EcR-RNAi和印楝素处理斜纹夜蛾幼虫诱导腹足发育受阻表型(英)简

蜕皮激素是一种可以诱导一系列变态发育关键过程的昆虫蜕皮调节激素,
与蜕皮激素受体结合以后与配体蛋白~Usp~作用形成一个复合体发挥作用.
通过兼并引物克隆获得斜纹夜蛾一个~600~bp~的~EcR
cDNAs~片段编码~200~个氨基酸, 斜纹夜蛾是东亚地区一种主要的农作物害虫.
利用这段序列设计了~EcR-dsRNA~通过注射幼虫的实验来分析~EcR~基因在不同发育阶段的功能.
同时利用印楝素喂食RNAi注射的幼虫观察其与正常对照组有何发育差异.
结果显示~EcR RNAi~会影响正常的蜕皮过程并导致不完成蛹化, 在~EcR
RNAi~注射并喂食印楝素的实验组,
幼虫出现生长迟缓、发育进程紊乱和腹足发育不正常等现象,
由此推测印楝素和~EcR RNAi~或许影响了蜕皮级联调控通路,
由此引发变态发育过程中组织重建紊乱.     

家蚕促咽侧体素受体基因克隆及发育表达

文章克隆得到家蚕(Bombyx mori)神经肽促咽侧体素受体基因(Allatotropin receptor,BommoATR),开放阅读框全长为1 254 bp,编码416个氨基酸.Bommo-ATR氨基酸序列的二级结构预测为7次穿膜蛋白,符合GPCR家族成员的典型特征.实时荧光定量PCR结果表明,家蚕脑-咽下神经节复合体中的ATR mRNA在5龄幼虫期表达量最高,其次为蛹后期,蛹前期和成虫阶段表达量最低.其中5龄幼虫第2天表达量最高,1～5 d持续维持较高的表达水平,这可能与保幼激素的合成有关.     

Abolition of the expression of inhibitory guanine nucleotide regulatory protein Gi activity in diabetes

Many cell-surface receptors for hormones appear to exert their effects on target cells by interacting with specific guanine nucleotide binding regulatory proteins (G-proteins) which couple receptors to their second-messenger signal generation systems. A common intracellular second messenger, which is used by many hormones, is cyclic AMP. This is produced by adenylate cyclase, whose activity is controlled by two G-proteins, Gs which mediates stimulatory effects and Gi inhibitory effects on adenylate cyclase activity. In liver, the hormone glucagon increases intracellular cAMP concentrations by activating adenylate cyclase by a Gs-mediated process. This effect of glucagon is antagonised by the hormone insulin, although the molecular mechanism by which insulin elicits its actions is obscure. However, insulin receptors exhibit a tyrosyl kinase activity and appear to interact with G-proteins, perhaps by causing phosphorylation of them. In type I diabetes, circulating insulin levels are abnormally low, giving rise to gross perturbations of metabolism as well as to a variety of complications such as ionic disturbances, neuropathies of the nervous system, respiratory and cardiovascular aberrations and predisposition to infection. We show here that experimentally-induced type I diabetes leads to the loss of expression of Gi in rat liver. As it has been suggested that Gi may couple receptors to K+-channels as well as mediating the inhibition of adenylate cyclase, aberrations in the control of expression of this key regulatory protein in type I diabetes may be expected to lead to pleiotropic effects.     

Molecular cloning and expression of brain-derived neurotrophic factor

During the development of the vertebrate nervous system, many neurons depend for survival on interactions with their target cells. Specific proteins are thought to be released by the target cells and to play an essential role in these interactions. So far, only one such protein, nerve growth factor, has been fully characterized. This has been possible because of the extraordinarily (and unexplained) large quantities of this protein in some adult tissues that are of no relevance to the developing nervous system. Whereas the dependency of many neurons on their target cells for normal development, and the restricted neuronal specificity of nerve growth factor have long suggested the existence of other such proteins, their low abundance has rendered their characterization difficult. Here we report the full primary structure of brain-derived neurotrophic factor. This very rare protein is known to promote the survival of neuronal populations that are all located either in the central nervous system or directly connected with it. The messenger RNA for brain-derived neurotrophic factor was found predominantly in the central nervous system, and the sequence of the protein indicates that it is structurally related to nerve growth factor. These results establish that these two neurotrophic factors are related both functionally and structurally.     

Fat cells reactivate quiescent neuroblasts via TOR and glial insulin relays in Drosophila

Many stem, progenitor and cancer cells undergo periods of mitotic quiescence from which they can be reactivated. The signals triggering entry into and exit from this reversible dormant state are not well understood. In the developing Drosophila central nervous system, multipotent self-renewing progenitors called neuroblasts undergo quiescence in a stereotypical spatiotemporal pattern. Entry into quiescence is regulated by Hox proteins and an internal neuroblast timer. Exit from quiescence (reactivation) is subject to a nutritional checkpoint requiring dietary amino acids. Organ co-cultures also implicate an unidentified signal from an adipose/hepatic-like tissue called the fat body. Here we provide in vivo evidence that Slimfast amino-acid sensing and Target of rapamycin (TOR) signalling activate a fat-body-derived signal (FDS) required for neuroblast reactivation. Downstream of this signal, Insulin-like receptor signalling and the Phosphatidylinositol 3-kinase (PI3K)/TOR network are required in neuroblasts for exit from quiescence. We demonstrate that nutritionally regulated glial cells provide the source of Insulin-like peptides (ILPs) relevant for timely neuroblast reactivation but not for overall larval growth. Conversely, ILPs secreted into the haemolymph by median neurosecretory cells systemically control organismal size but do not reactivate neuroblasts. Drosophila thus contains two segregated ILP pools, one regulating proliferation within the central nervous system and the other controlling tissue growth systemically. Our findings support a model in which amino acids trigger the cell cycle re-entry of neural progenitors via a fat-body-glia-neuroblasts relay. This mechanism indicates that dietary nutrients and remote organs, as well as local niches, are key regulators of transitions in stem-cell behaviour.     

稻水蝇(Ephydra macellaria Egger)生活史研究

稻水蝇在内蒙古东部地区年发生 4代 ,世代重叠 ,发育历期世代间存有极显著的差异 ,虫态间发育历期除幼虫与蛹外亦呈极显著差异 .成虫越冬 .4月下旬越冬成虫大量出现 .4月下旬见一代卵 ,5月 10日为一代幼虫盛发期 ,化蛹在 5月 2 5日始盛 ,一代成虫于 5月下旬可见 .第二代 5月下旬见卵 ,6月上旬至 7月上旬幼虫发生 ,6月中旬至 7月上旬化蛹 ,6月下旬至 7月中旬为二代成虫可见期 .第三、四代幼虫分别发生于 7月上旬及下旬 ,第四代成虫于 8月中旬羽化 ,8月下旬达到羽化高峰并越冬 .第 2代危害严重 ,发生数量极显著多于其它各代     

中国数学史断代研究的一项新成果：—《明清数学史论文集》简介

本文简介梅荣照主编的《明清数学史论文集》一书，对中国数学史开展断代专题研究，是我国数学史界继承并发展李俨、钱宝琮、严郭杰先生研究成果的宏大计划，持续近三十年，历来为国际科学史界所重视，文集收入论文15篇、附录2篇，其中严敦杰先生遗作7篇，本文对15篇论文逐一作了简介。     

Recognition of myelin-associated glycoprotein by the monoclonal antibody HNK-1

Myelin-associated glycoprotein (MAG) is a quantitatively minor component in both peripheral and central myelin sheaths that is thought to have a role in cell-cell interactions within the nervous system. We show here that a mouse monoclonal antibody, HNK-1, which is directed against human natural killer cells also recognizes an antigenic determinant of human central and peripheral nervous system white matter by immunoperoxidase staining of tissue sections. Immunoblot analysis of myelin proteins and purified extracted MAG indicates that the antigen recognized is MAG.     

梨六点天蛾形态生物学特性

梨六点天蛾（Matumbagaschkewitschicomplacens）是苹果、梨、枣等果树的常见害虫,本研究观察了该虫的形态特征和生活习性。结果表明,雌成虫有长翅型和短翅型,虹吸式口器,长3—7toni。幼虫有黄斜线绿色型、黄斜线淡蓝绿色型、黄斜线黄色型、黄斜线镶嵌型、黄斜线圆斑型等5种类型。在河北冀东地区每年发...     

Distribution of growth hormone-like immunoreactive cells and somatostatin receptors in the nervous system and Hatschek's pit of amphioxus, Branchiostoma belcheri

Using immunohistochemical method and double staining technique, the localization of growth hormone (GH) and somatostatin receptors in the nervous system and Hatschek's pit of amphioxus has been investigated. The results showed that the growth hormone-like nerve cells and endocrine cells as well as three subtypes of somatostatin receptors exist in the nervous system and Hatschek's pit, and GH-like nerve cells and endocrine cells co-exist with three subtypes of somatostatin receptors in the brain vesicle and Hatschek's pit. It is suggested that a primitive control system of inhibitory growth hormone secretion in Hatschek's pit could have been developed in amphioxus, as in vertebrates. The present study provides new evidence for the endocrinology and the evolution of Hatschek's pit.     

Distribution of growth hormone-like immunoreactive cells and somatostatin receptors in the nervous system and Hatschek''s pit of amphioxus, Branchiostoma belcheri

Using immunohistochemical method and double staining technique, the localization of growth hormone (GH) and somatostatin receptors in the nervous system and Hatschek's pit of amphioxus has been investigated. The results showed that the growth hormone-like nerve cells and endocrine cells as well as three subtypes of somatostatin receptors exist in the nervous system and Hatschek's pit, and GH-like nerve cells and endocrine cells co-exist with three subtypes of somatostatin receptors in the brain vesicle and Hatschek's pit. It is suggested that a primitive control system of inhibitory growth hormone secretion in Hatschek's pit could have been developed in amphioxus, as in vertebrates. The present study provides new evidence for the endocrinology and the evolution of Hatschek's pit.     

Adrenergic activation of triiodothyronine production in brown adipose tissue

There are several mechanisms by which homeothermic animals increase heat production, including shivering, sympathetic nervous system activation and stimulation of thyroid hormone secretion. Studies in rats have shown that increased sympathetic activity causes increased heat production in brown adipose tissue (BAT) after cold exposure or food ingestion. Acute cold exposure also increases circulating thyroid hormones which in turn stimulate cellular metabolism through induction of various enzymes. Most metabolic effects of thyroxine (T4) are thought to be due to the triiodothyronine (T3) which is produced from T4 by a process of 5' monodeiodination. There are two enzymes responsible for this reaction: type I, or propylthiouracil (PTU)-sensitive iodothyronine deiodinase (5'D-I), which is reduced in hypothyroidism, stimulated in hyperthyroidism and probably provides most of the circulating T3 in the adult rat. Type II 5'-deiodinase (5'D-II) is characteristic of brain and pituitary, is increased by thyroidectomy, is not inhibited by PTU and provides 50-80% of the intracellular T3 in these two tissues. Recently, 5'D-II activity was identified in interscapular BAT. As the sympathetic nervous system influences the metabolic activation of BAT, we have studied the effects of noradrenaline and acute cold exposure on BAT 5'D-II. We report here that both noradrenaline and cold exposure increase BAT 5'D-II through alpha 1-adrenergic receptors, whereas depletion of catecholamines with alpha-methyl-p-tyrosine (MPT) prevents the effect of cold but not that of noradrenaline. These results suggest that the sympathetic nervous system may increase T3 production in rats by stimulating BAT 5'D-II. By increasing metabolic rate, this rise in T3 would enhance the thermogenic response to sympathetic stimulation.     

Functional corticotropin releasing factor receptors in the primate peripheral sympathetic nervous system

Corticotropin releasing factor (CRF) is a key hormone in the integrated response to stress, acting both as the major regulator of pituitary adrenocorticotropic hormone (ACTH) release and as a neuropeptide in the brain. The actions of CRF are mediated by specific plasma membrane receptors in the anterior pituitary gland and in discrete brain areas including the cerebral cortex and several regions related to the limbic system. In addition to the pituitary and central actions of CRF, systemic administration of the peptide in the rat, dog, monkey and man causes hypotension and tachycardia because of a decrease in peripheral vascular resistance. These observations, in conjunction with the finding of immunoreactive and bioactive CRF in peripheral tissues, suggest that the peptide is locally released in tissues to act as a neurotransmitter or paracrine hormone. As CRF is present in the adrenal medulla and the peptide is known to modulate the central activity of the autonomic nervous system, we investigated the possibility that CRF is involved in the regulation of the peripheral autonomic nervous system. Such an action of CRF is supported by our demonstration of specific CRF receptors in the monkey adrenal medulla and sympathetic ganglia. In the adrenal medulla, these receptors are coupled to adenylate cyclase and can stimulate the secretion of catecholamines and Met-enkephalin.     

Distribution of growth hormone-like immunoreactive cells and somatostatin receptors in the nervous system and Hatschek''''s pit of amphioxus, Branchiostoma belcheri

Using immunohistochemical method and double staining technique, the localization of growth hormone (GH) and somatostatin receptors in the nervous system and Hatschek's pit of amphioxus has been investigated. The results showed that the growth hormone-like nerve cells and endocrine cells as well as three subtypes of somatostatin receptors exist in the nervous system and Hatschek s pit, and GH-like nerve cells and endocrine cells co-exist with three subtypes of somatostatin receptors in the brain vesicle and Hatschek s pit. It is suggested that a primitive control system of inhibitory growth hormone secretion in Hatschek s pit could have been developed in amphioxus, as in vertebrates. The present study provides new evidence for the endocrinology and the evolution of Hatschek's pit.     

AT1-receptor heterodimers show enhanced G-protein activation and altered receptor sequestration

The vasopressor angiotensin II regulates vascular contractility and blood pressure through binding to type 1 angiotensin II receptors (AT1; refs 1, 2). Bradykinin, a vasodepressor, is a functional antagonist of angiotensin II (ref. 3). The two hormone systems are interconnected by the angiotensin-converting enzyme, which releases angiotensin II from its precursor and inactivates the vasodepressor bradykinin. Here we show that the AT1 receptor and the bradykinin (B2) receptor also communicate directly with each other. They form stable heterodimers, causing increased activation of G alpha(q) and G alpha(i) proteins, the two major signalling proteins triggered by AT1. Furthermore, the endocytotic pathway of both receptors changed with heterodimerization. This is the first example of signal enhancement triggered by heterodimerization of two different vasoactive hormone receptors.     

Synthesis dynamic and developmental profile of prothoracicotropic hormone between diapause-and nondiapause-destined individuals in Helicoverpa armigera

Biosynthesis and secretion of prothoracicotropic hormone (PTTH) of diapause-and nondiapause-destined individuals in Helicoverpa armigera were studied using whole-mount immunocytochemistry and enzyme-linked immunosorbent assay (ELISA). The immunocytochemistry revealed that PTTH is expressed in two pairs of lateral neurosecretory cells of the brain. The presence of immunoreactivity has not significant difference between the brains of the diapause-and nondiapause-destined 6th instar larvae. However,the obvious differences of expressional pattern from day 4 pupae were observed be-tween the two types. PTTH titers in hemolymph from the 6th instar larvae to pharate adults were measured by the ELISA. Although there were similar titer changes between the two types of individuals at the larval stage,a significant difference from developmental expression was detected at the pupal stage,suggesting that the expression and secretion of PTTH does play a crucial role in regulation of pupal diapause of H. armigera.     

猪垂体Poly（A）~＋RNA的制备及其体外翻译

本文用ＬｉＣｌ沉淀法提取了猪垂体总ＲＮＡ，经。ｏｌｉｇｏ（ｄＴ）－ｃｅｌｌｕｌｏｓｅ柱亲和层析，分离纯化了猪垂体Ｐｏｌｙ（Ａ）＋ＲＮＡ．用自制的兔网织红细胞体外翻译体系鉴定，表明该Ｐｏｌｙ／（Ａ）＋ＲＮＡ具有较高的翻译活性．ＳＤＳ－ＰＡＯＥ，放射自显影分析翻译产物提示，在制各的猪垂体Ｐｏｌｙ（Ａ）＋ＲＮＡ中，编码猪生长激素前体的ｍＲＮＡ占有较高的比例．