Seasonal increase in nest defense,but not egg rejection,in a cuckoo host

The interactions between avian brood parasites and their hosts provide an informative and easy-to-handle system for studying coevolution.Avian brood parasitism reduces the reproductive success of hosts,and thus,hosts have evolved anti-parasitic strategies,such as rejecting parasitic eggs and adopting aggressive nest defense strategies,to avoid the cost brought on by brood parasitism.To test whether host anti-parasitic strategies are adjusted with the risk of being parasitized when the breeding seasons of brood parasites and hosts are not synchronous,we conducted a field experiment assessing nest defense and egg recognition behaviors of the Isabelline Shrike(Lanius isabellinus),a host of the Common Cuckoo(Cuculus canorus).In the local area,the host Isabelline Shrike begins to breed in April,whereas the summer migratory Common Cuckoo migrates to the local area in May and begins to lay parasitic eggs.Results showed that nest defense behaviors of the Isabelline Shrike increases significantly after cuckoo arrival,showing higher aggressiveness to cuckoo dummies,with no significant difference in attack rates among cuckoo,sparrowhawk and dove dummies,but their egg rejection did not change significantly.These results imply that Isabelline Shrikes may adjust their nest defense behavior,but not egg rejection behavior,with seasonality.

Integration of metabolomics and transcriptomics revealed the biosynthetic mechanism of anti-parasitic compounds in Salinivibrio proteolyticus strain YCSC6

The fermentation broth of Salinivibrio proteolyticus strain YCSC6 shows potent anti-parasitic activity against Uronema marinum,with activity varying in each fermentation stage.To investigate the biosynthetic mechanism of anti-parasitic compounds in strain YCSC6,a comprehensive analysis of metabolomics and transcriptomics over four diff erent time points(12,24,48,and 72 h)was performed.Metabolomics detected 17943 metabolites with 1129 known metabolites.A trend analysis of the known metabolites showed that 575 metabolites,including 69 polyketides,were continuously enhanced,being the potential source of anti-parasitic agents.In addition,941 genes mapped to the same pathways of these metabolites,were screened through the association analysis of metabolites and genes.KEGG pathway enrichment of these genes showed 270 genes mapped to the biosynthesis of secondary metabolites and 192 genes mapped to the biosynthesis of antibiotics.This demonstrates the potent secondary metabolic capacity of strain YCSC6.Finally,a gene-metabolite correlation network was created based on the 575 continuously enhanced metabolites and 43 continuously up-regulated genes.This revealed 13 genes at the key position that mapped to a putative metabolic pathway associated with the biosynthesis of polyketides and caprylic acid,which contributes to the potent anti-parasitic activity of strain YCSC6.This comprehensive analysis of metabolomics and transcriptomics provides insights into the biosynthetic mechanisms of anti-parasitic compounds in strain YCSC6 and guides the exploitation of more anti-parasitic agents for aquaculture.

Synthesis, Crystal Structure and Anti-parasitic Activity of 2-(2-Methoxy-4-nitrophenylcarbamoyl)phenyl 4-Fluorobenzoate

The title compound 2-（2-methoxy-4-nitrophenylcarbamoyl）phenyl-4＇-fluorobenzoate （C21H15FN206, Mr = 410.35）, a fluorine-containing derivative of salicylamide, was conve- niently synthesized through two steps and crystallized in the orthorhombic space group P21/c with a = 7.6453（15）, b = 14.323（3）, c = 17.035（3） A, V= 1865.4（6） A3, Z = 4, Dc = 1.461 Mg/m^3, 2 = 0.71073 A, μ（MoKa） = 0.115 mm-1, F（000） = 848, R = 0.0705 and wR = 0.1834 for 3267 independent refections with 1 〉 2σ（I）. X-ray analysis reveals that the dihedral angles formed between the 2-methoxy-4-nitrobenzene and benzene ring, the benzene and 4-fluorobenzene, and the 2-methoxy-4-nitrobenzene and 4-fluorobenzene ring are 3.2（4）, 69.8（3） and 72.9（2）~, respectively. Bioassay shows that the title compound has anti-parasitic activity against hydatid protoscoleces.

Coevolution of acoustical communication between obligate avian brood parasites and their hosts

The mutually antagonistic processes producing adaptations and counter-adaptations in avian brood parasites and their hosts provide a model system for the study of coevolution;this topic has long been an area of focus in ornithology and evolutionary biology.Although there is an extensive body of literature dealing with avian brood parasitism,few empirical studies have considered the effects of the coevolutionary processes associated with brood parasitism on the acoustic characteristics of parent–offspring communication.Under the strong selection pressures associated with brood parasitism,parasitic birds may,for instance,produce deceptive songs.The host may in turn evolve the ability to recognize these sounds as deceptive.At present,the mechanisms underlying the different competitive strategies employed by hosts and parasitic birds remain unclear.Here,we reviewed previous studies that investigated acoustic traits in scenarios of brood parasitism,highlighting possible adaptive functions.Using a meta-analysis,we identified no heterogeneity among studies of begging call adaptations in parasitic nestlings.However,our results may have been affected by the small number of applicable papers available for analysis.Our meta-analysis also suggested that studies of acoustic communication and transmission in adult hosts were highly heterogenous,suggesting that research methods were inconsistent among studies.Finally,we identified knowledge gaps and proposed several lines of future research.

Recent research progress on small molecule compounds and its derivatives of antiparasitic drugs

Neglected tropical diseases(NTDs)refer to infectious diseases caused by multiple pathogens that are prevalent in hot,humid climates in tropical areas.With the global economic growth and the improvement of public health status,eliminating neglected tropical diseases will be of great significance to the healthy development of human beings.However,the number of drugs and vaccines for NTDs treatment is extremely limited,so it is urgent to develop new drugs.Since most NTDs are caused by parasites,this paper selected parasitic diseases with high morbidity and mortality,and focused on new effective therapeutic targets and excellent lead compounds for these diseases.Schistosomiasis,human African trypanosomiasis(HAT),Chagas disease,leishmaniasis,filariasis and toxoplasmosis correspond to a series targets such as smHDAC8,thioredoxin glutathione reductase(TGR),T.cruzi glucokinase(TcGlcK),phosphofructokinase(PFK),type IB topoisomerase,cell division cycle-2-related Kinase,sterolmethyl transferase,calumenin,dihydrofolate reductase(DHFR)and Toxoplasma gondii farnesyl-diphosphate synthase(TgFPPs).In this paper,the pharmacological effects of typical lead compounds corresponding to each disease,the structural characteristics of the mother nucleus and the pharmacological activities of the substituent.In addition,the binding patterns of some involved targets(such as smHDAC8)with corresponding lead compounds(such as compound 13)and the signaling pathways associated with gluconeogenesis,glycolysis,and pentose phosphate pathways are analyzed in detail.In this paper,the interaction mechanism between the lead compounds and the target were thoroughly discussed,in order to provide the research ideas of potential anti-parasite compounds,and further improve the understanding and prevention ability of such diseases of NTDs.