容器形状和出口位置对台湾乳白蚁逃遁行为的影响(英文)

【目的】逃离危险对集群生活的动物来说是一项重要挑战。白蚁是真社会性昆虫,群体密度较大。因此,白蚁可能进化出了特殊的策略集体逃离危险情境。【方法】本研究比较了实验室条件下台湾乳白蚁Coptotermes formosanus工蚁在不同形状容器(没有出口的圆形和方形容器)的逃遁行为,并调查了在有出口的情况下,台湾乳白蚁工蚁从圆形容器边缘、方形容器直角处和方形容器直角边中间的撤离效 率。【结果】在没有出口的情况下,受惊的台湾乳白蚁立即移动到圆形或方形容器的边缘区域并沿着容器的壁移动。然而,在方形容器的直角处,逃遁的台湾乳白蚁工蚁形成明显的堵塞(直角附近的白蚁密度显著高于其他区域,而移动速度显著低于其他区域的白蚁)。当容器上有出口时,大部分台湾乳白蚁工蚁分散在容器边缘,因此在出口位置周围未发现明显的堵塞。有趣的是,台湾乳白蚁工蚁逃出有出口的圆形容器的时间与从出口在直角附近的方形容器的无显著差异,但其从出口在直角边中间的方形容器的逃出时间更长。【结论】研究结果表明容器形状与出口位置均对台湾乳白蚁工蚁的逃遁行为与撤离效率造成影响。此外,白蚁使用了特殊的策略来避免多见于其他群居动物(如人类、小鼠等)的“快即慢”效应。由于白蚁工蚁没有视觉,研究白蚁的逃遁策略可为人群如何高效撤离可视度较低的危险环境提供启示。     

病毒利用UPP逃避抗病毒反应的研究进展

泛素-蛋白酶体途径是溶酶体外蛋白降解的主要系统,在许多细胞功能中发挥重要作用。越来越多的证据表明病毒参与泛素-蛋白酶体途径,干扰IFN信号通路和免疫受体表达、凋亡抑制及介导病毒潜伏。深入理解病毒利用泛素-蛋白酶体途径逃避宿主抗病毒反应的策略,有助于揭示病毒的致病机理和鉴定抗病毒药物新靶标。     

Electron microscopic observations of Orientia tsutsugamushi in salivary gland cells of naturally Infected Leptotrombidium pallidum larvae during feeding

We performed a detailed electron microscopic observation on the escaping process of Orientia tsutsugamushi from the salivary gland cells of naturally infected trombiculid larvae into the acinar lumen of the gland during feeding on mice. In unfed larvae, many O. tsutsugamushi were intermingled with secretory granules in the cytoplasm of the salivary gland cell. O. tsutsugamushi was neither found in the acinar lumen nor observed escaping from the apical surface of the gland cell. In contrast, in the larvae fed on mice, many O. tsutsugamushi were observable in the acinar lumen. They were enveloped with the host glandular cell membrane. In salivary gland cells, secretory granules changed the distribution and accumulated in the apical region. In such cells, the majority of O. tsutsugamushi were found at the base of the cell. Some O. tsutsugamushi were pushing the glandular cell membrane outward in various degrees, showing different stages of escape. These findings suggest that larval feeding induced O. tsutsugamushi escape from salivary gland cells, that the escape was by budding, during which O. tsutsugamushi were enveloped in the host cell membrane, and that O. tsutsugamushi would be injected into the mouse skin as a mixture with mite saliva. The study also revealed the presence of many small vesicles that had the same cell wall structure as O. tsutsugamushi in the cytoplasm of the salivary gland cell. Most of them seemed to be products from degenerated Orientia.     

Dynamics of prey-flock escaping behavior in response to predator's attack

The dynamic behavior of prey-flock in response to predator's attack was investigated by using molecular dynamics (MD) simulations in a two-dimensional (2D) continuum model. By locally applying interactive forces between prey individuals (e.g. attraction, repulsion, and alignment), a coherently moving state in the same direction was obtained among individuals in prey-flock. When a single predator was introduced to the prey population, the prey-flock was correspondingly deformed by the predator's continuous attacks towards the prey-flock's center. In response to the predator's attack, three regimes in the flock size (compression (Regime I), expansion (Regime II), compression (Regime III)) were revealed if the predator's attack speed (kappa) was comparatively low to the escape speed of prey-flock. If noise was added to the predator's attacking course, a higher degree of variation was observed in the patterns of compression and expansion in the prey-flock size. However, the scaling behavior in the changes in prey-flock size was present in different levels of noise with the increase in predation risk (R) when kappa takes an appropriately low value. During the procedure of escaping, order breaking in alignment (phi) of prey population was observed, while the degree of alignment was dependent upon the changes in parameters of kappa and R.