Copy number and zygosity determination of transgenic rapeseed by droplet digital PCR

Establishing an accurate and rapid method for copy number and zygosity determination can accelerate genetic engineering research process. In this study, droplet digital PCR (ddPCR), an emerging DNA absolute quantification technology, was used to identify single-copy homozygous transgenic lines from a batch of T0 transgenic rapeseed harboring 11 exogenous elements. Copy number of exogenous gene was evaluated in T0 generation based on calculated ratio between transgene and reference CruA gene, single-copy transformants were selected for selfing followed by subsequent zygosity analysis. Single-copy homozygous transgenic plants were successfully screened out in T1 generation by ddPCR.Segregation analysis with T2 seedlings verified that identification results of ddPCR were accurate and reliable. This study provides a novel rapid and accurate method for copy number and zygosity determination in transgenic rapeseed which overcomes disadvantages of traditional Southern analysis and recently developed real-time quantitative method.

The evolution of China’s regulation of agricultural biotechnology

To ensure safe use of genetically modified organisms(GMOs),since 1993,China has made great efforts to establish and improve the safety regulatory system for GMOs.Here,we summarize and analyze the regulatory framework of agricultural GMOs,and the progress in regulatory approval of GM crops in China.In general,the development of GMO safety regulations underwent four stages:exploration(1993–2000),development(2001–2010),improvement(2011–2020)and current(2021-present)stage.The first formal regulation was promulgated in 1993,which provided a basis for further development of the regulations,during the exploration stage,when insect-resistant GM cotton,expressing genes from Bacillus thuringiensis(Bt),was approved for cultivation.During the development stage,the Chinese government issued a series of administrative measures,which covered almost all the fields relative to GMO safety when the basic regulatory system was established.Along with the controversy over GMO safety,the regulations have been further,and greatly improved,during improvement stage.From 2021,a few additional revisions have been made,and meanwhile,the new regulation on gene-edited crops was introduced with the development of biotechnology,forming a relative complete regulation and law system for China.The well-developed GMO regulations establishes a firm basis for safe use of GM crops in China.Currently,GM cotton and GM papaya have been widely grown on a large scale in China that have brought great economic and ecological benefits.In addition,12 corn events,3 soybean events,and 2 rice events have also obtained biosafety certification,but presently,these lines have yet to enter commercial production.However,several GM soybean and corn events have entered pilot industrialization,and can soon be expected to be commercially grown in China.In addition to planting,six GM crops,including soybean,corn,cotton,canola,papaya and sugar beet,with a total of 64 events,have been approved for import as processing material in China.

国际医疗卫生体制:模式、规律与启示

基于当前我国医改领域存在的薄弱环节和若干争论,本文选取美国、英国、德国、新加坡作为不同医疗卫生体制模式国家的代表,从医疗服务、医疗保障、管理服务三方面梳理了四国医疗卫生体制运行机制,并归纳了其中展现的医疗卫生体制的同质性规律。基于国际规律,回应了对于当前我国医改中的若干争论:对于“主体”和“方式”的异质性不必过于纠结,而其内在机理则不应被忽略。在我国医改发展的具体建议方面,本文提出应提升基层医疗服务供给能力,完善分级诊疗体系;加强医保调控能力,构建全链条的医保健康管理体系;增强社会力量介入医疗卫生体制的能力,营造竞争性氛围;完善组织管理机制建设,加强医疗协同能力。