樟树全基因组调查

樟树是我国特有的珍贵用材和经济树种,富含多糖多酚、萜类等次生代谢物质,是香精香料、油脂化工和医药等的重要原料树种。本研究采用高通量测序技术(Illumina HiseqTM2000)首次测定了樟树基因组大小,并利用生物信息方法估计樟树杂合率、重复序列情况和GC含量等基因组信息,为全基因组测序策略的选择提供依据。主要结论如下:(1)樟树基因组大小粗略估计为760 Mb左右;(2)樟树基因组有较高的杂合率和一定的重复,杂合率约为0.65%;(3)由于樟树杂合率较高,全基因组鸟枪法策略不适合该基因组测序分析,可尝试使用BAC-to-BAC策略或fosmid策略,有利于樟树基因组的序列拼接和组装。     

人乳头瘤病毒疫苗对宫颈以外部位肿瘤的保护效果研究

人乳头瘤病毒(human papillomavirus,HPV)感染可导致肛门-生殖器及口咽等多部位肿瘤.近年来,随着对HPV研究的深入及多种HPV疫苗陆续上市,HPV疫苗对于多部位肿瘤的保护效果受到越来越多的关注.已有大量研究证明HPV疫苗能够有效预防宫颈癌的发生,而近年也逐渐积累了一些HPV疫苗预防宫颈以外部位肿瘤的证据.本文拟综述HPV疫苗对于头颈、肛门、外阴与阴道、阴茎部位肿瘤保护效果的研究进展.     

Ecophysiological response and morphological adjustment of two Central Asian desert shrubs towards variation in summer precipitation

As part of global climate change, variation in precipitation in arid ecosystems is leading to plant adaptation in water-use strategies; significant interspecific differences in response will change the plant composition of desert communities. This integrated study on the ecophysiological and individual morphological scale investigated the response, acclimation and adaptation of two desert shrubs, with different water-use strategies, to variations in water conditions. The experiments were carried out on two native dominant desert shrubs, Tamarix ramosissima and Haloxylon ammodendron, under three precipitation treatments (natural, double and no precipitation, respectively), in their original habitats on the southern periphery of Gurbantonggut Desert, Central Asia, during the growing season in 2005. Changes in photosynthesis, transpiration, leaf water potential, water-use efficiency, above-ground biomass accumulation and root distribution of the two species were examined and compared under the contrasting precipitation treatments. There were significant interspecific differences in water-use strategy and maintenance of photosynthesis under variation in precipitation. For the phreatophyte T. ramosissima, physiological activity and biomass accumulation rely on the stable groundwater, which shields it from fluctuation in the water status of the upper soil layers caused by precipitation. For the non-phreatophyte H. ammodendron, efficient morphological adjustment, combined with strong stomatal control, contributes to its acclimation to variation in precipitation. On account of its positive responses to increased precipitation, H. ammodendron is predicted to succeed in interspecific competition in a future, moister habitat.     

小麦胚芽蛋白的研究进展

小麦胚芽是面粉加工过程中的副产物,小麦胚芽蛋白具有良好的氮溶解度、起泡性、乳化性以及保水性、氨基酸比例平衡,不仅是饮料、食品以及医疗产品良好的添加剂,而且具有较强的产品开发潜力。对小麦胚芽蛋白的组成成分、理化性质、提取以及麦胚蛋白产品开发利用这四个方面进行简要的介绍,旨在为小麦胚芽蛋白的全面开发利用提供依据。     

多巴胺能神经细胞慢性损伤过程中RET的表达变化

目的:为了检测RET在多巴胺能神经细胞损伤过程中中脑黑质部位的表达变化,并探索其在多巴胺能神经细胞损伤中的可能作用.方法:本实验将C57BL/6 d、鼠分为三组:MPTP组、NS组和空白对照组,采用MPTP腹腔注射建立小鼠中脑黑质多巴胺能神经细胞慢性损伤模型,设立第一周到第六周六个时间点(1w-6w),检测小鼠行为学变化,并采用免疫荧光染色和western blotting等方法检测中脑黑质部酪氨酸羟化酶(TH)和PET的表达情况.结果:行为学结果显示,随给药次数及时间延长,悬挂实验中,MPTP组悬挂评分逐渐下降,MPTP组第三周给药以后与NS组比较差异有统计学意义(P<0.05);跳台实验中,小鼠受电击后跳上跳台的时间逐渐延长,错误次数逐渐增多.免疫荧光双标结果显示,在检测的各时间点,在小鼠中脑黑质一直有RET阳性细胞存在,且与TH阳性细胞共表达;western blotting结果显示,TH在给予MPTP后第三周表达开始降低,RET在给予MPTP后第一周和第二周持续高表达,并且也从第三周开始,其表达量明显降低.结论:这种表达变化提示RET的表达与多巴胺能神经细胞损伤有关.     

一种新型H5N1禽流感病毒血凝素抗原快速检测试剂的建立

利用5株广谱特异性抗H5亚型血凝素单克隆抗体和酶联免疫渗滤技术成功地建立了一种适于现场检测H5亚型禽流感病毒血凝素蛋白的抗原快速检测试剂H5-HA(Ag)Dot-ELISA。该试剂对41株代表当前亚洲地区流行的各种遗传变异亚系H5N1禽流感病毒检测均为阳性,对多数毒株的分析灵敏度优于0.1个血凝滴度(HA titer),其中部分优于0.01个血凝滴度;比较该试剂与早期开发的同类ELISA试剂,发现前者对后者未能检出的H5N1新变异株检测均为阳性;利用该试剂和商品化Directigen Flu A(BD)试剂检测两株H5N1病毒株,提示前者灵敏度高于后者;该试剂对一株H5N1病毒的检测灵敏度与标准RT-PCR相当;该试剂对24株非H5亚型病毒检测均为阴性,显示出良好特异性。以上结果提示,此研究建立的H5N1病毒抗原快速检测试剂在H5禽流感现场检测上具有较好的应用前景。     

Cloned pig fetuses exhibit fatty acid deficiency from impaired placental transport

Cloned pig fetuses produced by somatic cell nuclear transfer show a high incidence of erroneous development in the uteri of surrogate mothers. The mechanisms underlying the abnormal intrauterine development of cloned pig fetuses are poorly understood. This study aimed to explore the potential causes of the aberrant development of cloned pig fetuses. The levels of numerous fatty acids in allantoic ?uid and muscle tissue were lower in cloned pig fetuses than in artificial insemination‐generated pig fetuses, thereby suggesting that cloned pig fetuses underwent fatty acid deficiency. Cloned pig fetuses also displayed trophoblast hypoplasia and a reduced expression of placental fatty acid transport protein 4 (FATP4), which is the predominant FATP family member expressed in porcine placentas. This result suggested that the placental fatty acid transport functions were impaired in cloned pig fetuses, possibly causing fatty acid deficiency in cloned pig fetuses. The present study provides useful information in elucidating the mechanisms underlying the abnormal development of cloned pig fetuses.     

Enhancement of butanol production and reducing power using a two-stage controlled-pH strategy in batch culture of Clostridium acetobutylicum XY16

The effects of pH control on the process of acetone/butanol/ethanol (ABE) production in batch cultures of Clostridium acetobutylicum XY16 have been investigated. Based on the specific acid- and solvent-forming rates in batch fermentation at different pH values (from 4.3 to 6.0), a two-stage controlled-pH strategy was developed in which the pH was shifted from 5.5 to 4.9 after a dry cell weight of 0.5 g L(-1) was achieved. By applying this strategy, the maximum ABE concentration and productivity reached 20.3 g L(-1) and 0.63 g L(-1) h (-1), and were significantly improved by 12.2 and 40.1 %, respectively, compared with the process with no pH control. In addition, reducing power capability was significantly enhanced by this strategy. The two-stage controlled-pH strategy was a convenient and rapid method for high intensity ABE production.