario, 40.09% of the geographical area (TGA) is covered by Ageratum species which will reach 76.51%, 77.44%, 82.58% for RCP 4.5, 6.0 and 8.5 respectively by the end of 2100. Both the AUC value (0.884) and Jackknife test have shown a good model performance. The Eastern Ghats, being a biodiversity-rich zone, needs efficient conservation and management strategies to decrease the extent of invaded areas to maximize biodiversity returns.

Nitric oxide (NO) and iNOS are crucial host factors in innate immunity against intracellular pathogens. However, the role of NO in Mycobacterium tuberculosis (M. tb) infection in humans remains controversial, unlike in the murine model of TB. To investigate this, levels of NO, iNOS, and L-arginine, as well as the NOS2A gene polymorphism rs57234985 at the promoter region of NOS2A, were evaluated in pulmonary TB (PTB) patients and their household contacts (HHCs). Increased levels of NO and iNOS expression in HHCs indicated exposure to M. tb infection which was confirmed by higher levels of iNOS and NO in Mantoux-positive individuals. Furthermore, higher levels of arginine were detected in HHCs, suggesting its potential role in promoting optimal NO synthesis. PTB patients had higher levels of these analytes due to ongoing active infection. Interestingly, iNOS and NO levels were inversely related to bacterial burden, suggesting their antimicrobial role. NOS2A gene polymorphism was found to be associated with disease susceptibility, with the TT genotype linked to increased iNOS expression. To conclude, iNOS plays a crucial role in controlling early M. tb infection in HHCs by inducing optimal NO production with help of L-arginine. Further longitudinal studies are needed to better understand the role of these host factors upon disease activation.

Amyloids interact with plasma membranes. Extracellular amyloids cross the plasma membrane barrier. Internalized extracellular amyloids are reported to trigger amyloidogenesis of endogenous proteins in recipient cells. To what extent these extracellular and intracellular amyloids perturb the plasma membrane proteome is not investigated. Using α-synuclein as a model amyloid protein, we performed membrane shaving followed by mass spectrometry experiments to identify the conformational changes in cell surface proteins after extracellular amyloid challenge. We also performed membrane proteomics after the biogenesis of intracellular α-synuclein amyloids. Our results suggest that promiscuous interactions with extracellular amyloids stochastically alter the conformation of plasma membrane proteins. This affects the biological processes through the plasma membrane and results in loss of cell viability. Cells that survive the extracellular amyloid shock can grow normally and gradually develop intracellular amyloids which do not directly impact the plasma membrane proteome and associated biological processes. Thus, our results suggest that α-synuclein amyloids can damage the plasma membrane and related processes during cell-to-cell transfer and not during their intracellular biogenesis.

Itch is a unique sensory experience that is responded to by scratching. How pruritogens, which are mechanical and chemical stimuli with the potential to cause itch, engage specific pathways in the peripheral and central nervous system has been a topic of intense investigation over the last few years. Studies employing recently developed molecular, physiological, and behavioral techniques have delineated the dedicated mechanisms that transmit itch information to the brain. This review outlines the genetically defined and evolutionary conserved circuits for itch ranging from the skin-innervating peripheral neurons to the cortical neurons that drive scratching. Moreover, scratch suppression of itch is attributed to the concurrent activation of pain and itch pathways. Hence, we discuss the similarities between circuits driving pain and itch.

Owing to the lack of effective vaccines, current control measures and eradication strategies for the African swine fever virus (ASFV) rely on early detection and stringent stamping-out procedures. In the present study, we developed two independent isothermal amplification assays, namely, loop-mediated isothermal amplification (LAMP) and polymerase spiral reaction (PSR), for quick visualization of the ASFV genome in clinical samples. Additionally, a quantitative real-time PCR (qRT-PCR)-based hydrolysis probe assay was developed for comparative assessment of sensitivity with the developed isothermal assays. The analytical sensitivity of the LAMP, PSR, and qRT-PCR was found to be 2.64 ×10⁵ copies/µL, 2.64 ×10² copies/µL, and 2.64 ×10¹ copies/µL, respectively. A total of 165 clinical samples was tested using the developed visual assays. The relative accuracy, relative specificity, and relative diagnostic sensitivity for LAMP vs PSR were found to be 95.37% vs 102.48%, 97.46% vs 101.36%, and 73.33% vs 113.33%, respectively.

Koragas, recognized as a particularly vulnerable tribal group (PVTG) by the Government of India, are from coastal Karnataka and Kerala. They are experiencing severe socioeconomic and health-related issues and rapid depopulation. The unique genetic makeup of Koragas has been maintained by the practice of endogamy. We aimed to identify genetic factors potentially associated with the predisposition of Koragas towards genetic and multifactorial disorders. We employed genome-wise data of 29 Koraga individuals genotyped on the Infinium Global Screening Array-24 v3.0 BeadChip platform and performed various population genetic analyses including kinship, identity by descent (IBD), and runs of homozygosity (RoH). A high degree of haplotype sharing among the Koraga participants may be indicative of a recent founder event. We identified genetic variants and genes associated with several genetic disorders, higher infant mortality rate, neurological disorders, deafness, and lower fertility rate of this agrarian tribe. Ours is the first genome-wide study on the Koraga tribe that identified genetic factors associated with various genetic disorders. Our findings can provide public healthcare providers with essential genetic information that can be useful in augmenting medical and healthcare services and improving the quality of life of Koragas.

Noradrenaline (NA) and serotonin (5-HT) induce nociception and antinociception. This antagonistic effect can be explained by the dose and type of activated receptors. We investigated the existence of synergism between the noradrenergic and serotonergic systems during peripheral antinociception. The paw pressure test was performed in mice that had increased sensitivity by intraplantar injection of prostaglandin E₂ (PGE₂). Noradrenaline (80 ng) administered intraplantarly induced an antinociceptive effect, that was reversed by the administration of selective antagonists of serotoninergic receptors 5-HT_1B isamoltan, 5-HT_1D BRL15572, 5-HT_2A ketanserin, 5-HT₃ ondansetron, but not by selective receptor antagonist 5-HT₇ SB-269970. The administration of escitalopram, a serotonin reuptake inhibitor, potentiated the antinociceptive effect at a submaximal dose of NA. These results, indicate the existence of synergism between the noradrenergic and serotonergic systems in peripheral antinociception in mice.

Fibroblasts embedded in a 3D matrix microenvironment can remodel the matrix to regulate cell adhesion and function. Collagen hydrogels are a useful in vitro system to study cell–matrix interactions in a 3D microenvironment. While major matrix reorganizations are easily recognizable, subtle changes in response to environmental or biochemical cues are challenging to discern in 3D hydrogels. Three-dimensional collagen gels at 1.0 mg/ml vs 1.5 mg/ml were labelled with DQ-collagen and imaged by confocal reflectance microscopy to evaluate these small changes. An image analysis pipeline was developed, hydrogel area and number of cross-sections analysed were optimized, and fibrillar collagen properties (number of branches, number of junctions, and average branch length) were quantified. While no significant changes were seen in fibrillar collagen organization between 1.0 mg/ml and 1.5 mg/ml collagen hydrogels, embedded mouse fibroblasts caused a significant increase in collagen branching and organization. Using the phalloidin-labelled cells, this change was quantitated in immediate proximity of the cell. A distinct increase in branch and junction numbers was observed, significantly altered by small changes in collagen concentration (1.0 mg/ml vs 1.5 mg/ml). Together, this analysis gives a quantitative evaluation of how cells respond to and modify their immediate microenvironment in a 3D collagen hydrogel.