果蝇分子群体遗传研究分析方法概述

果蝇属物种长期以来被作为基础生物学、特别是群体和进化遗传学的模式物种,来探讨生物学中的一些基本问题,如物种形成的遗传机制、新基因的起源及其方式、适应性进化的遗传机制等.群体遗传的方法贯穿于遗传学、生态学、古生物学、系统发育学等领域之中,已渐成为基础生物学研究的重要方法.围绕果蝇群体遗传研究中的3个主要问题,即起源地、群体历史动态和群体遗传结构,就当前用于分析上述问题的方法进行了概述,并强调了发展适用于多个座位数据的分析方法是将来的一个重要发展方向.     

An internal thermal sensor controlling temperature preference in Drosophila

Animals from flies to humans are able to distinguish subtle gradations in temperature and show strong temperature preferences. Animals move to environments of optimal temperature and some manipulate the temperature of their surroundings, as humans do using clothing and shelter. Despite the ubiquitous influence of environmental temperature on animal behaviour, the neural circuits and strategies through which animals select a preferred temperature remain largely unknown. Here we identify a small set of warmth-activated anterior cell (AC) neurons located in the Drosophila brain, the function of which is critical for preferred temperature selection. AC neuron activation occurs just above the fly's preferred temperature and depends on dTrpA1, an ion channel that functions as a molecular sensor of warmth. Flies that selectively express dTrpA1 in the AC neurons select normal temperatures, whereas flies in which dTrpA1 function is reduced or eliminated choose warmer temperatures. This internal warmth-sensing pathway promotes avoidance of slightly elevated temperatures and acts together with a distinct pathway for cold avoidance to set the fly's preferred temperature. Thus, flies select a preferred temperature by using a thermal sensing pathway tuned to trigger avoidance of temperatures that deviate even slightly from the preferred temperature. This provides a potentially general strategy for robustly selecting a narrow temperature range optimal for survival.     

论构建区域创新文化环境与对策

世界经济发展的历史表明 ,文化与经济的发展有着相当密切的关系 ,良好的创新文化氛围是企业成长的温床 ,有利于科学发展与技术创新。从区域经济发展的角度看 ,要加快企业的成长 ,必须营造一种有利于创业的文化氛围。如何寻求在恰当的区域落实创新文化的建设与发展 ,已经成为全球化国际竞争的重大课题 ,引起了各国政府、企业及科研机构的高度重视     

The ageing systemic milieu negatively regulates neurogenesis and cognitive function

In the central nervous system, ageing results in a precipitous decline in adult neural stem/progenitor cells and neurogenesis, with concomitant impairments in cognitive functions. Interestingly, such impairments can be ameliorated through systemic perturbations such as exercise. Here, using heterochronic parabiosis we show that blood-borne factors present in the systemic milieu can inhibit or promote adult neurogenesis in an age-dependent fashion in mice. Accordingly, exposing a young mouse to an old systemic environment or to plasma from old mice decreased synaptic plasticity, and impaired contextual fear conditioning and spatial learning and memory. We identify chemokines--including CCL11 (also known as eotaxin)--the plasma levels of which correlate with reduced neurogenesis in heterochronic parabionts and aged mice, and the levels of which are increased in the plasma and cerebrospinal fluid of healthy ageing humans. Lastly, increasing peripheral CCL11 chemokine levels in vivo in young mice decreased adult neurogenesis and impaired learning and memory. Together our data indicate that the decline in neurogenesis and cognitive impairments observed during ageing can be in part attributed to changes in blood-borne factors.     

Wolbachia在Drosophila auraria复合种和Drosophila simulans中的感染

用 Ｐ Ｃ Ｒ 方法检测了多种果蝇中共生菌 Ｗ ｏｌｂａｃｈｉａ 的感染,发现 Ｄｒｏｓｏｐｈｉｌａ ａｕｒａｒｉａ 复合种以及采集于北京地区的 Ｄｒｏｓｏｐｈｉｌａ ｓｉｍ ｕｌａｎｓ为 Ｗｏｌｂａｃｈｉａ 所感染, Ｒ Ｆ Ｌ Ｐ分析证实为单一感染．克隆了编码 Ｗ ｏｌｂａｃｈｉａ 外膜蛋白质的 ｗ ｓｐ 基因并进行了序列测定．同时比较了 Ｄｒｏｓｏｐｈｉｌａ ａｕｒａｒｉａ 复合种内 ４ 个种和采集于北京及美国加州的 Ｄｒｏｓｏｐｈｉｌａ ｓｉｍ ｕｌａｎｓ 的线粒体的细胞色素氧化酶 ２ 亚基基因的部分序列． 进而讨论了 Ｗｏｌｂａｃｈｉａ 对 Ｄｒｏｓｏｐｈｉｌａ ａｕｒａｒｉａ 复合种成员之间进化关系的影响．