Moth sex-pheromone biosynthesis is inhibited by the herbicide diclofop

Pheromones of nocturnal moths are derived from fatty acids produced as a result of the activity of acetyl-CoA carboxylase. This timely production is initiated in nocturnal moths by a tropic peptide, pheromone biosynthesis activating neuropeptide released into the hemolymph. In monocotyledonous plants, specific plastid acetyl-CoA carboxylase is inhibited by herbicides that target the eukaryotic form of the enzyme. We report evidence that these herbicides can also target pheromone biosynthesis by a moth, thereby implicating the acetyl-CoA carboxylase as a key regulatory enzyme in the pheromone biosynthetic pathway. These findings, whilst indicating the possible action of such herbicides on non-target organisms, also suggest a novel alternative method of insect pest management, which precludes sex-pheromone production and mating success, thereby reducing insect population growth.     

甘肃东方蜜蜂的形态特征研究

通过测定甘肃2个不同样点的4群东方蜜蜂发现,甘肃蜜蜂种群内遗传变异丰富,种群中许多形态性状特征表现出较明显的地理变异性;蜜蜂个体增大、体色变深,具体是:前翅长、前翅宽、背板3,4宽;后腿长、蜡镜长、蜡镜宽、蜡镜间距、腹片3,6的长和宽逐渐增加;背板3,4、小盾片的色素度逐渐加深。这些均具有生态适应意义。     

兔病毒性出血症、多杀性巴氏杆菌病、产气荚膜梭菌病(A)型三联灭活疫苗研制

对 5批兔病毒性出血症、多杀性巴氏杆菌病、产气荚膜梭菌病三联灭活疫苗进行了动物试验 ,结果表明该疫苗安全有效。近期效检对兔病毒性出血症的保护率为 1 0 0 % ,对兔多杀性巴氏杆菌病保护率为 92 % ,对产气荚膜梭菌病 (A)型保护率为 88%。在免疫期试验中 ,免疫 6个月后 ,对兔病毒性出血症保护率为 1 0 0 % ,对多杀性巴氏杆菌病的保护率为 79% ,对产气荚膜梭菌病 (A)型的保护率为 88%。在保存期试验中 ,4～ 8℃保存 1年仍有效。     

枯草芽孢杆菌G3菌株的抗菌物质及其特性

 产几丁质酶枯草芽孢杆菌G3菌株的固体培养物在黄瓜灰霉病菌和番茄叶霉病菌抑菌试验中证实,抑菌活性物质存在于过滤上清液中,它们是从酸沉淀物中提取出的伊枯草菌素、生物表面活性素和存在于盐析粗蛋白中的几丁质酶。在叶霉孢子萌发试验中,伊枯草菌素微弱地抑制孢子萌发但强烈破坏芽管和新生菌丝;生物表面活性素和几丁质酶则强烈抑制孢子萌发并长久性地抑制芽管伸长。在PDA平板上的灰霉菌丝抑菌试验中,伊枯草菌素抑制菌丝生长,引发菌丝顶端膨大,形成泡囊,泡囊破裂后原生质外泄;几丁质酶抑制菌丝生长,引发产生不规则的菌丝团;生物表面活性素在平皿上对菌丝则不显示出抑菌活性。     

木质包装中黄斑星天牛微波处理初探

为了探索微波处理作为木质包装替代处理方法的可能性,对不同规格和含水量的杨树木块进行微波处理试验,结果表明:频率为2450MHz的微波能够穿透厚度为10cm的杨树木材;当微波功率为900W时,规格为10cm×10cm×10cm和10cm×10cm×2.5cm的新木块中黄斑星天牛(Anoplophora nobolis)幼虫完全死亡所需时间分别为5min和2min;而干木块中则仅需3min和30s.对微波处理引起木材温度变化和水分损失以及天牛幼虫的水分损失进行了初步研究.     

Pocono mesic till barrens in retreat: topography,fire and forest contagion effects

The Pocono mesic till barrens (PMTB) are a unique assemblage of fire-maintained shrub communities that support numerous rare species. Historically these barrens covered a large area in the vicinity of Long Pond, Pennsylvania, USA. However, due largely to regional fire suppression instituted in the early 1960s, over 70% of the area covered by barrens succeeded to fire-intolerant forest that does not support the rare species. We investigated the influence of forest proximity on barrens succession across three geomorphic types during periods of high fire frequency and fire suppression, testing the hypothesis that forest processes such as seed rain, shading, and detrital enrichment of soils enhances barrens succession through a contagion effect. Evidence of a forest contagion effect should be shown by increased rates of barrens succession with increasing proximity to the nearest forest edge. In order to detect a forest contagion effect, barrens persistence and barrens succession were modeled in proximity zones of 0-50 m, 50-100 m, 100-200 m, and greater than 200 m from the nearest forest edge. We used existing GIS data layers for fire, geomorphology, and vegetation distribution in 1938, 1963, and 1992. The layers were modified and overlain using ArcView software to determine persistence and succession rates for each unique combination of layers in each proximity zone from 1938 to 1963 (pre-fire suppression) and 1963 to 1992 (post-fire suppression). ANCOVA results indicate that proximity to the nearest forest edge significantly affected barrens persistence rates in both time periods, but succession rates were significantly affected in 1938 to 1963 only. Twenty-eight percent of the 1938 barrens succeeded to forest by 1963; 56% of the 1963 barrens became forest by 1992. Results support previous findings that barrens persistence is enhanced by increased fire frequency, and that barrens persist longer where they overlie flat glacial till than on other geomorphology types.     

Upregulation of neurokinin A levels by nerve growth factor in the experimental asthmatic guinea pig

AIM: To explore the regulatory mechanism of nerve growth factor (NGF) on neurokinin A in the experimental asthmatic guinea pig. METHODS: Radioimmunoassay was used to determine the alteration of neurokinin A levels in the lower respiratory tract and visceral sensory afferent sites while NGF was absent (inhalation of NGF antibody through nasal cavity) in the asthmatic guinea pig. RESULTS: The contents of neurokinin A in the trachea, bronchus, lung, C₇-T₅ spinal ganglia and the correspondent spinal dorsal horn, nodose ganglia and solitary nucleus area in the experimental asthmatic guinea pig with the absent of NGF in the respiratory tract were much lower than those in the asthmatic and control groups (P＜0.01). CONCLUSION: NGF upregulated the contents of neurokinin A in the lower respiratory tract and visceral sensory sites of the experimental asthmatic guinea pig, and both might be involved in the pathogenesis of asthma.     

Human interleukin-1β induces A375-S2 human melanoma apoptosis through caspase pathway

AIM: To study the molecular biological mechanism and signal transduction pathway of interleukin-1β (IL-1β)-induced apoptosis in A375-S2 melanoma cells. METHODS: Photomicrocropy showed typical apoptotic changes. The cytotoxic effect of IL-1β in vitro and influences of caspases in this effect were measured by MTT assay. The cytotoxicity of cells was assessed by LDH-based assay. Degradation of DNA was detected by agarose gel electrophoresis. RESULTS: The inhibitory effect of IL-1β on A375-S2 cell growth was in a dose and time-dependent manner, and cell death rate reached more than 90% at 72 h after treatment with 10^-9mol/L IL-1β. The inhibitors of caspase-family, -1, -3, -8, -9, and -10, partially blocked cell death at early stage. LDH assay showed that major IL-1β-induced cell death was apoptosis, and in a dose and time-dependent manner. Typical apoptotic DNA ladder was observed in agarose gel electrophoresis. CONCLUSION: IL-1β induced apoptosis in melanoma A375-S2 cells by activating caspase pathway.     

昆虫抗菌肽生物学活性及其应用前景

昆虫抗菌肽是昆虫免疫后存在于血淋巴中的一类活性肽 ,具有广谱的抗菌、抗病毒、抑制肿瘤的生物活性 ,具有很高的应用潜力。本文主要介绍昆虫抗菌肽的类型、生理活性、基因的克隆与表达及在动物科学中的应用前景