Sleep‐like behavior and 24‐h rhythm disruption in the Tc1 mouse model of Down syndrome

Down syndrome is a common disorder associated with intellectual disability in humans. Among a variety of severe health problems, patients with Down syndrome exhibit disrupted sleep and abnormal 24‐h rest/activity patterns. The transchromosomic mouse model of Down syndrome, Tc1, is a trans‐species mouse model for Down syndrome, carrying most of human chromosome 21 in addition to the normal complement of mouse chromosomes and expresses many of the phenotypes characteristic of Down syndrome. To date, however, sleep and circadian rhythms have not been characterized in Tc1 mice. Using both circadian wheel‐running analysis and video‐based sleep scoring, we showed that these mice exhibited fragmented patterns of sleep‐like behaviour during the light phase of a 12:12‐h light/dark (LD) cycle with an extended period of continuous wakefulness at the beginning of the dark phase. Moreover, an acute light pulse during night‐time was less effective in inducing sleep‐like behaviour in Tc1 animals than in wild‐type controls. In wheel‐running analysis, free running in constant light (LL) or constant darkness (DD) showed no changes in the circadian period of Tc1 animals although they did express subtle behavioural differences including a reduction in total distance travelled on the wheel and differences in the acrophase of activity in LD and in DD. Our data confirm that Tc1 mice express sleep‐related phenotypes that are comparable with those seen in Down syndrome patients with moderate disruptions in rest/activity patterns and hyperactive episodes, while circadian period under constant lighting conditions is essentially unaffected.     

p100蛋白表达抑制的HepG2肝癌细胞稳定株的建立

目的建立p100表达抑制的HepG2肝癌细胞稳定株,并初步探讨p100在HepG2肝癌细胞中的功能。方法用脂质体将含有真核细胞筛选标记Neo和GFP的p100 shRNA表达质粒转染入HepG2细胞。经G418耐药筛选稳定整合抗药基因的细胞单克隆;荧光镜检GFP阳性细胞单克隆,挑取单克隆;Western检测HepG2细胞稳定株HepG2（p100I）中p100表达的抑制效果;平板细胞克隆形成实验检测细胞克隆形成能力;MTS法检测细胞存活;划痕实验检测细胞迁移能力。结果成功获得了p100表达抑制的HepG2肝癌细胞稳定株HepG2（p100I）,其中p100的表达明显降低。并且实验表明,该p100表达抑制稳定株的克隆形成能力,抵抗化疗药物Cisplatin诱导的细胞死亡的能力和迁移能力明显低于对照组细胞。结论p100表达抑制的HepG2肝癌细胞稳定株的建立为研究p100蛋白在肝癌中的作用提供了体外细胞系模型,基于此稳定株的研究,发现p100能够影响HepG2肝癌细胞的多种细胞功能。     

锦鲤鳍条组织细胞系的建立及其生物学特性

采用组织块移植培养技术,对来源于锦鲤（Cryprinus carpiod）鳍条组织的细胞进行原代培养,建立了锦鲤鳍条组织细胞系,已稳定传代60多次,命名为Koi-Fin。锦鲤鳍条组织细胞为成纤维样细胞,最佳培养基为MEME,最适血清体积分数为10%,最适培养温度为25 oC,群体倍增时间为43.5 h。该细胞经液氮冷冻保藏12个月后采用台盼蓝染色,约（80.21±5.84）%的细胞具有细胞活性,复苏细胞生长旺盛。细胞染色体分析显示,第16代锦鲤鳍条组织细胞的染色体数目为正常二倍体2n=100,第40代细胞的染色体众数为52。病毒敏感性试验结果表明,Koi-Fin细胞系对锦鲤疱疹病毒（Koi Herpesvirus,KHV）敏感,可产生典型细胞病变效应,病毒滴度为107.86±0.51TCID50/mL。针对锦鲤疱疹病毒胸苷激酶（thymidine kinase,TK）基因设计特异性引物进行PCR检测,可扩增出病毒靶基因片段。     

Evidence for instantaneous e-vector detection in the honeybee using an associative learning paradigm

Many insects use the polarization pattern of the sky for obtaining compass information during orientation or navigation. E-vector information is collected by a specialized area in the dorsal-most part of the compound eye, the dorsal rim area (DRA). We tested honeybees' capability of learning certain e-vector orientations by using a classical conditioning paradigm with the proboscis extension reflex. When one e-vector orientation (CS+) was associated with sugar water, while another orientation (CS-) was not rewarded, the honeybees could discriminate CS+ from CS-. Bees whose DRA was inactivated by painting did not learn CS+. When ultraviolet (UV) polarized light (350 nm) was used for CS, the bees discriminated CS+ from CS-, but no discrimination was observed in blue (442 nm) or green light (546 nm). Our data indicate that honeybees can learn and discriminate between different e-vector orientations, sensed by the UV receptors of the DRA, suggesting that bees can determine their flight direction from polarized UV skylight during foraging. Fixing the bees' heads during the experiments did not prevent learning, indicating that they use an 'instantaneous' algorithm of e-vector detection; that is, the bees do not need to actively scan the sky with their DRAs ('sequential' method) to determine e-vector orientation.     

小麦重组近交系群体株高和千粒重的抗旱遗传特性

以小麦重组近交系(RIL)群体(陇鉴19×Q9086)120个株系及其亲本为材料,研究雨养(DS)和灌溉(WW)条件下不同发育时期株高动态发育和千粒重的遗传特点及其相互关系,并且评价群体性状的遗传变异.结果表明:在2种水分条件下,小麦RIL群体表型变异广泛且存在超亲分离,对水分环境敏感,拔节期株高具有较高的旱胁迫系数(DSC=0.851).不同发育时期株高与千粒重呈显著正相关,与其他时期相比,拔节期株高与千粒重有较高的相关系数(R2DS=0.32,R2ww=0.28).拔节期株高和开花期株高对千粒重有显著的正向直接作用,但间接总效应为负向作用;抽穗期株高和成熟期株高的作用与此相反.各性状遗传力普遍较低,为0.27 ～0.60;在雨养和灌溉条件下,控制千粒重的基因对数分别为10和13,控制株高的基因对数分别为3～7和4～ 14.表型DSC聚类将小麦RIL群体分为5类,群体内表型和对水分敏感程度变异丰富,该群体适合进行抗旱性状数量遗传研究.     

东乡野生稻回交重组系的抗旱性评价体系

选用协青早B//东乡野生稻/协青早B回交重组系及其亲本共79份水稻材料,研究了水稻发芽期、苗期、孕穗期、成熟期的种子萌发抗旱指数等31个指标与东乡野生稻回交重组系抗旱性的关系.结果表明:15％ PEG-6000溶液处理的相对发芽势、20％ PEG-6000溶液处理的种子萌发抗旱指数和相对发芽势及水分胁迫后最长根长、苗高、根鲜质量、根干质量、根系相对含水量、萎蔫率、叶片可溶性糖含量、叶片脯氨酸含量、叶片丙二醛含量、叶片相对含水量、卷叶级别、株高、单株分蘖数、单株有效穗数、穗实粒数、着粒密度、结实率、千粒重等21个指标的相对值与抗旱系数或抗旱指数的相关性显著.通过逐步回归分析筛选出9个抗旱性鉴定指标:20％ PEG-6000溶液处理的相对发芽势及水分胁迫后根干质量、根系相对含水量、叶片可溶性糖含量、叶片脯氨酸含量、叶片丙二醛含量、单株有效穗、结实率和千粒重的相对值.根据这些指标和偏相关系数,建立了不同时期的抗旱性评价(D值)方程和评价体系,可对东乡野生稻回交重组系抗旱性进行较好的评价.     

人胃癌细胞株裸鼠皮下移植瘤模型的建立及其生物学特性

目的初步建立不同浓度下制备人胃癌细胞株BGC-823裸鼠皮下移植瘤模型,观察其生物学特性。方法培养人胃癌细胞系BGC-823细胞,并分别以四个浓度皮下注射于裸鼠腋下每只0.2 mL。根据BGC-823细胞注射浓度将40只裸鼠随机分为四组：组一5×107个活细胞/mL（n=10）;组二1×107个活细胞/mL（n=10）;组三1×106个活细胞/mL（n=10）;组四1×105个活细胞/mL（n=10）。观察各组裸鼠摄食、活动情况、精神状态、死亡率、成瘤时间、成瘤率、肿瘤生长情况,采用免疫组化法检测肿瘤微血管密度。结果各组裸鼠摄食、精神情况正常,无死亡现象。除组四1×105个活细胞/mL浓度组成瘤率为0%外,其余各组成瘤率均为100%,瘤体出现时间在3～7 d,肿瘤血管密度MVD平均为：（123.26±31.57）个/mm2。结论初步建立了人胃癌裸鼠皮下移植瘤模型及建立此细胞系模型的最低浓度。为胃癌的进一步研究奠定了基础。     

流感病毒在Vero细胞系与MDCK细胞系增殖条件的比较

目的研究流感病毒H1N1及其他亚型在Vero细胞系和MDCK细胞系高效增殖的最适条件,比较两种细胞系对流感病毒的敏感性差异及影响敏感性差异的条件。方法在培养好的Vero细胞系与MDCK细胞系用不同的病毒感染复数(M.O.I)、胰酶浓度、病毒吸附时间、病毒维持液血清质量浓度等条件进行流感病毒在细胞上的增殖。结果在M.O.I为0.01接种流感病毒,吸附时间为1 h,胰酶质量浓度2μg/mL,血清质量浓度为8%时,流感病毒血凝素在MDCK细胞系可获得较高的滴度。结论 MDCK细胞系是适于流感病毒培养的细胞,它作为生产新型流感病毒疫苗的主要细胞基质需要进一步的研究。