RNAi的抗病毒研究进展

RNA干扰(RNA interference,RNAi)是真核生物中的特异核苷酸序列产生的基因沉默现象,被认为有抑制病毒复制的功能。最近的研究表明,通过诱导RNAi可以抑制多种病毒的复制,包括人类免疫缺陷病毒Ⅰ型,乙型肝炎病毒,丙型肝炎病毒,登革热病毒,脊髓灰质炎病毒,流感病毒,口蹄疫病毒和重症急性呼吸综合征病毒等。总结了目前运用RNA干扰技术抑制病毒复制的研究进展,展望基于RNAi技术的抗病毒治疗的可能性。     

利用信息化学物质研究松树小蠹虫的扬飞规律

于2005～2006年在辽宁省千山利用信息化学物质野外诱捕黄色梢小蠹Gryphalus fulvus、红松根小蠹Hylastes plumbeus、横坑切梢小蠹Tomicus minor及纵坑切梢小蠹Tomicus piniperda成虫,结果显示:这4种小蠹在4月18日至8月10日期间都明显出现2次扬飞高峰。第1次扬飞高峰持续均为30d左右,第2次扬飞高峰期约为15d;黄色梢小蠹和红松根小蠹第1次扬飞高峰期在5月上中旬出现,第2次扬飞高峰期分别在7月中下旬和上中旬;横坑切梢小蠹与纵坑切梢小蠹的扬飞高峰期基本一致,第1次扬飞高峰期为4月下旬到5月上旬,第2次扬飞高峰在7月上中旬;结果同时还表明诱虫量第1次扬飞高峰一般都明显大于第2次,只是黄色梢小蠹在首次利用信息化学物质进行监测且密度较高时例外。     

In Vitro Dynamic Visualization Analysis of Fluorescently Labeled Minor Capsid Protein IX and Core Protein V by Simultaneous Detection

Oncolytic adenoviruses represent a promising therapeutic medicine for human cancer therapy, but successful translation into human clinical trials requires careful evaluation of their viral characteristics. While the function of adenovirus proteins has been analyzed in detail, the dynamics of adenovirus infection remain largely unknown due to technological constraints that prevent adequate tracking of adenovirus particles after infection. Fluorescence labeling of adenoviral particles is one new strategy designed to directly analyze the dynamic processes of viral infection in virus-host cell interactions. We hypothesized that the double labeling of an adenovirus with fluorescent proteins would allow us to properly analyze intracellular viruses and the fate of viral proteins in a live analysis of an adenovirus as compared to single labeling. Thus, we generated a fluorescently labeled adenovirus with both a red fluorescent minor capsid protein IX (pIX) [pIX monomeric red fluorescent protein 1 (mRFP1)] and a green fluorescent minor core protein V (pV) [pV enhanced green fluorescent protein (EGFP)], resulting in Ad5-IX-mRFP1-E3-V-EGFP. The fluorescent signals for pIX-mRFP1 and pV-EGFP were detected within 10 min in living cells. However, a growth curve analysis of Ad5-IX-mRFP1-E3-V-EGFP showed an approximately 150-fold reduced production of the viral progeny at 48 h postinfection as compared to adenovirus type 5. Interestingly, pIX-mRFP1 and pV-EGFP were initially localized in the cytoplasm and nucleolus, respectively, at 18 h postinfection. These proteins were observed in the nucleus during the late stage of infection, and relocalization of the proteins was observed in an adenoviral-replication-dependent manner. These results indicate that simultaneous detection of adenoviruses using dual-fluorescent proteins is suitable for real-time analysis, including identification of infected cells and monitoring of viral spread, which will be required for a complete evaluation of oncolytic adenoviruses.     

Base pair stacking in nucleosome DNA and bendability sequence pattern

DNA deformation in the nucleosome involves partial unstacking between bases and base pairs. By adjusting orientations of different base-pair stacks relative to the histone octamer surface, the optimal set of stacks and their positions is derived, resulting in a sequence pattern, theoretically best suitable for nucleosome DNA. The sequence is very much consistent with available experimental data, thus, suggesting a common eukaryotic nucleosome DNA bendability sequence pattern based exclusively on the very basics of DNA.     

黑脸琵鹭在澳门的越冬分布和人为干扰影响

澳门路凼连贯公路西侧的湿地保护区是黑脸琵鹭(Platalea minor)重要的越冬地之一,每年的越冬数量稳定增长。2007～2009年度2个冬季的调查结果显示,黑脸琵鹭每年11月初至次年4月底在澳门越冬,12月至翌年2月份种群数量达到最大,超过50只。其中人工湿地是黑脸琵鹭主要的休息场所,沿岸滩涂是其重要觅食地。黑脸琵鹭昼间栖息行为以休息为主,其次是护理行为。栖息地周边主要人为干扰为噪声污染,但噪声水平较低,经噪声预测模型计算出传播至黑脸琵鹭停歇处的噪声水平为45.4dB(A)及46.5dB(A),低于鸟类耐受阈值,警觉受惊行为多数由大型牵引车和直升飞机引起。随着保护区周边地区的开发,车流量将进一步增加,建议加强保护区的科学管理,控制周边交通干线的车流量,并调整直升飞机飞行路线,尽量绕行保护区上空,以减少对黑脸琵鹭栖息的干扰。     

Development of strain specific molecular markers for the Sclerotinia minor bioherbicide strain IMI 344141

The plant pathogenic fungus, Sclerotinia minor IMI 344141, has been developed as a bioherbicide for broadleaf weed control in turfgrass and a means to differentiate this biocontrol agent from like organisms is required. A strain specific molecular marker was developed to detect and monitor the Sclerotinia minor IMI 344141 bioherbicide strain. The method was based on polymerase chain reaction (PCR) amplification of two sequence-characterized amplified regions (SCAR) primer pairs for a first round PCR, and another two sets of nested primers was used for a second round PCR if higher sensitivity was needed. Sclerotinia minor IMI 344141 was successfully traced from both pure cultures and environmental samples originating from bioherbicide-released field trials. DNA of the S. minor bioherbicide isolate IMI 344141 was detected in the soil 2 months after application, but was not detected in the 3- and 9-month samples after application. When applied as a bioherbicide, S. minor (IMI 344141) did not persist into the following spring season in turf environments. This molecular detection method provides a mechanism to distinguish this isolate from related organisms and a tool to monitor behavior of the biocontrol agent S. minor IMI 344141 in nature, particularly in soil.     

A molecular genetic analysis of the communal nesting of the ostrich (Struthio camelus)

The ostrich breeding system is complex and unique; communal clutches are laid by several females, although only one female, the major female, and the resident territorial male provide parental care. More eggs are laid in the nest than can be incubated and the major female ejects surplus eggs from the incubated central clutch. Microsatellite markers were used to analyse the parentage of communal nests in Nairobi National Park. This revealed that major females contributed a disproportionate number of fertile eggs to the central, incubated clutch and that multiple paternity and maternity within a nest were common; 68.9% of all incubated eggs on a nest were not parented by both the resident territorial male and the major female of that nest. All the males fertilized eggs on the clutches of neighbouring males. Unexpectedly, every major female with her own nest was also simultaneously a minor female with incubated eggs on neighbouring clutches. The relatedness between females laying in the same nest was not significantly different from the population average and significantly less than that between chicks hatched from the same nest.     

Somatic embryogenesis in elm

We show that isolated zygotic embryos of Ulmus minor and U. glabra can produce embryogenic cultures provided they are isolated from immature seeds before storage proteins begin to accumulate. Rates of somatic embryogenesis were highest among zygotic embryos collected 6 weeks post-anthesis when they were at the midcotyledonary stage, were about 5 mm long and had a fresh weight of approx. 10 mg. At this time, induction was even possible in Murashige and Skoog basal medium with no plant growth regulators, but addition of 2,4-dichlorophenoxyacetic acid was necessary at earlier stages of zygotic development. In medium supplemented with benzyladenine (BA) only, no embryogenic induction was observed. The formation of callus was an essential step not only for the induction of embryogenic masses, but also for the maintenance of embryogenic competence through successive subculture of callus on induction media supplemented with 0.1 mg l(-1) BA. Nine embryogenic U. minor lines and 24 U. glabra lines have been maintained in this way for 3 years. However, conversion into plantlets has occurred only rarely.     

Oviposition and development of the immature stages of Tomicus minor (Coleoptera, Scolytidae)

1 This paper describes the construction process of the brood gallery of Tomicus minor and its total length as well as the length of each arm, the fertile part where the female lays her eggs and also, the infertile part. >2 The presence of the parents during the process and their position in the brood gallery (arms or mating chamber) is studied and how it influences the number of eggs laid. Both the first brood galleries and those burrowed by the repenetrating females were observed. 3 The development and duration of the immature stages of the insect in the 3-year study period, from laying to the emergence of the young beetles from the F₁ generation, were also studied.