21 results on '"Bo Luan"'
Search Results
2. Cellular and molecular remodelling of a host cell for vertical transmission of bacterial symbionts.
- Author
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Jun-Bo Luan, Hong-Wei Shan, Isermann, Philipp, Jia-Hsin Huang, Lammerding, Jan, Shu-Sheng Liu, and Douglas, Angela E.
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PROKARYOTES , *BACTERIOPHAGES , *OLIGONUCLEOTIDE arrays , *GENE expression , *GENETIC regulation - Abstract
Various insects require intracellular bacteria that are restricted to specialized cells (bacteriocytes) and are transmitted vertically via the female ovary, but the transmission mechanisms are obscure. We hypothesized that, in the whitefly Bemisia tabaci, where intact bacteriocytes (and not isolated bacteria) are transferred to oocytes, the transmission mechanism would be evident as cellular and molecular differences between the nymph (pre-adult) and adult bacteriocytes. We demonstrate dramatic remodelling of bacteriocytes at the developmental transition from nymph to adulthood. This transition involves the loss of cell-cell adhesion, high division rates to constant cell size and onset of cell mobility, enabling the bacteriocytes to crawl to the ovaries. These changes are accompanied by cytoskeleton reorganization and changes in gene expression: genes functioning in cell-cell adhesion display reduced expression and genes involved in cell division, cell motility and endocytosis/exocytosis have elevated expression in adult bacteriocytes, relative to nymph bacteriocytes. This study demonstrates, for the first time, how developmentally orchestrated remodelling of gene expression and correlated changes in cell behaviour underpin the capacity of bacteriocytes to mediate the vertical transmission and persistence of the symbiotic bacteria on which the insect host depends. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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- View/download PDF
3. Leaf substrates determine oviposition and in turn frequency of copulation in the whitefly Bemisia tabaci.
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Di-Bing Sun, Jun-Bo Luan, and Shu-Sheng Liu
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SWEETPOTATO whitefly , *ANIMAL courtship , *ANIMAL sexual behavior , *SEXUAL intercourse , *OVIPARITY - Abstract
The article offers information on the study made by researchers to analyze the mating behaviour of whitefly Bemisia tabaci (B. tabaci). It states that the aspects of mating behaviour impact the competitive interactions between alien and indigenous whiteflies. Scientists closely observed the oviposition and copulation of B. tabaci on leaf subtrates created with the help of different plant species.
- Published
- 2011
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4. Dynamic Constitutive Modeling of Partially Saturated Clay under Impact Loading.
- Author
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Yue-Xiang He, Guang-Bo Luan, and Zhi-Wu Zhu
- Abstract
In this study, an elasto-plastic constitutive model is presented to study the behavior of partially saturated clay under impact loading. In plasticity, a modified Mohr-Coulomb yield function is adopted. The cohesion and internal frictional angle of clay are calculated through static experiment. Based on the experimental investigations at different strain rates by means of split Hopkinson pressure bar (SHPB), the Mohr-Coulomb criterion is modified by taking into account the effect of strain rate, and the parameters are determined. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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- View/download PDF
5. De novo characterization of a whiteflytranscriptome and analysis of its gene expressionduring development.
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Xiao-Wei Wang, Jun-Bo Luan, Jun-Min Li, Yan-Yuan Bao, Chuan-Xi Zhang, and Shu-Sheng Liu
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GENE expression , *GENES , *INSECTICIDES , *PESTICIDE resistance , *PROTEINS - Abstract
Background: Whitefly (Bemisia tabaci) causes extensive crop damage throughout the world by feeding directly on plants and by vectoring hundreds of species of begomoviruses. Yet little is understood about its genes involved in development, insecticide resistance, host range plasticity and virus transmission. Results: To facilitate research on whitefly, we present a method for de novo assembly of whitefly transcriptome using short read sequencing technology (Illumina). In a single run, we produced more than 43 million sequencing reads. These reads were assembled into 168,900 unique sequences (mean size = 266 bp) which represent more than 10-fold of all the whitefly sequences deposited in the GenBank (as of March 2010). Based on similarity search with known proteins, these analyses identified 27,290 sequences with a cut-off E-value above 10-5. Assembled sequences were annotated with gene descriptions, gene ontology and clusters of orthologous group terms. In addition, we investigated the transcriptome changes during whitefly development using a tag-based digital gene expression (DGE) system. We obtained a sequencing depth of over 2.5 million tags per sample and identified a large number of genes associated with specific developmental stages and insecticide resistance. Conclusion: Our data provides the most comprehensive sequence resource available for whitefly study and demonstrates that the Illumina sequencing allows de novo transcriptome assembly and gene expression analysis in a species lacking genome information. We anticipate that next generation sequencing technologies hold great potential for the study of the transcriptome in other non-model organisms. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
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6. Pre-copulation intervals, copulation frequencies, and initial progeny sex ratios in two biotypes of whitefly, Bemisia tabaci.
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Jun-Bo Luan, Yong-Ming Ruan, Li Zhang, and Shu-Sheng Liu
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SWEETPOTATO whitefly , *PLANT species , *PLANT genetics , *EGG incubation , *PLANT fibers - Abstract
The whitefly Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) is a species complex, and its systematic classification requires controlled crossing experiments among its genetic groups. Accurate information on pre-copulation intervals, copulation frequencies, and initial frequency of egg fertilization of newly emerged adults is critical for designing procedures for collecting the virgin adults necessary for these experiments. In the literature, considerable variation is reported between B. tabaci populations, with respect to the length of the pre-copulation interval and the initial frequency of egg fertilization. Here, we used a video-recording method to observe continuously the copulation behaviour of the Mediterranean/Asia Minor/Africa (B biotype) and the Asia II (ZHJ1 biotype) groups of B. tabaci. We also recorded the initial frequency of egg fertilization, as determined by the sex of the progeny. When adults were caged in female–male pairs on leaves of cotton plants, the earliest copulation events occurred 2–6 h after emergence; at 12 h after emergence 56–84% of the females had copulated at least once, and nearly all (92–100%) had copulated at least once by 36 h after emergence. Both females and males copulated repeatedly. Approximately 80 and 20% of copulation events occurred during the photophase and scotophase, respectively. By 72 h post-emergence, the females of the B and ZHJ1 biotypes had copulated on average 6.1 and 3.9 times, respectively. When adults were caged in groups on plants 1–13 h after emergence, 30–35% of the eggs deposited during this period were fertilized, and approximately 90% of females were fertilized by the end of the 13 h. Although timing of copulation differed in detail between the two genetic groups, the results demonstrate that B. tabaci adults can start to copulate as early as 2–6 h post-emergence and the majority of females can become fertilized on the day that they emerge. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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7. Observing and recording copulation events of whiteflies on plants using a video camera.
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Yong-Ming Ruan, Jun-Bo Luan, Lian-Sheng Zang, and Shu-Sheng Liu
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SWEETPOTATO whitefly , *ANIMAL sexual behavior , *SEXUAL intercourse , *ALEYRODIDAE , *VIDEO recording - Abstract
The article presents a study which investigates the copulation events of whiteflies on plants by using a video camera. Bemisia tabaci is a genetically diverse group with more than 20 biotypes. Newly emerged adult whiteflies were placed in pairs into a clip cage which was attached to a leaf and observed by a video camera. The results indicated that of the 25 virgin B-biotype females, 10 did not mate, 12 mated once and 3 mated more than once.
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- 2007
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8. Rickettsia symbionts spread via mixed mode transmission, increasing female fecundity and sex ratio shift by host hormone modulating.
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Bing-Qi Liu, Xi-Yu Bao, Jin-Yang Yan, Dan Zhang, Xiang Sun, Chu-Qiao Li, Zhan-Bo Chen, and Jun-Bo Luan
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RICKETTSIA , *FERTILITY , *SEX ratio , *SWEETPOTATO whitefly , *JUVENILE hormones - Abstract
Heritable symbionts are common among animals in nature, but the molecular mechanisms underpinning symbiont invasions of host populations have been elusive. In this study, we demonstrate the spread of Rickettsia in an invasive agricultural pest, the whitefly Bemisia tabaci Mediterranean (MED), across northeastern China from 2018 to 2023. Here, we show that the beneficial symbiont Rickettsia spreads by manipulating host hormone signals. Our analyses suggest that Rickettsia have been horizontally acquired by B. tabaci MED from another invasive whitefly B. tabaci Middle East-Asia Minor 1 during periods of coexistence. Rickettsia is transmitted maternally and horizontally from female B. tabaci MED individuals. Rickettsia infection enhances fecundity and results in female bias among whiteflies. Our findings reveal that Rickettsia infection stimulates juvenile hormone (JH) synthesis, in turn enhancing fecundity, copulation events, and the female ratio of the offspring. Consequently, Rickettsia infection results in increased whitefly fecundity and female bias by modulating the JH pathway. More female progeny facilitates the transmission of Rickettsia. This study illustrates that the spread of Rickettsia among invasive whiteflies in northeastern China is propelled by host hormone regulation. Such symbiont invasions lead to rapid physiological and molecular evolution in the host, influencing the biology and ecology of an invasive species. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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9. TCTAP A-026 The Angiotensin Converting Enzyme-2 Local Activated in Infarct-Related Coronary Accelerated Myocardial Reverse Remodeling After Myocardial Infarction.
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Bo, Luan and Peng, Guo
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MYOCARDIAL infarction , *ANGIOTENSIN converting enzyme , *CORONARY disease , *VENTRICULAR remodeling , *CORONARY angiography - Published
- 2015
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10. Gambogic acid exerts cardioprotective effects in a rat model of acute myocardial infarction through inhibition of inflammation, iNOS and NF-κB/p38 pathway.
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Na, Duan, Aijie, Hou, Bo, Luan, Zhilin, Miao, and Long, Yuan
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MYOCARDIAL infarction treatment , *GARCINIA , *CARDIOTONIC agents , *INFLAMMATION , *LABORATORY rats , *THERAPEUTICS - Abstract
Gamboge, the dried resin secreted by Garcinia maingayii (gambogic tree), was previously demonstrated to exert anti-inflammatory effects. The present study examined the effects of gambogic acid, the major active constituent of gamboge, on myocardial infarction (MI) and inflammation in a rat model and explored the possible underlying mechanisms. The results demonstrated that gambogic acid inhibited the ratio of heart weight to body weight and myocardial damage (via lactate dehydrogenase and cardiac troponin T) in rats with MI. Gambogic acid suppressed the activation of interleukin (IL)-6 and tumor necrosis factor-α, and increased IL-10 levels in MI rats. Furthermore, gambogic acid reduced inducible nitric oxide synthase (iNOS), matrix metalloproteinase (MMP)-2, MMP-9, intercellular adhesion molecule-1 (ICAM-1), nuclear factor (NF)-κB/p65 and phosphorylated p38 protein in ischemic myocardial tissue of MI rats. In conclusion, gambogic acid exerted anti-inflammatory effects in MI rats by targeting the iNOS, MMPs, ICAM-1, NF-κB and p38 pathways. Gambogic acid may protect against MI-induced inflammation in rats, which may be associated with the activation of the NF-κB/p38 pathway. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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11. Global Analysis of the Transcriptional Response of Whitefly to Tomato Yellow Leaf Curl China Virus Reveals the Relationship of Coevolved Adaptations.
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Jun-Bo Luan, Jun-Min Li, Varela, Nélia, Yong-Liang Wang, Fang-Fang Li, Yan-Yuan Bao, Chuan-Xi Zhang, Shu-Sheng Liu, and Xiao-Wei Wang
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PLANT viruses , *MITOGEN-activated protein kinases , *PEPTIDE antibiotics , *WESTERN immunoblotting , *POLYMERASE chain reaction - Abstract
The begomoviruses are the largest and most economically important group of plant viruses transmitted exclusively by the whitefly Bemisia tabaci in a circulative, persistent manner. The circulation of the viruses within the insect vectors involves complex interactions between virus and vector components; however, the molecular mechanisms of these interactions remain largely unknown. Here we investigated the transcriptional response of the invasive B. tabaci Middle East-Asia Minor 1 species to Tomato yellow leaf curl China virus (TYLCCNV) using Illumina sequencing technology. Results showed that 1,606 genes involved in 157 biochemical pathways were differentially expressed in the viruliferous whiteflies. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that TYLCCNV can perturb the cell cycle and primary metabolism in the whitefly, which explains the negative effect of this virus on the longevity and fecundity of B. tabaci. Our data also demonstrated that TYLCCNV can activate whitefly immune responses, such as autophagy and antimicrobial peptide production, which might lead to a gradual decrease of viral particles within the body of the viruliferous whitefly. Furthermore, PCR results showed that TYLCCNV can invade the ovary and fat body tissues of the whitefly, and Lysotracker and Western blot analyses revealed that the invasion of TYLCCNV induced autophagy in both the ovary and fat body tissues. Surprisingly, TYLCCNV also suppressed the whitefly immune responses by downregulating the expression of genes involved in Toll-like signaling and mitogen-activated protein kinase (MAPK) pathways. Taken together, these results reveal the relationship of coevolved adaptations between begomoviruses and whiteflies and will provide a road map for future investigations into the complex interactions between plant viruses and their insect vectors. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
12. A comparative analysis of swallowing accelerometry and sounds during saliva swallows.
- Author
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Dudik, Joshua M., Jestrović, Iva, Bo Luan, Coyle, James L., and Sejdić, Ervin
- Abstract
Background: Accelerometry (the measurement of vibrations) and auscultation (the measurement of sounds) are both non-invasive techniques that have been explored for their potential to detect abnormalities in swallowing. The differences between these techniques and the information they capture about swallowing have not previously been explored in a direct comparison. Methods: In this study, we investigated the differences between dual-axis swallowing accelerometry and swallowing sounds by recording data from adult participants and calculating a number of time and frequency domain features. During the experiment, 55 participants (ages 18-65) were asked to complete five saliva swallows in a neutral head position. The resulting data was processed using previously designed techniques including wavelet denoising, spline filtering, and fuzzy means segmentation. The pre-processed signals were then used to calculate 9 time, frequency, and time-frequency domain features for each independent signal. Wilcoxon signed-rank and Wilcoxon rank-sum tests were utilized to compare feature values across transducers and patient demographics, respectively. Results: In addition to finding a number of features that varied between male and female participants, our statistical analysis determined that the majority of our chosen features were statistically significantly different across the two sensor methods and that the dependence on within-subject factors varied with the transducer type. However, a regression analysis showed that age accounted for an insignificant amount of variation in our signals. Conclusions: We conclude that swallowing accelerometry and swallowing sounds provide different information about deglutition despite utilizing similar transduction methods. This contradicts past assumptions in the field and necessitates the development of separate analysis and processing techniques for swallowing sounds and vibrations. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
13. A comparative analysis of swallowing accelerometry and sounds during saliva swallows.
- Author
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Dudik, Joshua M., Jestroviċ, Iva, Bo Luan, Coyle, James L., and Sejdiċ, Ervin
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ACCELEROMETRY , *AUSCULTATION , *DEGLUTITION , *SALIVA , *PHYSICAL diagnosis - Abstract
Background: Accelerometry (the measurement of vibrations) and auscultation (the measurement of sounds) are both non-invasive techniques that have been explored for their potential to detect abnormalities in swallowing. The differences between these techniques and the information they capture about swallowing have not previously been explored in a direct comparison. Methods: In this study, we investigated the differences between dual-axis swallowing accelerometry and swallowing sounds by recording data from adult participants and calculating a number of time and frequency domain features. During the experiment, 55 participants (ages 18-65) were asked to complete five saliva swallows in a neutral head position. The resulting data was processed using previously designed techniques including wavelet denoising, spline filtering, and fuzzy means segmentation. The pre-processed signals were then used to calculate 9 time, frequency, and time-frequency domain features for each independent signal. Wilcoxon signed-rank and Wilcoxon rank-sum tests were utilized to compare feature values across transducers and patient demographics, respectively. Results: In addition to finding a number of features that varied between male and female participants, our statistical analysis determined that the majority of our chosen features were statistically significantly different across the two sensor methods and that the dependence on within-subject factors varied with the transducer type. However, a regression analysis showed that age accounted for an insignificant amount of variation in our signals. Conclusions: We conclude that swallowing accelerometry and swallowing sounds provide different information about deglutition despite utilizing similar transduction methods. This contradicts past assumptions in the field and necessitates the development of separate analysis and processing techniques for swallowing sounds and vibrations. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
14. A comparative analysis of swallowing accelerometry and sounds during saliva swallows.
- Author
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Dudik, Joshua M., Jestrović, Iva, Bo Luan, Coyle, James L., and Sejdić, Ervin
- Subjects
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DEGLUTITION , *DEGLUTITION disorders , *ESOPHAGUS diseases , *INGESTION disorders , *COMPARATIVE studies , *SPITTING (Oral habit) , *PAROTID glands - Abstract
Background: Accelerometry (the measurement of vibrations) and auscultation (the measurement of sounds) are both non-invasive techniques that have been explored for their potential to detect abnormalities in swallowing. The differences between these techniques and the information they capture about swallowing have not previously been explored in a direct comparison. Methods: In this study, we investigated the differences between dual-axis swallowing accelerometry and swallowing sounds by recording data from adult participants and calculating a number of time and frequency domain features. During the experiment, 55 participants (ages 18-65) were asked to complete five saliva swallows in a neutral head position. The resulting data was processed using previously designed techniques including wavelet denoising, spline filtering, and fuzzy means segmentation. The pre-processed signals were then used to calculate 9 time, frequency, and time-frequency domain features for each independent signal. Wilcoxon signed-rank and Wilcoxon rank-sum tests were utilized to compare feature values across transducers and patient demographics, respectively. Results: In addition to finding a number of features that varied between male and female participants, our statistical analysis determined that the majority of our chosen features were statistically significantly different across the two sensor methods and that the dependence on within-subject factors varied with the transducer type. However, a regression analysis showed that age accounted for an insignificant amount of variation in our signals. Conclusions: We conclude that swallowing accelerometry and swallowing sounds provide different information about deglutition despite utilizing similar transduction methods. This contradicts past assumptions in the field and necessitates the development of separate analysis and processing techniques for swallowing sounds and vibrations. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
15. The effects of increased fluid viscosity on swallowing sounds in healthy adults.
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Jestrović, Iva, Dudik, Joshua M., Bo Luan, Coyle, James L., and Sejdić, Ervin
- Abstract
Background: Cervical auscultation (CA) is an affordable, non-invasive technique used to observe sounds occurring during swallowing. CA involves swallowing characterization via stethoscopes or microphones, while accelerometers can detect other vibratory signals. While the effects of fluid viscosity on swallowing accelerometry signals is well understood, there are still open questions about these effects on swallowing sounds. Therefore, this study investigated the influence of fluids with increasing thickness on swallowing sound characteristics. Method: We collected swallowing sounds and swallowing accelerometry signals from 56 healthy participants. Each participant completed five water swallows, five swallows of nectar-thick apple juice, and five swallows of honey-thick apple juice. These swallows were completed in neutral head and chin-tuck head positions. After pre-processing of collected signals, a number of features in time, frequency and time-frequency domains were extracted. Results: Our numerical analysis demonstrated that significant influence of viscosity was found in most of the features. In general, features extracted from swallows in the neutral head position were affected more than swallows from the chin-tuck position. Furthermore, most of the differences were found between water and fluids with higher viscosity. Almost no significant differences were found between swallows involving nectar-thick and honey-thick apple juices. Our results also showed that thicker fluids had higher acoustic regularity and predictability as demonstrated by the information-theoretic features, and a lower frequency content as demonstrated by features in the frequency domain. Conclusions: According to these results, we can conclude that viscosity of fluids should be considered in future investigations involving swallowing sounds. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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16. Analysis of a native whitefly transcriptome and its sequence divergence with two invasive whitefly species.
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Xiao-Wei Wang, Qiong-Yi Zhao, Jun-Bo Luan, Yu-Jun Wang, Gen-Hong Yan, and Shu-Sheng Liu
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CITRUS whitefly , *SPECIES , *GENETIC polymorphisms , *GLUTATHIONE , *BIOCHEMISTRY - Abstract
Background: Genomic divergence between invasive and native species may provide insight into the molecular basis underlying specific characteristics that drive the invasion and displacement of closely related species. In this study, we sequenced the transcriptome of an indigenous species, Asia II 3, of the Bemisia tabaci complex and compared its genetic divergence with the transcriptomes of two invasive whiteflies species, Middle East Asia Minor 1 (MEAM1) and Mediterranean (MED), respectively. Results: More than 16 million reads of 74 base pairs in length were obtained for the Asia II 3 species using the Illumina sequencing platform. These reads were assembled into 52,535 distinct sequences (mean size: 466 bp) and 16,596 sequences were annotated with an E-value above 10-5. Protein family comparisons revealed obvious diversification among the transcriptomes of these species suggesting species-specific adaptations during whitefly evolution. On the contrary, substantial conservation of the whitefly transcriptomes was also evident, despite their differences. The overall divergence of coding sequences between the orthologous gene pairs of Asia II 3 and MEAM1 is 1.73%, which is comparable to the average divergence of Asia II 3 and MED transcriptomes (1.84%) and much higher than that of MEAM1 and MED (0.83%). This is consistent with the previous phylogenetic analyses and crossing experiments suggesting these are distinct species. We also identified hundreds of highly diverged genes and compiled sequence identify data into gene functional groups and found the most divergent gene classes are Cytochrome P450, Glutathione metabolism and Oxidative phosphorylation. These results strongly suggest that the divergence of genes related to metabolism might be the driving force of the MEAM1 and Asia II 3 differentiation. We also analyzed single nucleotide polymorphisms within the orthologous gene pairs of indigenous and invasive whiteflies which are helpful for the investigation of association between allelic and phenotypes. Conclusions: Our data present the most comprehensive sequences for the indigenous whitefly species Asia II 3. The extensive comparisons of Asia II 3, MEAM1 and MED transcriptomes will serve as an invaluable resource for revealing the genetic basis of whitefly invasion and the molecular mechanisms underlying their biological differences. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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17. Autophagy Regulates Whitefly-Symbiont Metabolic Interactions.
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Yan-Bin Wang, Ce Li, Jin-Yang Yan, Tian-Yu Wang, Ya-Lin Yao, Fei-Rong Ren, and Jun-Bo Luan
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SWEETPOTATO whitefly , *AUTOPHAGY , *ESSENTIAL amino acids , *VITAMIN B complex , *ESSENTIAL nutrients , *CELL physiology - Abstract
Nutritional symbionts are restricted to specialized host cells called bacteriocytes in various insect orders. These symbionts can provide essential nutrients to the host. However, the cellular mechanisms underlying the regulation of these insect-symbiont metabolic associations remain largely unclear. The whitefly Bemisia tabaci MEAM1 hosts “Candidatus Portiera aleyrodidarum” (here, “Ca. Portiera”) and “Candidatus Hamiltonella defensa” (here, “Ca. Hamiltonella”) bacteria in the same bacteriocyte. In this study, the induction of autophagy by chemical treatment and gene silencing decreased symbiont titers and essential amino acid (EAA) and B vitamin contents. In contrast, the repression of autophagy in bacteriocytes via Atg8 silencing increased symbiont titers, and amino acid and B vitamin contents. Furthermore, dietary supplementation with non-EAAs or B vitamins alleviated autophagy in whitefly bacteriocytes, elevated TOR (target of rapamycin) expression, and increased symbiont titers. TOR silencing restored symbiont titers in whiteflies after dietary supplementation with B vitamins. These data suggest that “Ca. Portiera” and “Ca. Hamiltonella” evade autophagy of the whitefly bacteriocytes by activating the TOR pathway via providing essential nutrients. Taken together, we demonstrate that autophagy plays a critical role in regulating the metabolic interactions between the whitefly and two intracellular symbionts. Therefore, this study reveals that autophagy is an important cellular basis for bacteriocyte evolution and symbiosis persistence in whiteflies. The whitefly symbiosis unravels the interactions between cellular and metabolic functions of bacteriocytes. IMPORTANCE Nutritional symbionts, which are restricted to specialized host cells called bacteriocytes, can provide essential nutrients for many hosts. However, the cellular mechanisms of regulation of animal-symbiont metabolic associations have been largely unexplored. Here, using the whitefly-“Ca. Portiera”/“Ca. Hamiltonella” endosymbiosis, we demonstrate autophagy regulates the symbiont titers and thereby alters the essential amino acid and B vitamin contents. For persistence in the whitefly bacteriocytes, “Ca. Portiera” and “Ca. Hamiltonella” alleviate autophagy by activating the TOR (target of rapamycin) pathway through providing essential nutrients. Therefore, we demonstrate that autophagy plays a critical role in regulating the metabolic interactions between the whitefly and two intracellular symbionts. This study also provides insight into the cellular basis of bacteriocyte evolution and symbiosis persistence in the whitefly. The mechanisms underlying the role of autophagy in whitefly symbiosis could be widespread in many insect nutritional symbioses. These findings provide a new avenue for whitefly control via regulating autophagy in the future. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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18. Social-Sensed Image Search.
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PENG CUI, SHAO-WEI LIU, WEN-WU ZHU, HUAN-BO LUAN, TAT-SENG CHUA, and SHI-QIANG YANG
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WEB search engines , *INFORMATION retrieval , *SOCIAL media , *DIGITAL images - Abstract
Although Web search techniques have greatly facilitate users' information seeking, there are still quite a lot of search sessions that cannot provide satisfactory results, which are more serious in Web image search scenarios. How to understand user intent from observed data is a fundamental issue and of paramount significance in improving image search performance. Previous research efforts mostly focus on discovering user intent either from clickthrough behavior in user search logs (e.g., Google), or from social data to facilitate vertical image search in a few limited social media platforms (e.g., Flickr). This article aims to combine the virtues of these two information sources to complement each other, that is, sensing and understanding users' interests from social media platforms and transferring this knowledge to rerank the image search results in general image search engines. Toward this goal, we first propose a novel social-sensed image search framework, where both social media and search engine are jointly considered. To effectively and efficiently leverage these two kinds of platforms, we propose an example-based user interest representation and modeling method, where we construct a hybrid graph from social media and propose a hybrid random-walk algorithm to derive the user-image interest graph. Moreover, we propose a social-sensed image reranking method to integrate the user-image interest graph from social media and search results from general image search engines to rerank the images by fusing their social relevance and visual relevance. We conducted extensive experiments on real-world data from Flickr and Google image search, and the results demonstrated that the proposed methods can significantly improve the social relevance of image search results while maintaining visual relevance well. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
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19. Transcriptomic Analysis of the Salivary Glands of an Invasive Whitefly.
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Yun-Lin Su, Jun-Min Li, Meng Li, Jun-Bo Luan, Xiao-Dong Ye, Xiao-Wei Wang, and Shu-Sheng Liu
- Subjects
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SWEETPOTATO whitefly , *VIRAL transmission , *SALIVARY glands , *GENE expression , *PROTEINS , *BEMISIA - Abstract
Background: Some species of the whitefly Bemisia tabaci complex cause tremendous losses to crops worldwide through feeding directly and virus transmission indirectly. The primary salivary glands of whiteflies are critical for their feeding and virus transmission. However, partly due to their tiny size, research on whitefly salivary glands is limited and our knowledge on these glands is scarce. Methodology/Principal Findings: We sequenced the transcriptome of the primary salivary glands of the Mediterranean species of B. tabaci complex using an effective cDNA amplification method in combination with short read sequencing (Illumina). In a single run, we obtained 13,615 unigenes. The quantity of the unigenes obtained from the salivary glands of the whitefly is at least four folds of the salivary gland genes from other plant-sucking insects. To reveal the functions of the primary glands, sequence similarity search and comparisons with the whole transcriptome of the whitefly were performed. The results demonstrated that the genes related to metabolism and transport were significantly enriched in the primary salivary glands. Furthermore, we found that a number of highly expressed genes in the salivary glands might be involved in secretory protein processing, secretion and virus transmission. To identify potential proteins of whitefly saliva, the translated unigenes were put into secretory protein prediction. Finally, 295 genes were predicted to encode secretory proteins and some of them might play important roles in whitefly feeding. Conclusions/Significance:: The combined method of cDNA amplification, Illumina sequencing and de novo assembly is suitable for transcriptomic analysis of tiny organs in insects. Through analysis of the transcriptome, genomic features of the primary salivary glands were dissected and biologically important proteins, especially secreted proteins, were predicted. Our findings provide substantial sequence information for the primary salivary glands of whiteflies and will be the basis for future studies on whitefly-plant interactions and virus transmission. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
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20. Overexpression of cellular repressor of E1A-stimulated genes inhibits TNF-α-induced apoptosis via NF-κB in mesenchymal stem cells
- Author
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Peng, Cheng-Fei, Han, Ya-Ling, Jie-Deng, Yan, Cheng-Hui, Jian-Kang, Bo-Luan, and Jie-Li
- Subjects
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GENE expression , *TUMOR necrosis factors , *APOPTOSIS , *MESENCHYMAL stem cells , *NF-kappa B , *MYOCARDIAL infarction , *BONE marrow , *GENETIC repressors - Abstract
Abstract: Bone marrow-derived mesenchymal stem cells (MSCs) show great potential for therapeutic repair after myocardial infarction. However, poor viability of transplanted MSCs in the ischemic heart has limited their use. Cellular repressor of E1A-stimulated genes (CREG) has been identified as a potent inhibitor of apoptosis. This study therefore aimed to determine if rat bone marrow MSCs transfected with CREG-were able to effectively resist apoptosis induced by inflammatory mediators, and to demonstrate the mechanism of CREG action. Apoptosis was determined by flow cytometric and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling assays. The pathways mediating these apoptotic effects were investigated by Western blotting. Overexpression of CREG markedly protected MSCs from tumor necrosis factor-α (TNF-α) induced apoptosis by 50% after 10h, through inhibition of the death-receptor-mediated apoptotic pathway, leading to attenuation of caspase-8 and caspase-3. Moreover, CREG resisted the serine phosphorylation of IκBα and prevented the nuclear translocation of the transcription factor nuclear factor-κB (NF-κB) under TNF-α stimulation. Treatment of cells with the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) significantly increased the transcription of pro-apoptosis proteins (p53 and Fas) by NF-κB, and attenuated the anti-apoptotic effects of CREG on MSCs. The results of this study indicate that CREG acts as a novel and potent survival factor in MSCs, and may therefore be a useful therapeutic adjunct for transplanting MSCs into the damaged heart after myocardial infarction. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
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21. Asymmetric Mating Interactions Drive Widespread Invasion and Displacement in a Whitefly.
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Shu-Sheng Liu, De Barro, P. J., Jing Xu, Jun-Bo Luan, Lian-Sheng Zang, Yong-Ming Ruan, and Fang-Hao Wan
- Subjects
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INTRODUCED insects , *INTRODUCED species , *BEMISIA , *ALEYRODIDAE , *HAPLODIPLOIDY , *INSECT populations - Abstract
The article demonstrates that the asymmetric mating interactions between closely related but formerly allopatric genetic groups of the whitefly Bemisia tabaci, a haplodiploid species, have been a contributing factor in the widespread invasion and displacement by alien whitefly populations. Long-term field surveys, detailed behavioral observations and caged population experiments were conducted in Queensland and Zhejiang, China. It is pointed out asymmetric mating interplay may be essential in finding out the capacity of a haplodiploid invading species and the consequences.
- Published
- 2007
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