果蝇昼夜节律16维数学模型的构建及数值模拟

基于包含果蝇生物钟两个基因per和clk的已有数学模型,增加基因tim对生物钟系统的影响作用,构建了一个果蝇的16维数学模型并进行昼夜节律的仿真研究。数值仿真实验表明,所提出的16维模型比低维的模型有相同的振荡频率,但却有着更广的振荡区间。     

jet基因与时差对果蝇寿命的调控研究

果蝇是理想的节律、睡眠与寿命机制研究的模式生物之一.研究已表明果蝇中因表达Jetlag(Jet)蛋白,进而调节重要生物钟蛋白Timeless(Tim)的降解,使得果蝇能很快适应新的光照周期,即表现出不明显的时差反应.为了研究jet基因和时差对果蝇寿命影响,利用jet突变体果蝇进行睡眠与寿命监测,结果表明:两种同类型jet突变体果蝇的睡眠时间显著高于对照组果蝇,其睡眠次数相对较少,每次睡眠时间较长,提示Jet蛋白功能的缺失反而能促进果蝇睡眠的维持,出现嗜睡症状.进一步探讨了两种不同的时差生活环境对jet突变体与对照组果蝇寿命的影响.研究表明,两种jet突变体寿命在时差环境中表现出显著性延长,而对照组则没有明显变化.以上结果提示jet基因的缺失对于果蝇寿命可能产生部分影响,其作用机制与生物学意义还有待进一步研究.     

ROS介导γ-氨基丁酸调控拟南芥根毛发育机制研究

以拟南芥根特异性表达的γ-氨基丁酸(GABA)合成酶基因(GAD1)突变体(gad1)为材料,探讨了GABA在根毛发育中的调控机制.结果表明,gad1突变体中根毛的长度明显高于野生型,外源GABA的添加会抑制拟南芥野生型和gad1突变体根毛的长度.活性氧(ROS)染色证实了gad1突变体根尖和根毛区域ROS的水平高于野生型, qRT-PCR实验表明gad1突变体中参与ROS清除基因(CSD1、CSD2和MSD1)的表达受到了抑制.研究初步证实了GABA代谢参与了ROS介导的根毛生长调控, GABA作为一种负调控信号参与了根毛生长的调节.     

耳针对脑缺血后睡眠剥夺大鼠下丘脑单胺类神经递质和细胞因子IL-1β的影响

目的:通过观察耳针对脑缺血后睡眠剥夺大鼠下丘脑单胺类神经递质和细胞因子IL-1β的影响,探讨耳针治疗卒中后失眠的作用机制.方法:取SPF级Wistar雄性大鼠,用Zea Logna等报道的大脑中动脉栓线法(MCAO)制备大脑中动脉闭塞再灌注模型,模型成功后将动物随机分为对照组、模型组、安定组和耳针组4组,再对除对照组外的其他3组动物腹腔注射对氯苯丙氨酸(PCPA)造成脑缺血后睡眠剥夺大鼠模型,安定组每日腹腔注射安定,耳针组取耳穴神门(TF4)进行皮内针埋藏,均连续治疗7 d.采用酶联免疫吸附测定法(ELISA)检测下丘脑单胺类神经递质5-羟色胺(5-HT)、5-羟引哚乙酸(5-HIAA)、多巴胺(DA)、去甲肾上腺素(NE)和白介素-1β(IL-1β)的含量.结果:与对照组相比模型组大鼠下丘脑5-HT、5-HIAA和IL-1β含量减低(P0.05),DA、NE含量显著升高(P0.01);与模型组相比安定组与耳针组大鼠下丘脑5-HT和IL-1β含量显著升高(P0.01),DA、NE含量显著降低(P0.01).结论:耳针治疗卒中后失眠可能通过提高机体下丘脑5-HT、5-HIAA及细胞因子IL-1β含量,降低NE和DA的含量以调节和改善睡眠.     

果蝇锌离子转运蛋白Catsup亚细胞定位分析

Catsup是果蝇体内一个功能重要的基因,其突变会导致体内多巴胺含量过高,引起果蝇致死及生殖障碍.绿色荧光蛋白(green fluorescent protein,GFP)在确定蛋白的亚细胞定位进而在研究蛋白功能方面起着重要的作用.为了探索Catsup的亚细胞定位进而能够更好地研究Catsup的功能,文章利用基因工程技术和生物学方法,聚合酶链式反应(polymerase chain reaction,PCR)扩增Catsup基因全长,与GFP一起连接至pUAST质粒,构建载体pUAST-Catsup-GFP,通过显微注射技术导入果蝇,获得UAS-Catsup-GFP转基因果蝇.通过克隆验证了转基因果蝇构建成功.利用该果蝇进行Catsup的亚细胞定位,确定其定位在高尔基体上,为进一步研究该基因的功能奠定基础.     

酸枣仁汤用于失眠症治疗的效果探究

探究酸枣仁汤用于失眠症治疗的效果。将镇原县第一人民医院2018年3月～2019年6月收治的102例失眠症患者按照随机数字表法划分成对照组和治疗组,各51例。对照组采用艾司唑仑治疗,治疗组在对照组基础上加用酸枣仁汤治疗。比较两组临床疗效、睡眠质量及血清神经递质水平。治疗后,治疗组总有效率总有效率92.16%较对照组的74.51%高(P0.05);两组匹兹堡睡眠质量指数量表(PSQI)与睡眠状况自评量表(SRSS)评分与治疗前相比均有下降(P0.05),且治疗组均较对照组低(P0.05);两组5-羟色胺(5-HT)与γ-氨基丁酸(GA-BA)与治疗前相比均有增高(P0.05),且治疗组均较对照组高(P0.05)。应用酸枣仁汤治疗失眠症的效果较好,可显著改善患者睡眠质量,有效上调血清5-HT、GA-BA水平。     

黑米花青素延缓果蝇衰老作用研究

探究黑米花青素延缓衰老的能力及其作用机制。以2d龄的野生型果蝇模型生物为研究对象,饲喂添加不同质量浓度(0、1、5mg/mL)黑米花青素的培养基,采用寿命实验、饮食量检测和逆重力爬行实验方法研究黑米花青素对果蝇平均寿命和健康寿命的影响;采用蓝精灵实验检测黑米花青素对果蝇肠道完整性的影响;用荧光实时PCR测定果蝇体内抗氧化基因SOD、CAT、Rpn11 mRNA表达量的变化。研究发现,饲喂黑米花青素后果蝇平均寿命和健康寿命均高于对照组;黑米花青素对果蝇肠道有一定的保护作用;抗氧化基因mRNA表达水平显著提高(Cu/Zn-SOD,P<0.01;Mn-SOD、CAT和Rpn11, P<0.05)。研究认为,黑米花青素延缓衰老的作用可能是通过上调内源性抗氧化基因来实现的。     

自杀的生物学因素研究现状

自杀是心理、社会和生物诸因素相互作用的结果。目前研究涉及的生物学因素可分为遗传因素和生化因素。近年来自杀的分子遗传学研究发现某些相关基因与自杀可能存在关联,其中研究最多的是5-HT系统的自杀候选基因。目前研究较多的是神经生物学方面,其主要生化因素包括血清素、去钾肾上腺素(NE)、其他神经递质、胆固醇、下丘脑-垂体-肾上腺(HPA)轴。     

成都动物园野生动物源贾第虫的多位点基因分型鉴定

为了解四川省成都市动物园野生动物贾第虫的流行及基因型,本研究采集了146份不同野生动物的新鲜粪便并提取基因组DNA.通过巢式PCR扩增β-giardin、tpi和gdh基因,扩增产物测序后进行种系发育分析.结果表明,CDZOO1黇鹿源和CDZOO3龟源贾第虫通过多位点基因分型(MLG)鉴定为AI-1亚型;CDZOO2鹿源贾第虫为E型(β-giardin基因位点);CDZOO4黇鹿源贾第虫为A型(β-giardin和tpi基因位点);CDZOO5浣熊源和CDZOO6细尾獴源贾第虫在β-giardin位点为D型而在tpi位点为A型.     

五参胶囊镇静催眠作用及其机制的实验研究

目的观察五参胶囊(Wu Shen Capsules,WSh C)对小鼠镇静催眠作用的影响,并探讨其作用机制.方法将ICR小鼠随机分为对照组、五参胶囊高剂量组、中剂量组和低剂量组.五参胶囊高剂量组用药量为200 mg/(kg·d~(-1)),中剂量组用药量为100 mg/(kg·d~(-1)),低剂量组用药量为50 mg/(kg·d~(-1)),给药时间为15 d,于给药结束后进行小鼠自主活动实验和协同戊巴比妥钠阈上剂量睡眠时间实验,测定5 min内各组小鼠的活动次数和站立次数,记录各组小鼠的睡眠潜伏期和睡眠持续时间.采用酶联免疫吸附法检测小鼠下丘脑5-羟色胺(5-Hydroxytryptamine,5-HT)、5-羟吲哚乙酸(5-Hydroxyindole acetic acid,5-HIAA)、γ-氨基丁酸(γ-aminobutyric acid,GABA)、谷氨酸(glutamine,Glu)含量,并计算5-HIAA/5-HT比值及Glu/GABA比值.结果与对照组比较,WSh C各给药组小鼠活动次数减少,睡眠潜伏期缩短,睡眠持续时间延长(P0.01),WSh C能升高小鼠下丘脑5-HIAA含量和5-HIAA/5-HT比值,降低Glu含量和Glu/GABA比值.结论 WSh C具有明显镇静催眠作用,其机制可能与调节中枢兴奋性和抑制性神经递质有关.     

Stress response genes protect against lethal effects of sleep deprivation in Drosophila

Sleep is controlled by two processes: a homeostatic drive that increases during waking and dissipates during sleep, and a circadian pacemaker that controls its timing. Although these two systems can operate independently, recent studies indicate a more intimate relationship. To study the interaction between homeostatic and circadian processes in Drosophila, we examined homeostasis in the canonical loss-of-function clock mutants period (per(01)), timeless (tim(01)), clock (Clk(jrk)) and cycle (cyc(01)). cyc(01) mutants showed a disproportionately large sleep rebound and died after 10 hours of sleep deprivation, although they were more resistant than other clock mutants to various stressors. Unlike other clock mutants, cyc(01) flies showed a reduced expression of heat-shock genes after sleep loss. However, activating heat-shock genes before sleep deprivation rescued cyc(01) flies from its lethal effects. Consistent with the protective effect of heat-shock genes, was the observation that flies carrying a mutation for the heat-shock protein Hsp83 (Hsp83(08445)) showed exaggerated homeostatic response and died after sleep deprivation. These data represent the first step in identifying the molecular mechanisms that constitute the sleep homeostat.     

Circadian rhythms in olfactory responses of Drosophila melanogaster.

The core mechanism of circadian timekeeping in arthropods and vertebrates consists of feedback loops involving several clock genes, including period (per) and timeless (tim). In the fruitfly Drosophila, circadian oscillations in per expression occur in chemosensory cells of the antennae, even when the antennae are excised and maintained in isolated organ culture. Here we demonstrate a robust circadian rhythm in Drosophila in electrophysiological responses to two classes of olfactory stimuli. These rhythms are observed in wild-type flies during light-dark cycles and in constant darkness, but are abolished in per or tim null-mutant flies (per01 and tim01) which lack rhythms in adult emergence and locomotor behaviour. Olfactory rhythms are also abolished in the per 7.2:2 transgenic line in which per expression is restricted to the lateral neurons of the optic lobe. Because per 7.2:2 flies do not express per in peripheral oscillators, our results provide evidence that peripheral circadian oscillators are necessary for circadian rhythms in olfactory responses. As olfaction is essential for food acquisition, social interactions and predator avoidance in many animals, circadian regulation of olfactory systems could have profound effects on the behaviour of organisms that rely on this sensory modality.     

蜜蜂生物节律研究进展

 生物节律主要指有机体生命活动的内在节律性。蜜蜂生物节律受到其社会性的影响,从而参与许多复杂行为的调控。与果蝇相比,蜜蜂的生物节律与哺乳动物更相似。工蜂和蜂王的生物节律表现出高度的可塑性。例如,工蜂的昼夜节律受其劳动分工形式的调控,并通过与幼蜂的直接接触来调节,哺育蜂昼夜照料幼虫,在行为或时钟基因表达方面没有昼夜节律变化。从蜜蜂的社会性、蜜蜂生物节律产生的分子机制、神经基础、研究方法、可塑性、蜜蜂的睡眠等方面综述了蜜蜂生物节律的研究进展。     

A new role for cryptochrome in a Drosophila circadian oscillator

Cryptochromes are flavin/pterin-containing proteins that are involved in circadian clock function in Drosophila and mice. In mice, the cryptochromes Cry1 and Cry2 are integral components of the circadian oscillator within the brain and contribute to circadian photoreception in the retina. In Drosophila, cryptochrome (CRY) acts as a photoreceptor that mediates light input to circadian oscillators in both brain and peripheral tissue. A Drosophila cry mutant, cryb, leaves circadian oscillator function intact in central circadian pacemaker neurons but renders peripheral circadian oscillators largely arrhythmic. Although this arrhythmicity could be caused by a loss of light entrainment, it is also consistent with a role for CRY in the oscillator. A peripheral oscillator drives circadian olfactory responses in Drosophila antennae. Here we show that CRY contributes to oscillator function and physiological output rhythms in the antenna during and after entrainment to light-dark cycles and after photic input is eliminated by entraining flies to temperature cycles. These results demonstrate a photoreceptor-independent role for CRY in the periphery and imply fundamental differences between central and peripheral oscillator mechanisms in Drosophila.     

Keeping time with the human genome

The cloning and characterization of 'clock gene' families has advanced our understanding of the molecular control of the mammalian circadian clock. We have analysed the human genome for additional relatives, and identified new candidate genes that may expand our knowledge of the molecular workings of the circadian clock. This knowledge could lead to the development of therapies for treating jet lag and sleep disorders, and add to our understanding of the genetic contribution of clock gene alterations to sleep and neuropsychiatric disorders. The human genome will also aid in the identification of output genes that ultimately control circadian behaviours.     

Morning and evening peaks of activity rely on different clock neurons of the Drosophila brain

In Drosophila, a 'clock' situated in the brain controls circadian rhythms of locomotor activity. This clock relies on several groups of neurons that express the Period (PER) protein, including the ventral lateral neurons (LN(v)s), which express the Pigment-dispersing factor (PDF) neuropeptide, and the PDF-negative dorsal lateral neurons (LN(d)s). In normal cycles of day and night, adult flies exhibit morning and evening peaks of activity; however, the contribution of the different clock neurons to the rest-activity pattern remains unknown. Here, we have used targeted expression of PER to restore the clock function of specific subsets of lateral neurons in arrhythmic per(0) mutant flies. We show that PER expression restricted to the LN(v)s only restores the morning activity, whereas expression of PER in both the LN(v)s and LN(d)s also restores the evening activity. This provides the first neuronal bases for 'morning' and 'evening' oscillators in the Drosophila brain. Furthermore, we show that the LN(v)s alone can generate 24 h activity rhythms in constant darkness, indicating that the morning oscillator is sufficient to drive the circadian system.     

The mPer2 gene encodes a functional component of the mammalian circadian clock.

Circadian rhythms are driven by endogenous biological clocks that regulate many biochemical, physiological and behavioural processes in a wide range of life forms. In mammals, there is a master circadian clock in the suprachiasmatic nucleus of the anterior hypothalamus. Three putative mammalian homologues (mPer1, mPer2 and mPer3) of the Drosophila circadian clock gene period (per) have been identified. The mPer genes share a conserved PAS domain (a dimerization domain found in Per, Arnt and Sim) and show a circadian expression pattern in the suprachiasmatic nucleus. To assess the in vivo function of mPer2, we generated and characterized a deletion mutation in the PAS domain of the mouse mPer2 gene. Here we show that mice homozygous for this mutation display a shorter circadian period followed by a loss of circadian rhythmicity in constant darkness. The mutation also diminishes the oscillating expression of both mPer1 and mPer2 in the suprachiasmatic nucleus, indicating that mPer2 may regulate mPer1 in vivo. These data provide evidence that an mPer gene functions in the circadian clock, and define mPer2 as a component of the mammalian circadian oscillator.     

Functional consequences of a CKIdelta mutation causing familial advanced sleep phase syndrome

Familial advanced sleep phase syndrome (FASPS) is a human behavioural phenotype characterized by early sleep times and early-morning awakening. It was the first human, mendelian circadian rhythm variant to be well-characterized, and was shown to result from a mutation in a phosphorylation site within the casein kinase I (CKI)-binding domain of the human PER2 gene. To gain a deeper understanding of the mechanisms of circadian rhythm regulation in humans, we set out to identify mutations in human subjects leading to FASPS. We report here the identification of a missense mutation (T44A) in the human CKIdelta gene, which results in FASPS. This mutant kinase has decreased enzymatic activity in vitro. Transgenic Drosophila carrying the human CKIdelta-T44A gene showed a phenotype with lengthened circadian period. In contrast, transgenic mice carrying the same mutation have a shorter circadian period, a phenotype mimicking human FASPS. These results show that CKIdelta is a central component in the mammalian clock, and suggest that mammalian and fly clocks might have different regulatory mechanisms despite the highly conserved nature of their individual components.