极小种群野生植物海南风吹楠的遗传多样性研究

为探讨海南风吹楠(Horsfieldiahainanensis)的濒危原因,利用限制性酶切位点相关的DNA测序技术(RAD-seq)开发单核苷酸多态性(SNPs),评估居群的遗传多样性和遗传结构。结果表明,海南风吹楠的遗传多样性较低(Ho=0.167),其中BWL居群表现出最高的遗传多样性;居群间存在中等程度的遗传分化(Fst=0.120)。Structure分析表明居群的最佳聚类值为2,但个别居群的遗传结构混杂,Mantel检测结果也表明遗传距离和地理距离没有相关性(r=0.733,P0.075)。自身更新能力低以及过度的人为活动干扰,可能是导致其濒危的主要原因。建议加强对遗传多样性高的居群(BWL和YGL)进行就地保护;对生境破坏严重的居群(EXL和DLS)进行近地或迁地保护,以增加居群间的基因交流,同时构建核心种质,防止遗传资源丢失加剧。     

Molecular underpinnings of the early brain developmental response to differential feeding in the honey bee Apis mellifera

Brain differential morphogenesis in females is one of the major phenotypic manifestations of caste development in honey bees. Brain diphenism appears at the fourth larval phase as a result of the differential feeding regime developing females are submitted during early phases of larval development. Here, we used a forward genetics approach to test the early brain molecular response to differential feeding leading to the brain diphenism observed at later developmental phases. Using RNA sequencing analysis, we identified 53 differentially expressed genes (DEGs) between the brains of queens and workers at the third larval phase. Since miRNAs have been suggested to play a role in caste differentiation after horizontal and vertical transmission, we tested their potential participation in regulating the DEGs. The miRNA-mRNA interaction network, including the DEGs and the royal- and worker-jelly enriched miRNA populations, revealed a subset of miRNAs potentially involved in regulating the expression of DEGs. The interaction of miR-34, miR-210, and miR-317 with Takeout, Neurotrophin-1, Forked, and Masquerade genes was experimentally confirmed using a luciferase reporter system. Taken together, our results reconstruct the regulatory network that governs the development of the early brain diphenism in honey bees.     

竹叶菜的组织培养研究

竹叶菜为百合科鹿药属一种多年生草本植物,因做菜口感好,且营养丰富、药用价值高而成为深受人们喜爱的一种野生蔬菜.有关竹叶菜及其同属的组织培养研究均未见报道.本文以竹叶菜的顶芽为外植体,通过器官发生途径,初步探索了竹叶菜的组织培养技术,结果表明:芽诱导的合适培养基为:MS +6-BA 1.5 +NAA 0.05+0.6％琼脂+3％蔗糖;芽继代培养的合适培养基为:MS+6-BA 1.2 +NAA 0.05 +0.6％琼脂+3％蔗糖;无菌小苗生根的合适培养基为:MS+ IAA 1.5+ NAA 0.2+ 0.6％琼脂+3％蔗糖.为竹叶菜今后较大规模地栽培或生产提供种苗及技术贮备,为实现竹叶菜资源的可持续性开发利用奠定了基础.     

Proximity association in polygynous western black crested gibbons (Nomascus concolor jingdongensis): network structure and seasonality

We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons (Nomascus concolor) using social network analysis. The spatial proximity changed seasonally and was affected by temperature and rainfall. Preferred proximity association was not distributed randomly among individuals. Kinship was one explanation for the social structure, as offspring preferred to maintain close proximity with their mothers. The proximity of infants to mothers decreased with age, and independent offspring had lower proximity to mothers than dependent ones. We found that the adult male had different proximity relationships with two different adult females. The frequency of proximity between the male and the infant-carrying female was significantly higher than that between the male and the female who had immigrated carrying one offspring of uncertain paternity into the group. Infanticide avoidance and/or predation protection for dependent infants might explain the proximity relationship differences. Temperature influenced group proximity association, with individual proximity increasing in the cold months and decreasing in the hot months. Group proximity decreased in months with higher anthropogenic disturbance.     

Blockage of glucocorticoid receptors during memory acquisition, retrieval and reconsolidation prevents the expression of morphine-induced conditioned place preferences in mice

Association between the reward caused by consuming drugs and the context in which they are consumed is essential in the formation of morphine-induced conditioned place preference (CPP). Glucocorticoid receptor (GRs) activation in different regions of the brain affects reward-based reinforcement and memory processing. A wide array of studies have demonstrated that blockage of GRs in some brain areas can have an effect on reward-related memory; however, to date there have been no systematic studies about the involvement of glucocorticoids (GCs) in morphine-related reward memory. Here, we used the GR antagonist RU38486 to investigate how GRs blockage affects the sensitization and CPP behavior during different phases of reward memory included acquisition, retrieval and reconsolidation. Interestingly, our results showed RU38486 has the ability to impair the acquisition, retrieval and reconsolidation of reward-based memory in CPP and sensitization behavior. But RU38486 by itself cannot induce CPP or conditioned place aversion (CPA) behavior. Our data provide a much more complete picture of the potential effects that glucocorticoids have on the reward memory of different phases and inhibit the sensitization behavior.     

烟草二脂酰甘油酰基转移酶基因(NtDGAT2)的克隆与功能分析

二脂酰甘油酰基转移酶(diacylglycerol acyltransferase,DGAT2)是植物储存油脂生物合成过程中的关键酶,对种子储存油脂累积具有重要的生理作用。本文采用电子克隆与实验相结合的方法,从烟草种子cDNA中克隆到DGAT2基因的开放阅读框序列,命名为NtDGAT2(GenBank登录号JX843807),其序列长999bp,编码332个氨基酸。多序列比对和进化分析表明该基因编码蛋白与其他植物DGAT2具有较高相似性和典型的DGAT2结构域。利用Real-time PCR定量表达分析显示Nt-DGAT2在烟草种子、花、茎、叶和根里面都有表达,且在发育中的种子和花的发育过程大量表达。酵母互补实验证实该基因编码蛋白具有DGAT酶活性。     

中国淡水鱼类人工增殖放流现状

随着鱼类资源的持续衰退以及保护水产学的兴起,鱼类人工增殖放流已由传统渔业增殖发展成为特有珍稀鱼类种群恢复的主要技术手段。近年来,我国淡水鱼类人工增殖放流涉及水系多、规模大且种类丰富,取得了显著效果并积累了大量基础资料和经验。为深入开展人工增殖放流基础研究,规范技术并提升生态效益,该文收集整理了国内、外相关文献资料,分别从基础理论、塘养种群管理及效果评价等方面阐述人工增殖放流的理论背景,并结合我国"四大家鱼"、中华鲟、胭脂鱼、滇池金线鲃及其他珍稀濒危鱼类人工增殖放流现状,讨论了野外监测和效果评价的作用和意义,提出放流种群遗传局限性、数量和规格权衡以及经济效益与生态效益权衡等问题,旨在为相关研究和人工放流实践提供系统资料。     

树鼩IL-2全长编码序列的克隆及分子特征分析

树鼩作为多种人类疾病模型已受到广泛关注,而免疫因子对于树鼩模型评价至关重要,但目前对其白细胞介素-2(IL-2)的研究鲜有报道。该实验以经ConA(concanavalin)诱导培养的树鼩淋巴细胞总RNA为模板,RT-PCR克隆出465bp的树鼩IL-2全长编码序列,并采用ClustalW软件分析其序列和分子特征。结果表明树鼩IL-2cDNA编码一个由154个氨基酸组成的蛋白质,其cDNA及氨基酸序列与人的同源性分别为93%及80%,且其整体结构与人IL-2相似。MEGA5.0软件构建的进化树表明,树鼩与人及恒河猴的亲缘关系较近。Pymol软件对树鼩和人IL-2氨基酸序列进行的三维结构模建表明,两者的IL-2分子三维空间结构基本相似,表面大部分区域所带电荷相同,但在某些区域差异较大,且树鼩多出一个糖基化位点,这些差异对抗体的结合可能存在影响。该研究为今后树鼩IL-2单克隆抗体的制备及功能研究奠定了基础。     

Molecular dynamics simulation of PNPLA3 I148M polymorphism reveals reduced substrate access to the catalytic cavity

A missense mutation I148M in PNPLA3 (patatin‐like phospholipase domain‐containing 3 protein) is significantly correlated with nonalcoholic fatty liver disease (NAFLD). To glean insights into mutation's effect on enzymatic activity, we performed molecular dynamics simulation and flexible docking studies. Our data show that the size of the substrate‐access entry site is significantly reduced in mutants, which limits the access of palmitic acid to the catalytic dyad. Besides, the binding free energy calculations suggest low affinity for substrate to mutant enzyme. The substrate‐bound system simulations reveal that the spatial arrangement of palmitic acid is distinct in wild‐type from that in mutant. The substrate recognition specificity is lost due to the loop where the I148M mutation was located. Our results provide strong evidence for the mechanism by which I148M affects the enzyme activity and suggest that mediating the dynamics may offer a potential avenue for NAFLD. Proteins 2013. © 2012 Wiley Periodicals, Inc.