Comparative Transcriptomic Analysis of Genes in the 20-Hydroxyecdysone Biosynthesis in the Fern Microsorum scolopendria towards Challenges with Foliar Application of Chitosan.

Microsorum scolopendria is an important medicinal plant that belongs to the Polypodiaceae family. In this study, we analyzed the effects of foliar spraying of chitosan on growth promotion and 20-hydroxyecdysone (20E) production in M. scolopendria. Treatment with chitosan at a concentration of 50 mg/L in both young and mature sterile fronds induced the highest increase in the amount of accumulated 20E. Using RNA sequencing, we identified 3552 differentially expressed genes (DEGs) in response to chitosan treatment. The identified DEGs were associated with 236 metabolic pathways. We identified several DEGs involved in the terpenoid and steroid biosynthetic pathways that might be associated with secondary metabolite 20E biosynthesis. Eight upregulated genes involved in cholesterol and phytosterol biosynthetic pathway, five upregulated genes related to the methylerythritol 4-phosphate (MEP) and mevalonate (MVA) pathways, and several DEGs that are members of cytochrome P450s and ABC transporters were identified. Quantitative real-time RT-PCR confirmed the results of RNA-sequencing. Taken together, we showed that chitosan treatment increased plant dry weight and 20E accumulation in M. scolopendria. RNA-sequencing and DEG analyses revealed key enzymes that might be related to the production of the secondary metabolite 20E in M. scolopendria.

Transcriptional Analysis of the Differences between ToLCNDV-India and ToLCNDV-ES Leading to Contrary Symptom Development in Cucumber.

Tomato leaf curl New Delhi virus-ES (ToLCNDV-ES), a high threat to cucurbits in the Mediterranean Basin, is listed as a different strain from the Asian ToLCNDV isolates. In this study, the infectivity of two clones previously isolated from Italy and Pakistan were compared in cucumbers, which resulted in the opposite symptom appearance. The swapping subgenome was processed; however, the mechanisms related to the disease phenotype remain unclear. To identify the disease-associated genes that could contribute to symptom development under the two ToLCNDV infections, the transcriptomes of ToLCNDV-infected and mock-inoculated cucumber plants were compared 21 days postinoculation. The number of differentially expressed genes in ToLCNDV-India-infected plants was 10 times higher than in ToLCNDV-ES-infected samples. The gene ontology (GO) and pathway enrichment were analyzed using the Cucurbits Genomics Database. The flavonoid pathway-related genes were upregulated in ToLCNDV-ES, but some were downregulated in ToLCNDV-India infection, suggesting their role in resistance to the two ToLCNDV infections. The relative expression levels of the selected candidate genes were validated by qRT-PCR under two ToLCNDV-infected conditions. Our results reveal the different infectivity of the two ToLCNDVs in cucumber and also provide primary information based on RNA-seq for further analysis related to different ToLCNDV infections.

Marine Bacterioplankton Community Dynamics and Potentially Pathogenic Bacteria in Seawater around Jeju Island, South Korea, via Metabarcoding.

Understanding marine bacterioplankton composition and distribution is necessary for improving predictions of ecosystem responses to environmental change. Here, we used 16S rRNA metabarcoding to investigate marine bacterioplankton diversity and identify potential pathogenic bacteria in seawater samples collected in March, May, September, and December 2013 from two sites near Jeju Island, South Korea. We identified 1343 operational taxonomic units (OTUs) and observed that community diversity varied between months. Alpha- and Gamma-proteobacteria were the most abundant classes, and in all months, the predominant genera were Candidatus Pelagibacter, Leisingera, and Citromicrobium. The highest number of OTUs was observed in September, and Vibrio (7.80%), Pseudoalteromonas (6.53%), and Citromicrobium (6.16%) showed higher relative abundances or were detected only in this month. Water temperature and salinity significantly affected bacterial distribution, and these conditions, characteristic of September, were adverse for Aestuariibacter but favored Citromicrobium. Potentially pathogenic bacteria, among which Vibrio (28 OTUs) and Pseudoalteromonas (six OTUs) were the most abundant in September, were detected in 49 OTUs, and their abundances were significantly correlated with water temperature, increasing rapidly in September, the warmest month. These findings suggest that monthly temperature and salinity variations affect marine bacterioplankton diversity and potential pathogen abundance.

Zooming on dynamics of marine microbial communities in the phycosphere of Akashiwo sanguinea (Dinophyta) blooms.

Characterizing ecological relationships between viruses, bacteria and phytoplankton in the ocean is critical to understanding the ecosystem; however, these relationships are infrequently investigated together. To understand the dynamics of microbial communities and environmental factors in harmful algal blooms (HABs), we examined the environmental factors and microbial communities during Akashiwo sanguinea HABs in the Jangmok coastal waters of South Korea by metagenomics. Specific bacterial species showed complex synergistic and antagonistic relationships with the A. sanguinea bloom. The endoparasitic dinoflagellate Amoebophrya sp. 1 controlled the bloom dynamics and correlated with HAB decline. Among nucleocytoplasmic large DNA viruses (NCLDVs), two Pandoraviruses and six Phycodnaviruses were strongly and positively correlated with the HABs. Operational taxonomic units of microbial communities and environmental factors associated with A. sanguinea were visualized by network analysis: A. sanguinea-Amoebophrya sp. 1 (r = .59, time lag: 2 days) and A. sanguinea-Ectocarpus siliculosus virus 1 in Phycodnaviridae (0.50, 4 days) relationships showed close associations. The relationship between A. sanguinea and dissolved inorganic phosphorus relationship also showed a very close correlation (0.74, 0 day). Microbial communities and the environment changed dynamically during the A. sanguinea bloom, and the rapid turnover of microorganisms responded to ecological interactions. A. sanguinea bloom dramatically changes the environments by exuding dissolved carbohydrates via autotrophic processes, followed by changes in microbial communities involving host-specific viruses, bacteria and parasitoids. Thus, the microbial communities in HAB are composed of various organisms that interact in a complex manner.

Biomechanical Parameters that May Influence Lower Limb Injury during Landing in Taekwondo.

Background and Objectives: The jumping kick of Taekwondo was a unilateral exercise that repeatedly moves in one direction. The exercise was exposed to the risk of injury due to the heavy ground reaction force and load in the landing. The first purpose of this study was to compare the impact force (IF), peak vertical ground reaction force (PVGRF), vertical loading rate (VLR), vertical stiffness (VS), and landing foot angle (LFA) during the landing of the jumping kick according to the experience of lower injury. The second purpose of this study was to investigate the lower extremities' strength and the bilateral/ipsilateral asymmetry between the groups; Material and Methods: Ten injury-experience athletes (IG, age: 21.0 ± 0.8 years; height: 170.5 ± 4.1 cm; body weight: 66.7 ± 6.0 kg; career: 8.1 ± 5.0 years) and seven non-injury experience athletes (NG, age: 22.9 ± 4.0 years; height: 173.4 ± 3.1 cm; body weight: 67.9 ± 7.9 kg; career: 8.3 ± 5.0 years) participated; Results: There was no statistical difference between the two groups in the landing and lower extremity muscle strength impact variables. However, in the bilateral asymmetry of the ankle plantar flexor and the ipsilateral asymmetry of the hip abductor/adductor, IG was statistically larger than NG (p < 0.05). The landing foot angle also showed negative correlation to all impact variables (IF, PVGRF, VLR, and VS) (p < 0.05); Conclusions: It is desirable to place the landing foot down at a wide angle to prevent injury in performing Taekwondo jumping kicks. Although NGs have been shown to have better muscle strength symmetry and balance in some areas compared to IG, further research is needed to determine whether they are effective in preventing injury.

FHIT suppresses epithelial-mesenchymal transition (EMT) and metastasis in lung cancer through modulation of microRNAs.

Metastasis is the principal cause of cancer death and occurs through multiple, complex processes that involve the concerted action of many genes. A number of studies have indicated that the Fragile Histidine Triad (FHIT) gene product, FHIT, functions as a tumor suppressor in a variety of common human cancers. Although there are suggestions of a role for FHIT loss in progression of various cancers, a role for such loss in metastasis has not been defined. Here, via in vivo and in vitro assays, we reveal that the enforced expression of FHIT significantly suppresses metastasis, accompanied by inhibition of the epithelial-mesenchymal transition (EMT), a process involved in metastasis through coordinate modulation of EMT-related genes. Specifically, miR-30c, a FHIT-upregulated microRNA, contributes to FHIT function in suppression of EMT and metastasis by directly targeting metastasis genes Metadherin (MTDH), High-mobility group AT-hook 2 (HMGA2), and the mesenchymal markers, Vimentin (VIM) and Fibronectin (FN1), in human lung cancer. Finally, we demonstrate that the expression pattern of FHIT and miR-30c is inversely correlated with that of MTDH and HMGA2 in normal tissue, non-metastatic and metastatic tumors, serving as a potential biomarker for metastasis in lung cancer.

Differential gene expression patterns during embryonic development of sea urchin exposed to triclosan.

Triclosan (TCS; 2,4,4'-trichloro-2'-hydroxydiphenyl ether) is a broad-spectrum antibacterial agent used in common industrial, personal care and household products which are eventually rinsed down the drain and discharged with wastewater effluent. It is therefore commonly found in the aquatic environment, leading to the continual exposure of aquatic organisms to TCS and the accumulation of the antimicrobial and its harmful degradation products in their bodies. Toxic effects of TCS on reproductive and developmental progression of some aquatic organisms have been suggested but the underlying molecular mechanisms have not been defined. We investigated the expression patterns of genes involved in the early development of TCS-treated sea urchin Strongylocentrotus nudus using cDNA microarrays. We observed that the predominant consequence of TCS treatment in this model system was the widespread repression of TCS-modulated genes. In particular, empty spiracles homeobox 1 (EMX-1), bone morphogenic protein, and chromosomal binding protein genes showed a significant decrease in expression in response to TCS. These results suggest that TCS can induce abnormal development of sea urchin embryos through the concomitant suppression of a number of genes that are necessary for embryonic differentiation in the blastula stage. Our data provide new insight into the crucial role of genes associated with embryonic development in response to TCS. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 426-433, 2017.

A nucleic-acid hydrolyzing single chain antibody confers resistance to DNA virus infection in hela cells and C57BL/6 mice.

Viral protein neutralizing antibodies have been developed but they are limited only to the targeted virus and are often susceptible to antigenic drift. Here, we present an alternative strategy for creating virus-resistant cells and animals by ectopic expression of a nucleic acid hydrolyzing catalytic 3D8 single chain variable fragment (scFv), which has both DNase and RNase activities. HeLa cells (SCH07072) [corrected] expressing 3D8 scFv acquired significant resistance to DNA viruses. Virus challenging with Herpes simplex virus (HSV) in 3D8 scFv transgenic cells and fluorescence resonance energy transfer (FRET) assay based on direct DNA cleavage analysis revealed that the induced resistance in HeLa cells was acquired by the nucleic acid hydrolyzing catalytic activity of 3D8 scFv. In addition, pseudorabies virus (PRV) infection in WT C57BL/6 mice was lethal, whereas transgenic mice (STG90) that expressed high levels of 3D8 scFv mRNA in liver, muscle, and brain showed a 56% survival rate 5 days after PRV intramuscular infection. The antiviral effects against DNA viruses conferred by 3D8 scFv expression in HeLa cells as well as an in vivo mouse system can be attributed to the nuclease activity that inhibits viral genome DNA replication in the nucleus and/or viral mRNA translation in the cytoplasm. Our results demonstrate that the nucleic-acid hydrolyzing activity of 3D8 scFv confers viral resistance to DNA viruses in vitro in HeLa cells and in an in vivo mouse system.

Detection of the dinoflagellate, Cochlodinium polykrikoides, that forms algal blooms using sandwich hybridization integrated with nuclease protection assay.

OBJECTIVES: To detect Cochlodinum polykrikoides in long-term monitoring and high-throughput sampling projects using an integrated sandwich hybridization and nuclease protection assay (NPA-SH). RESULTS: The specificity of the probes was verified with individual and mixed cultures as well as field collection, and the quantity of C. polykrikoides determined by NPA-SH analysis showed a good correlation with that determined by cell-counting with a light microscope. In addition a standard curve for C. polykrikoides was established to represent the correlation between optical absorbance in the NPA-SH assay and cell density. CONCLUSIONS: This approach provides an efficient alternative to traditional, morphology-based methods for the rapid identification and quantification of harmful algal species and could be used to monitor phytoplankton in field surveys.

A study on macronutrient self-selection after acute aerobic exercise in college females.

[Purpose] This study was conducted to determine whether acute aerobic exercise (climbing) is associated with changes in the dietary intake pattern. [Subjects and Methods] Food intake and physical activity data for 15 female college students were sampled for 3 days and categorized according to routine activity or high-intensity activity such as hiking. Nutrient intake based on the data was analyzed using a nutrition program. [Results] Carbohydrate and protein intake was significantly decreased after exercise compared to before acute aerobic exercise, but lipid intake showed no significant difference. Calorie intake was significantly decreased after exercise compared to before exercise; however, calorie consumption was significantly increased after exercise. [Conclusion] Aerobic exercise causes a decrease in total calories by inducing reduction in carbohydrate and protein intake. Therefore, aerobic exercise is very important for weight (body fat) control since it causes positive changes in the food intake pattern in female students.

Development of Lactobacillus paracasei harboring nucleic acid-hydrolyzing 3D8 scFv as a preventive probiotic against murine norovirus infection.

The protein 3D8 single-chain variable fragment (3D8 scFv) has potential anti-viral activity due to its ability to penetrate into cells and hydrolyze nucleic acids. Probiotic Lactobacillus paracasei engineered to secrete 3D8 scFv for oral administration was used to test the anti-viral effects of 3D8 scFv against gastrointestinal virus infections. We found that injection of 3D8 scFv into the intestinal lumen resulted in the penetration of 3D8 scFv into the intestinal villi and lamina propria. 3D8 scFv secreted from engineered L. paracasei retained its cell-penetrating and nucleic acid-hydrolyzing activities, which were previously shown with 3D8 scFv expressed in Escherichia coli. Pretreatment of RAW264.7 cells with 3D8 scFv purified from L. paracasei prevented apoptosis induction by murine norovirus infection and decreased messenger RNA (mRNA) expression of the viral capsid protein VP1. In a mouse model, oral administration of the engineered L. paracasei prior to murine norovirus infection reduced the expression level of mRNA encoding viral polymerase. Taken together, these results suggest that L. paracasei secreting 3D8 scFv provides a basis for the development of ingestible anti-viral probiotics active against gastrointestinal viral infection.

Electromyography comparison of normal chair-desk system and assistant chair-desk system on fatigue.

[Purpose] This study was designed to test the effects of the Assistant Chair-Desk System (ACDS), which can reduce the forward tilt of the neck and trunk and the level of fatigue during long lasting study in the sitting position. [Subjects] Fourteen middle school students and 14 college students of mixed gender participated in this study. [Methods] Fatigue level, the trapezius muscle, and the forward tilt angle of the head and trunk as well as distance factors were assessed before after using a normal chair-desk system (NCDS) and the ACDS for 120 minutes. [Results] There was an interaction effect in the angle and length of the neck from the sitting posture changes after 2 hours of studying using the NCDS and ACDS. There were also significant differences in the fatigue levels, hip joint angles and the lengths from the head according to the main effects of the chair-systems. [Conclusion] The studying position while using the ACDS was determined to prevent significant fatigue levels of the muscle and body, provide support to the head, by limiting the forward movement of the neck, and prevent forward tilt of the neck and trunk, by enabling the target point and gaze to be closer to the horizontal direction.

Anti-inflammation activities of mycosporine-like amino acids (MAAs) in response to UV radiation suggest potential anti-skin aging activity.

Certain photosynthetic marine organisms have evolved mechanisms to counteract UV-radiation by synthesizing UV-absorbing compounds, such as mycosporine-like amino acids (MAAs). In this study, MAAs were separated from the extracts of marine green alga Chlamydomonas hedleyi using HPLC and were identified as porphyra-334, shinorine, and mycosporine-glycine (mycosporine-Gly), based on their retention times and maximum absorption wavelengths. Furthermore, their structures were confirmed by triple quadrupole MS/MS. Their roles as UV-absorbing compounds were investigated in the human fibroblast cell line HaCaT by analyzing the expression levels of genes associated with antioxidant activity, inflammation, and skin aging in response to UV irradiation. The mycosporine-Gly extract, but not the other MAAs, had strong antioxidant activity in the 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. Furthermore, treatment with mycosporine-Gly resulted in a significant decrease in COX-2 mRNA levels, which are typically increased in response to inflammation in the skin, in a concentration-dependent manner. Additionally, in the presence of MAAs, the UV-suppressed genes, procollagen C proteinase enhancer (PCOLCE) and elastin, which are related to skin aging, had increased expression levels equal to those in UV-mock treated cells. Interestingly, the increased expression of involucrin after UV exposure was suppressed by treatment with the MAAs mycosporine-Gly and shinorine, but not porphyra-334. This is the first report investigating the biological activities of microalgae-derived MAAs in human cells.

Effects of triclosan on reproductive prarmeters and embryonic development of sea urchin, Strongylocentrotus nudus.

Triclosan (TCS, 2,4,4'-trichloro-2'-hydroxydiphenyl ether), a broad-spectrum antibacterial agent, is commonly found in the aquatic environment. In this study, we investigated TCS toxicity with pertaining to gamete viability, fertilization, and embryogenesis up to pluteus stage of the sea urchin, (Strongylocentrotus nudus). When the sperm and eggs were exposed to TCS (0-3.0 µM), the viability of sperm was significantly decreased at molarities higher than 1 µM of TCS. In addition, for exposure of 2.0 µM TCS the viability of eggs was not influenced and none of the sperm was viable. Fertilization rate was significantly decreased when sperm were exposed to 0.5 and 1 µM of TCS (p<0.001) and no fertilization was observed for the exposure of 1.5 µM of TCS. In embryonic development, embryos are treated with higher than 1.0 µM levels of TCS displayed arrested development. For TCS, the EC50 and LOECs values were 1.8, 1.49 and 0.99 µM and 0.53, 0.62 and 0.39 µM for sperm viability, fertilization rate, and larval development to pluteus, respectively. In the recovery test regarding normal development of arrested embryos based upon TCS exposure time, it was observed that embryos exposed to 1 µM TCS for 15 h were normally recovered for normal development, while embryos with more than 30 h exposure were not recovered to normal larvae. Overall, the results of this study strongly suggest that the gametes and embryos of S. nudus can provide the basis for an effective bioassay, with a fast and sensitive means of evaluating TCS contamination in the marine ecosystem.

Hypoxia-modulated gene expression profiling in sea urchin (Strongylocentrotus nudus) immune cells.

Hypoxia is an issue that affects ocean coastal waters worldwide. It has severe consequences for marine organisms, including death and rapid adaptive changes in metabolic organization. Although some aquatic animals are routinely exposed and resistant to severe environmental hypoxia, others such as sea urchins (Strongylocentrotus nudus) have a limited capacity to withstand this stress. In this study, hypoxia induced a significant increase in the number of red spherule cells among coelomocytes, which function as immune cells. This suggests that sea urchin immune cells could be used as a biological indicator of hypoxic stress. In the current study, we used cDNA microarrays to investigate the differential expression patterns of hypoxia-regulated genes to better understand the molecular mechanisms underlying the response of immune cells to hypoxia. Surprisingly, the predominant major effect of hypoxia was the widespread suppression of gene expression. In particular, the expression of RNA helicase and GATA-4/5/6 was decreased significantly in response to hypoxia, even in field conditions, suggesting that they could be utilized as sensitive bioindicators of hypoxic stress in the sea urchin.

A synergistic therapy against influenza virus A/H1N1/PR8 by a HA1 specific neutralizing single-domain VL and an RNA hydrolyzing scFv.

The emergence of anti-influenza drug-resistant strains poses a challenge for influenza therapy due to mutations in the virus's surface protein. Recently, there has been increasing interest in combination therapy consisting of two or more drugs as a potential alternative approach, aiming to enhance therapeutic efficacy. In this study, we investigated a novel synergistic therapy with a vertical effect using a single-domain VL-HA1-specific antibody against H1N1/PR8 and a horizontal effect using an RNA catalytic antibody with broad-spectrum influenza antiviral drug. We isolated a single-domain VL-HA1-specific (NVLH8) antibody binding to the virus particles showing a neutralizing activity against influenza virus A, specifically H1N1/PR8, as determined by the reduction in plaque number and lower viral HA protein expression in vitro. The neutralizing antibody likely prevented the viral entry, specifically at the viral genome-releasing step. Additionally, the 3D8 scFv hydrolyzed viral RNAs in the cytoplasm, including mRNA, vRNA, and cRNA in MDCK cells. The combined treatment of neutralizing antibodies for a vertical effect and 3D8 scFv for a horizontal effect produced a synergistic effect providing a novel approach against viral diseases when compared with a single treatment. Our results indicated that combining treatment, in particular two proteins exhibiting different mechanisms of action increased the antiviral activity against the influenza virus.

Ecological Interaction between Bacteriophages and Bacteria in Sub-Arctic Kongsfjorden Bay, Svalbard, Norway.

Marine virus diversity and their relationships with their hosts in the marine environment remain unclear. This study investigated the co-occurrence of marine DNA bacteriophages (phages) and bacteria in the sub-Arctic area of Kongsfjorden Bay in Svalbard (Norway) in April and June 2018 using metagenomics tools. Of the marine viruses identified, 48-81% were bacteriophages of the families Myoviridae, Siphoviridae, and Podoviridae. Puniceispirillum phage HMO-2011 was dominant (7.61%) in April, and Puniceispirillum phage HMO-2011 (3.32%) and Pelagibacter phage HTVC008M (3.28%) were dominant in June. Gammaproteobacteria (58%), including Eionea flava (14.3%) and Pseudomonas sabulinigri (12.2%), were dominant in April, whereas Alphaproteobacteria (87%), including Sulfitobacter profundi (51.5%) and Loktanella acticola (32.4%), were dominant in June. The alpha diversity of the bacteriophages and bacterial communities exhibited opposite patterns. The diversity of the bacterial community was higher in April and lower in June. Changes in water temperature and light can influence the relationship between bacteria and bacteriophages.

An RNA-hydrolyzing recombinant minibody prevents both influenza A virus and coronavirus in co-infection models.

With the lifting of COVID-19 non-pharmaceutical interventions, the resurgence of common viral respiratory infections was recorded in several countries worldwide. It facilitates viral co-infection, further burdens the already over-stretched healthcare systems. Racing to find co-infection-associated efficacy therapeutic agents need to be rapidly established. However, it has encountered numerous challenges that necessitate careful investigation. Here, we introduce a potential recombinant minibody-associated treatment, 3D8 single chain variable fragment (scFv), which has been developed as a broad-spectrum antiviral drug that acts via its nucleic acid catalytic and cell penetration abilities. In this research, we demonstrated that 3D8 scFv exerted antiviral activity simultaneously against both influenza A viruses (IAVs) and coronaviruses in three established co-infection models comprising two types of coronaviruses [beta coronavirus-human coronavirus OC43 (hCoV-OC43) and alpha coronavirus-porcine epidemic diarrhea virus (PEDV)] in Vero E6 cells, two IAVs [A/Puerto Rico/8/1934 H1N1 (H1N1/PR8) and A/X-31 (H3N2/X-31)] in MDCK cells, and a combination of coronavirus and IAV (hCoV-OC43 and adapted-H1N1) in Vero E6 cells by a statistically significant reduction in viral gene expression, proteins level, and approximately around 85%, 65%, and 80% of the progeny of 'hCoV-OC43-PEDV', 'H1N1/PR8-H3N2/X-31', and 'hCoV-OC43-adapted-H1N1', respectively, were decimated in the presence of 3D8 scFv. Taken together, we propose that 3D8 scFv is a promising broad-spectrum drug for treatment against RNA viruses in co-infection.

Altered invertase activities of symptomatic tissues on Beet severe curly top virus (BSCTV) infected Arabidopsis thaliana.

Arabidopsis thaliana infected with Beet severe curly top virus (BSCTV) exhibits systemic symptoms such as stunting of plant growth, callus induction on shoot tips, and curling of leaves and shoot tips. The regulation of sucrose metabolism is essential for obtaining the energy required for viral replication and the development of symptoms in BSCTV-infected A. thaliana. We evaluated the changed transcript level and enzyme activity of invertases in the inflorescence stems of BSCTV-infected A. thaliana. These results were consistent with the increased pattern of ribulose-1,5-bisphosphate carboxylase/oxygenase activity and photosynthetic pigment concentration in virus-infected plants to supply more energy for BSCTV multiplication. The altered gene expression of invertases during symptom development was functionally correlated with the differential expression patterns of D-type cyclins, E2F isoforms, and invertase-related genes. Taken together, our results indicate that sucrose sensing by BSCTV infection may regulate the expression of sucrose metabolism and result in the subsequent development of viral symptoms in relation with activation of cell cycle regulation.

Metavirome Profiling and Dynamics of the DNA Viral Community in Seawater in Chuuk State, Federated States of Micronesia.

Despite their abundance and ecological importance, little is known about the diversity of marine viruses, in part because most cannot be cultured in the laboratory. Here, we used high-throughput viral metagenomics of uncultivated viruses to investigate the dynamics of DNA viruses in tropical seawater sampled from Chuuk State, Federated States of Micronesia, in March, June, and December 2014. Among the identified viruses, 71-79% were bacteriophages belonging to the families Myoviridae, Siphoviridae, and Podoviridae (Caudoviriales), listed in order of abundance at all sampling times. Although the measured environmental factors (temperature, salinity, and pH) remained unchanged in the seawater over time, viral dynamics changed. The proportion of cyanophages (34.7%) was highest in June, whereas the proportion of mimiviruses, phycodnaviruses, and other nucleo-cytoplasmic large DNA viruses (NCLDVs) was higher in March and December. Although host species were not analysed, the dramatic viral community change observed in June was likely due to changes in the abundance of cyanophage-infected cyanobacteria, whereas that in NCLDVs was likely due to the abundance of potential eukaryote-infected hosts. These results serve as a basis for comparative analyses of other marine viral communities, and guide policy-making when considering marine life care in Chuuk State.