Antagonistic interaction between male-killing and cytoplasmic incompatibility induced by Cardinium and Wolbachia in the whitefly,Bemisia tabaci

Cardinium and Wolbachia are maternally inherited bacterial symbionts of arthropods that can manipulate host reproduction by increasing the fitness of infected females.Here,we report that Cardinium and Wolbachia coinfection induced male-killing and cytoplasmic incompatibility(CI)when they coexisted in a cryptic species of whitefly,Bemisia tabaci Asia II7.Cardinium and Wolbachia symbionts were either singly or simul-taneously localized in the bacteriocytes placed in the abdomen of B.tabaci nymphs and adults.Cardinium-Wolbachia coinfection induced male-killing and resulted in a higher female sex ratio in the intraspecific amphigenetic progeny of Asia II7 IcwH and IcwL lines;interestingly,male-illing induction was enhanced with increased Cardinium titer.Moreover,single infection of Wolbachia induced partial CI in the Asia II7 Iw line and resulted in reduced fecundity,higher embryonic mortality,and lower female sex ratio.The uninfected Asia II7 Iu line had significantly higher fecundity,lower embryonic and nymphal mortalities,and a lower level of CI than both the Wolbachia infected Asia II7 Iw line and the Cardinium--Wolbachia-coinfected Asia II7 IcwH line.Our findings indicate that Cardinium-Wolbachia coinfection induced male-killing,which may have had antag-onistic effects on Wolbachia-induced CI in the Asia II7 whiteflies.For the first time,our study revealed that B.tabaci Asia II7 reproduction is co-manipulated by Cardinium and Wolbachia endosymbionts.

Distributed H_(∞)Consensus Problem for First-Order Multi-Agent Systems with Antagonistic Interactions and Nonconvex Constraints

This paper investigates the distributed H_(∞)consensus problem for a first-order multiagent system where both cooperative and antagonistic interactions coexist.In the presence of external disturbances,a distributed control algorithm using local information is addressed and a sufficient condition to get the H_(∞)control gain is obtained,which make the states of the agents in the same group converge to a common point while the inputs of each agent are constrained in the nonconvex sets.Finally,a numerical simulation is exhibited to illustrate the theory.

Antagonistic formation motion of cooperative agents

This paper investigates a new formation motion problem of a class of first-order multi-agent systems with antagonistic interactions.A distributed formation control algorithm is proposed for each agent to realize the antagonistic formation motion.A sufficient condition is derived to ensure that all of the agents make an antagonistic formation motion in a distributed manner.It is shown that all of the agents can be spontaneously divided into several groups and that agents in the same group collaborate while agents in different groups compete.Finally,a numerical simulation is included to demonstrate our theoretical results.

Vigilance behavior of Pyrenean chamois Rupicapra pyrenaica pyrenaica:Effect of sex and position in the herd

The Pyrenean chamois Rupicapra pyrenaica pyrenaica is a mountain-dwelling ungulate with an extensive presence in open areas. Optimal group size results from the trade off between advantages （a reduction in the risk of predation） and disadvantages （competition between members of the herd） of group living. In addition, advantages and disadvantages of group living may vary depending on the position of each individual within the herd. Our objective was to study the effect of central vs. peripheral position in the herd on feeding and vigilance behavior in male and female Pyrenean chamois and to ascertain if a group size effect existed. We used focal animal sampling and recorded social interactions when a focal animal was involved. With males, vigilance rate was higher in the central part of the group than at the periphery, probably due to a higher density of animals in the central part of the herd and a higher probability of being disturbed by conspecifics. With females, vigilance rate did not differ according to position in the herd. Females spent more time feeding than males, and males showed a higher frequency of the vigilance behavior than females. We did not observe a clear relationship between group size and vigilance behavior. The differences in vigilance behavior might be due to social interactions

Ruminal bacteria lipopolysaccharides:an immunological and microbial outlook

Lipopolysaccharides(LPS)are outer membrane components of Gram-negative bacteria made of three regions:the O-antigen;the core oligosaccharide;and a glucosamine disaccharide linked to hydroxy fatty acids,which is named lipid A.The number phosphate groups,and hydroxy fatty acid chains is associated with the immunopotency and the immunomodulatory activity of LPS,where six-acyl chain lipid A with two phosphate groups is found in virulent strains and five-or four-acyl chain lipid A with one phosphate group are found in non-virulent bacteria strains.Ruminal bacteria are predominantly Gram-negative and their LPS have not been thoroughly investigated.In the rumen,LPS is comprised of mixed ruminal LPS.Drawing upon a body of theoretical and applied work,this paper aims to critically review the scientific literature regarding single-species and mixed ruminal bacteria LPS,highlighting the importance of ruminal LPS to the host.Lastly,future research directions are suggested in order to further our understanding of the roles of LPS in the rumen.Possible suggestions for further understanding ruminal LPS include(1)in silico evaluation of major bacteria contributing to ruminal LPS,(2)structural characterization of LPS from prominent ruminal bacteria species,such as ruminal selenomonads and Megasphaera elsdenii,and,(3)ruminal epithelial tissue immune response evaluation from single-species and mixed ruminal LPS.In conclusion,this review identifies numerous areas for future research,including setting the basis for future modeling and simulation of host microbiome interactions in ruminants.

Disagreement and Antagonism in Signed Networks: A Survey

Signed networks refer to a class of network systems including not only cooperative but also antagonistic interactions among nodes.Due to the existence of antagonistic interactions in signed networks,the agreement of nodes may not be established,instead of which disagreement behaviors generally emerge.This paper reviews several different disagreement behaviors in signed networks under the single-integrator linear dynamics,where two classes of topologies,namely,the static topology and the dynamic topology,are considered.For the static signed networks with the adjacency weights as(time-varying)scalars,we investigate the convergence behaviors and the fluctuation behaviors with respect to fixed topologies and switching topologies,respectively,and give some brief introductions on the disagreement behaviors of general time-varying signed networks.Correspondingly,several classes of behavior analysis approaches are also provided.For the dynamic signed networks with the adjacency weights as transfer functions or linear time-invariant systems,we show the specific descriptions and characteristics of them such that the disagreement behaviors can be obtained by resorting to the derived static signed graphs.Furthermore,we give their applications to the behavior analysis of static signed networks in the presence of high-order dynamics or communication delays.

ORA59 and EIN3 interaction couples jasmonate-ethylene synergistic action to antagonistic salicylic acid regulation of PDF expression

Hormonal crosstalk is central for tailoring plant responses to the nature of challenges encountered. The role of antagonism between the two major defense hormones, salicylic acid （SA） and jasmonic acid （JA）, and modulation of this interplay by ethylene （ET） in favor of JA signaling pathway in plant stress responses is well recognized, but the underlying mechanism is not fully understood. Here, we show the opposing function of two transcription factors, ethylene insensitive3 （EIN3） and EIN3-Like1 （EIL1）, in SA-mediated suppression and JA- mediated activation of PLANT DEFENSINI.2 （PDFI.2）. This functional duality is mediated via their effect on protein, not transcript levels of the PDF1.2 transcriptional activator octadecanoid-responsive Arabidopsis59 （ORA59）. Specifically, JA induces ORA59 protein levels independently of EIN3/EIL1, whereas SA reduces the protein levels dependently of EIN3/EIL1. Co-infiltration assays revealed nuclear co-localization of ORA59 and EIN3, and split- luciferase together with yeast-two-hybrid assays established their physical interaction. The functional ramification of the physical interaction is EIN3-dependent degradation of ORA59 by the 26S proteasome. These findings allude to SA-responsive reduction of ORA59 levels mediated by EIN3 binding to and targeting of ORA59 for degrada4tion, thus nominating ORA59 pool as a coordination node for the antagonistic function of ET/JA and SA.