Ingestion of proteoglycan fraction from shark cartilage increases serum inhibitory activity against matrix metalloproteinase-9 and suppresses development of N-nitrosobis(2-oxopropyl)amine-induced pancreatic duct carcinogenesis in hamster

A water extract of shark cartilage was fractionated into acidic and basic fractions by preparative isoelectric focusing on the basis of the amphoteric nature of samples. The acidic fraction was further fractionated into ethanol-soluble and -precipitate fractions. After the carcinogenesis treatment using N-nitrosobis(2-oxopropyl)amine, hamsters received a diet containing each fraction or purified chondroichin sulfate to give 0.4% (w/w) for 50 days. Only administration of the acidic ethanol-precipitate-fraction-containing diet significantly increased serum inhibitory activity against matrix metalloproteinase (MMP)-9 and reduced the number of adenocarcinomas in the pancreatic duct. The active fraction predominantly consisted of chondroichin sulfate-containing proteoglycan. However, the purified chondroichin sulfate had no significant activity. These results suggest that the protein moiety of the proteoglycan might be involved in the increase of serum inhibitory activity against MMP-9 and suppression of pancreatic carcinogenesis in hamster.     

小麦种子发育期麦谷蛋白的累积

用SDS-PAGE分析表明:小麦开花后7d出现LMW麦谷蛋白,13d出现HMW麦谷蛋白;花后28d是麦谷蛋白累积的高峰期,36d麦谷蛋白积累量达最大值。麦谷蛋白直接决定小麦面筋的弹性和强度,所以小麦最佳收获期应在开花36d以后。如果过早收获,则会降低麦谷蛋白含量,影响小麦的加工品质。     

海洋多肽功能活性与氨基酸组成的研究进展

海洋生态系统具有高压高盐、常年低温低光照、营养寡且竞争大的特点,因此海洋生物在其生长与代谢过程中产生了大量化学结构特殊、生理活性与功能特殊的物质。其中,海洋生物活性多肽因具有抗高血压、抗氧化、抗凝血以及抗菌等活性,引起了研究者的极大兴趣。目前,从鱼类、贝类、甲壳类等动物中提取的生物多肽或类似物,部分已上市或已进入临床试验阶段。本文主要对这些生物多肽在功能性食品、营养食品和药物中的作用进行综述。     

Genomic evaluation using SNP‐ and haplotype‐based genomic relationship matrices in a closed line of Duroc pigs

A simulation analysis and real phenotype analysis were performed to evaluate the impact of three different relationship matrices on heritability estimation and prediction accuracy in a closed‐line breeding of Duroc pigs. The numerator relationship matrix (NRM), single nucleotide polymorphism (SNP)‐based genomic relationship matrix (GRM) (G_S), and haplotype‐based GRM (G_H) were applied in this study. We used PorcineSNP60 genotype array data (38 114 SNPs) of 831 Duroc pigs with four selection traits. In both heritability estimation and prediction accuracy, the accuracy depended on the number of animals with records. For heritability estimation, a large difference in the results among three relationship matrices was not shown, but the trend of the estimated heritabilities between GRMs, that is G_S < G_H, was shown in this population. For the accuracy of prediction values in test animals, the accuracies of prediction values obtained by two GRMs were higher than that by the NRM in this population. The accuracies obtained by GRMs using animals with no records were lower than that by the NRM using animals with their performance records, but were close to that by the NRM using animals with full‐sib testing records.     

基于农用地分等的基本农田保护空间规划方法研究

耕地中直接影响到粮食安全的是基本农田,实施耕地保护实质上就是实施基本农田保护。针对当前基本农田保护规划中存在的问题,以及本轮土地利用规划修编的特点和要求,考虑土地利用数据共享原则,对在基本农田保护规划中充分利用农用地分等成果进行了探讨,即在进行基本农田保护空间布局过程中,把农用地综合等作为一个重要因素加以考虑。在考虑粮食安全的基础上,再依据基本农田的内涵,建立了以基本农田保护规划决策模型为核心的技术方法。通过熵权系数法、理想点法与GIS技术的结合,基于Mapbasic编程并在Mapinfo平台上试验,建立了一套基本农田保护空间规划的技术路线,完成了从专业模型分析到规划图自动生成的全过程,实现了基本农田规划编制的决策支持和决策可视化,使规划成果更加科学合理。通过在济南市的实证,取得了令人满意的结果。     

稻瘟病菌一个假定的漆酶基因功能分析

漆酶可能是病原真菌毒力因子之一。稻瘟病菌基因组共有16个假定的漆酶类基因,对其中的Mgg_00551.5进行了生物信息学和分子遗传学分析,以明确其功能。生物信息学分析表明该漆酶是具有3个多铜氧化酶结构域、可以分泌到胞外的蛋白。经基因敲除表明,Mgg_00551.5功能缺失突变体ΔMG0551-13的漆酶活性比野生型菌株稍低,但是其生长速度、产孢能力、致病性等方面与野生型菌株相比均无明显差异,可能是功能冗余所致。进一步的双突变或多突变可能是明确漆酶功能的重要方法。