Duplicated chalcone synthase(CHS)genes modulate flavonoid production in tea plants in response to light stress

In tea plants,the abundant flavonoid compounds are responsible for the health benefits for the human body and define the astringent flavor profile.While the downstream mechanisms of flavonoid biosynthesis have been extensively studied,the role of chalcone synthase(CHS)in this secondary metabolic process in tea plants remains less clear.In this study,we compared the evolutionary profile of the flavonoid metabolism pathway and discovered that gene duplication of CHS occurred in tea plants.We identified three CsCHS genes,along with a CsCHS-like gene,as potential candidates for further functional investigation.Unlike the CsCHS-like gene,the CsCHS genes effectively restored flavonoid production in Arabidopsis chs-mutants.Additionally,CsCHS transgenic tobacco plants exhibited higher flavonoid compound accumulation compared to their wild-type counterparts.Most notably,our examination of promoter and gene expression levels for the selected CHS genes revealed distinct responses to UV-B stress in tea plants.Our findings suggest that environmental factors such as UV-B exposure could have been the key drivers behind the gene duplication events in CHS.

CHS-DRG付费下超支病例分析及对策

按疾病诊断相关分组(diagnosis related groups,DRG)付费是国际公认较为先进和科学的支付方式之一。实践证明,DRG的引入能够增强医疗服务的可比性,提高医疗服务效率、降低医疗服务成本[1~4]。近年来,国家医保局加快推进医保支付方式改革。北京市作为国家医疗保障疾病诊断相关分组(China health-care security DRG,CHS-DRG)国家试点城市于2022年3月15日启动66家试点医院的实际付费。

CHS-DRG和耗材集采下关节置换病组费用结构变化研究

目的:研究CHS-DRG付费联合人工关节集采改革措施实施前后关节置换病组(IC29)住院患者费用结构变化情况及影响因素,揭示改革给医院运营带来的影响。方法:分析北京某三级医院改革实施前后IC29病组住院患者的信息以及住院费用变化情况;运用结构变动度分析法,分析病组费用变化的主要类别和方向。结果:改革前后IC29病组次均住院费的结构变动度为39.4%,其中耗材费、手术费是影响住院费用变动的主要项目,累计贡献率为80.15%。改革后月均住院患者人次增加,次均住院费与耗材费下降,手术费占比升高,DRG医保盈余升高。结论:改革措施推进了CHS-DRG落地实施,使IC29病组住院费用结构趋于合理化,增加了医院可支配收入,降低了患者就医负担。但体现医务人员劳动技术价值的手术治疗费增幅有限,改革面临可能出现的诸多负性问题,需要进一步研究制定配套政策。

CHS-DRG付费改革对医院医疗质量和运行效率影响的实证分析

[目的]分析北京市某三甲医院在CHS-DRG实际付费改革前、后的医院医疗质量和运行效率的变化情况,评价改革实施效果。[方法]通过Donabedian模型建立指标集,收集其中8个指标2021年4月-2023年3月的住院数据进行中断时间序列分析。[结果]CHS-DRG付费改革后,CMI值在改革时短暂下降了0.04,但后续呈上升趋势(P<0.05),显示在长期受到了政策正向的积极影响;平均住院日在观测期内水平下降0.183天,但改革后趋势显著上升(P<0.05);住院例均费用在改革时显著下降,降低了493.45元,但改革后趋势变为上升;费用消耗指数在改革后变为上升趋势(P<0.05)。[结论]CHS-DRG支付改革推动了技术难度的提升、平均住院日和患者医疗经济负担的即时下降,但改革后长期的时间消耗和费用消耗未得到显著优化。

青蒿查尔酮合成酶(AaCHS)基因家族鉴定及光调控分析

[目的]为了解青蒿(Artemisia annua L.)查尔酮合成酶(chalcone synthase,CHS)基因家族的分子进化特性及其在不同组织部位的表达情况。[方法]从Pfam数据库下载CHS蛋白HMM模型,并使用HUMMER 3.0、Blastp和CD-search鉴定出青蒿基因组中的CHS基因家族成员。采用TBtools、EXPASy、CELLO v.2.5、MEGA 7.0、MEME、SOPMA、SWISSMODEL和PlantCARE等软件对其氨基酸与碱基序列进行生物信息学分析,通过8个不同组织部位的转录组数据对AaCHS基因家族成员进行表达分析。[结果]青蒿基因组中共有16个AaCHS基因家族成员,蛋白结构分析显示AaCHS蛋白质结构并不稳定,将其分为4个组,基因结构分析显示所有AaCHS基因蛋白均具有外显子,数量为2~4,内含子数量为0~2,其中8个AaCHS基因不具有内含子。启动子顺式作用元件分析表明该基因家族成员启动子上含有大量光响应、植物激素响应元件;CD-search验证结果发现每个AaCHS蛋白均有Chal-sti-synt_N结构域。[结论]AaCHS家族成员表达分析结果表明,16个AaCHS基因在不同组织和光处理下表达不同。GO富集结果得到GO二级分类的生物过程和分子功能,生物过程共富集了80条序列;细胞组分共富集了19条序列,其中二级分类过程细胞质中富集了11条序列,数量最多,与亚细胞定位预测结果一致;推测AaCHS基因在细胞质中调控黄酮类化合物的累积。通过青蒿光调控差异表达分析,推测AaCHS7、AaCHS10在青蒿受到红光光处理中起正向调控作用。

多花黄精查尔酮合酶PcCHS的原核表达、亚细胞定位及表达分析

【目的】探究查尔酮合酶(chalcone synthase,PcCHS)基因在多花黄精类黄酮合成中的作用,为后续解析PcCHS功能以及多花黄精新品种选育提供可靠的理论依据。【方法】以多花黄精为cDNA模板,克隆多花黄精PcCHS基因的编码序列,对该基因进行生物信息学分析。通过构建PcCHS的原核表达载体,纯化目的重组蛋白,验证该酶的体外表达活性。利用瞬时超表达体系探究该基因过表达后总黄酮的含量变化。利用Gateway技术构建亚细胞定位载体35S::PcCHS-GFP,通过本氏烟草表达系统确定目的蛋白亚细胞定位情况。【结果】PcCHS基因的开放阅读框为1 251 bp,理论分子量为44.63 kD,等电点为5.89,属于亲水蛋白,与石刁柏(Asparagus officinalis)CHS亲缘关系较近。原核表达实验表明,pET28a-PcCHS经IPTG(异丙基-β-D-硫代半乳糖苷)诱导表达可溶性重组蛋白,Western-blot显示大小约为45 kD,与预期大小一致,且纯化的目的蛋白具有一定的酶活性,能催化对香豆酰辅酶A和丙二酰辅酶A转化为柚皮素查尔酮。此外,PcCHS瞬时超表达中,PcCHS组的表达量显著高于空载K组,总黄酮含量也显著高于空载K组,最高可达1.83倍。亚细胞定位结果显示,该基因在细胞膜和细胞核中发挥作用。【结论】PcCHS基因原核表达的酶具有体外酶活性,其亚细胞定位于细胞膜和细胞核,且瞬时超表达能够显著提高多花黄精叶片总黄酮含量。

Genetic dissection and validation of a major QTL for grain weight on chromosome 3B in bread wheat(Triticum aestivum L.)

Grain weight is one of the key components of wheat(Triticum aestivum L.)yield.Genetic manipulation of grain weight is an efficient approach for improving yield potential in breeding programs.A recombinant inbred line(RIL)population derived from a cross between W7268 and Chuanyu 12(CY12)was employed to detect quantitative trait loci(QTLs)for thousand-grain weight(TGW),grain length(GL),grain width(GW),and the ratio of grain length to width(GLW)in six environments.Seven major QTLs,QGl.cib-2D,QGw.cib-2D,QGw.cib-3B,QGw.cib-4B.1,QGlw.cib-2D.1,QTgw.cib-2D.1 and QTgw.cib-3B.1,were consistently identified in at least four environments and the best linear unbiased estimation(BLUE)datasets,and they explained 2.61 to 34.85%of the phenotypic variance.Significant interactions were detected between the two major TGW QTLs and three major GW loci.In addition,QTgw.cib-3B.1 and QGw.cib-3B were co-located,and the improved TGW at this locus was contributed by GW.Unlike other loci,QTgw.cib-3B.1/QGw.cib-3B had no effect on grain number per spike(GNS).They were further validated in advanced lines using Kompetitive Allele Specific PCR(KASP)markers,and a comparison analysis indicated that QTgw.cib-3B.1/QGw.cib-3B is likely a novel locus.Six haplotypes were identified in the region of this QTL and their distribution frequencies varied between the landraces and cultivars.According to gene annotation,spatial expression patterns,ortholog analysis and sequence variation,the candidate gene of QTgw.cib-3B.1/QGw.cib-3B was predicted.Collectively,the major QTLs and KASP markers reported here provide valuable information for elucidating the genetic architecture of grain weight and for molecular marker-assisted breeding in grain yield improvement.

Genetically modified non-human primate models for research on neurodegenerative diseases

Neurodegenerative diseases(NDs)are a group of debilitating neurological disorders that primarily affect elderly populations and include Alzheimer's disease(AD),Parkinson's disease(PD),Huntington's disease(HD),and amyotrophic lateral sclerosis(ALS).Currently,there are no therapies available that can delay,stop,or reverse the pathological progression of NDs in clinical settings.As the population ages,NDs are imposing a huge burden on public health systems and affected families.Animal models are important tools for preclinical investigations to understand disease pathogenesis and test potential treatments.While numerous rodent models of NDs have been developed to enhance our understanding of disease mechanisms,the limited success of translating findings from animal models to clinical practice suggests that there is still a need to bridge this translation gap.Old World nonhuman primates(NHPs),such as rhesus,cynomolgus,and vervet monkeys,are phylogenetically,physiologically,biochemically,and behaviorally most relevant to humans.This is particularly evident in the similarity of the structure and function of their central nervous systems,rendering such species uniquely valuable for neuroscience research.Recently,the development of several genetically modified NHP models of NDs has successfully recapitulated key pathologies and revealed novel mechanisms.This review focuses on the efficacy of NHPs in modeling NDs and the novel pathological insights gained,as well as the challenges associated with the generation of such models and the complexities involved in their subsequent analysis.

AMME chromosomal region gene 1基因变异矮小相关综合征一例及文献复习

目的探讨1例身材矮小、面中部发育不全患儿的病因,以提高临床医师对特殊矮小综合征的认识。方法收集1例身材矮小、面中部发育不全患儿的临床资料,对患儿及父母行基因检测,并给予患儿常规治疗、随访。结果结合患儿特殊面容及基因检测,诊断为AMMECR1基因变异矮小相关综合征,结合文献复习总结AMMECR1基因变异矮小相关综合征特点。结论AMMECR1基因变异矮小相关综合征是一种罕见的X连锁遗传性疾病,临床主要表现为身材矮小、运动语言落后、肌张力减低、听力损失、面中部发育不全,部分存在心脏改变、腭裂、骨骼改变及椭圆形红细胞增多症、智力落后和肾钙质沉着症。该文报道1例AMMECR1基因新变异引起身材矮小、面中部发育不全患儿的病例资料,结合特殊面容及基因检测,诊断为AMMECR1基因变异矮小相关综合征。AMMECR1基因变异矮小相关综合征是一种罕见的X连锁遗传性疾病,本文初步概括其特点,并结合文献进行分析,以提高临床医师对AMMECR1基因变异矮小相关综合征的诊治。

一份新的玉米永久性失绿突变体chs10的鉴定及基因克隆

【目的】利用60Co-γ射线处理自交系齐319获得了一份新的玉米叶色突变体,对该突变体进行遗传分析、基因定位与克隆,并对候选基因的功能进行初步分析。【方法】以该突变体为亲本,构建遗传分析群体和基因定位群体;通过图位克隆技术获得关键候选基因;利用生物信息学方法分析关键候选基因的结构和进化关系;通过qRT-PCR技术检测候选基因在不同组织中的表达差异;同时运用烟草瞬时表达技术对候选基因进行亚细胞定位表达分析。【结果】鉴定了一份玉米永久性失绿突变体chs10(Permanent chlorosis 10),chs10自V2时期开始,叶片从幼苗基部到顶部逐渐由绿转黄,后期的生长发育过程中不再复绿,并且,整个植株包括叶鞘、叶环、茎秆、苞叶和雄穗也均为黄色。该突变体受一对隐性核基因控制,可稳定遗传,植株生长发育正常,可正常授粉结实。突变基因被定位于玉米第10染色体长臂标记SNP-2和SNP-3之间约0.17 Mb范围内,确定了关键候选基因Zm00001d025860,qRT-PCR结果显示Zm00001d025860在玉米根、茎、叶和叶鞘中均有表达,但在叶片中高表达,亚细胞定位结果显示目标蛋白被定位在细胞膜和叶绿体中。利用STRING预测发现Zm00001d025860与卟啉结合蛋白GUN4基因互作,GUN4与叶绿素合成中的镁离子螯合酶(MgCh)具有反馈调节作用。【结论】Zm00001d025860基因的突变导致突变体chs10叶色的改变,并且Zm00001d025860可能通过参与叶绿素合成途径来调控叶色变化。突变体chs10的发现一方面丰富了玉米叶色突变体研究的基因资源,同时为解析镁离子螯合酶在叶绿素合成途径中的作用机理奠定了材料基础。

RNA sequencing of exosomes secreted by fibroblast and Schwann cells elucidates mechanisms underlying peripheral nerve regeneration

Exosomes exhibit complex biological functions and mediate a variety of biological processes,such as promoting axonal regeneration and functional recove ry after injury.Long non-coding RNAs(IncRNAs)have been reported to play a crucial role in axonal regeneration.Howeve r,the role of the IncRNA-microRNAmessenger RNA(mRNA)-competitive endogenous RNA(ceRNA)network in exosome-mediated axonal regeneration remains unclear.In this study,we performed RNA transcriptome sequencing analysis to assess mRNA expression patterns in exosomes produced by cultured fibroblasts(FC-EXOs)and Schwann cells(SCEXOs).Diffe rential gene expression analysis,Gene Ontology analysis,Kyoto Encyclopedia of Genes and Genomes analysis,and protein-protein intera ction network analysis were used to explo re the functions and related pathways of RNAs isolated from FC-EXOs and SC-EXOs.We found that the ribosome-related central gene Rps5 was enriched in FC-EXOs and SC-EXOs,which suggests that it may promote axonal regeneration.In addition,using the miRWalk and Starbase prediction databases,we constructed a regulatory network of ceRNAs targeting Rps5,including 27 microRNAs and five IncRNAs.The ceRNA regulatory network,which included Ftx and Miat,revealed that exsosome-derived Rps5 inhibits scar formation and promotes axonal regeneration and functional recovery after nerve injury.Our findings suggest that exosomes derived from fibro blast and Schwann cells could be used to treat injuries of peripheral nervous system.

Fine mapping and characterization of stripe rust resistance gene YrAYH in near-isogenic lines derived from a cross involving wheat landrace Anyuehong

Stripe rust,caused by Puccinia striiformis f.sp.tritici(Pst),is a devastating disease in wheat worldwide.Discovering and characterizing new resistance genes/QTL is crucial for wheat breeding programs.In this study,we fine-mapped and characterized a stripe rust resistance gene,YRAYH,on chromosome arm 5BL in the Chinese wheat landrace Anyuehong(AYH).Evaluations of stripe rust response to prevalent Chinese Pst races in near-isogenic lines derived from a cross of Anyuehong and Taichung 29 showed that YrAYH conferred a high level of resistance at all growth stages.Fine mapping using a large segregating population of 9748 plants,narrowed the YRAYH locus to a 3.7 Mb interval on chromosome arm 5BL that included 61 annotated genes.Transcriptome analysis of two NIL pairs identified 64 upregulated differentially expressed genes(DEGs)in the resistant NILs(NILs-R).Annotations indicated that many of these genes have roles in plant disease resistance pathways.Through a combined approach of fine-mapping and transcriptome sequencing,we identified a serine/threonine-protein kinase SRPK as a candidate gene underlying YrAYH.A unique 25 bp insertion was identified in the NILs-R compared to the NILs-S and previously published wheat genomes.An InDel marker was developed and co-segregated with YrAYH.Agronomic trait evaluation of the NILs suggested that YrAYH not only reduces the impact of stripe rust but was also associated with a gene that increases plant height and spike length.

Screening biomarkers for spinal cord injury using weighted gene co-expression network analysis and machine learning

Immune changes and inflammatory responses have been identified as central events in the pathological process of spinal co rd injury.They can greatly affect nerve regeneration and functional recovery.However,there is still limited understanding of the peripheral immune inflammato ry response in spinal cord inju ry.In this study.we obtained microRNA expression profiles from the peripheral blood of patients with spinal co rd injury using high-throughput sequencing.We also obtained the mRNA expression profile of spinal cord injury patients from the Gene Expression Omnibus(GEO)database(GSE151371).We identified 54 differentially expressed microRNAs and 1656 diffe rentially expressed genes using bioinformatics approaches.Functional enrichment analysis revealed that various common immune and inflammation-related signaling pathways,such as neutrophil extracellular trap formation pathway,T cell receptor signaling pathway,and nuclear factor-κB signal pathway,we re abnormally activated or inhibited in spinal cord inju ry patient samples.We applied an integrated strategy that combines weighted gene co-expression network analysis,LASSO logistic regression,and SVM-RFE algorithm and identified three biomarke rs associated with spinal cord injury:ANO10,BST1,and ZFP36L2.We verified the expression levels and diagnostic perfo rmance of these three genes in the original training dataset and clinical samples through the receiver operating characteristic curve.Quantitative polymerase chain reaction results showed that ANO20 and BST1 mRNA levels were increased and ZFP36L2 mRNA was decreased in the peripheral blood of spinal cord injury patients.We also constructed a small RNA-mRNA interaction network using Cytoscape.Additionally,we evaluated the proportion of 22 types of immune cells in the peripheral blood of spinal co rd injury patients using the CIBERSORT tool.The proportions of naive B cells,plasma cells,monocytes,and neutrophils were increased while the proportions of memory B cells,CD8^(+)T cells,resting natural killer cells,resting dendritic cells,and eosinophils were markedly decreased in spinal cord injury patients increased compared with healthy subjects,and ANO10,BST1 and ZFP26L2we re closely related to the proportion of certain immune cell types.The findings from this study provide new directions for the development of treatment strategies related to immune inflammation in spinal co rd inju ry and suggest that ANO10,BST2,and ZFP36L2 are potential biomarkers for spinal cord injury.The study was registe red in the Chinese Clinical Trial Registry(registration No.ChiCTR2200066985,December 12,2022).

Biotin-modified Galactosylated Chitosan-gene Carrier in Hepatoma Cells Targeting Delivery

Our previous studies have successfully grafted biotin and galactose onto chitosan(CS)and synthesized biotin modified galactosylated chitosan(Bio-GC).The optimum N/P ratio of Bio-GC and plasmid DNA was 3:1.At this N/P ratio,the transfection efficiency in the hepatoma cells was the highest with a slow release effect.Bio-GC nanomaterials exhibit the protective effect of preventing the gene from nuclease degradation,and can target the transfection into hepatoma cells by combination with galactose and biotin receptors.The transfection rate was inhibited by the competition of galactose and biotin.Bio-GC nanomaterials were imported into cells’cytoplasm by their receptors,followed by the imported exogenous gene transfected into the cells.Bio-GC nanomaterials can also cause inhibitory activity in the hepatoma cells in the model of orthotopic liver transplantation in mice,by carrying the gene through the blood to the hepatoma tissue.Taken together,bio-GC nanomaterials act as gene vectors with the activity of protecting the gene from DNase degradation,improving the rate of transfection in hepatoma cells,and transporting the gene into the cytoplasm in vitro and in vivo.Therefore,they are efficient hepatoma-targeting gene carriers.

Cost-Effective Method of Gene Synthesis by Sequencing from Microchip-Derived Oligos for Droplet Cloning

Gene synthesis has provided important contributions in various fields including genomics and medicine. Current genes are 7 - 30 cents depending on the assembly and sequencing methods performed. Demand for gene synthesis has been increasing for the past few decades, yet available methods remain expensive. A solution to this problem involves microchip-derived oligonucleotides (oligos), an oligo pool with a substantial number of oligo fragments. Microchips have been proposed as a tool for gene synthesis, but this approach has been criticized for its high error rate during sequencing. This study tests a possible cost-effective method for gene synthesis utilizing fragment assembly and golden gate assembly, which can be employed for quicker manufacturing and efficient execution of genes in the near future. The droplet method was tested in two trials to determine the viability of the method through the accuracy of the oligos sequenced. A preliminary research experiment was performed to determine the efficacy of oligo lengths ranging from two to four overlapping oligos through Gibson assembly. Of the three oligo lengths tested, only two fragment oligos were correctly sequenced. Two fragment oligos were used for the second experiment, which determined the efficacy of the droplet method in reducing gene synthesis cost and speed. The first trial utilized a high-fidelity polymerase and resulted in 3% correctly sequenced oligos, so the second trial utilized a non-high-fidelity polymerase, resulting in 8% correctly sequenced oligos. After calculating, the cost of gene synthesis lowers down to 0.8 cents/base. The final calculated cost of 0.8 cents/base is significantly cheaper than other manufacturing costs of 7 - 30 cents/base. Reducing the cost of gene synthesis provides new insight into the cost-effectiveness of present technologies and protocols and has the potential to benefit the fields of bioengineering and gene therapy.

Genetic mechanism of body size variation in groupers:Insights from phylotranscriptomics

Animal body size variation is of particular interest in evolutionary biology,but the genetic basis remains largely unknown.Previous studies have shown the presence of two parallel evolutionary genetic clusters within the fish genus Epinephelus with evident divergence in body size,providing an excellent opportunity to investigate the genetic basis of body size variation in vertebrates.Herein,we performed phylotranscriptomic analysis and reconstructed the phylogeny of 13 epinephelids originating from the South China Sea.Two genetic clades with an estimated divergence time of approximately 15.4 million years ago were correlated with large and small body size,respectively.A total of 180 rapidly evolving genes and two positively selected genes were identified between the two groups.Functional enrichment analyses of these candidate genes revealed distinct enrichment categories between the two groups.These pathways and genes may play important roles in body size variation in groupers through complex regulatory networks.Based on our results,we speculate that the ancestors of the two divergent groups of groupers may have adapted to different environments through habitat selection,leading to genetic variations in metabolic patterns,organ development,and lifespan,resulting in body size divergence between the two locally adapted populations.These findings provide important insights into the genetic mechanisms underlying body size variation in groupers and species differentiation.

Increasingβ-hexosaminidase A activity using genetically modified mesenchymal stem cells

GM2 gangliosidoses are a group of autosomal-recessive lysosomal storage disorde rs.These diseases result from a deficiency of lysosomal enzymeβ-hexosaminidase A(HexA),which is responsible for GM2 ganglioside degradation.HexA deficiency causes the accumulation of GM2-gangliosides mainly in the nervous system cells,leading to severe progressive neurodegeneration and neuroinflammation.To date,there is no treatment for these diseases.Cell-mediated gene therapy is considered a promising treatment for GM2 gangliosidoses.This study aimed to evaluate the ability of genetically modified mesenchymal stem cells(MSCs-HEXA-HEXB)to restore HexA deficiency in Tay-Sachs disease patient cells,as well as to analyze the functionality and biodistribution of MSCs in vivo.The effectiveness of HexA deficiency cross-correction was shown in mutant MSCs upon intera ction with MSCs-HEXA-HEXB.The results also showed that the MSCs-HEXA-HEXB express the functionally active HexA enzyme,detectable in vivo,and intravenous injection of the cells does not cause an immune response in animals.These data suggest that genetically modified mesenchymal stem cells have the potentials to treat GM2 gangliosidoses.

Application of Transgenic Technology in Identification for Gene Function on Grasses

Perennial grasses have developed intricate mechanisms to adapt to diverse environments,enabling their resistance to various biotic and abiotic stressors.These mechanisms arise from strong natural selection that contributes to enhancing the adaptation of forage plants to various stress conditions.Methods such as antisense RNA technology,CRISPR/Cas9 screening,virus-induced gene silencing,and transgenic technology,are commonly utilized for investigating the stress response functionalities of grass genes in both warm-season and cool-season varieties.This review focuses on the functional identification of stress-resistance genes and regulatory elements in grasses.It synthesizes recent studies on mining functional genes,regulatory genes,and protein kinase-like signaling factors involved in stress responses in grasses.Additionally,the review outlines future research directions,providing theoretical support and references for further exploration of(i)molecular mechanisms underlying grass stress responses,(ii)cultivation and domestication of herbage,(iii)development of high-yield varieties resistant to stress,and(iv)mechanisms and breeding strategies for stress resistance in grasses.

Genes controlling grain chalkiness in rice

With rising living standards,there is an increasing demand for high-quality rice.Rice quality is mainly defined by milling quality,appearance quality,cooking and eating quality,and nutrition quality.Among them,chalkiness is a key trait for appearance quality,which adversely affects cooking and eating quality,head rice yield,and commercial value.Therefore,chalkiness is undesirable,and reducing chalkiness is a major goal in rice quality improvement.However,chalkiness is a complex trait jointly influenced by genetic and environmental factors,making its genetic study and precision improvement a huge challenge.With the rapid development of molecular techniques,much knowledge has been gained about the genes and molecular networks involved in chalkiness formation.The present review describes the major environmental factors affecting chalkiness and summarizes the quantitative trait loci(QTL)associated with chalkiness.More than 150 genes related to chalkiness formation have been reported.The functions of the genes regulating chalkiness,primarily those involved in starch synthesis,storage protein synthesis,transcription regulation,organelle development,grain shape regulation,and hightemperature response,are described.Finally,we identify the challenges associated with genetic improvement of chalkiness and suggest potential strategies.Thus,the review offers insight into the molecular dynamics of chalkiness and provides a strong basis for the future breeding of high-quality rice varieties.

Molecular Detection of Resistance and Virulence Genes in Coagulase Negative Staphylococci Isolated from Blood Cultures at the University Teaching Hospital of Bouake

Introduction: Coagulase-negative staphylococci (CoNS) are currently recognized as genuine pathogens. However, little is known about the resistance and virulence genes that explain their pathogenicity in hospitals in Cte d'Ivoire. The aim of this study was to contribute to the genotypic identification of resistance and virulence genes in CoNS isolated from blood cultures at the University Teaching Hospital (CHU) of Bouak, in order to improve patient management. Material and Methods: This was a descriptive study conducted from September to December 2023. The CoNS isolates studied came from the collection of strains isolated from blood cultures of febrile patients hospitalized or attending consultations at the CHU of Bouak. The strains were analyzed using conventional simplex PCR. Results: Of the 45 isolates analyzed, 46.7% carried both the aacA-aphD and tetK genes and 40% carried the mecA gene. With regard to virulence genes, only the LukS-PV gene was observed in S. epidermidis and S. haemolyticus isolates. Conclusion: The high prevalence of CoNS isolates carrying the mecA gene and the presence of virulence genes observed in this study give cause for concern in hospitals. It is important to develop comprehensive surveillance strategies against nosocomial and multi-resistant infections at the CHU of Bouak.