河西走廊天然固沙植被区地表甲虫多样性及其对沙漠化的指示作用

干旱、半干旱区沙漠化强烈影响动植物分布及多样性,地表甲虫是荒漠中主要的动物类群,它们对沙漠化引起的植被和土壤环境变化响应十分敏感。鉴于此,以河西走廊中部张掖绿洲外围的天然固沙植被区作为研究区,依据沙漠化发育程度选择流动沙丘（ASD）、丘间低地（IL）、半固定（SFSD）和固定沙丘（FSD）4种生境,调查了地表甲虫群落组成及影响甲虫分布的植被和土壤环境。研究发现,4种生境地表甲虫群落组成明显不同并存在季节变异,5月ASD与IL、SFSD和FSD生境地表甲虫群落的相异性大于8月。5月和8月SFSD生境地表甲虫活动密度均显著高于其他生境,8月FSD生境地表甲虫多样性指数显著高于其他生境。不同大小甲虫对沙漠化的响应模式不同,大中型甲虫对沙漠化的响应较小型甲虫敏感,这在5月表现尤为明显。地表甲虫与环境因子的RDA分析结果表明,12个植被和土壤环境因子解释了49.8%的地表甲虫群落变异,其中植被环境解释了甲虫群落变异的16.3%,土壤环境解释了甲虫群落变异的4.2%,植被和土壤环境相互作用解释了甲虫群落变异的29.3%。pRDA分析结果表明,草本物种丰富度、灌木盖度、土壤有机碳含量和粗砂含量是影响地表甲虫分布的主要环境因子,它们解释了43.7%的地表甲虫群落变异。Pearson相关分析表明,草本物种丰富度与地表甲虫活动密度呈显著正相关,而与地表甲虫均匀度呈显著负相关;灌木盖度与地表甲虫多样性呈显著正相关;地表甲虫物种丰富度与灌木盖度和草本物种丰富度均呈显著正相关。此外,研究还发现戈壁琵甲、克氏扁漠甲、中华砚甲和甘肃齿足象可以用于指示FSD生境,东鳖甲属昆虫可以用于指数SFSD生境,谢氏宽漠王可以用于指示IL及ASD生境。     

肠内营养对乳腺癌术后化疗患者肠道菌群及生活质量的影响

目的研究肠内营养对乳腺癌术后化疗患者肠道菌群、生活质量、营养指标水平的影响。方法选取2012年7月至2018年1月于我院进行乳腺癌术后化疗的91例女性乳腺癌患者为研究对象,根据是否进行肠内营养将患者分为肠内营养组和对照组,观察化疗前后2组患者肠道菌群、生活质量、营养指标水平的变化及不良反应发生情况。结果治疗前2组患者肠道菌群、生活质量、营养指标水平差异无统计学意义(均P0.05)。治疗后,肠内营养组患者肠道双歧杆菌数量为(6.7±0.5)lg CFU/g、乳杆菌数量为(8.5±0.4)lg CFU/g,均显著高于治疗前,同时显著高于对照组(均P0.05)。治疗后肠内营养组患者出现反酸、腹胀、便秘等胃肠道不良反应的比例与对照组比较差异无统计学意义(均P0.05)。治疗后两组患者总体健康、认知功能、情绪功能、角色功能、社会功能、活力、躯体疼痛、躯体功能评分显著高于治疗前(均P0.05),且肠内营养组患者生活质量各指标的评分显著高于对照组(均P0.05)。治疗后肠内营养组患者血清总蛋白(TB)、血清清蛋白(ALB)、血清前清蛋白(PA)、转铁蛋白(TF)水平均显著高于对照组(均P0.05)。结论肠内营养可预防乳腺癌术后化疗患者肠道菌群的紊乱及营养不良的发生,安全有效,有助于提高乳腺癌患者的生活质量。     

天然和人工固沙灌木林蜘蛛和甲虫分布与环境因子的关系

干旱区人工植被恢复驱动的土地利用变化强烈影响了地表和土栖的节肢动物群落结构及多样性。然而,我们对地表节肢动物群落关键类群-蜘蛛和甲虫对固沙植被恢复的响应及与环境变化关系的认识还很有限。以天然固沙灌木林和2种人工固沙灌木林为研究对象,运用方差分析和多变量分析等方法定量研究了干旱区天然和人工固沙植被区地表蜘蛛和甲虫分布特征及影响要素。结果表明,天然灌木林与人工梭梭、柽柳林地表蜘蛛和甲虫群落组成明显不同,人工梭梭、柽柳林地表蜘蛛活动密度和甲虫多样性均显著高于天然灌木林,而地表甲虫密度和蜘蛛多样性变化与之相反。两种人工固沙灌木林之间蜘蛛和甲虫群落组成也存在一定差异,人工柽柳林地表蜘蛛活动密度、多样性和甲虫物种丰富度均显著高于人工梭梭林。进一步分析发现,蜘蛛群落中狼蛛科、平腹蛛科、皿蛛亚科和球蛛科与甲虫群落中拟步甲科、步甲科和象甲科等一些甲虫种属对3种生境的选择模式不同决定了蜘蛛和甲虫群落聚集结构。植被、土壤环境因子与蜘蛛和甲虫pRDA和pCCA结果表明,草本生物量、凋落物量、土壤含砂量、电导率和灌木盖度是影响蜘蛛分布的主要环境因子,它们解释了82.1%的蜘蛛群落变异;灌木盖度、草本生物量、土壤pH和砂含量是影响甲虫群落分布的主要环境因子,它们解释了60.6%的甲虫群落变异。总之,人工固沙灌木恢复影响了植被和土壤环境,它们相互作用改变了荒漠-绿洲过渡区蜘蛛和甲虫等地表节肢动物的分布格局。     

Hybridization between diploid Centaurea pseudophrygia and tetraploid C. jacea (Asteraceae): the role of mixed pollination,unreduced gametes,and mentor effects

We studied hybridization between the diploid Centaurea pseudophrygia and the tetraploid C. jacea by performing crossing experiments and screening natural populations using flow cytometry. The experiments confirm that the studied species exhibit strong reproductive isolation. Interspecific hybrids were formed at a low frequency, including triploids (originating from reduced gametes) and tetraploids (involving unreduced gametes of the diploids). In contrast, hybrids were almost absent among seeds and adult plants of natural mixed populations and among the offspring from experimental pollinations with a mixture of pollen of both ploidy levels. We found that mixed pollination is an important mechanism for preventing hybridization between plants of different ploidy levels and sustaining the reproduction of the tetraploids. A mentor effect (induced selfing in the presence of pollen of different ploidy levels) was observed in both diploids and tetraploids, reinforcing the reproductive isolation between cytotypes. Higher ploidy levels (pentaploid, hexaploid) involving unreduced gametes of the tetraploid species were identified. Notably, pentaploids were discovered for the first time in Centaurea sect. Jacea. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 93–106.     

马卵母细胞体外成熟的初步研究

采用抽吸法和切割法两种采卵方法收集马卵母细胞,显示采用切割法的卵母细胞回收率为83%,高于抽吸法的回收率46.5%(P＜0.05),在卵母细胞的成熟上,使用M199和DMEM/F12两种培养液为基础液的成熟体系,紧凑型(Cp)COCs和扩展型(Ex)COCs在以M199为基础液和以DMEM/F12为基础液的培养液中的卵母细胞成熟率分别为41.7%和64.7%、46.7%和66.7%,差异不显著(P＞0.05).两种培养体系中成熟的Cp COCs采用Ionomycin与6-DMAP和CHX联合激活,在以M199和以DMEM/F12为基础液的培养液中成熟的卵母细胞的卵裂率分别为45%和57.1%,差异不明显(P＞0.05).     

Developmental stage of the oocyte during antral follicle growth and cumulus investment determines in vitro embryo development of sow oocytes

The aim of the study was to determine the contribution of cumulus cells on the developmental competence of porcine oocytes during follicle growth. Oocytes from large (5-8mm) and small (2-3mm) follicles were cultured with or without follicle stimulating hormone (FSH), subsequently examined for nuclear stage and spindle morphology, or fertilized and cultured for embryo development, or analyzed for glutathione content. Additionally, the significance of cumulus investment, corona radiata cells, cumulus cell number and origin of cumulus cells for oocyte maturation were investigated. Small follicle oocytes cultured without FSH exhibited the highest incidence of spindle aberrations. Oocytes cultured without FSH exhibited reduced sperm penetration and blastocyst rates, and a higher proportion monospermic oocytes developed to the blastocyst stage when derived from large follicles. The glutathione content in oocytes increased during follicle growth and oocyte maturation, but no direct correlation between oocyte glutathione content and oocyte developmental capacity was observed. Oocytes with a bigger cumulus investment exhibited better embryo development. Oocytes with a single corona radiata cell layer (CROs) exhibited similar progression through meiosis to oocytes with more cumulus cell layers, but showed reduced embryo development. More blastocysts were observed when CROs were cultured with disconnected cumulus cells during IVM, but no blastocyst increase was observed when CROs were cocultured with a higher number of cumulus cells or with cumulus cells from large follicles. We conclude that increased developmental capacity of oocytes during follicle growth is intrinsic and whether cumulus cells originate from large or small follicles, their contribution to oocyte maturation remains unchanged. Further, cumulus investment can be used as a variable to predict oocyte developmental capacity.     

黑素皮质素受体-4的研究进展

黑素皮质素受体 4 (MC4R)是人类中枢神经系统中参与调节肥胖症发生的重要因素 ,可调节动物的体重和采食量。自MC4R基因克隆以来 ,学者们对MC4R的结构 ,生理功能 ,调控 ,作用机制及其基因突变与体重的关系等方面进行了大量的研究。     

用酵母双杂交系统筛选影响apo-AI和SR-BI相互作用的苦豆子活性成分

本文通过将苦豆子总提取物及其分离得到的10个组分加入含有AH109菌株(携带大鼠apo-AI及其受体SR-BI全基因)的培养基中,利用报告基因半乳糖苷酶活力有无变化来寻找能够促进大鼠载脂蛋白apo-AI及其受体SR-BI相互作用的激动剂.经测试,我们观察到苦豆子总提取物(K-1),在上述系统中能显著增强这两种蛋白的相互作用.继续用硅胶柱层析方法从k-1中分出10个组分后,利用酵母双杂交系统再次筛选,发现有五个组分能增强两种蛋白的相互作用,(与空白对照组相比其中有两个组分有极显著差异)另外三个组分显著地抑制上述两种蛋白的相互作用,剩下的两个组分则没有差异.该实验还提示该酵母双杂交系统可能成为一种跟踪具有调脂功能的先导化合物的有效方法.     

运用稳定同位素技术分析大宁河主要鱼类营养层级

运用氮稳定同位素技术分析了大宁河静水水域和流水河段主要鱼类的氮稳定同位素比值和营养层级,并对静水水域不同水文时期相同鱼类的营养层级进行了比较研究。结果表明, 颗粒有机物(POM)氮稳定性同位素变化幅度较大, 并存在季节差异。大宁河下游静水水域鱼类15N 值范围为4.5417.51, 营养级处于1.513.88, 平均营养层级为2.49;上游流水水域鱼类的15N 值范围为2.2510.81, 营养层级范围为1.494.01, 平均营养层级为2.87。大宁河上游鱼类的平均营养层级大于下游静水水域, 可能是由于上游底栖生物丰富, 鱼类倾向摄食适口性更高的动物性食物而导致。大宁河下游静水水域汛期的鱼类营养层级较非汛期的值显著降低, 可能是因为汛期的水文扰动影响鱼类摄食中间捕食者, 以及水位的降低导致鱼类食物竞争增加迫使其摄食低营养水平的食物。重复基准生物采样建立精确充足的基线值以及确定合适的富集度,是提高营养层级评估准确性的重要手段。