Application of an antibody chip for screening differentially expressed proteins during peach ripening and identification of a metabolon in the SAM cycle to generate a peach ethylene biosynthesis model

Peach(Prunus persica)is a typical climacteric fruit that produces ethylene rapidly during ripening,and its fruit softens quickly.Stony hard peach cultivars,however,do not produce large amounts of ethylene,and the fruit remains firm until fully ripe,thus differing from melting flesh peach cultivars.To identify the key proteins involved in peach fruit ripening,an antibody-based proteomic analysis was conducted.A mega-monoclonal antibody(mAb)library was generated and arrayed on a chip(mAbArray)at a high density,covering~4950 different proteins of peach.Through the screening of peach fruit proteins with the mAbArray chip,differentially expressed proteins recognized by 1587 mAbs were identified,and 33 corresponding antigens were ultimately identified by immunoprecipitation and mass spectrometry.These proteins included not only important enzymes involved in ethylene biosynthesis,such as ACO1,SAHH,SAMS,and MetE,but also novel factors such as NUDT2.Furthermore,protein–protein interaction analysis identified a metabolon containing SAHH and MetE.By combining the antibody-based proteomic data with the transcriptomic and metabolic data,a mathematical model of ethylene biosynthesis in peach was constructed.Simulation results showed that MetE is an important regulator during peach ripening,partially through interaction with SAHH.

Self-compatibility in peach[Prunus persica(L.)Batsch]:patterns of diversity surrounding the S-locus and analysis of SFB alleles

Self-incompatibility(SI)to self-compatibility(SC)transition is one of the most frequent and prevalent evolutionary shifts in flowering plants.Prunus L.(Rosaceae)is a genus of over 200 species most of which exhibit a Gametophytic SI system.Peach[Prunus persica(L.)Batsch;2n=16]is one of the few exceptions in the genus known to be a fully selfcompatible species.However,the evolutionary process of the complete and irreversible loss of SI in peach is not well understood and,in order to fill that gap,in this study 24 peach accessions were analyzed.Pollen tube growth was controlled in self-pollinated flowers to verify their self-compatible phenotypes.The linkage disequilibrium association between alleles at the S-locus and linked markers at the end of the sixth linkage group was not significant(P>0.05),except with the closest markers suggesting the absence of a signature of negative frequency dependent selection at the S-locus.Analysis of SFB1 and SFB2 protein sequences allowed identifying the absence of some variable and hypervariable domains and the presence of additionalα-helices at the C-termini.Molecular and evolutionary analysis of SFB nucleotide sequences showed a signature of purifying selection in SFB2,while the SFB1 seemed to evolve neutrally.Thus,our results show that the SFB2 allele diversified after P.persica and P.dulcis(almond)divergence,a period which is characterized by an important bottleneck,while SFB1 diversified at a transition time between the bottleneck and population expansion.

Prevalence and risk factors associated with malaria infection among pregnant women in a semi-urban community of north-western Nigeria

Background:Malaria during pregnancy remains a serious public health problem,with substantial risks for the mother,her foetus and the newborn.The aim of this study was to determine the prevalence of malaria and possible risk factors for malaria infection among pregnant women in a semi-urban area in north-western Nigeria.Pregnant women are among the most susceptible to malaria infection.Knowledge of their malaria infection status is an important yardstick to measure the effectiveness of any malaria control programme.Methods:We conducted a cross sectional study in the semi-urban area of Argungu,Kebbi State Nigeria.Two hundred and fifty five pregnant women were included in the study after informed verbal consent was obtained.For each participant,the socio-demographic profile,stage of pregnancy and attitude to the use of insecticide-treated nets(ITNs)were investigated using a questionnaire.Peripheral blood samples were collected and thick blood smears were prepared and stained with Giemsa stains to check for malaria parasitaemia.The associations between age,education level and use of ITNs with occurrence of malaria infection during pregnancy were analysed using the chi-square test.Results:One hundred and six(41.6%)out of 255 pregnant women were infected with malaria parasites,with a mean parasite density of 800 parasitesμl−1.It was found that prevalence and parasite density decreased as age increased.The chi-square test indicated that a lack of education and non-usage of ITNs were significantly associated with malaria infection.Conclusion:Malaria is still a major public health issue among pregnant women mainly due to illiteracy and non-compliance to using ITNs.Increasing awareness about malaria preventive measures and early attendance of antenatal care services will help to reduce malaria and,consequently,its associated morbidities and mortalities.

Insecticide resistance in phlebotomine sandflies in Southeast Asia with emphasis on the Indian subcontinent

Background:Visceral leishmaniasis,commonly known as kala-azar in India,is a global public health problem.In Southeast Asia,Bangladesh,Bhutan,India,Nepal,Sri Lanka and Thailand are endemic for visceral leishmaniasis.The role of sandflies as the vector of kala-azar was first confirmed in 1942 in India.Insecticide resistance in Phlebotomus argentipes Annandale and Brunetti,the vector of kala-azar in the Indian subcontinent,was first reported in 1987 in Bihar,India.This article provides a scoping review of the studies undertaken from 1959 to 2015 on insecticide resistance in P.argentipes and P.papatasi(Scopoli),the vectors of visceral and cutaneous leishmaniasis respectively,in Southeast Asia,mainly in Bangladesh,India,Nepal and Sri Lanka.Results:Studies undertaken in areas of Bihar and West Bengal in India where kala-azar is endemic have reported resistance of P.argentipes to DDT,while in non-endemic areas it has been reported to be susceptible.In areas of Nepal bordering India,there are indications of resistance to DDT;biochemical resistance has been reported in Sri Lanka.No laboratory studies have been undertaken in Bangladesh;however,the sandfly vector is reported to be still susceptible to pyrethroids in all kala-azar endemic areas in the aforementioned countries.Conclusions:Studies are needed to determine the resistance of sandfly vectors to all available classes of potential insecticides in kala-azar endemic areas.There is a need to assess the impact of indoor residual spraying with DDT and pyrethroids on the incidence of kala-azar in India where 54 districts remain endemic for the disease,strengthen entomological surveillance capacity,and develop and implement an insecticide management plan.Alpha-cypermethrin indoor residual spraying has been introduced in 33 kala-azar endemic districts in Bihar State of India in a pilot trial;the outcomes should be used to inform decisions on expanding coverage with alpha-cypermethrin in all remaining endemic districts to achieve the revised goal of elimination of visceral leishmaniasis by 2020.

Spatiotemporal dynamics of the microbial diversity on salt-preserved goatskins assessed by culturing and 16S rRNA gene amplicon sequencing

Wet-salted skin,as a special artificial high-salt environment,is rich in protein,fat,collagen and other nutrient substrates,and is a rich resource of halotolerant and halophilic microorganisms.However,knowledge gaps regarding the microbial community structure and inter taxa associations of wet-salted skin are large.In this study,the spatiotemporal dynamics and community structure of microorganisms present on wet-salted goatskins were investigated using 16S rRNA gene amplicon sequencing and culturable technique.Alpha diversity analysis based on Sobs,Chao,Ace and Shannon indices revealed that microbial diversity on the wet-salted goatskins exhibited a trend of‘down→up→down→flat’with time.During preservation,genera belonging to the bacteria domain such as Aci-netobacter,Weissella and Streptococcus were slowly dying out,whereas those belonging to halophilic archaea such as Natrialba and Haloterrigena were gradually flourishing.Moreover,to resist high-salt stress,microorganisms on the wet-salted goatskin gradually migrated from the outside to the inside,eventually leading to the microbial diversity inside the skin being the same as or even higher than that on the skin surface.Venn diagram analysis revealed that the strains of some genera,including Psychrobacter,Salimicrobium,Salinicola,Ornithinibacillus,Halomonas,Bacillus and Chromohalobacter,were distributed throughout the interior and exterior of the wet-salted goatskin and existed during various periods.Accordingly,45 protease-producing halophilic or halotolerant microorganisms were isolated and screened from the wet-salted goatskin using the gradient dilution plate method.Importantly,16S rRNA genes of some bacteria exhibited less than 99.5%similarity to valid published species,indicating that they likely are novel spe-cies and have a good potential for application.

Comparison of approaches to quantify SARS-CoV-2 in wastewater using RT-qPCR: Results and implications from a collaborative inter-laboratory study in Canada

Detection of SARS-CoV-2 RNA in wastewater is a promising tool for informing public health decisions during the COVID-19 pandemic.However,approaches for its analysis by use of reverse transcription quantitative polymerase chain reaction(RT-q PCR)are still far from standardized globally.To characterize inter-and intra-laboratory variability among results when using various methods deployed across Canada,aliquots from a real wastewater sample were spiked with surrogates of SARS-CoV-2(gamma-radiation inactivated SARS-CoV-2 and human coronavirus strain 229E[HCoV-229E])at low and high levels then provided"blind"to eight laboratories.Concentration estimates reported by individual laboratories were consistently within a 1.0-log_(10) range for aliquots of the same spiked condition.All laboratories distinguished between low-and high-spikes for both surrogates.As expected,greater variability was observed in the results amongst laboratories than within individual laboratories,but SARS-CoV-2 RNA concentration estimates for each spiked condition remained mostly within 1.0-log_(10) ranges.The no-spike wastewater aliquots provided yielded non-detects or trace levels(<20 gene copies/mL)of SARS-CoV-2 RNA.Detections appear linked to methods that included or focused on the solids fraction of the wastewater matrix and might represent in-situ SARS-CoV-2 to the wastewater sample.HCoV-229E RNA was not detected in the no-spike aliquots.Overall,all methods yielded comparable results at the conditions tested.Partitioning behavior of SARS-CoV-2 and spiked surrogates in wastewater should be considered to evaluate method effectiveness.A consistent method and laboratory to explore wastewater SARS-CoV-2 temporal trends for a given system,with appropriate quality control protocols and documented in adequate detail should succeed.