An efficient method for measuring copy number variation applied to improvement of nematode resistance in soybean

Copy number variation (CNV) is implicated in important traits in multiple crop plants, but can be challenging to genotype using conventional methods. The Rhg1 locus of soybean, which confers resistance to soybean cyst nematode (SCN), is a CNV of multiple 31.2‐kb genomic units each containing four genes. Reliable, high‐throughput methods to quantify Rhg1 and other CNVs for selective breeding were developed. The CNV genotyping assay described here uses a homeologous gene copy within the paleopolyploid soybean genome to provide the internal control for a single‐tube TaqMan copy number assay. Using this assay, CNV in breeding populations can be tracked with high precision. We also show that extensive CNV exists within Fayette, a released, inbred SCN‐resistant soybean cultivar with a high copy number at Rhg1 derived from a single donor parent. Copy number at Rhg1 is therefore unstable within a released variety over a relatively small number of generations. Using this assay to select for individuals with altered copy number, plants were obtained with both increased copy number and increased SCN resistance relative to control plants. Thus, CNV genotyping technologies can be used as a new type of marker‐assisted selection to select for desirable traits in breeding populations, and to control for undesirable variation within cultivars.     

Variability and divergence in Pongamia pinnata (L.) Pierre germplasm – a candidate tree for biodiesel

Three explorations were undertaken in South East Coastal zone of India covering parts of Andhra Pradesh (AP) and Orissa states to collect Pongamia pinnata (L.) Pierre germplasm during March–June 2007. A total of 123 accessions were collected and seed data recorded were analyzed for morphometric traits viz., seed length, seed width, seed thickness, 100‐seed weight and oil content. Variation in the collected germplasm was analyzed using anova , simple measures of variation and D² statistics. Significant genetic variability between seed traits and oil content and association among the seed traits was recorded. Phenotypic variance was higher than genotypic variance for all the characters indicating dominant role of environment. High heritability (broad sense) for 100‐seed weight (97.6%) and oil content (86.7%) indicated the reliability of these characters as selection criteria for plus trees. Genetic gain was maximum for 100‐seed weight (62.6%) followed by oil content (30.5%). D² analysis grouped the accessions into 12 clusters. Cluster XII and cluster IX were the most diverse based on the intercluster distance. Based on the observed diversity, Chittoor, Srikakulam and Adilabad districts of AP are most suitable for collecting diverse germplasm lines and also for in situ conservation.     

高雄山虫草无性型—细脚拟青霉的研究进展

高雄山虫草 (CordycepstakaomontanaYakushiji&Kumazawa)及其无性型细脚拟青霉 [Paecilomycestenuipes(Peck)Samson]是近年来在日本和韩国研究开发较为成功的一个虫草资源。文章综述了它们在生物学、药理学、毒理学、化学及人工培养等方面的研究进展 ,为国内进一步开发利用这一虫草资源提供参考。     

Against autonomy: How proposed solutions to the problems of living wills forgot its underlying principle

Significant criticisms have been raised regarding the ethical and psychological basis of living wills. Various solutions to address these criticisms have been advanced, such as the use of surrogate decision makers alone or data science-driven algorithms. These proposals share a fundamental weakness: they focus on resolving the problems of living wills, and, in the process, lose sight of the underlying ethical principle of advance care planning, autonomy. By suggesting that the same sweeping solutions, without opportunities for choice, be applied to all, individual patients are treated as population-level groups—as a theoretical patient who represents a population, not the specific patient crafting his or her individualized future care plans. Instead, advance care planning can be improved through a multimodal approach that both mitigates cognitive biases and allows for customization of the decision-making process by allowing for the incorporation of a variety of methods of advance care planning.     

A removable virus vector suitable for plant genome editing

Plant genome editing is achieved by the expression of sequence‐specific nucleases (SSNs). RNA virus vector‐mediated expression of SSNs is a promising approach for transgene integration‐free targeted mutagenesis in plants. However, the removal of virus vectors from infected plants is challenging because no antiviral drugs are available against plant viruses. Here, we developed a removable RNA virus vector that carries the target site of tobacco microRNA398 (miR398) whose expression is induced during shoot regeneration. In the inoculated leaves in which expression of miR398 is not induced, insertion of the miR398 target site did not affect the practicability of the virus vector. When shoots were regenerated from the infected leaves, miR398 was expressed and viral RNA was eliminated. The virus vector successfully expressed SSNs in inoculated leaves, from which virus‐free genome‐edited plants were regenerated via tissue culture.     

丙型病毒性肝炎母婴传播的现状、进展及未来

丙型肝炎病毒(HCV)可引起急性和慢性病毒性肝炎,可发展成肝纤维化、肝硬化,甚至肝细胞癌。HCV经典的传播途径为经血液或血液制品传播,但1992年后献血员HCV的筛检已使输血后肝炎大为减少。在发达国家,HCV传播途径正在发生改变,儿童非血液制品的丙肝日渐增多。母婴间宫内、分娩时及产后感染已成为当前及今后的重要研究课题。研究证实,HCV可经胎盘引起胎儿感染,宫内感染是HCV传播的一条重要途径。尽管人们对HCV母婴传播中所涉及的风险因素逐渐明确,但到目前为止对具体的传播机制和传播时机仍知之甚少。我们就丙型病毒性肝炎母婴传播的现状、进展及未来做简要综述。     

挥发性有机化合物(VOCs)采样方法的研究进展

对近年来国内外挥发性有机化合物（VOCs）采集方法的研究进展进行了综合和概括。对VOCs几种主要的采样方法包括顶空收集法、液液萃取法、超临界流体萃取、吸附剂收集法、吹扫捕集法、画相微萃取等技术进行了阐述和比较,提出应根据实验材料的特性选择合适的采样方法,旨在为应用VOCs的采集方法及相关研究提供参考和借鉴。     

Identification of the phosphorylation targets of symbiotic receptor‐like kinases using a high‐throughput multiplexed assay for kinase specificity

Detecting the phosphorylation substrates of multiple kinases in a single experiment is a challenge, and new techniques are being developed to overcome this challenge. Here, we used a multiplexed assay for kinase specificity (MAKS) to identify the substrates directly and to map the phosphorylation site(s) of plant symbiotic receptor‐like kinases. The symbiotic receptor‐like kinases nodulation receptor‐like kinase (NORK) and lysin motif domain‐containing receptor‐like kinase 3 (LYK3) are indispensable for the establishment of root nodule symbiosis. Although some interacting proteins have been identified for these symbiotic receptor‐like kinases, very little is known about their phosphorylation substrates. Using this high‐throughput approach, we identified several other potential phosphorylation targets for both these symbiotic receptor‐like kinases. In particular, we also discovered the phosphorylation of LYK3 by NORK itself, which was also confirmed by pairwise kinase assays. Motif analysis of potential targets for these kinases revealed that the acidic motif xxxsDxxx was common to both of them. In summary, this high‐throughput technique catalogs the potential phosphorylation substrates of multiple kinases in a single efficient experiment, the biological characterization of which should provide a better understanding of phosphorylation signaling cascade in symbiosis.     

Flexible chromosome painting based on multiplex PCR of oligonucleotides and its application for comparative chromosome analyses in Cucumis

Chromosome painting is a powerful technique for chromosome and genome studies. We developed a flexible chromosome painting technique based on multiplex PCR of a synthetic oligonucleotide (oligo) library in cucumber (Cucumis sativus L., 2n = 14). Each oligo in the library was associated with a universal as well as nested specific primers for amplification, which allow the generation of different probes from the same oligo library. We were also able to generate double‐stranded labelled oligos, which produced much stronger signals than single‐stranded labelled oligos, by amplification using fluorophore‐conjugated primer pairs. Oligos covering cucumber chromosome 1 (Chr1) and chromosome 4 (Chr4) consisting of eight segments were synthesized in one library. Different oligo probes generated from the library painted the corresponding chromosomes/segments unambiguously, especially on pachytene chromosomes. This technique was then applied to study the homoeologous relationships among cucumber, C. hystrix and C. melo chromosomes based on cross‐species chromosome painting using Chr4 probes. We demonstrated that the probe was feasible to detect interspecies chromosome homoeologous relationships and chromosomal rearrangement events. Based on its advantages and great convenience, we anticipate that this flexible oligo‐painting technique has great potential for the studies of the structure, organization, and evolution of chromosomes in any species with a sequenced genome.