Comparative evolutionary analyses of eight whitefly Bemisia tabaci sensu lato genomes: cryptic species, agricultural pests and plant-virus vectors.

BACKGROUND: The group of > 40 cryptic whitefly species called Bemisia tabaci sensu lato are amongst the world's worst agricultural pests and plant-virus vectors. Outbreaks of B. tabaci s.l. and the associated plant-virus diseases continue to contribute to global food insecurity and social instability, particularly in sub-Saharan Africa and Asia. Published B. tabaci s.l. genomes have limited use for studying African cassava B. tabaci SSA1 species, due to the high genetic divergences between them. Genomic annotations presented here were performed using the 'Ensembl gene annotation system', to ensure that comparative analyses and conclusions reflect biological differences, as opposed to arising from different methodologies underpinning transcript model identification. RESULTS: We present here six new B. tabaci s.l. genomes from Africa and Asia, and two re-annotated previously published genomes, to provide evolutionary insights into these globally distributed pests. Genome sizes ranged between 616-658 Mb and exhibited some of the highest coverage of transposable elements reported within Arthropoda. Many fewer total protein coding genes (PCG) were recovered compared to the previously published B. tabaci s.l. genomes and structural annotations generated via the uniform methodology strongly supported a repertoire of between 12.8-13.2 × 103 PCG. An integrative systematics approach incorporating phylogenomic analysis of nuclear and mitochondrial markers supported a monophyletic Aleyrodidae and the basal positioning of B. tabaci Uganda-1 to the sub-Saharan group of species. Reciprocal cross-mating data and the co-cladogenesis pattern of the primary obligate endosymbiont 'Candidatus Portiera aleyrodidarum' from 11 Bemisia genomes further supported the phylogenetic reconstruction to show that African cassava B. tabaci populations consist of just three biological species. We include comparative analyses of gene families related to detoxification, sugar metabolism, vector competency and evaluate the presence and function of horizontally transferred genes, essential for understanding the evolution and unique biology of constituent B. tabaci. s.l species. CONCLUSIONS: These genomic resources have provided new and critical insights into the genetics underlying B. tabaci s.l. biology. They also provide a rich foundation for post-genomic research, including the selection of candidate gene-targets for innovative whitefly and virus-control strategies.

Identifying potential insecticide resistance markers through genomic-level comparison of Bemisia tabaci (Gennadius) lines.

The invasive whitefly (Bemisia tabaci) MED is one of the most economically damaging plant pests. The extensive use of insecticide over decades has led to that the invasive B. tabaci MED has developed resistance to a wide range of insecticide classes, but little is known about the genetic background associated with resistance. To this end, we conducted a comparative genome-wide analysis of single-base nucleotide polymorphisms between MED whitefly lines collected from fields that were recently infested and an insecticide-susceptible MED whitefly line collected in 1976. First, low-coverage genome sequencings were conducted on DNA isolated from individual whiteflies. The sequencing results were evaluated using an available B. tabaci MED genome as a reference. Significant genetic differences were discovered between MED whitefly lines collected from fields that were recently infested and an insecticide-susceptible MED whitefly line based on the principal component analyses. Top GO categories and KEGG pathways that might be involved in insecticide resistance development were identified, and several of them have not been previously associated with resistance. Additionally, we identified several genetic loci with novel variations including Cytochrome P450 monooxygenases (P450s), UDP-glucuronosyltransferases (UGTs), Glutathione S-transferases (GSTs), esterase, carboxyl-esterases (COE), ABC transporters, fatty acyl-CoA reductase, voltage-gated sodium channels, GABA receptor, and cuticle proteins (CPs) that were previously reported to have close associations with pesticide resistance in well-studied insect groups that provide an essential resource for the design of insecticide resistance-linked loci arrays insecticide. Our results was obtained solely on resequencing genome data sets, more pesticide bio-assays combined with omics datasets should be further used to verify the markers identified here.

Similar gut bacteria composition in Apriona germari on two preferred host plants.

Apriona germari is one of the most serious wood-boring pests that cause damage to economic and landscaping trees and has adapted to a wide range of plants as diet. Gut bacteria play an important role in biology and ecology of herbivores, especially in growth and adaptation. To investigate how plant hosts shape A. germari gut microbiota, A. germari larvae were collected from Populus tomentosa and Malus pumilal, and gut microbiomes were sequenced based on 16S rDNA high-throughput sequencing technology. A total of 853,424 high-quality reads were obtained and clustered into 196 operational taxonomic units under a 97% similarity cutoff, which were annotated into 8 phyla, 10 classes, 21 orders, 34 families, 59 genera, and 39 species. Gibbsiella was the most dominant genus of intestinal bacteria, followed by Enterobacter and Acinetobacter. No significant difference was observed in larvae gut bacterial richness and diversity of A. germari collected from two hosts, though alpha diversity showed that the richness of gut bacteria in A. germari larvae collected on P. tomentosa was slightly higher than that in A. germari on M. pumilal, and beta diversity showed little difference between two host plants. The functional abundance analysis of the detected bacteria revealed fermentation, chemoheterotrophy, symbionts, and nitrate relative functions that highly possibly support wood-boring beetles to feed on woody tissues. Our study provided a theoretical basis for investigating the function of intestinal symbiosis bacteria of A. germari.

Initial fluid resuscitation (30 mL/kg) in patients with septic shock: More or less?

OBJECTIVES: The 2018 Surviving Sepsis Campaign (SSC) recommends rapid administration of 30 mL/kg crystalloid fluids for hypotension or lactate ≥4 mmol/L in patients with septic shock; however, there is limited evidence to support this recommendation. The purpose of this study was to examine the relationship between initial fluid resuscitation doses and prognosis in patients with septic shock. METHODS: This was a multicenter prospective observational study of adult patients with septic shock who were admitted to four intensive care units (ICUs) in a total of three Jiangsu Province teaching hospitals over a 3-year span from May 8, 2018, to June 15, 2021. Each enrolled patients with septic shock was categorized into the low-volume (below 20 mL/kg fluid), medium-volume (20-30 mL/kg fluid) or high-volume (above 30 mL/kg fluid) fluid group according to the initial infusion dose given for fluid resuscitation. Various demographic attributes and other variables were collected from medical records. Logistic regression and Kaplan-Meier curve analysis were used to determine the relationship between initial fluid resuscitation doses and patient outcomes. MEASUREMENTS AND MAIN RESULTS: A total of 302 patients who presented to the ICU were diagnosed with septic shock. The 28-day mortality was highest in the high-volume group (48.3%) and lowest in the medium-volume group (26.3%, P < 0.05). Patients who completed 30 mL/kg initial fluid resuscitation in the first 1-2 h had the lowest 28-day mortality rate (22.8%, P < 0.05). Logistic regression showed that a medium initial fluid volume dose was an independent protective factor, with the odds ratio (OR) indicating significantly decreased mortality (OR, 0.507; 95% confidence interval, 0.310-0.828; P = 0.007; P < 0.05). A Kaplan-Meier curve stratified by initial fluid resuscitation dose was constructed for the probability of 28-day mortality. The medium-volume fluid group showed a significantly lower 28-day mortality rate than the high-volume group or the low-volume group (log-rank test, P = 0.0016). CONCLUSION: In septic shock patients, an initial fluid resuscitation rate of 20-30 mL/kg within the first hour may be associated with reduced 28-day mortality; however, this result needs to be confirmed by further high-quality randomized controlled clinical trials. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR-OOC-17013223. Registered 2 November 2017, http://www.chictr.org.cn/showproj.aspx?proj=22674.

A newly recorded Rickettsia of the Torix group is a recent intruder and an endosymbiont in the whitefly Bemisia tabaci.

The bacterium Rickettsia is found widely in phytophagous insects and often exerts profound effects on the phenotype and fitness of its hosts. Here, we decrypt a new, independent, phylogenetically ancient Torix Rickettsia endosymbiont found constantly in a laboratory line of an economically important insect Asia II 7, a putative species of the Bemisia tabaci whitefly complex (Hemiptera: Aleyrodidae), and occasionally in field whitefly populations. This new Rickettsia distributes throughout the body of its whitefly host. Genetically, compared to Rickettsia_bellii_MEAM1 found earlier in whiteflies, the new Rickettsia species has more gene families and pathways, which may be important factors in shaping specific symbiotic relationships. We propose the name 'Candidatus Rickettsia_Torix_Bemisia_tabaci (RiTBt)' for this new endosymbiont associated with whiteflies. Comparative genomic analyses indicate that RiTBi may be a relatively recent intruder in whiteflies given its low abundance in the field and relatively larger genome compared to Rickettsia_bellii_MEAM1.

Effects of restrictive red blood cell transfusion on the prognoses of adult patients undergoing cardiac surgery: a meta-analysis of randomized controlled trials.

PURPOSE: Restrictive red blood cell transfusion strategies remain controversial in patients undergoing cardiac surgery. We performed a meta-analysis to assess the prognostic benefits of restrictive red blood cell transfusion strategies in patients undergoing cardiac surgery. METHODS: We identified randomized clinical trials through the 9th of December 2017 that investigated a restrictive red blood cell transfusion strategy versus a liberal transfusion strategy in patients undergoing cardiac surgery. Individual patient data from each study were collected. Meta-analyses were performed for the primary and secondary outcomes. The risk of bias was assessed using the Cochrane Risk of Bias Tool. A trial sequential analysis (TSA)-adjusted random-effects model was used to pool the results from the included studies for the primary outcomes. RESULTS: Seven trials involving a total of 8886 patients were included. The TSA evaluations suggested that this meta-analysis could draw firm negative results, and the data were sufficient. There was no evidence that the risk of 30-day mortality differed between the patients assigned to a restrictive blood cell transfusion strategy and a liberal transfusion strategy (odds ratio (OR) 0.98; 95% confidence interval (CI) 0.77 to 1.24; p = 0.87). Furthermore, the study suggested that the restrictive transfusion strategy was not associated with significant increases in pulmonary morbidity (OR 1.09; 95% CI 0.88 to 1.34; p = 0.44), postoperative infection (OR 1.11; 95% CI 0.95 to 1.3; p = 0.58), acute kidney injury (OR 1.03; 95% CI 0.92 to 1.14; p = 0.71), acute myocardial infarction (OR 1.01; 95% CI 0.80 to 1.27; p = 0.78), or cerebrovascular accidents (OR 0.97; 95% CI 0.72 to 1.30; p = 0.66). CONCLUSIONS: Our meta-analysis demonstrates that the restrictive red blood cell transfusion strategy was not inferior to the liberal strategy with respect to 30-day mortality, pulmonary morbidity, postoperative infection, cerebrovascular accidents, acute kidney injury, or acute myocardial infarction, and fewer red blood cells were transfused.

Effect of levosimendan on prognosis in adult patients undergoing cardiac surgery: a meta-analysis of randomized controlled trials.

BACKGROUND: Small trials suggest that levosimendan is associated with a favorable outcome in patients undergoing cardiac surgery. However, recently published larger-scale trials did not provide evidence for a similar benefit from levosimendan. We performed a meta-analysis to assess the survival benefits of levosimendan in patients undergoing cardiac surgery and to investigate its effects in subgroups of patients with preoperative low-ejection fraction (EF). METHODS: We identified randomized clinical trials through 20 April 2017 that investigated levosimendan therapy versus control in patients undergoing cardiac surgery. Individual patient data from each study were compiled. Meta-analyses were performed for primary outcomes, secondary outcomes and serious adverse events, and subgroup analyses according to the preoperative EF of enrolled patients were also conducted. The risk of bias was assessed using the Cochrane risk-of-bias tool. RESULTS: Seventeen studies involving a total of 2756 patients were included. Levosimendan therapy was associated with a significant reduction in 30-day mortality (RR 0.67; 95% CI, 0.49 to 0.93; p = 0.02) and reduced the risk of death in single-center trials (RR 0.49; 95% CI, 0.30 to 0.79; p = 0.004) and in subgroup trials of inferior quality (RR 0.39; 95% CI, 0.17 to 0.92; p = 0.02); however, in multicenter and in high-quality subgroup-analysis trials, no significant difference in mortality was observed between patients who received levosimendan therapy and controls (p > 0.05). However, in high-quality subgroup trials, levosimendan therapy was associated with reduced mortality in patients in a preoperative low-EF subgroup (RR 0.58; 95% CI, 0.38 to 0.88; p = 0.01). Similarly, only patients in the preoperative low-EF subgroup benefited in terms of reduced risk of renal replacement therapy (RR 0.54; 95% CI, 0.34 to 0.85; p = 0.007). Furthermore, levosimendan therapy was associated with a significant reduction in intensive care unit (ICU) length of stay (MDR -17.19; 95% CI, -34.43 to -2.94; p = 0.02). CONCLUSIONS: In patients undergoing cardiac surgery, the benefit of levosimendan in terms of survival was not shown in multicenter or in high-quality trials; however, levosimendan therapy was associated with reduced mortality in patients with preoperative ventricular systolic dysfunction.

The effect of glutamine therapy on outcomes in critically ill patients: a meta-analysis of randomized controlled trials.

INTRODUCTION: Glutamine supplementation is supposed to reduce mortality and nosocomial infections in critically ill patients. However, the recently published reducing deaths due to oxidative stress (REDOX) trials did not provide evidence supporting this. This study investigated the impact of glutamine-supplemented nutrition on the outcomes of critically ill patients using a meta-analysis. METHODS: We searched for and gathered data from the Cochrane Central Register of Controlled Trials, MEDLINE, Elsevier, Web of Science and ClinicalTrials.gov databases reporting the effects of glutamine supplementation on outcomes in critically ill patients. We produced subgroup analyses of the trials according to specific patient populations, modes of nutrition and glutamine dosages. RESULTS: Among 823 related articles, eighteen Randomized Controlled Trials (RCTs) met all inclusion criteria. Mortality events among 3,383 patients were reported in 17 RCTs. Mortality showed no significant difference between glutamine group and control group. In the high dosage subgroup (above 0.5 g/kg/d), the mortality rate in the glutamine group was significantly higher than that of the control group (relative risk (RR) 1.18; 95% confidence interval (CI), 1.02 to 1.38; P = 0.03). In 15 trials, which included a total of 2,862 patients, glutamine supplementation reportedly affected the incidence of nosocomial infections in the critically ill patients observed. The incidence of nosocomial infections in the glutamine group was significantly lower than that of the control group (RR 0.85; 95% CI, 0.74 to 0.97; P = 0.02). In the surgical ICU subgroup, glutamine supplementation statistically reduced the rate of nosocomial infections (RR 0.70; 95% CI, 0.52 to 0.94; P = 0.04). In the parental nutrition subgroup, glutamine supplementation statistically reduced the rate of nosocomial infections (RR 0.83; 95% CI, 0.70 to 0.98; P = 0.03). The length of hospital stay was reported in 14 trials, in which a total of 2,777 patients were enrolled; however, the patient length of stay was not affected by glutamine supplementation. CONCLUSIONS: Glutamine supplementation conferred no overall mortality and length of hospital stay benefit in critically ill patients. However, this therapy reduced nosocomial infections among critically ill patients, which differed according to patient populations, modes of nutrition and glutamine dosages.

A comprehensive framework for the delimitation of species within the Bemisia tabaci cryptic complex, a global pest-species group.

Identifying cryptic species poses a substantial challenge to both biologists and naturalists due to morphological similarities. Bemisia tabaci is a cryptic species complex containing more than 44 putative species; several of which are currently among the world's most destructive crop pests. Interpreting and delimiting the evolution of this species complex has proved problematic. To develop a comprehensive framework for species delimitation and identification, we evaluated the performance of distinct data sources both individually and in combination among numerous samples of the B. tabaci species complex acquired worldwide. Distinct datasets include full mitogenomes, single-copy nuclear genes, restriction site-associated DNA sequencing, geographic range, host speciation, and reproductive compatibility datasets. Phylogenetically, our well-supported topologies generated from three dense molecular markers highlighted the evolutionary divergence of species of the B. tabaci complex and suggested that the nuclear markers serve as a more accurate representation of B. tabaci species diversity. Reproductive compatibility datasets facilitated the identification of at least 17 different cryptic species within our samples. Native geographic range information provides a complementary assessment of species recognition, while the host range datasets provide low rate of delimiting resolution. We further summarized different data performances in species classification when compared with reproductive compatibility, indicating that combination of mtCOI divergence, nuclear markers, geographic range provide a complementary assessment of species recognition. Finally, we represent a model for understanding and untangling the cryptic species complexes based on the evidence from this study and previously published articles.

The characteristics and expression profiles of the mitochondrial genome for the Mediterranean species of the Bemisia tabaci complex.

BACKGROUND: The whiteflies under the name Bemisia tabaci (Gennadius) (Aleyrodidae: Hemiptera) are species complex of at least 31 cryptic species some of which are globally invasive agricultural pests. Previously, the mitochondrial genome (mitogenome) of the indigenous New World B. tabaci species was sequenced and major differences of gene order from the postulated whitefly ancestral gene order were found. However, the sequence and gene order of mitogenomes in other B. tabaci species are unknown. In addition, the sequence divergences and gene expression profiles of mitogenomes in the B. tabaci species complex remain completely unexplored. RESULTS: In this study, we obtained the complete mitogenome (15,632 bp) of the invasive Mediterranean (MED), which has been identified as the type species of the B. tabaci complex. It encodes 37 genes, including 13 protein-coding genes (PCGs), 2 ribosomal RNAs and 22 transfer RNAs (tRNA). Comparative analyses of the mitogenomes from MED and New World (previously published) species reveal that there are no gene arrangements. Based on the Illumina sequencing data, the gene expression profile of the MED mitogenome was analyzed. We found that a number of genes were polyadenylated and the partial stop codons in cox1, cox2 and nd5 are completed via polyadenylation that changed T to the TAA stop codon. In addition, combining the transcriptome with the sequence alignment data, the possible termination site of some PCGs were defined. Our analyses also revealed that atp6 and atp8, nd4 and nd4l, nd6 and cytb were found on the same cistronic transcripts, whereas the other mature mitochondrial transcripts were monocistronic. Furthermore, RT-PCR analyses of the mitochondrial PCGs expression in different developmental stages revealed that the expression level of individual mitochondrial genes varied in each developmental stage of nymph, pupa and adult. Interestingly, mRNA levels showed significant differences among genes located in the same transcription unit suggesting that mitochondrial mRNA abundance is heavily modulated by post-transcriptional regulation. CONCLUSIONS: This work provides novel insights into the mitogenome evolution of B. tabaci species and demonstrates that utilizing RNA-seq data to obtain the mitogenome and analyze mitochondrial gene expression characteristics is practical.

Spatio-temporal changes in endosymbiont diversity and composition in the African cassava whitefly, Bemisia tabaci SSA1.

Sap-sucking insects, including whiteflies, are amongst the most devastating and widely distributed organisms on the planet. They are often highly invasive and endosymbiont communities within these insects help them adapt to new or changing environments. Bemisia tabaci (Gennadius; Hemiptera: Aleyrodidae) whitefly species are vectors of more than 500 known plant-viruses and harbour highly diverse endosymbionts communities. To date, however, whitefly-endosymbiont interactions, community structure and their spatio-temporal changes are still poorly understood. In this study, we investigated the spatio-temporal changes in the composition and diversity of bacterial endosymbionts in the agricultural crop pest whitefly species, Bemisia tabaci sub-Saharan Africa 1-subgroup 1 and 2 (SSA1-SG1 and SSA1-SG2). 16S rRNA amplicon sequencing analysis was carried out to characterise endosymbiont compositionsin field-collected SSA1 (SSA1-SG1 and SSA1-SG2) populations infesting cassava in Uganda in 1997 and 2017. We detected Portiera, Arsenophonus, Wolbachia, Hamiltonella and Hemipteriphilus, with Arsenophonus and Wolbachia infections being predominant. Hemipteriphilus and Hamiltonella frequencies were very low and were detected in seven and two samples, respectively. Bacterial diversity based on three independent parameters including Simpson index, number of haplotypes and Bray-Curtis dissimilarity matrix was significantly higher in 1997 than in 2017. This period also coincided with the advent of super-abundant cassava-whitefly populations on cassava crops in Uganda. We discuss how endosymbionts may influence the biology and behaviour of whiteflies leading to population explosions.

[The impact of different fluid management on mortality in patients with septic shock].

OBJECTIVE: To find out the influential effect of different fluid management on mortality of patients with septic shock in different phases. METHODS: From March 2007 to December 2009, a retro spective controlled study was conducted on the clinical data of 107 adult patients with septic shock in the intensive care unit (ICU) of Subei Hospital of Jiangsu Province. The patients were divided into survival group ( n =68) and non survival group ( n =39) according to the final outcome. A number of demographic and variables were collected from the medical record. The acute physiology and chronic health evaluationII (APACHEII) score, sequential organ failure assessment (SOFA), liquid intake and output volume and its balance daily within 1 week, 24 hour early goal directed therapy (EGDT) and conservative late fluid management (CLFM) were compared between two groups. The Logistic regression statistics was used to determine the relationship between APACHEII, SOFA, EGDT, CLFM and survival. RESULTS: The single variable analysis showed that there was significant difference in the parameters of oxygenation index in 7 days ,arterial blood lactate clearance within 24 hours, acute lung injury, length of mechanical ventilation, length of ICU stay and in hospital, the goal of fluid management including 24 hour EGDT, 24 hour CLFM, fluid balance in 24 hours, total fluid input within 7 days, negative fluid balance and times during 7 days between two groups. Logistic regression showed that failure to achieve 24 hour EGDT and late CLFM,a negative balance of <2 000 ml, total fluid input of >20 000 ml within 1 week were independent risk factors of death, and odds ratio ( OR ) was 4.159, 4.431, 23.788 and 4.353, respectively, the P value was 0.035, 0.019, 0.000, 0.025, respectively. The 28 day mortality in 24 hour EGDT and CLFM group (12.5%) was significantly lower than that of 24 hour EGDT with liberal late fluid management (LLFM) group (46.2%) and that in the group of patients in whom with failure to have 24 hour EGDT with CLFM or LLFM (30.0%, 76.2%, P<0.05 or P <0.01). CONCLUSION: Both early achievement of 24 hour EGDT and late CLFM for the patients with septic shock can lower mortality.

Whole-genome single nucleotide polymorphism and mating compatibility studies reveal the presence of distinct species in sub-Saharan Africa Bemisia tabaci whiteflies.

In sub-Saharan Africa cassava growing areas, two members of the Bemisia tabaci species complex termed sub-Saharan Africa 1 (SSA1) and SSA2 have been reported as the prevalent whiteflies associated with the spread of viruses that cause cassava mosaic disease (CMD) and cassava brown streak disease (CBSD) pandemics. At the peak of CMD pandemic in the late 1990s, SSA2 was the prevalent whitefly, although its numbers have diminished over the last two decades with the resurgence of SSA1 whiteflies. Three SSA1 subgroups (SG1 to SG3) are the predominant whiteflies in East Africa and vary in distribution and biological properties. Mating compatibility between SSA1 subgroups and SSA2 whiteflies was reported as the possible driver for the resurgence of SSA1 whiteflies. In this study, a combination of both phylogenomic methods and reciprocal crossing experiments were applied to determine species status of SSA1 subgroups and SSA2 whitefly populations. Phylogenomic analyses conducted with 26 548 205 bp whole genome single nucleotide polymorphisms (SNPs) and the full mitogenomes clustered SSA1 subgroups together and separate from SSA2 species. Mating incompatibility between SSA1 subgroups and SSA2 further demonstrated their distinctiveness from each other. Phylogenomic analyses conducted with SNPs and mitogenomes also revealed different genetic relationships among SSA1 subgroups. The former clustered SSA1-SG1 and SSA1-SG2 together but separate from SSA1-SG3, while the latter clustered SSA1-SG2 and SSA1-SG3 together but separate from SSA1-SG1. Mating compatibility was observed between SSA1-SG1 and SSA1-SG2, while incompatibility occurred between SSA1-SG1 and SSA1-SG3, and SSA1-SG2 and SSA1-SG3. Mating results among SSA1 subgroups were coherent with phylogenomics results based on SNPs but not the full mitogenomes. Furthermore, this study revealed that the secondary endosymbiont-Wolbachia-did not mediate reproductive success in the crossing assays carried out. Overall, using genome wide SNPs together with reciprocal crossings assays, this study established accurate genetic relationships among cassava-colonizing populations, illustrating that SSA1 and SSA2 are distinct species while at least two species occur within SSA1 species.

Impact of a novel Rickettsia symbiont on the life history and virus transmission capacity of its host whitefly (Bemisia tabaci).

Rickettsia consists of some of the most prevalent symbionts of insects and often plays a significant role in the biology of its hosts. Recently, a maternally inherited Torix group Rickettsia, provisionally named as RiTBt, was recorded in a species of notorious pest whitefly, tentatively named as Asia II 1, from the Bemisia tabaci complex. The role of this Rickettsia in the biology of its host is unknown. Here we investigated the impact of RiTBt on the performance and virus transmission capacity of Asia II 1. RiTBt did not significantly affect the life history parameters of the whitefly when the host insect was reared on tobacco, tomato, and cotton, three host plants with relatively low, medium and high suitability to the whitefly. Intriguingly, RiTBt slightly enhanced whitefly transmission of cotton leaf curl Multan virus (CLCuMuV), a virus that is transmitted by the whitefly in the field and has caused extensive damage to cotton production. Specifically, compared with whiteflies without RiTBt, following a 48 h virus acquisition whiteflies with RiTBt had higher titer of virus and showed higher efficiency of virus transmission. A rickettsial secretory protein BtR242 was identified as a putative virus-binding protein, and was observed to interact with the coat protein of CLCuMuV in vitro. Viral infection of the whitefly downregulated gene transcript levels of the BtR242 gene. These observations indicate that RiTBt has limited impact on the biology of the Asia II 1 whitefly, and whether this symbiont has functions in the biology of other host whiteflies warrants future investigation.

Transcriptome analysis and comparison reveal divergence between the Mediterranean and the greenhouse whiteflies.

Both the Mediterranean (MED) species of the Bemisia tabaci whitefly complex and the greenhouse whitefly (Trialeurodes vaporariorum, TV) are important agricultural pests. The two species of whiteflies differ in many aspects such as morphology, geographical distribution, host plant range, plant virus transmission, and resistance to insecticides. However, the molecular basis underlying their differences remains largely unknown. In this study, we analyzed the genetic divergences between the transcriptomes of MED and TV. In total, 2,944 pairs of orthologous genes were identified. The average identity of amino acid sequences between the two species is 93.6%. The average nonsynonymous (Ka) and synonymous (Ks) substitution rates and the ratio of Ka/Ks of the orthologous genes are 0.0389, 2.23 and 0.0204, respectively. The low average Ka/Ks ratio indicates that orthologous genes tend to be under strong purified selection. The most divergent gene classes are related to the metabolisms of xenobiotics, cofactors, vitamins and amino acids, and this divergence may underlie the different biological characteristics between the two species of whiteflies. Genes of differential expression between the two species are enriched in carbohydrate metabolism and regulation of autophagy. These findings provide molecular clues to uncover the biological and molecular differences between the two species of whiteflies.

Evolutionary Patterns of Sex-Biased Genes in Three Species of Haplodiploid Insects.

Females and males often differ obviously in morphology and behavior, and the differences between sexes are the result of natural selection and/or sexual selection. To a great extent, the differences between the two sexes are the result of differential gene expression. In haplodiploid insects, this phenomenon is obvious, since males develop from unfertilized zygotes and females develop from fertilized zygotes. Whiteflies of the Bemisia tabaci species complex are typical haplodiploid insects, and some species of this complex are important pests of many crops worldwide. Here, we report the transcriptome profiles of males and females in three species of this whitefly complex. Between-species comparisons revealed that non-sex-biased genes display higher variation than male-biased or female-biased genes. Sex-biased genes evolve at a slow rate in protein coding sequences and gene expression and have a pattern of evolution that differs from those of social haplodiploid insects and diploid animals. Genes with high evolutionary rates are more related to non-sex-biased traits-such as nutrition, immune system, and detoxification-than to sex-biased traits, indicating that the evolution of protein coding sequences and gene expression has been mainly driven by non-sex-biased traits.

Mesenchymal stem cells regulate the Th17/Treg cell balance partly through hepatocyte growth factor in vitro.

INTRODUCTION: Mesenchymal stem cells (MSCs) exert immunomodulatory functions by inducing the development and differentiation of naive T cells into T cells with an anti-inflammatory regulatory T cell (Treg) phenotype. Our previous study showed that hepatocyte growth factor (HGF) secreted by MSCs had immunomodulatory effects in the context of lipopolysaccharide (LPS) stimulation. We hypothesized that HGF is a key factor in the MSC-mediated regulation of the T helper 17 (Th17) cell/regulatory T (Treg) cell balance. METHODS: We investigated the effects of MSCs on the differentiation of CD4+ T cells and the functions of Th17/Treg cells in response to LPS stimulation by performing in vitro coculture experiments. MSCs were added to the upper chambers of cell culture inserts, and CD4+ T cells were plated in the lower chambers, followed by treatment with LPS or an anti-HGF antibody. Th17 (CD4+CD3+RORrt+) and Treg (CD4+CD25+Foxp3+) cell frequencies were analysed by flow cytometry, and the expression of Th17 cell- and Treg cell-related cytokines in the CD4+ T cells or culture medium was measured by quantitative PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Neutrophil functions were determined by flow cytometry after a coculture with Th17/Treg cells. RESULTS: The percentage of CD4+CD25+Foxp3+ cells was significantly increased in the CD4+ T cell population, while the percentage of CD4+CD3+RORrt+ cells was significantly decreased after MSC coculture. However, the MSC-induced effect was significantly inhibited by the anti-HGF antibody (p < 0.05). Furthermore, MSCs significantly inhibited the CD4+ T cell expression of IL-17 and IL-6 but increased the expression of IL-10 (p < 0.05 or p < 0.01); these effects were inhibited by the anti-HGF antibody (p < 0.05). In addition, CD4+ T cells cocultured with MSCs significantly inhibited neutrophil phagocytic and oxidative burst activities (p < 0.05 or p < 0.01); however, these MSC-induced effects were inhibited by the anti-HGF antibody (p < 0.05). CONCLUSION: These data suggested that MSCs induced the conversion of fully differentiated Th17 cells into functional Treg cells and thereby modulated the Th17/Treg cell balance in the CD4+ T cell population, which was partly attributed to HGF secreted by the MSCs.

[A prospective randomized control clinical study of the effect of Xuebijing injection on prognosis of acute respiratory distress syndrome patients].

OBJECTIVE: To study the effect of Xuebijing injection on prognosis, immune function, adrenal function and inflammatory reaction during the treatment of acute respiratory distress syndrome (ARDS). METHODS: From January 2008 through December 2008, a clinical study was conducted on consecutive adult patients with ARDS in intensive care unit (ICU). The patients were divided into Xuebijing group (31 patients) and control group (30 patients). Both groups were treated with the routine therapy of ARDS, and in addition, Xuebijing injection was used in a dose of 100 ml twice a day for 7 days in Xuebijing group. Duration of mechanical ventilation (MV) and ICU length of stay, 28-day mortality, acute physiology and chronic health evaluation II (APACHE II), Murray and Marshall scores were recorded in both groups. Every patient was given one injection of corticotrophin 250 microg intravenously before and after treatment, and plasma cortisol level was detected by radio-immunoassay before the injection (T0) and 30 minutes (T30) and 60 minutes (T60) after the injection. The ratio of adrenal insufficiency was evaluated according to diagnostic criteria of relative adrenal insufficiency, which was defined as the difference between T0 and the highest value of T30 or T60 (Delta Tmax)< or =248.4 nmol/L. Human leukocyte antigen-DR (HLA-DR), subpopulations of T lymphocyte (CD4(+)/CD8(+)), interleukin-6 (IL-6), IL-10 in peripheral blood was also determined. RESULTS: Murray (1.5+/-1.5) and Marshall score (2.9+/-2.7) and the level of IL-6 [(3.4+/-1.9) micromol/L], IL-10 [(1.5+/-0.8) micromol/L] in the Xuebijing group were decreased significantly after the use of Xuebijing compared with control group [4.3+/-3.1, 6.3+/-4.1, (8.9+/-10.2) micromol/L, (4.2+/-4.8) micromol/L, respectively, all P<0.01], while the values of HLA-DR (41.1+/-10.1), CD4(+) (58.0+/-10.7), CD4(+)/CD8(+) (1.9+/-0.3) were increased compared with control group [30.6+/-15.0, 50.5+/-16.2, 1.4+/-0.7, respectively, P<0.05 or P<0.01]. The ratio of adrenal insufficiency in Xuebijing group (45.2%) was lower than that of control group (83.3%), while that of Delta Tmax [(328.4+/-278.3) micromol/L] was higher than that of control group [(172.8+/-110.8) micromol/L, both P<0.01]. MV duration [(4.0+/-3.3) days] and ICU length of stay [(8.4+/-4.2) days] were less than those of control group [(5.9+/-3.8) days, (12.0+/-7.6) days, both P<0.05], and 28-day mortality in Xuebijing group was 35.5%, which was 11.2% less than that of control group (46.7%), but there was no statistically significant difference between two groups (P>0.05). CONCLUSION: Xuebijing injection improves organ function, decreases MV duration and ICU length of stay in ARDS patients. The underlying mechanism may involve modulation of the immune function, decrease in the degree of adrenal insufficiency, and modulation of regulating inflammatory reaction.

A complete mitochondrial DNA genome of whitefly species (Hemiptera: Aleyrodidae) from Litchi chinensis.

A novel complete mitochondrial genome (mitogenome) of whitefly species, collected from Litchi chinensis at Fujian province of China (hereafter whitefly_Litchi chinensis _China) (GenBank accession number: MH999477), was described in this study. The mitogenome of whitefly_Litchi chinensis _China is 15,360 bp in length and contains 13 protein-coding genes, 21 transfer RNAs, 2 ribosomal RNAs and a non-coding AT-rich region (D-loop). The arrangement of mitochondrial genes of whitefly_Litchi chinensis_China are identical with Aleurochiton aceris, but remarkably different from the mitogenomes of the other whitefly genus. Most protein-coding genes (PCGs) start with ATN, except for nad2, cox2 and atp6 genes starting with TTG, GTG, and TTG, respectively; 10 of the 13 PCGs use the typical stop codon TAN, whereas cox1, and cox2 stop with a single T. Phylogenetic analyses based on 13 PCGs support the close relationship of the sample with Aleurochiton aceris, which would provide us further insights on the taxonomy and phylogeny of Aleyrodidae.

Conservation of transcriptional elements in the obligate symbiont of the whitefly Bemisia tabaci.

BACKGROUND: Bacterial symbiosis is widespread in arthropods, especially in insects. Some of the symbionts undergo a long-term co-evolution with the host, resulting in massive genome decay. One particular consequence of genome decay is thought to be the elimination of transcriptional elements within both the coding region and intergenic sequences. In the whitefly Bemisia tabaci species complex, the obligate symbiont Candidatus Portiera aleyrodidarum is of vital importance in nutrient provision, and yet little is known about the regulatory capacities of it. METHODS: Portiera genomes of two whitefly species in China were sequenced and assembled. Gene content of these two Portiera genomes was predicted, and then subjected to Kyoto Encyclopedia of Genes and Genomes pathway analysis. Together with two other Portiera genomes from whitefly species available previously, four Portiera genomes were utilized to investigate regulatory capacities of Portiera, focusing on transcriptional elements, including genes related with transcription and functional elements within the intergenic spacers. RESULTS: Comparative analyses of the four Portiera genomes of whitefly B. tabaci indicate that the obligate symbionts Portiera is similar in different species of whiteflies, in terms of general genome features and possible functions in the biosynthesis of essential amino acids. The screening of transcriptional factors suggests compromised ability of Portiera to regulate the essential amino acid biosynthesis pathways. Meanwhile, thermal tolerance ability of Portiera is indicated with the detection of a σ32 factor, as well as two predicted σ32 binding sites. Within intergenic spacers, functional elements are predicted, including 37 Shine-Dalgarno sequences and 34 putative small RNAs.