大豆饱和脂肪酸组分改良研究进展

为了更好地满足消费者的需要,遗传改良豆油中脂肪酸含量已经取得很大进展,并有3个油分改良的大豆品种已经商品化,其油分中亚麻酸的含量已经从原来的8%降到了1%,油酸含量也已从25%增加到80%,棕榈酸从11%降到小于4%。传统育种和基因工程育种都是遗传改良大豆油的手段。阐述了遗传改良、基因型和表现型的选择等多方法对脂肪酸的影响,总结了大豆饱和脂肪酸组翻改良的主要进展。     

Genetic diversity for grain nutrients in wild emmer wheat: potential for wheat improvement

Background and Aims

Micronutrient malnutrition, particularly zinc and iron deficiency, afflicts over three billion people worldwide due to low dietary intake. In the current study, wild emmer wheat (Triticum turgidum ssp. dicoccoides), the progenitor of domesticated wheat, was tested for (1) genetic diversity in grain nutrient concentrations, (2) associations among grain nutrients and their relationships with plant productivity, and (3) the association of grain nutrients with the eco-geographical origin of wild emmer accessions.

Methods

A total of 154 genotypes, including wild emmer accessions from across the Near Eastern Fertile Crescent and diverse wheat cultivars, were characterized in this 2-year field study for grain protein, micronutrient (zinc, iron, copper and manganese) and macronutrient (calcium, magnesium, potassium, phosphorus and sulphur) concentrations.

Key Results

Wide genetic diversity was found among the wild emmer accessions for all grain nutrients. The concentrations of grain zinc, iron and protein in wild accessions were about two-fold greater than in the domesticated genotypes. Concentrations of these compounds were positively correlated with one another, with no clear association with plant productivity, suggesting that all three nutrients can be improved concurrently with no yield penalty. A subset of 12 populations revealed significant genetic variation between and within populations for all minerals. Association between soil characteristics at the site of collection and grain nutrient concentrations showed negative associations between soil clay content and grain protein and between soil-extractable zinc and grain zinc, the latter suggesting that the greatest potential for grain nutrient minerals lies in populations from micronutrient-deficient soils.

Conclusions

Wild emmer wheat germplasm offers unique opportunities to exploit favourable alleles for grain nutrient properties that were excluded from the domesticated wheat gene pool.     

Rapid pre-screening of cervical smears as a method of internal quality control in a cervical screening programme

Objective:  To evaluate the performance of rapid pre-screening (RPS) as a method of internal quality control in the cytopathological examination of cervical smears for cervical cancer screening.
Methods:  The sample consisted of 6135 cervical smears submitted to RPS and routine screening (RS) methods. The smears classified as negative in RPS and RS were considered final diagnoses, and were not, therefore, submitted to any additional review. The smears identified as suspect or unsatisfactory according to RPS were analysed separately by two different cytologists irrespective of the diagnosis reached in RS. Smears considered abnormal or unsatisfactory at RS were also reviewed. When both cytologists issued concordant diagnoses, this was considered the final diagnosis. Discordant results were analysed by a third cytologist and a consensus meeting was held to define the final diagnosis.
Results:  Taking abnormalities detected by RS as the denominator, RPS had a sensitivity of 63.0% for the detection of all abnormal smears and 96.7% for high grade squamous intraepithelial lesion (HSIL). When compared with the final diagnosis, sensitivity of RPS for all abnormal smears was 74.9% and for HSIL 95.0%. Of the 529 abnormal smears confirmed in the final diagnosis, 2.15% were detected only by the RPS.
Conclusion:  RPS is an effective alternative method of internal quality control with high sensitivity for the detection of more severe lesions. It also permits monitoring of the laboratory rate of false-negative results, and allows constant evaluation of the performance both of the pre-screening and RS cytologists.     

兔卵巢组织石蜡切片技术的改良

针对常规石蜡切片方法步骤繁多,耗时长,所用的二甲苯试剂对人体健康有较大毒害性的缺陷,探讨提高制作兔卵巢组织石蜡切片质量的方法。试验从脱水和透明环节进行技术改良,用正丁醇与无水乙醇混合剂取代常规的脱水剂和透明剂。该混合剂具有良好的脱水和透明作用。实验结果表明：通过该技术改良,镜下观察组织结构清晰可辨、颜色鲜艳、对比度好、层次分明,组织切片效果良好。试验改良技术的工艺简单,具有质优、省时、快捷和实用性较好等优点,有推广应用价值。     

Recent insights into cotton functional genomics: progress and future perspectives

Functional genomics has transformed from futuristic concept to well‐established scientific discipline during the last decade. Cotton functional genomics promise to enhance the understanding of fundamental plant biology to systematically exploit genetic resources for the improvement of cotton fibre quality and yield, as well as utilization of genetic information for germplasm improvement. However, determining the cotton gene functions is a much more challenging task, which has not progressed at a rapid pace. This article presents a comprehensive overview of the recent tools and resources available with the major advances in cotton functional genomics to develop elite cotton genotypes. This effort ultimately helps to filter a subset of genes that can be used to assemble a final list of candidate genes that could be employed in future novel cotton breeding programme. We argue that next stage of cotton functional genomics requires the draft genomes refinement, re‐sequencing broad diversity panels with the development of high‐throughput functional genomics tools and integrating multidisciplinary approaches in upcoming cotton improvement programmes.     

Surface-Matrix Screening Identifies Semi-specific Interactions that Improve Potency of a Near Pan-reactive HIV-1-Neutralizing Antibody

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细菌双杂交系统的改进

解析蛋白质之间的相互作用,对理解调控和代谢等生物学过程具有重要意义。其中基于互补腺苷酸环化酶功能的细菌双杂交系统是一种研究蛋白质之间相互作用的有效手段。本文在利用该系统时发现存在假阳性高的缺陷。进一步报告基因活性分析表明产生假阳性的原因是不同克隆的生理状态影响了LacZ的输出,即lacZ启动子除了受cAMP信号分子的控制,还受到其他调控蛋白的直接或间接的调控。为了降低生理因素对报告基因的影响,我们向该系统引入用多拷贝lacZ启动子控制的gfp报告基因。这不仅通过增加lacZ启动子的数量,弱化了生理因素的影响;还实现了第二个报告基因gfp与lacZ同时报告蛋白质之间的相互作用情况,提高了输出的准确性。系统的实验验证表明,我们改进的细菌双杂交系统的灵敏性确实得到大幅提高。     

Genetics of grain amaranths

Summary Two landrace populations of Amaranthus cruentus L. were crossed to generate F₂ populations for quantitative genetic analyses of variation. Evidence for significant inbreeding depression in comparisons of F₁ and F₂generation means suggested some role of nonadditive gene action for days to first anthesis, leaf length, leaf width, petiole length, plant height, panicle length, and panicle weight. A pooled F₂ population was subjected to bidirectional mass selection for time of first anthesis (two cycles) and leaf length (one cycle). Responses to selection were asymmetrical and the second cycle response for anthesis time was smaller than for the first cycle. Overall, selection gains were significant and gave estimates of heritability in the range of 0.35 to 0.66 for anthesis time and 0.08 to 0.19 for leaf length. This suggested a large additive term in the total genetic variance especially for anthesis time where early and late flowering selection lines diverged by 20.5 days.Correlations between the selected traits (anthesis time, leaf length) and single plant yield or yield components were also studied to evaluate correlated responses to selection. Selection for optimal flowering time in amaranth cultivation areas is very likely to result in rapid yield improvement.