Shared genetic basis and causality between schizophrenia and inflammatory bowel disease: evidence from a comprehensive genetic analysis.

BACKGROUND: The comorbidity between schizophrenia (SCZ) and inflammatory bowel disease (IBD) observed in epidemiological studies is partially attributed to genetic overlap, but the magnitude of shared genetic components and the causality relationship between them remains unclear. METHODS: By leveraging large-scale genome-wide association study (GWAS) summary statistics for SCZ, IBD, ulcerative colitis (UC), and Crohn's disease (CD), we conducted a comprehensive genetic pleiotropic analysis to uncover shared loci, genes, or biological processes between SCZ and each of IBD, UC, and CD, independently. Univariable and multivariable Mendelian randomization (MR) analyses were applied to assess the causality across these two disorders. RESULTS: SCZ genetically correlated with IBD (rg = 0.14, p = 3.65 × 10−9), UC (rg = 0.15, p = 4.88 × 10−8), and CD (rg = 0.12, p = 2.27 × 10−6), all surpassed the Bonferroni correction. Cross-trait meta-analysis identified 64, 52, and 66 significantly independent loci associated with SCZ and IBD, UC, and CD, respectively. Follow-up gene-based analysis found 11 novel pleiotropic genes (KAT5, RABEP1, ELP5, CSNK1G1, etc) in all joint phenotypes. Co-expression and pathway enrichment analysis illustrated those novel genes were mainly involved in core immune-related signal transduction and cerebral disorder-related pathways. In univariable MR, genetic predisposition to SCZ was associated with an increased risk of IBD (OR 1.11, 95% CI 1.07­1.15, p = 1.85 × 10−6). Multivariable MR indicated a causal effect of genetic liability to SCZ on IBD risk independent of Actinobacteria (OR 1.11, 95% CI 1.06­1.16, p = 1.34 × 10−6) or BMI (OR 1.11, 95% CI 1.04­1.18, p = 1.84 × 10−3). CONCLUSIONS: We confirmed a shared genetic basis, pleiotropic loci/genes, and causal relationship between SCZ and IBD, providing novel insights into the biological mechanism and therapeutic targets underlying these two disorders.

[Application of CAD in custom tray design for teaching of dental postgraduates].

PURPOSE: To evaluate the teaching effect of making custom trays via CAD in dental postgraduates. METHODS: Twenty-seven dental postgraduates from first to third grade at the School and Hospital of Stomatology, Tongji University, Shanghai were given an informed consent to explain and request participation in the study. First, a lecture about the theory and process of fabricating custom tray via traditional hand-made method and CAD technique was given, then the students fabricated custom trays via the two methods and completed an online survey. The working time, margin extension and students' preference were analyzed with SPSS 22.0 software package. RESULTS: The working time was shorter, the margin extension was superior, and students' preference was higher via CAD than traditional method, the difference was significant(P＜0.05). CONCLUSIONS: CAD is more conducive to enhance students' understanding of custom tray manufacturing process and relevant theoretical knowledge. It is recommended to integrate digital technology into dental curriculum.

Trueness of One Stationary and Two Mobile Systems for Three-Dimensional Facial Scanning.

PURPOSE: To evaluate the trueness of one stationary and two mobile systems for 3D facial scanning. MATERIALS AND METHODS: Twenty participants were included in this study. After marking facial soft tissue landmarks, their faces were scanned using three facial scanning systems: the Bellus3D Dental Pro app on an iPad Pro 2020 (Apple; IP); the ARC-7 Face Scanning System (Bellus3D; BA); and the EinScan Pro 2X Plus (Shining 3D Tech; EP) following the manufacturers' operating instructions. Three-dimensional images were reconstructed with corresponding software and saved in object (OBJ) file format. The interlandmark distances were measured and compared to direct caliper measurements, and absolute error (AE) was chosen as the measurement to determine the trueness of the three scanners. The normal distribution and variance of homogeneity were measured, and then the data were analyzed using one-way ANOVA or Kruskal-Wallis H test. The significance level was set at P = .05. RESULTS: For the measurement of interlandmark distances, no significant differences were found among the four measuring techniques, and the mean AEs of the IP, BA, and EP systems were 1.17 ± 0.80 mm, 0.76 ± 0.61 mm, and 0.69 ± 0.65 mm. CONCLUSION: The three facial scanning systems tested provided a reliable 3D facial reconstruction. The portable IP system could meet the clinical requirements for facial scanning, but it is suggested to select the EP and BA systems when a higher trueness is required.

Identification of a novel allele HLA-C*03:560N by next-generation sequencing in a hematopoietic stem cell recipient.

A frameshift because of a single nucleotide deletion results in a novel null allele, HLA-C*03:560N.

Photographic Reproduction and Enhancement Using HVS-Based Modified Histogram Equalization.

Photographic reproduction and enhancement is challenging because it requires the preservation of all the visual information during the compression of the dynamic range of the input image. This paper presents a cascaded-architecture-type reproduction method that can simultaneously enhance local details and retain the naturalness of original global contrast. In the pre-processing stage, in addition to using a multiscale detail injection scheme to enhance the local details, the Stevens effect is considered for adapting different luminance levels and normally compressing the global feature. We propose a modified histogram equalization method in the reproduction stage, where individual histogram bin widths are first adjusted according to the property of overall image content. In addition, the human visual system (HVS) is considered so that a luminance-aware threshold can be used to control the maximum permissible width of each bin. Then, the global tone is modified by performing histogram equalization on the output modified histogram. Experimental results indicate that the proposed method can outperform the five state-of-the-art methods in terms of visual comparisons and several objective image quality evaluations.

Microbial characteristics response to the soil quality of newly created farmland on the Loess Plateau.

Microbiome plays an important role in evaluating soil quality for sustainable agriculture. However, the suitability of biological indicators in reclaimed farmland is less understood. Using high-throughput sequencing, we evaluated the soil microbial community of the newly created farmland (NF) after reclamation with two local high-yield farmlands (slope farmland (SF), check-dam farmland (CF)) on the Loess Plateau. Soil enzyme activities and the amount of culturable microorganism were also quantified to assess the soil quality. Results showed that the microbial diversity, cultural microorganism abundance, and soil enzyme activities indicated poor soil quality in NF. The dominant bacterial phyla were Proteobacteria, Bacteroidetes, Acidobacteria, and Cyanobacteria. The abundance of Acidobacteria was significantly lower in NF (13.31%) than in SF (27.25%) and CF (27.91%). Soil enzyme activities had a significant correlation with the abundance of culturable microorganism, Proteobacteria and Bacteroidetes, soil organic matter, total nitrogen, cation exchange capacity, and pH, suggesting that soil microbes have driven the formation of nutrition and further mediated crop growth. Therefore, the application of bacterial fertilizers could be a potential way to improve the soil quality of reclaimed farmland for crop growth.

Potential health risk assessment of HFRs, PCBs, and OCPs in the Yellow River basin.

The concentrations of PBDEs, NBFRs, DP, PCBs, and OCPs were analyzed in water samples of the Yellow River Basin (YRB) and in soil and maize samples collected from basin irrigation areas to understand the status of POPs and associated health risks. The results showed: (1) the congeners of eight PBDEs and seven NBFRs were detected in 10 tributaries, with average concentrations of 1575 and 4288 pg. L-1. Thirty-three congeners of PCBs were detected, and the average concentration of PCB was 232 pg. L-1. Five HCHs were the primary congeners among twenty-three congeners of OCPs in the ten tributaries, accounting for 79% of the total. The average concentration of OCPs was 8287 pg. L-1. (2) Similar congeners of HFRs, PCBs, and OCPs were found in the trunk water. The ranking based on the HFR concentration was upstream > downstream > midstream, and that of the PCB and OCP concentration was downstream > upstream > midstream. (3) PCBs and OCPs in the trunk water of the YRB and in the soil and maize irrigated with river water pose potential carcinogenic and non-carcinogenic risks. The results indicate considerable organic pollution in the YRB, suggesting that national emission standards for POPs should be implemented soon.

Accuracy of digital complete dentures: A systematic review of in vitro studies.

STATEMENT OF PROBLEM: Reports on digital complete dentures (CDs) are increasing. However, systematic reviews on their accuracy and influencing factors are lacking. PURPOSE: The purpose of this systematic review was to evaluate the accuracy of digital CDs and to summarize influencing factors. MATERIAL AND METHODS: An electronic search of the English language literature from January 2009 to October 2019 was performed in the database PubMed/MEDLINE, with the results enriched by manual searches and citation mining. Factors investigated in the selected articles included the fabrication technique, type of computer-aided design and computer-aided manufacturing (CAD-CAM) system, shape of reference model, long-term service, analytical method, and statistical indicators. RESULTS: A total of 522 articles were identified, of which 14 in vitro articles met the inclusion criteria. Eight articles compared the adaptation of the denture base between digital and conventional methods, 4 studies evaluated the occlusal discrepancies, 4 compared the trueness or adaptation of the denture fabricated with CAD-CAM milling and 3D printing, 1 compared the denture adaptation with 4 different CAD-CAM systems, and 2 evaluated the adaptation of the denture base before and after incubation in artificial saliva. CONCLUSIONS: Most of the studies reported clinically acceptable values for the occlusal trueness and adaptation of digital CDs. The digital CDs showed similar or better adaptation than conventionally fabricated CDs, and the greatest misfit of the intaglio surface was reported in the posterior palatal seal area and border seal area. The fabrication technique, CAD-CAM system, and long-term service were statistically significant in relation to denture accuracy. Clarification is needed concerning the accuracy of digital CDs according to the shape of the cast, the parameters related to the CAD-CAM process, the analytical method, and the statistical indicators. No clear conclusions can be drawn about the superiority of CAD-CAM milling and 3D printing regarding denture accuracy.

COVID-19 in Children: Clinical Characteristics and Follow-Up Study.

Since December 2019, the coronavirus disease 2019 (COVID-19) has spread globally. But the clinical symptoms and detailed follow-up of children with COVID-19 infection are lacking. Here, we conducted a retrospective study including children with confirmed COVID-19. We recorded patients' epidemiological, clinical features, and follow-up data after discharging in order to improve the awareness and treatment of children with COVID-19.

Association of HLA class II (-DRB1,-DQB1,-DPB1) alleles and haplotypes on susceptibility to aplastic anemia in northern Chinese Han.

The Human Leukocyte Antigen (HLA) genes, playing key roles in mediating the immune response, especially HLA class II alleles were suggested to play a role in the activation of autoreactive T-cells in aplastic anemia (AA). Previous studies in different ethnic groups have indicated that some of HLA-A,-B,-DRB1 alleles had a protective or susceptive association with the prevalence, pathogenesis and development of AA. HLA class II genes, especially HLA-DQB1 and -DPB1 alleles or haplotypes at high-resolution level associated with AA have not been fully identified in northern Chinese Han populations. The aim of this study was to identify association of the variations in HLA class II region with AA in northern Chinese Han population. A recent case-control study, including 96 AA patients and 824 healthy controls was performed. The high-resolution HLA genotyping was conducted by PCR-SBT, -SSO and NGS-ION S5TM platform. Based on genotypic data of the three loci, haplotype estimation was carried out. HLA-DRB1*15:01 (Pc = 2.87 × 10-3; OR = 2.11, 95% CI = 1.45-3.07) and HLA-DQB1*06:02 (Pc = 1.86 × 10-2; OR = 2.01, 95% CI = 1.32-3.06) were the risk and predisposition alleles to AA in northern Chinese Han after considering multiple testing. Moreover, the HLA-DRB1*15:01-DQB1*06:02 (Pc = 4.90 × 10-3; OR = 2.09, 95% CI = 1.37-3.19) and HLA-DRB1*14:05-DQB1*05:03 (Pc = 2.65 × 10-2; OR = 2.82, 95%CI = 1.45-5.50) haplotypes had direct strong relevance to AA and were the susceptible haplotypes. HLA-DPB1 alleles and 23 polymorphic amino acid residues spanning exon 2 ~ 4 of DPß1 molecules have showed no statistically significant associations between AA and controls. The present findings establish a novel link between inherited HLA-DRB1,-DQB1,-DPB1 risk alleles and haplotypes in northern Chinese Han with AA, and open new avenues for development of targeted therapies to prevent or redirect immunopathology in AA.

Pollution status of the Yellow River tributaries in middle and lower reaches.

To determine the water quality status of the primary tributaries in middle and lower reaches of the Yellow River Basin, water collected from the confluence of the ten tributaries and some physical, chemical and biological parameters were analyzed, and then water quality index and health risk were evaluated. Of the ten main tributaries in the middle and lower reaches, only the Qingshui River had water of medium quality in the upper reaches, while all the other tributaries contributed water of poor quality. The Jindi and Dawen rivers in the lower reaches had the poorest water quality, especially the Jindi River. TP, TN, BOD5, COD, TOC and coliform bacteria exceeded the national criteria by 155%, 1%, 97.5%, 35.5%, 114.2%, and 80%, respectively. Cluster analysis indicated that industrial, agricultural, and domestic sewage, along with industrial waste gas, were the main sources of pollution in these tributaries. An analysis of the bacterial community structure showed that the Jindi River was the most polluted and had the largest species diversity and richness of bacteria. Also, its number of pathogenic microorganisms was much higher than that of other areas, and the bacterial functional genes of related metabolic pathways were significantly enriched. This was in sharp contrast with that of the Qingshui River, which had the best water quality. We suggest more specifics policy should be taken for different tributaries, and poor water quality of Jindi and Dawen River should be further studied to explore the most suitable pollution control methods.

Utility of next-generation sequencing methods to identify the novel HLA alleles in potential stem cell donors from Chinese Marrow Donor Program.

The human leucocyte antigen (HLA) is the most polymorphic region of the human genome. Compared with Sanger-sequencing-based typing (SBT) methods, next-generation sequencing (NGS) has significantly higher throughput and depth sequencing characteristics, having dramatic impacts on HLA typing in clinical settings. Here, we performed NGS technology with Ion Torrent S5 platform to evaluate the potential four novel HLA alleles detected in five donors from Chinese Marrow Donor Program (CMDP, Shaanxi Province) during routine Sanger SBT testing. We also predicted the highest estimated relative frequency novel allele-bearing haplotypes according to their phenotypes and HaploStats database. NGS assays, as it provided the phase-defined and complete sequencing information, undoubtedly increase novel allele identification which will greatly enrich HLA database and provide more information for donor selection.

Targeted co-delivery of Beclin 1 siRNA and FTY720 to hepatocellular carcinoma by calcium phosphate nanoparticles for enhanced anticancer efficacy.

PURPOSE: FTY720, known as fingolimod, is a new immunosuppressive agent with effective anticancer properties. Although it was recently confirmed that FTY720 inhibits cancer cell proliferation, FTY720 can also induce protective autophagy and reduce cytotoxicity. Blocking autophagy with Beclin 1 siRNA after treatment with FTY720 promotes apoptosis. The objective of this study was to enhance the anticancer effect of FTY720 in hepatocellular carcinoma (HCC) by targeted co-delivery of FTY720 and Beclin 1 siRNA using calcium phosphate (CaP) nanoparticles (NPs). MATERIALS AND METHODS: First, the siRNA was encapsulated within the CaP core. To form an asymmetric lipid bilayer structure, we then used an anionic lipid for the inner leaflet and a cationic lipid for the outer leaflet; after removing chloroform by rotary evaporation, these lipids were dispersed in a saline solution with FTY720. The NPs were analyzed by transmission electron microscopy, dynamic light scattering and ultraviolet-visible spectrophotometry. Cancer cell viability and cell death were analyzed by MTT assays, fluorescence-activated cell sorting analysis and Western blotting. In addition, the in vivo effects of the NPs were investigated using an athymic nude mouse subcutaneous transplantation tumor model. RESULTS: When the CaP NPs, called LCP-II NPs, were loaded with FTY720 and siRNA, they exhibited the expected size and were internalized by cells. These NPs were stable in systemic circulation. Furthermore, co-delivery of FTY720 and Beclin 1 siRNA significantly increased cytotoxicity in vitro and in vivo compared with that caused by treatment with the free drug alone. CONCLUSION: The CaP NP system can be further developed for co-delivery of FTY720 and Beclin 1 siRNA to treat HCC, enhancing the anticancer efficacy of FTY720. Our findings provide a new insight into HCC treatment with co-delivered small molecules and siRNA, and these results can be readily translated into cancer clinical trials.

Exosome-Mimetic Nanovesicles from Hepatocytes promote hepatocyte proliferation in vitro and liver regeneration in vivo.

The liver has great regenerative capacity after functional mass loss caused by injury or disease. Many studies have shown that primary hepatocyte-derived exosomes, which can deliver biological information between cells, promote the regenerative process of the liver. However, the yield of exosomes is very limited. Recent studies have demonstrated that exosome-mimetic nanovesicles (NVs) can be prepared from cells with almost 100 times the production yield compared with exosomes. Thus, this study investigated the therapeutic capacity of exosome-mimetic NVs from primary hepatocytes in liver regeneration. Exosome-mimetic NVs were prepared by serial extrusions of cells through polycarbonate membranes, and the yield of these NVs was more than 100 times that of exosomes. The data indicated that the NVs could promote hepatocyte proliferation and liver regeneration by significantly enhancing the content of sphingosine kinase 2 in recipient cells. To the best of our knowledge, this is the first time that exosome-mimetic NVs from primary hepatocytes have been prepared, and these NVs have components similar to exosomes from primary hepatocytes and, in some respects, biofunctions similar to exosomes. Strategies inspired by this study may lead to substitution of exosomes with exosome-mimetic NVs for biofunctional purposes, including utilization in tissue repair and regeneration.

[Relationship between High-Resolution HLA-A,-B,-DRB1 Alleles and Haplotype Polymorphisms with Myeloid Leukemia of Han People in North China].

OBJECTIVE: To investigate the potential relationship between the high-resolution HLA-A,-B,-DRB1 alleles and haplotype polymorphism with actute myeloid leukemia (AML) and chronic myeloid leukemia (CML) of Han people in North China. METHODS: A total of 1241 healthy unrelated Han people's bone marrow donors in North China were used as a control group, 259 patients with myeloid leukemia were genotyped at high-resolution level by means of PCR-SBT, -SSO and -SSP typing methods for HLA-A,-B,-DRB1 loci. The frequencies of HLA allele and haplotype were calculated by software Arleguin 3.5.2. The different distribution of genes and haplotypes was analyzed by case control study, and the odd ratio (OR) of leukemia was also calculated. The structural difference of HLA alleles was analyzed 111by HLA three-dimensional structure modeling and software Swiss-PdbViewer v4.1. RESULTS: χ2 test and correction showed that an increased frequency of A*02:07 (8.47% vs 5.28%, P' =0.013), A*29:01 (1.85% vs 0.68%, P=0.044), B*07:02 (5.29% vs 3.10%, P=0.029), B*07:05:01G (1.85% vs 0.68%, P=0.044) and B*35:02 (1.06% vs 0.20%, P=0.023) were found in AML patients (n=189) as compared with controls, respectively; whereas A*02:03 was less frequent in AML as compared with controls (0.79% vs 3.10%, P=0.011). The frequency of B*46:01 was lower in CML patients (n=70) as compared with controls (2.86% vs 7.82%, P=0.031). However, the above-mentioned discrepancies were not statistically significant by Bonferroni correction. Through Fisher exact test and Bonferroni correction, the frequency of DRB1*11:28 and its haplotype A*24:02-B*15:01-DRB1*11:28 in CML group were very significantly higher than in controls (1.43% vs 0.00%, Pc=0.015; 1.43% vs 0.00%, P=0.003). Three-dimensional structure modeling of DRB1*11:28 and DRB1*11:01 presented significant structure differentiation (RMSD=0.09 nm) in peptide binding region of the backbone calculated by Swiss-PdbViewer v4.1. The haplotype A*03:01-B*50:01-DRB1*07:01 in AML and A*11:01-B*40:06-DRB1*09:01 in CML patients were significantly higher than that in controls (1.06% vs 0.00%, Pc=0.000; 2.86% vs 0.07%, Pc=0.000), and positively correlated with leukemia (OR=59.66, 95% CI=3.21-1110.39; OR=42.91, 95% CI=7.07-260.32). CONCLUSION: The relationship of HLA-A,-B,-DRB1 alleles and haplotype polymorphism with leukemia at high-resolution level were obtained and unique in north Chinese Han population. AML and CML patients in Northern Han people carry particular susceptible haplotypes. DRB1*11:28, which might not actively present bcr-abl peptide to CD4+ T cells, and is a susceptibile gene for CML patients of Northern Han people, especially in Shaanxi Province (OR=89.62, 95% CI=4.28-1875.87), as well as correlated with its particular haplotype.

Role of stem cell-derived exosomes in cancer.

Exosomes are small, extracellular membrane- enclosed vesicles that contain a variety of molecules, including proteins, DNA, mRNA and non-coding RNA; these vesicles have been defined as new tools for intercellular communication between cells. Numerous types of cells, including stem cells, secrete exosomes into the extracellular environment, and are significant communicators in the tumor microenvironment. Stem cells are a unique cell population defined by their ability to indefinitely self-renew, differentiate into a variety of cell lines, and form clonal cell populations. Stem cells also secrete large amounts of exosomes, which have demonstrated great potential in a variety of diseases. Increasing evidence has revealed that the mechanism of interaction between stem cells and human tumor cells involves the exchange of biological material through exosomes. In this review, the latest developments in the role of stem cell-derived exosomes in cancer are highlighted.

A Highly Stretchable and Autonomous Self-Healing Polymer Based on Combination of Pt···Pt and π-π Interactions.

A new self-healing polymer has been obtained by incorporating a cyclometalated platinum(II) complex Pt(C∧ N∧ N)Cl (C∧ N∧ N = 6-phenyl-2,2'-bipyridyl) into a polydimethylsiloxane (PDMS) backbone. The molecular interactions (a combination of Pt···Pt and π-π interactions) between cyclometalated platinum(II) complexes are strong enough to crosslink the linear PDMS polymer chains into an elastic film. The as prepared polymer can be stretched to over 20 times of its original length. When damaged, the polymer can be healed at room temperature without any healants or external stimuli. Moreover, the self-healing is insensitive to surface aging. This work represents the first example where the attractive metallophilic inter-actions are utilized to design self-healing materials. Moreover, our results suggest that the stretchability and self-healing properties can be obtained simultaneously without any conflict by optimizing the strength of crosslinking interactions.

Synthesis of bi-phase dispersible core-shell FeAu@ZnO magneto-opto-fluorescent nanoparticles.

Bi-phase dispersible core-shell FeAu@ZnO magneto-opto-fluorescent nanoparticles were synthesized by a modified nanoemulsion process using poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEO-PPO-PEO) as the surfactant. The morphology and crystal structure of the nanoparticles were studied by TEM/HRTEM and XRD. The nanoparticles manifest soft ferromagnetic and/or near superparamagnetic behavior with a small coercivity of ~19 Oe at room temperature. The corresponding magnetic hysteresis curves were elucidated by the modified Langevin equation. The FTIR study confirms the PEO-PPO-PEO molecules on the surface of the nanoparticles. The UV-vis and PL results reveal the well-behaved absorption bands including surface plasmon resonance and multiple visible fingerprint photoluminescent emissions of the nanoparticles dispersed in both hydrophilic and hydrophobic solvents. Moreover, the processes of solvent dispersion-collection of the nanoparticles were demonstrated for application readiness of such core-shell nanostructures.

MiR-24 functions as a tumor suppressor in nasopharyngeal carcinoma through targeting FSCN1.

BACKGROUND: Increasing evidence indicates that the dysregulation of miRNAs expression is involved in the tumorigenesis by acting as tumor suppressors or oncogenes. However, no study investigates the function and mechanisms of miR-24 in nasopharyngeal carcinoma (NPC). METHODS: Quantitative RT-PCR, MTT, colony formation, soft-agar, wound healing, Transwell migration and invasion assays, and xenograft tumor growth and lung metastasis models were performed to test the expression levels and functions of miR-24 in NPC. Luciferase reporter assay, quantitative RT-PCR, Western blotting, and immunohistochemistry were used to identify and verify the target of miR-24. RESULTS: The results showed that MiR-24 was obviously downregulated in NPC cell lines and tissue samples (P < 0.05). Ectopic expression of miR-24 inhibited the cell viability, proliferation, migration, and invasion in vitro (all P < 0.05), and suppressed the xenograft tumor growth and lung metastasis formation in vivo (all P < 0.05). Fascin homologue 1 (FSCN1) was verified as a direct target of miR-24, and silencing FSCN1 expression with small interfering RNA inhibited NPC cell proliferation and invasion (all P < 0.05). CONCLUSIONS: Overall, miR-24 acts as a novel tumor suppressor in the development and progression of NPC through targeting FSCN1, which providing new insight into the mechanisms of NPC carcinogenesis and suggesting the possibility of miR-24 as a therapeutic target.

Comparative transcriptomics analysis reveals difference of key gene expression between banana and plantain in response to cold stress.

BACKGROUND: Banana and plantain (Musa spp.) comprise an important part of diets for millions of people around the globe. Low temperature is one of the key environmental stresses which greatly affects the global banana production. To understand the molecular mechanism of the cold-tolerance in plantain we used RNA-Seq based comparative transcriptomics analyses for both cold-sensitive banana and cold-tolerant plantain subjected to the cold stress for 0, 3 and 6 h. RESULTS: The cold-response genes at early stage are identified and grouped in both species by GO analysis. The results show that 10 and 68 differentially expressed genes (DEGs) are identified for 3 and 6 h of cold stress respectively in plantain, while 40 and 238 DEGs are identified respectively in banana. GO classification analyses show that the majority of DEGs identified in both banana and plantain belong to 11 categories including regulation of transcription, response to stress signal transduction, etc. A similar profile for 28 DEGs was found in both banana and plantain for 6 h of cold stress, suggesting both share some common adaptation processes in response to cold stress. There are 17 DEGs found uniquely in cold-tolerance plantain, which were involved in signal transduction, abiotic stress, copper ion equilibrium, photosynthesis and photorespiration, sugar stimulation, protein modifications etc. Twelve early responsive genes including ICE1 and MYBS3 were selected and further assessed and confirmed by qPCR in the extended time course experiments (0, 3, 6, 24 and 48 h), which revealed significant expression difference of key genes in response to cold stress, especially ICE1 and MYBS3 between cold-sensitive banana and cold-tolerant plantain. CONCLUSIONS: We found that the cold-tolerance pathway appears selectively activated by regulation of ICE1 and MYBS3 expression in plantain under different stages of cold stress. We conclude that the rapid activation and selective induction of ICE1 and MYBS3 cold tolerance pathways in plantain, along with expression of other cold-specific genes, may be one of the main reasons that plantain has higher cold resistance than banana.