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Tetraselmis subcordiformis, a unicellular marine green alga, is used widely in aquaculture as an initial feeding for fish, bivalve mollusks, penaeid shrimp larvae, and rotifers because of its rich content of amino acids and fatty acids. A stable nuclear transformation system using the herbicide phosphinothricin (PPT) as a selective reagent was established previously. In this research, the recombinant expression in T. subcordiformis was investigated by particle bombardment with the rt-PA gene that encodes the recombinant human tissue-type plasminogen activator (Reteplase), which is a thrombolytic agent for acute myocardial infarction treatment. Transgenic algal strains were selected by their resistance to PPT, and expression of rt-PA was validated by PCR, Southern blotting, and Western blotting, and bioactivity of rt-PA was confirmed by the fibrin agarose plate assay for bioactivity. The results showed that rt-PA was integrated into the genome of T. subcordiformis, and the expression product was bioactive, indicating proper post-transcriptional modification of rt-PA in T. subcordiformis. This report contributes to efforts that take advantage of marine microalgae as cell factories to prepare recombinant drugs and in establishing a characteristic pathway of oral administration in aquaculture.
Chunhui Wu; Caiyun Zheng; Jinxia Wang; Peng Jiang. Recombinant Expression of Thrombolytic Agent Reteplase in Marine Microalga Tetraselmis subcordiformis (Chlorodendrales, Chlorophyta). Marine Drugs 2021, 19, 315 .
AMA StyleChunhui Wu, Caiyun Zheng, Jinxia Wang, Peng Jiang. Recombinant Expression of Thrombolytic Agent Reteplase in Marine Microalga Tetraselmis subcordiformis (Chlorodendrales, Chlorophyta). Marine Drugs. 2021; 19 (6):315.
Chicago/Turabian StyleChunhui Wu; Caiyun Zheng; Jinxia Wang; Peng Jiang. 2021. "Recombinant Expression of Thrombolytic Agent Reteplase in Marine Microalga Tetraselmis subcordiformis (Chlorodendrales, Chlorophyta)." Marine Drugs 19, no. 6: 315.
Intrusion detection systems are widely implemented to protect computer networks from threats. To identify unknown attacks, many machine learning algorithms like neural networks have been explored for anomaly based detection. However, in real‐world applications, the performance of classifiers might be fluctuant with different data sets, while one main reason is due to some redundant or ineffective features. To mitigate this issue, this study investigates some feature selection methods and introduces an ensemble of Neural Networks and Random Forest to improve the detection performance. In particular, we design an intelligent system that can choose an appropriate algorithm in an adaptive way. In the evaluation, we study the feasibility of our approach with KDD99 data set and evaluate its practical performance with a real data set collected from a Honeynet environment. The experimental results indicate that as compared with similar approaches, our approach can overall provide a better result, through identifying important and closely related features.
Chunhui Wu; Wenjuan Li. Enhancing intrusion detection with feature selection and neural network. International Journal of Intelligent Systems 2021, 1 .
AMA StyleChunhui Wu, Wenjuan Li. Enhancing intrusion detection with feature selection and neural network. International Journal of Intelligent Systems. 2021; ():1.
Chicago/Turabian StyleChunhui Wu; Wenjuan Li. 2021. "Enhancing intrusion detection with feature selection and neural network." International Journal of Intelligent Systems , no. : 1.
Green tides, dominated by Ulva, are on the rise worldwide, and invasive Ulva spp. tend to bloom in new habitats. Over the last decade, green tides have caused serious problems in all marine regions of China, especially the Yellow Sea, but there has been no study emphasizing alien species or new records of Ulva in China. In this study, based on a molecular investigation spanning over 10 years, we found six new records of Ulva in China and analysed their distribution patterns. Three northern temperate species – Ulva simplex, U. splitiana and U. partita – were also distributed in temperate marine areas in China. Meanwhile, three subtropical species – U. meridionalis, U. tepida and U. chaugulii – were found to be dominant in the green tides in the South China Sea, and have also successfully exploited temperate areas, especially U. meridionalis which has a wide distribution in China. U. meridionalis has an unusual morphology distinct from the other three types reported in Ulva: along the middle of the longitudinal axis, both sides of the thallus are connected, forming a thin sheet in the middle with bilateral tubular structures, like a bow-tie in transverse view. We found a rapid Ulva bioinvasion and we provide fundamental new data for the future monitoring and risk assessment of green tides in China.
Wei Feng Xie; Chun Hui Wu; Jin Zhao; Xu Yin Lin; Peng Jiang. New records of Ulva spp. (Ulvophyceae, Chlorophyta) in China, with special reference to an unusual morphology of U. meridionalis forming green tides. European Journal of Phycology 2020, 55, 412 -425.
AMA StyleWei Feng Xie, Chun Hui Wu, Jin Zhao, Xu Yin Lin, Peng Jiang. New records of Ulva spp. (Ulvophyceae, Chlorophyta) in China, with special reference to an unusual morphology of U. meridionalis forming green tides. European Journal of Phycology. 2020; 55 (4):412-425.
Chicago/Turabian StyleWei Feng Xie; Chun Hui Wu; Jin Zhao; Xu Yin Lin; Peng Jiang. 2020. "New records of Ulva spp. (Ulvophyceae, Chlorophyta) in China, with special reference to an unusual morphology of U. meridionalis forming green tides." European Journal of Phycology 55, no. 4: 412-425.
Protoplast isolation was relevant for gene manipulation in Ulva, and universal protocols have been proposed based on evaluation for various wildly collected species. However, only clonal laboratory cultures were practical for genetic transformation, and whether applicability of such universal protocol existed for these artificial cultures has never been investigated. In this research, samples in different physiological states or developmental stages were tested in U. prolifera. The results proved that the protoplast yields were strongly dependent on the characteristics of samples. Neither Fv/Fm value nor chlorophyll content exhibited an ideal correlation with the protoplast yields. Alternatively, specific growth rate, coupled with developmental stage, could serve as an effective combined index to determine the right time for protoplast isolation. According to this instruction, here we reported the highest yields of protoplast ((31.5±1.9)×10 6 cells/g f. wt.) in U. prolifera, following comparison between protocols, and further optimizations on enzyme content, incubation period, starting biomass and pretreatment. This specified protocol for artificially cultured clonal samples could meet the need for protoplast-mediated genetic transformation in U. prolifera.
Chunhui Wu; Peng Jiang; Jin Zhao; Huihui Fu. High efficiency of protoplast preparation for artificially cultured Ulva prolifera (Ulvophyceae, Chlorophyta). Journal of Oceanology and Limnology 2018, 36, 1806 -1811.
AMA StyleChunhui Wu, Peng Jiang, Jin Zhao, Huihui Fu. High efficiency of protoplast preparation for artificially cultured Ulva prolifera (Ulvophyceae, Chlorophyta). Journal of Oceanology and Limnology. 2018; 36 (5):1806-1811.
Chicago/Turabian StyleChunhui Wu; Peng Jiang; Jin Zhao; Huihui Fu. 2018. "High efficiency of protoplast preparation for artificially cultured Ulva prolifera (Ulvophyceae, Chlorophyta)." Journal of Oceanology and Limnology 36, no. 5: 1806-1811.
Ulva prolifera is a green macroalgae with an extremely high growth rate that can accumulate biomass with considerable protein content. To set up an available seaweed expression system, a prior step is to isolate endogenous and strong constitutive promoters. For this reason, the full-length genomic actin1 gene from U. prolifera (Upactin1) was cloned and its 5′ flanking sequence was obtained by genome walking. The Upactin1 open reading frame consisted of 1134 nucleotides encoding 377 amino acid residues. Besides 4 exons and 3 introns in the coding region, an extra leader intron was identified in the 5′ untranslated region. According to quantitative GUS assays based on transient expression, the promoter activity of the Upactin1 5′ flanking region was found to be several times higher than that of the widely-used cauliflower mosaic virus 35S (CaMV35S) in all tested species of Ulva. In addition, precise deletion of the leader intron led to a significant decrease of promoter strength in U. prolifera, and almost entire loss of strength in U. linza and U. pertusa. To our knowledge, this is the first report to prove function of a leader intron in algae. The 5′ flanking region of Upactin1 was shown to be a much stronger promoter than the foreign CaMV35S, and its activity was highly dependent on the presence of the leader intron. We propose that the Upactin1 promoter could serve as an endogenous and strong constitutive element for genetic engineering of U. prolifera.
Chunhui Wu; Peng Jiang; Yang Guo; Jianguo Liu; Jin Zhao; Huihui Fu. Isolation and characterization of Ulva prolifera actin1 gene and function verification of the 5′ flanking region as a strong promoter. Bioengineered 2017, 9, 124 -133.
AMA StyleChunhui Wu, Peng Jiang, Yang Guo, Jianguo Liu, Jin Zhao, Huihui Fu. Isolation and characterization of Ulva prolifera actin1 gene and function verification of the 5′ flanking region as a strong promoter. Bioengineered. 2017; 9 (1):124-133.
Chicago/Turabian StyleChunhui Wu; Peng Jiang; Yang Guo; Jianguo Liu; Jin Zhao; Huihui Fu. 2017. "Isolation and characterization of Ulva prolifera actin1 gene and function verification of the 5′ flanking region as a strong promoter." Bioengineered 9, no. 1: 124-133.