海南万泉河中发现外来有害种——马那瓜丽体鱼

2011年在海南琼海万泉河发现外来鱼种马那瓜丽体鱼(Parachromis managuensis)。该种为凶猛的肉食性鱼类,已在野外建立种群,可能会对本土鱼类产生不利影响。建议主管部门禁止人为放生。     

气调包装生鲜冷却牛肉贮藏中微生物多样性分析

【目的】分析普通包装和气调包装(65%O2和35%CO2)生鲜冷却牛肉在贮藏(4°C)过程中的微生物多样性。【方法】通过16S rDNA V3区PCR-DGGE(变性梯度凝胶电泳)方法和16S rDNA克隆分析法研究生鲜冷却牛肉中微生物菌落结构及菌相变化规律。【结果】初始菌相主要有嗜冷杆菌属(Psychrobacter)和假单胞菌属(Pseudomonas)。贮藏过程中,普通包装和气调包装生鲜冷却牛肉中优势菌均为Brochothrix和Pseudomonas。气调包装冷却牛肉中细菌种类较少,两种包装生鲜牛肉在贮藏前期菌相变化明显。【结论】不同包装冷却牛肉中微生物菌落结构有较大差异,气调包装中CO2对Pseudomonas等细菌起到了一定的抑制作用。     

浙江拟漆姑草属一新变种

对浙江省石竹科Caryophyllaceae一新变种闭花拟漆姑草（Spergulariamarinavat．cleistogama）进行了描述和绘图。与原变种的主要区别在于本变种托叶三角状卵形,萼片宽度不等,花瓣0～4枚,有的花瓣变为雄蕊,闭锁,雌蕊具0．2～0．3nlm的柄,雄蕊5～7枚,蒴果为宿存的花萼所包被,种子扁平,卵形。     

裸盖菇和斑褶菇属真菌菌种的有效分离方法

【目的】探讨获取裸盖菇属及斑褶菇属真菌纯培养的有效分离方法。【方法】采用菌褶接种法和孢子弹射法进行分离,以形态鉴定为基础,通过ITS区测序并与DNA序列库中已知序列进行比对的分子鉴定方法鉴别分离培养物的真伪,以确定分离方法的可靠性。【结果】对采自云南的28个裸盖菇属和斑褶菇属菌株进行了分离,菌褶接种法有24个菌株分离纯化成功,成功率达86%,而孢子弹射法仅有7个菌株分离成功,成功率为25%。【结论】菌褶接种法对于裸盖菇属和斑褶菇属真菌是一种有效而简便易行的分离方法,该法利用菌褶为产孢组织的优势,无需对菌褶进行表面消毒,易于纯化成功,值得在其他类似的腐生小型薄盖伞菌类群的分离中尝试应用。     

Spatial and temporal nature of reactive oxygen species production and programmed cell death in elm (Ulmus pumila L.) seeds during controlled deterioration

Seed deterioration is poorly understood and remains an active area for research. Seeds of elm (Ulmus pumila L.) were aged at 37 °C above water [controlled deterioration treatment (CDT)] for various lengths of time to assess programmed cell death (PCD) and reactive oxygen species (ROS) product in embryonic tissues during a 5 d period. The hallmarks of PCD were identified in the elm seeds during CDT including TUNEL experiments, DNA laddering, cytochrome c (cyt c) leakage and enzymatic activities. These analyses indicated that PCD occurred systematically and progressively in deteriorated elm seeds. Cyt c release and increase in caspase‐3‐like/DEVDase activity occurred during CDT, which could be suppressed by ascorbic acid (AsA) and caspase‐3 inhibitor Ac‐DEVD‐CHO, respectively. In situ localization of ROS production indicated that the distinct spatial‐temporal signature of ROS during CDT coincided with the changes in PCD hallmark features. Multiple antioxidant elements were activated during the first few days of CDT, but were subsequently depleted as PCD progressed. Taken together, our findings identify PCD as a key mechanism that occurs asymmetrically during elm seeds CDT and suggest an important role for PCD in seeds deterioration.     

Differential expression of disialic acids in the cerebellum of senile mice

It is known that disialic acids (diSia) are present in the mammalian brain. However, the precise anatomical distribution and the chronology of its expression along life are not well studied yet. It is accepted that the transfer of diSia in the brain is mediated mainly by the enzyme ST8Sia III (α2,8-sialyltransferase III). We studied the expression of diSia glycoepitopes and of the ST8Sia III gene in different structures of the mouse brain at different postnatal stages by immunohistochemistry and real-time polymerase chain reaction, respectively. C57BL/6 mice of different stages were used. Samples of hippocampus, olfactory bulb, cortex and cerebellum were processed for studies of molecular biology and immunohistochemistry. Histological analysis revealed an important decrease in diSia labeling in the senile cerebellum compared with other structures and stages (P???0.001). In concordance with these results, a significant decrease in ST8Sia III gene expression was found in the cerebellum of senile animals (P?相似文献   

A combination of hydrodynamical and statistical modelling reveals non-stationary climate effects on fish larvae distributions

Biological processes and physical oceanography are often integrated in numerical modelling of marine fish larvae, but rarely in statistical analyses of spatio-temporal observation data. Here, we examine the relative contribution of inter-annual variability in spawner distribution, advection by ocean currents, hydrography and climate in modifying observed distribution patterns of cod larvae in the Lofoten-Barents Sea. By integrating predictions from a particle-tracking model into a spatially explicit statistical analysis, the effects of advection and the timing and locations of spawning are accounted for. The analysis also includes other environmental factors: temperature, salinity, a convergence index and a climate threshold determined by the North Atlantic Oscillation (NAO). We found that the spatial pattern of larvae changed over the two climate periods, being more upstream in low NAO years. We also demonstrate that spawning distribution and ocean circulation are the main factors shaping this distribution, while temperature effects are different between climate periods, probably due to a different spatial overlap of the fish larvae and their prey, and the consequent effect on the spatial pattern of larval survival. Our new methodological approach combines numerical and statistical modelling to draw robust inferences from observed distributions and will be of general interest for studies of many marine fish species.     

Variability and adaptability of Miscanthus species evaluated for energy crop domestication

A growing body of evidence indicates that second‐generation energy crops can play an important role in the development of renewable energy and the mitigation of climate change. However, dedicated energy crops have yet to be domesticated in order to fully realize their productive potential under unfavorable soil and climatic conditions. To explore the possibility of domesticating Miscanthus crops in northern China where marginal and degraded land is abundant, we conducted common garden experiments at multiple locations to evaluate variation and adaptation of three Miscanthus species that are likely to serve as the wild progenitors of the energy crops. A total of 93 populations of Miscanthus sinensis, Miscanthus sacchariflorus, and Miscanthus lutarioriparius were collected across their natural distributional ranges in China and grown in three locations that represent temperate grassland with cold winter, the semiarid Loess Plateau, and relatively warm and wet central China. Evaluated with growth traits such as plant height, tiller number, tiller diameter, and flowering time, the Miscanthus species showed high levels of genetic variation within and between species. There were significant site × population interactions for almost all traits of M. sacchariflorus and M. sinensis, but not M. lutarioriparius. The northern populations of M. sacchariflorus had the highest establishment rates at the most northern site owing to their strong cold tolerance. An endemic species in central China, M. lutarioriparius, produced not only the highest biomass of the three species but also higher biomass at the Loess Plateau than the southern site near its native habitats. These results demonstrated that the wild species harbored a high level of genetic variation underlying traits important for crop establishment and production at sites that are colder and drier than their native habitats. The natural variation and adaptive plasticity found in the Miscanthus species indicated that they could provide valuable resources for the development of second‐generation energy crops.     

An Outbreak of Tularemia in a Colony of Outdoor-Housed Rhesus Macaques (Macaca mulatta)

Since an epizootic and detection of clinical cases of tularemia (Francisella tularensis) in 1996 at the Oregon National Primate Research Center, only 8 cases were identified in the succeeding 13 y. However, within a period of 7 mo, primarily during Winter 2010, 6 rhesus macaques were confirmed positive for Francisella tularensis type B by the Centers for Disease Control and Prevention by culture and fluorescent antibody testing. All cases had similar gross pathologic findings, which included necrotizing splenitis and lymphadenitis. Recent colony management efforts have focused on minimizing nonhuman primate exposure to commonly observed reservoir species and controlling rodent access to corral-style housing. Strategies continue to evolve with regard to managing a large breeding colony of nonhuman primates in the presence of this threat.Abbreviation: ONPRC, Oregon National Primate Research CenterFrancisella tularensis, the causative agent of tularemia, is a small pleomorphic gram-negative coccobacillus.¹¹ Severe disease and potentially death in humans can result from exposure to as few as 10 cfu of this highly infectious organism.^7,10 The disease is also known as rabbit fever and deer-fly fever, reflecting 2 common sources of infection for humans.³ F. tularensis is classified by the United States Department of Health and Human Services as a Category A Select Agent.⁶ It is considered a potential agent of biologic warfare, and in fact, has been weaponized and stockpiled in the past.¹⁰ The 2 biovars that are referenced most frequently in published human and nonhuman primate literature are tularensis (type A) and holarctica (formerly paleartica; type B).^4,12,13,23 An additional biovar, novicida (type C), has been described, but its virulence in humans is decreased due to its lack of a capsule.¹⁰Tularemia is endemic to many parts of the northern hemisphere, which includes the region surrounding the Oregon National Primate Research Center (ONPRC), an AAALAC-accredited facility.²⁰ Tularemia has one of the broadest host ranges of all bacteria, encompassing well over 200 mammalian species primarily, in addition to birds, amphibians, fish, and various arthropods such as fleas, ticks, mosquitoes, and flies.^10,15,19,20 The ONPRC is located in a mixed forest and field environment which is bordered by wetlands and residential neighborhoods outside of Portland. More than 4500 nonhuman primates are housed here, and most live outdoors in breeding groups. Therefore, exposure to this potentially life-threatening and zoonotic pathogen is inevitable, due to its persistence in the environment and the close proximity of several reservoir species. Presumed reservoir species commonly observed at ONPRC include meadow voles (Microtus pennsylvanicus), brown rats (Rattus norvegicus), deer mice (genus Peromyscus), house mice (Mus musculus), and California ground squirrels (Spermophilus beecheyi). Potential arthropod vectors that are monitored regularly at ONPRC include biting flies and mosquitoes. At this time, testing of prospective rodent carriers for tularemia is ongoing; therefore, in the interest of caution, all of the rodent and arthropod species listed are considered potential carriers of the disease.Tularemia was first recognized at the ONPRC in 1996 during an epizootic that resulted in 24 deaths among corral-housed rhesus macaques. Serology results from banked sera and sera collected during and after the outbreak demonstrated a seroconversion rate of approximately 25% in 723 animals. During the succeeding 13 y, only 8 sporadic cases were diagnosed. However, within a period of 3 mo during the winter of 2010, 5 rhesus macaques were diagnosed with Francisella tularensis type B by the Centers for Disease Control and Prevention (Atlanta, GA). Four months later, an additional case was confirmed. All 6 macaques were younger than 1 y and were assigned to a breeding colony protocol approved by the ONPRC Animal Care and Use Committee. The current report describes the clinical signs and gross and histologic findings associated with these cases, as well as methods for prevention and control of future cases of disease.