897 resultados para melanogaster subgroup
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Ticks are blood-feeding arthropods that may secrete immunosuppressant molecules, which inhibit host inflammatory and immune responses and provide survival advantages to pathogens at tick bleeding sites in hosts. In the current work, two families of immunoregulatory peptides, hyalomin-A and -B, were first identified from salivary glands of hard tick Hyalomma asiaticum asiaticum. Three copies of hyalomin-A are encoded by an identical gene and released from the same protein precursor. Both hyalomin-A and -B can exert significant anti-inflammatory functions, either by directly inhibiting host secretion of inflammatory factors such as tumor necrosis factor-alpha, monocyte chemotectic protein-1, and interferon-gamma or by indirectly increasing the secretion of immunosuppressant cytokine of interleukin-10. Hyalomin-A and -B were both found to potently scavenge free radical in vitro in a rapid manner and inhibited adjuvant-induced inflammation in mouse models in vivo. The JNK/SAPK subgroup of the MAPK signaling pathway was involved in such immunoregulatory functions of hyalomin-A and -B. These results showed that immunoregulatory peptides of tick salivary glands suppress host inflammatory response by modulating cytokine secretion and detoxifying reactive oxygen species.
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Regulation of neuronal gene expression is critical to nervous system development. REST (RE1-silencing transcription factor) regulates neuronal gene expression through interacting with a group of corepressor proteins including REST corepressors (RCOR). Here we show that Xenopus RCOR2 is predominantly expressed in the developing nervous system. Through a yeast two-hybrid screen, we isolated Xenopus ZMYND8 (Zinc finger and MYND domain containing 8) as an XRCOR2 interacting factor. XRCOR2 and XZMYND8 bind each other in co-immunoprecipitation assays and both of them can function as transcriptional repressors. XZMYND8 is co-expressed with XRCOR2 in the nervous system and overexpression of XZMYND8 inhibits neural differentiation in Xenopus embryos. These data reveal a RCOR2/ZMYND8 complex which might be involved in the regulation of neural differentiation. (C) 2010 Elsevier Inc. All rights reserved.
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An association of the dopamine receptor D4 (DRD4) gene located on chromosome 11p15.5 and attention deficit/hyperactivity disorder (ADHD) has been demonstrated and replicated by multiple investigators. A specific allele [the 7-repeat of a 48-bp variable number of tandem repeats (VNTR) in exon 3] has been proposed as an etiological factor in attentional deficits manifested in some children diagnosed with this disorder. In the current study, we evaluated ADHD subgroups defined by the presence or absence of the 7-repeat allele of the DRD4 gene, using neuropsychological tests with reaction time measures designed to probe attentional networks with neuroanatomical foci in D4-rich brain regions. Despite the same severity of symptoms on parent and teacher ratings for the ADHD subgroups, the average reaction times of the 7-present subgroup showed normal speed and variability of response whereas the average reaction times of the 7-absent subgroup showed the expected abnormalities (slow and variable responses). This was opposite the primary prediction of the study. The 7-present subgroup seemed to be free of some of the neuropsychological abnormalities thought to characterize ADHD.
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Three new and two known species of the Drosophila (Sophophora) obscura species-group are reported from Yunnan Province, southern China. The sinobscura species-subgroup is newly established by D. sinobscura, D. hubeiensis and D. luguensis sp. nov. Geographic distribution of the obscura group in and around China is discussed, and a key to 10 Chinese species of the obscura group is provided.
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The fourth chromosome of Drosophila melanogaster and its sister species are believed to be nonrecombining and have been a model system for testing predictions of the effects of selection on linked, neutral variation. We recently examined nucleotide variat
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Data on sexual behavior were collected in six groups of semi-commensal Macaca thibetana along the trail on the slope habitat between 1987 and 1989. Ignoring the common items such as mounting, presenting etc., 20 categories of sexual behavior were described. Most of the descriptions were likely to have enlarged the behavior repertoire reported in macaques, showing a great complexity of sociosexual interactions under the principally natural condition. A great diversity of grouping appeared in the mating season. The copulatory pattern was found to be the serial type contrary to previous speculation, and the mount-to-ejaculation ratio was higher in the central subgroup, as compared with the far-peripheral adult subgroup (FAS) with less male and female rivals. An age-class subdivision of sexually active males made it possible to show that the young adult male immigrants were the most active class in sexual activity. Subgrouping form FAS was a ''space-segregation'' tactic of mating for the losers of both sexes in the competition. Some parameters of copulation were also documented.
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Testosterone undecanoate (TU) is under phase III clinical trial as a hormonal male contraceptive in China. Sex hormones can modulate the immune system. Female hormonal contraceptives may affect SIV/HIV-1 transmission. To evaluate the safety of TU and to understand whether long-term use of TU for a male contraceptive affects users' immunological features, adult male rats were treated for a 32-week TU-treated phase at the dose of 20 mg TU/kg body weight and a 24-week recovery phase. The reproductive and immunological parameters of 4-6 rats in each subgroup were examined at the stated time point. The mean sperm count and viability in the treated rats were significantly suppressed (p < 0.01). In the TU-treated group: the mean blood leukocyte and lymphocyte counts; the proliferation indexes of T cells from peripheral blood mononuclear cells (PBMC) and spleen; and, of B cells from spleen, as well as the mean counts of blood T, NK, and B cells decreased in comparison with those of control group. These decreases were not significant (p > 0.01). Similarly, the mean serum IgM, IgG, and IgA levels and complement activity in TU-treated rats were lower than those in control group (p > 0.01), and the changes in the antibody levels of the examined genital secretions were not significant (p > 0.01). The changes in the thickness of urethra epithelium, and in secretory component (SC) expression in genitals were not observed in the treated group. These results demonstrated that long-term supraphysiological TU injection did not obviously affect the examined rat immunological parameters.
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The genus Pseudostegana is revised, with descriptions of 20 new species from Southeast Asia: P. angustifasciata Chen and Wang, sp. n., P. atrofrons Chen and Toda, sp. n., P. bifasciata Chen and Toda, sp. n., P. bisetosa Chen and Toda, sp. n., P. curvata Chen and Toda, sp. n., P. dactylis Chen and Toda, sp. n., P. dolichopoda Chen and Wang, sp. n., P. hamata Chen and Toda, sp. n., P. latifasciata Chen and Toda, sp. n., P. leptoptera Chen and Toda, sp. n., P. melanogaster Chen and Toda, sp. n., P. melanopogonias Chen and Toda, sp. n., P. myrmecoformis Chen and Toda, sp. n., P. nitidifrons Chen and Wang, sp. n., P. nitidiventris Chen and Toda, sp. n., P. orbicapitata Chen and Toda, sp. n., P. oxycephala Chen and Toda, sp. n., P. pallidimaculata Chen and Wang, sp. n., P. philoga Chen and Wang, sp. n. and P xanthoptera Chen and Wang, sp. n. On the basis of the wing patterns, six species-groups are established: the atrofrons, grandipalpis, fleximediata, javana, latiparma and zonaria groups. A key to the all species of this genus is provided.
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Engineering changes (ECs) are raised throughout the lifecycle of engineering products. A single change to one component produces knock-on effects on others necessitating additional changes. This change propagation significantly affects the development time and cost and determines the product's success. Predicting and managing such ECs is, thus, essential to companies. Some prediction tools model change propagation by algorithms, whereof a subgroup is numerical. Current numerical change propagation algorithms either do not account for the exclusion of cyclic propagation paths or are based on exhaustive searching methods. This paper presents a new matrix-calculation-based algorithm which can be applied directly to a numerical product model to analyze change propagation and support change prediction. The algorithm applies matrix multiplications on mutations of a given design structure matrix accounting for the exclusion of self-dependences and cyclic propagation paths and delivers the same results as the exhaustive search-based Trail Counting algorithm. Despite its factorial time complexity, the algorithm proves advantageous because of its straightforward matrix-based calculations which avoid exhaustive searching. Thereby, the algorithm can be implemented in established numerical programs such as Microsoft Excel which promise a wider application of the tools within and across companies along with better familiarity, usability, practicality, security, and robustness. © 1988-2012 IEEE.
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Acoustic communication in drosophilid flies is based on the production and perception of courtship songs, which facilitate mating. Despite decades of research on courtship songs and behavior in Drosophila, central auditory responses have remained uncharacterized. In this study, we report on intracellular recordings from central neurons that innervate the Drosophila antennal mechanosensory and motor center (AMMC), the first relay for auditory information in the fly brain. These neurons produce graded-potential (nonspiking) responses to sound; we compare recordings from AMMC neurons to extracellular recordings of the receptor neuron population [Johnston's organ neurons (JONs)]. We discover that, while steady-state response profiles for tonal and broadband stimuli are significantly transformed between the JON population in the antenna and AMMC neurons in the brain, transient responses to pulses present in natural stimuli (courtship song) are not. For pulse stimuli in particular, AMMC neurons simply low-pass filter the receptor population response, thus preserving low-frequency temporal features (such as the spacing of song pulses) for analysis by postsynaptic neurons. We also compare responses in two closely related Drosophila species, Drosophila melanogaster and Drosophila simulans, and find that pulse song responses are largely similar, despite differences in the spectral content of their songs. Our recordings inform how downstream circuits may read out behaviorally relevant information from central neurons in the AMMC.
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This work considers the problem of fitting data on a Lie group by a coset of a compact subgroup. This problem can be seen as an extension of the problem of fitting affine subspaces in n to data which can be solved using principal component analysis. We show how the fitting problem can be reduced for biinvariant distances to a generalized mean calculation on an homogeneous space. For biinvariant Riemannian distances we provide an algorithm based on the Karcher mean gradient algorithm. We illustrate our approach by some examples on SO(n). © 2010 Springer -Verlag Berlin Heidelberg.
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黄土高原(土娄)土在《中国土壤系统分类(修订方案)》中属土垫旱耕人为土类的相应亚类,其土壤水分状况是诊断表层所属人为表层类堆垫表层(覆盖层)和诊断表下层(黏化层)的重要诊断特征。以土壤持水性能、蒸发性能和水分移动性能为切入点,对(土娄)土覆盖层和黏化层的土壤水文效应进行研究论证,以期对土垫旱耕人为土类及其亚类的诊断层与诊断特征获取更深层的认识。
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本论文结合功能研究和进化遗传学方法对动物天然免疫(innate immunity)相关分子的进化历程进行深入研究。受体对病原微生物的识别是天然免疫系统发挥功能的基础。作为模式识别受体(pattern recognition receptor, PRR),果蝇肽聚糖识别蛋白SD(PGRP-SD)在识别革兰氏阳性细菌的过程中发挥了重要作用。针对已有的黑腹果蝇(Drosophila melanogaster)群体数据,我们发现PGRP-SD在群体中存在2类高频的等位基因(分别为等位基因1和等位基因2)。以D. simulans为外群,我们追溯了黑腹果蝇2类等位基因上氨基酸的变化。这些氨基酸的结构特征和在蛋白质上所处的位置提示这2类等位基因在功能方面可能存在分化。通过功能研究的方法,我们发现在黑腹果蝇中该基因功能方面发生了显著的变化。等位基因2在有微生物时能激活天然免疫反应,但等位基因1的转基因果蝇成虫只要有外伤即便没有微生物的情况下即能激发天然免疫反应,而带有等位基因2果蝇成虫则不具有该功能。这一结果提示我们,发生在该等位基因上的氨基酸变化导致了其识别功能的变化。与推导的祖先基因相比,等位基因1发生了一个氨基酸的变化,因此导致其功能从识别细菌细胞壁组分肽聚糖转变为一未知的自身组分,即从病原相关分子模式(pathogen-associated molecular pattern,PAMP)识别受体转变为损伤相关识别模式(damage-associated molecular pattern, DAMP)识别受体。通过这一功能变化, 果蝇成虫可以通过仅识别自身损伤即可激活相应的免疫反应,对后续可能侵入的微生物进行杀伤。已有研究结果显示,微生物在进化过程中已经形成针对DAMP和PAMP规避策略。上述2类等位基因的同时存在能使黑腹果蝇同时具备两个机制,更加充分地抵抗病原微生物的入侵。结合功能研究和针对自然群体的群体遗传学分析,我们认为在黑腹果蝇群体中以高频共存的2类PGRP-SD等位基因可能可能受到了平衡选择(balancing selection)作用。上述工作主要研究了天然免疫系统识别受体的进化。而本论文的另一部分则主要针对天然免疫系统的效应分子(effector)进行了研究。作为重要的效应分子,抗菌肽在杀菌方面发挥着最为直接的作用。因此,研究抗菌肽的进化对于探索天然免疫系统的进化具有重要意义。本研究以两栖类动物大蹼铃蟾抗菌肽基因家族为例,通过对分别来自2个大蹼铃蟾个体的皮肤cDNA文库进行测序,我们鉴别出56个不同的抗菌肽cDNA序列。每一个cDNA均编码2个不同的抗菌肽,maximin 和maximin H。基于针对这些cDNA序列的分析,我们发现2类抗菌肽编码序列的非同义替代率均高于同义替代率,呈现高度分化的特征。但是,在信号肽和其它非抗菌肽编码区域并没有发现这种情况。这一结果提示抗菌肽可能受到超显性选择(overdominent selection, 即平衡选择)的影响。同时,我们分别从皮肤和肝脏克隆基因了7个抗菌肽的基因组编码序列并进行了测序。这些从不同组织获得的抗菌肽在各个编码序列中均存在序列的差异的同时呈现了相同的结构。这一结果提示不同抗菌肽间的差异不太可能来自于体细胞突变而是快速序列进化的结果。通过构建来自于同一个体的抗菌肽的不同编码区的基因树,我们发现结构域重排(domain shuffling)和/或基因转换(gene conversion)在这些抗菌肽的进化历程中发挥作用。
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本实验室果蝇研究工作,主要集中在黑腹果蝇的新基因起源的研究。新基因起源的分子机制主要包括:外显子重排、基因复制、基因逆转座、移动元件介导、基因水平转移、基因从头起源、基因的断裂融合。为了阐述这些新基因的产生和它们所带来的物种适应性,我们对这些新近起源的基因进行了功能研究。但是,仅仅限于新基因所在物种的功能研究并不能完全解释新基因产生的进化原因,我们需要了解它是否能够给没有该基因的果蝇物种带来一定的适应性。例如一些生殖相关新基因,如果我们将它们转入没有该基因的果蝇,那是否能够给该果蝇带来生殖能力的提高?无论结果如何,这都为我们研究新基因的起源提供一个重要线索。由此,黑腹果蝇以外的其它果蝇物种中实现转基因成为该研究的重要技术环节。但是,实验室目前的转基因系统仅限于P转座子介导的黑腹果蝇转基因系统,因而我们需要建立一种新的转基因平台。而转座子Minos打破物种范围的转基因特性,以及它的转座特点为我们提供了选择。转座子Minos是从果蝇D. hydei中克隆出来长约1.8kb的Ⅱ型转座子,Tc1家族转座元件成员。Minos的转座机制与大部分转座子一样,在宿主基因组里面实行着剪切和粘贴的运作机制。Minos在转座时,偏向插入TA位点并且主要集中于内含子区域,这样可以减少对插入位置基因的影响。此外,Minos在黑腹果蝇中的转座效率约30%,并且拥有一套成熟的选择标记。因此,Minos成为我们解决非黑腹果蝇转基因技术难题的首选。 在本文的工作中,我们采用由希腊Savakis教授(希腊分子生物学与生物技术研究所)提供的Minos转基因系统,完成果蝇的转基因实验。在这套转基因系统中,非自主的转座子Minos和转座酶基因被克隆到了不同载体当中。其中Minos转座子序列中插入了由3xP3眼睛特异表达的启动子介导表达的eGFP报告基因,而转座酶基因则由热激蛋白hsp70启动子调控表达。实验过程中,我们在果蝇D. melanogaster 和D. yakuba的胚胎中分别同时显微注射入含有转座子和转座酶本实验室果蝇研究工作,主要集中在黑腹果蝇的新基因起源的研究。新基因起源的分子机制主要包括:外显子重排、基因复制、基因逆转座、移动元件介导、基因水平转移、基因从头起源、基因的断裂融合。为了阐述这些新基因的产生和它们所带来的物种适应性,我们对这些新近起源的基因进行了功能研究。但是,仅仅限于新基因所在物种的功能研究并不能完全解释新基因产生的进化原因,我们需要了解它是否能够给没有该基因的果蝇物种带来一定的适应性。例如一些生殖相关新基因,如果我们将它们转入没有该基因的果蝇,那是否能够给该果蝇带来生殖能力的提高?无论结果如何,这都为我们研究新基因的起源提供一个重要线索。由此,黑腹果蝇以外的其它果蝇物种中实现转基因成为该研究的重要技术环节。但是,实验室目前的转基因系统仅限于P转座子介导的黑腹果蝇转基因系统,因而我们需要建立一种新的转基因平台。而转座子Minos打破物种范围的转基因特性,以及它的转座特点为我们提供了选择。转座子Minos是从果蝇D. hydei中克隆出来长约1.8kb的Ⅱ型转座子,Tc1家族转座元件成员。Minos的转座机制与大部分转座子一样,在宿主基因组里面实行着剪切和粘贴的运作机制。Minos在转座时,偏向插入TA位点并且主要集中于内含子区域,这样可以减少对插入位置基因的影响。此外,Minos在黑腹果蝇中的转座效率约30%,并且拥有一套成熟的选择标记。因此,Minos成为我们解决非黑腹果蝇转基因技术难题的首选。 在本文的工作中,我们采用由希腊Savakis教授(希腊分子生物学与生物技术研究所)提供的Minos转基因系统,完成果蝇的转基因实验。在这套转基因系统中,非自主的转座子Minos和转座酶基因被克隆到了不同载体当中。其中Minos转座子序列中插入了由3xP3眼睛特异表达的启动子介导表达的eGFP报告基因,而转座酶基因则由热激蛋白hsp70启动子调控表达。实验过程中,我们在果蝇D. melanogaster 和D. yakuba的胚胎中分别同时显微注射入含有转座子和转座酶所在的质粒。转座酶在37度条件诱导下进行表达,协助Minos完成转座过程。在转基因果蝇的阳性筛选中,我们利用眼睛特异表达的绿色荧光蛋作为选择标记。并且,我们通过PCR实验进一步验证了转基因果蝇的真实性。本研究中,我们对转基因实验条件进行了初步优化。我们通过对黑腹果蝇白眼突变品系W1118和D. yakuba注射后胚胎进行保湿,对D. yakuba注射胚胎进行非退壳处理。在改进条件下W1118和D. yakuba的存活率分别为10%和3%左右。通过筛选转基因阳性果蝇,我们得出Minos在W1118和D. yakuba中的转座效率分别在32%和20%左右。我们的实验结果再一次证实了Minos在果蝇D. melanogaster中可行性。同时,该工作也初步完成了在果蝇D. yakuba 中的第一次Minos介导的转基因实验,为新基因的跨物种功能研究奠定了实验基础。在未来的工作计划中,我们将采用Minos转基因系统,把实验室目前研究的黑腹果蝇新基因导入其它物种果蝇进行功能研究。 水稻是一种重要的世界粮食作物,世界上过半的人口以水稻为主食。水稻相对别的粮食作物来讲具有较小的基因组,并且拥有较好的基因组注释,是一种理想的单子叶模式生物。植物转基因技术的发展推动着水稻功能基因组学的研究,目前水稻的转基因技术主要依赖于土壤细菌农杆菌(Agrobacterium tumefaciens)T-DNA介导的外源基因染色体插入。在自然状态下,农杆菌的T-DNA位于Ti致瘤质粒当中。它包括了一些转座元件和一些帮助T-DNA转座的毒性蛋白基因和调节基因。由于Ti质粒上的T-DNA太长,并且没有太多的酶切位点,因此自然状态的T-DNA不适合进行转基因实验。为了方便T-DNA的实际应用,研究人员创立了双载体转基因系统。T-DNA转座区被分离到出Ti载体,并且装载到另外一个适合实验操作的质粒当中,而毒性蛋白表达基因等则保留在Ti质粒上。因此,在进行T-DNA介导的转基因实验时,需要同时存在T-DNA载体和Ti质粒。 本文以“水稻注释计划数据库RAP-DB”的表达数据为参考,选择了60个高表达基因的启动子区域进行克隆。通过对T-DNA载体pCAMBIA1301 进行改造,去掉其原来的35S启动子,将预测的基因启动子克隆到该载体中并与报告基 摘要 因GUS 基因融合。通过分子克隆实验,我们得到了45个高表达基因的启动子载体。最终,为了测试这45个启动子的启动效率,我们会将它们转化到水稻愈伤组织中通过启动子融合的GUS基于表达情况来判断我们启动子的启动效率。
Resumo:
双尾-C 基因 (Bicaudal-C)首先在果蝇(Drosophila melanogaster)中发现,其功能丧失导致果蝇胚胎滤泡细胞的错误迁移、头部的缺失和双尾结构的形成。后来发现多个物种都含有Bicaudal-C 的同源基因,其中小鼠中的同源基因Bicc1 的缺失导致小鼠产生肾脏等脏器的病变,其症状与人类多囊肾疾病高度相似,但其具体机制还不清楚。本研究以小鼠肾脏组织总RNA 为模板体外反转录为cDNA,通过分段巢式 PCR 及酶切连接的方法获得了全长约3Kb 的小鼠Bicc1 cDNA 序列。根据生物信息学分析全长的Bicc1 蛋白,选择两个免疫原性较好的区段作为抗原位点构建相应的原核表达载体;IPTG 诱导表达并纯化融合蛋白,制备两种兔抗Bicc1 蛋白多克隆抗体,并通过Western blot 证实这两种抗体具有高度特异性。用细胞免疫荧光方法及免疫组织化学方法对该蛋白的定位做了一些初步研究。发现Bicc1 蛋白定位于体外培养的小鼠肾细胞的细胞质内,并在胚胎发育于期表达仅在心脏,后来逐步地在各个组织器官内出现,并在出生后的小鼠体内表达稳定。Bicc1 mDNA 也表达于多个器官内,并且在肾脏中有明显较高的表达量。找到了的两个针对Bicc1 基因的RNAi 的序列,通过荧光强度变化和Western blot 均证明这两个序列能明显降低Bicc1 蛋白在体外培养细胞中的表达水平,为下一步建立稳定的细胞株奠定了良好的基础。