昆虫化学感受受体的研究进展

化学感受这一重要的生化过程对于昆虫的生存来说是十分必要的,昆虫的化学感受受体家族由气味(嗅觉)受体和味觉受体组成。嗅觉可以识别挥发性的化学物质,使昆虫发现食物、寻找配偶和逃避敌害;而味觉能识别可溶性刺激物,以引起觅食、交配和产卵等行为。文章主要介绍了昆虫气味受体及味觉受体家族的特性,以及目前对多种昆虫化学感受受体超家族的研究进展。     

家蚕嗅觉相关蛋白质的研究进展

昆虫对气味物质的识别是一个非常复杂的连锁反应过程,气味分子首先被嗅觉感器淋巴液中的气味结合蛋白或化学感受蛋白所结合,然后运转到位于嗅觉神经元末梢膜上的气味受体并将其激活,最后引起嗅觉神经兴奋,并传入中枢神经而被感知。家蚕成虫的嗅觉十分灵敏,长期以来一直作为研究昆虫化学通讯的理想模型。近年来,随着家蚕分子生物学研究的不断深入,在家蚕中已发现了7种气味结合蛋白、多种化学感受蛋白和气味受体蛋白,这些蛋白质因子对于家蚕识别气味分子起着关键作用,但多数蛋白因子的具体生理功能仍不清楚。以家蚕方面的研究为重点,综述了与嗅觉相关的蛋白质的生化特性、分子结构、基因表达及其生理功能等方面的研究进展。     

调味剂对动物嗅觉、味觉、肠道功能的调控研究进展

饲料的适口性是动物对饲料的气味及口感等的综合感知,在一定程度上影响动物的采食量,而动物的采食量与生产性能有较高的正相关。气味的感知主要源于鼻腔内嗅觉神经的突起,口感的感知主要由口腔内的味觉受体来完成,主要味觉受体包括甜味受体、鲜味受体和苦味受体等。食物进入胃肠道后,胃肠道上的味觉受体感应程度可影响并调节动物对食物的吸收率和采食行为。本文主要介绍了近年来有关鼻腔的嗅觉受体、口腔内的味觉受体和胃肠道内味觉受体和信号传递等相关研究,并就调味剂在动物生产上的应用进行综述,为调味剂的应用及相关研究提供一定借鉴。     

嗅觉与味觉对动物采食作用研究进展

良好的采食行为是动物机体维持生长发育和提高生产性能的基础,而嗅觉和味觉是动物采食过程中最重要的两种感官感受,它们分别由嗅觉受体和味觉受体基因决定,这些受体基因家族是哺乳动物基因组中较大的基因家族,不仅在感觉器官中表达,还广泛表达于呼吸、消化、生殖等系统中。作者对中国羊肉消费和羊的饲养情况,当前嗅觉、味觉及其受体基因的最新研究进展,嗅觉和味觉在动物采食中的作用和机制,以及嗅觉和味觉在畜禽养殖中的应用进行了综述,为研究嗅觉和味觉在动物采食尤其是羊上的作用提供参考。     

哺乳类动物胃肠道内味觉受体的信号研究

胃肠道内容物的分子识别对食物的消化、摄取量的控制、胰岛素的分泌、新陈代谢等起到重要作用。这些过程很有可能受到激素/中枢神经通路的介导。但是,有关于胃肠道的味觉识别机制还不清楚。本文综述了最新的研究结果,表明了舌上皮组织的特异性味觉受体细胞的化学感应机制在内分泌细胞中也发挥作用,用来感知肠腔内容物的化学组成。     

动物鲜味受体的研究进展及其基因表达调控

动物的鲜味受体包括代谢型谷氨酸受体(m GluR)和味觉受体异源二聚体(T1R1/T1R3),是C型G蛋白偶联受体,N末端捕蝇草模块(VFT)区域可与鲜味配体结合,识别鲜味。本文主要论述了鲜味受体的研究进展、鲜味识别转导机制及鲜味受体基因的表达调控等,以期为相关研究提供参考。     

家蚕嗅觉和味觉产生的分子机制研究进展 国外重要学术期刊发表论文简介

<正>1 Kana Tanaka,Yusuke Uda,Yukiteru Ono,Tatsuro Nakagawa,Makiko Suwa,Ryohei Yamaoka,Kazushige Touhara.Highly selective tuning of a silkworm olfactory receptor to a key mulberry leaf volatile.Current Biology,2009,19(11):881-890题目家蚕嗅觉受体对桑叶释放的气味分子具有高度选择性摘要食叶昆虫的嗅觉系统在识别气味分子以便寻找到合适的宿主植物等方面起着重要作用。日本东京大学综合生物科学部Tanaka等人对桑叶的挥发性气味分子进行鉴定,分析家蚕幼虫对这些气味分子识别的趋     

哺乳动物消化道味觉受体和味觉感应研究进展

味觉受体自从被发现以来,人们因对其浓厚的研究兴趣增加了研究的强度和深度,人们对哺乳动物感知味觉的理解也更加深入,包括味觉感知过程的分子基础及其功能等方面。这不仅对人和动物的日常饮食调控具有重大意义,而且可以为治疗某些疾病提供新方法和新思路。本文综述了味觉受体和味觉感知过程的相关研究成果,以期加深对味觉受体分子基础的认识,促进对味觉感知过程的理解,为哺乳动物营养平衡和健康饲养提供重要参考。     

禽类味觉系统研究进展

文章基于哺乳动物的味觉系统,分析了家禽味觉的结构和功能,着重从不同类型的味觉受体的研究进展进行了综述,并指出了今后禽类味觉的研究方向。     

昆虫气味受体的分子进化与信号转导的研究进展

昆虫气味受体(Odorant receptors, Or)基因家族的分子演变与其对环境的生态适应性密切相关,在昆虫的生存和种族繁衍及躲避敌害中起着重要作用。Or基因展现出多种进化模式,有基因结构的变化、染色体位置的变化和复制变化,通过这些变化获得或失去某种功能,以适应生态环境变化。昆虫气味受体的拓扑学证明,它是与典型的G-蛋白耦联受体(哺乳类气味受体)反向的跨膜分布,通过特殊的离子门控通道和环核苷酸激活的非选择性离子通道,将气味分子信号传递到嗅觉感受器内嗅觉神经元,从而对气味作出简单、快速而有效的反应。     

Apomorphine-induced emesis in the dog-routes of administration, efficacy and synergism by naloxone

Apomorphine proved to be more effective as an emetic in dogs after s.c. administration than after i.m. injection with doses of 0.04 and 0.1 mg/kg. This effect is explained by an anti-emetic effect mediated by mu-receptors in the vomiting centre in the brain, which, in contrast to the chemoreceptor trigger zone, is within the blood-brain barrier. A certain delay between the stimulation of D2-receptors in the chemoreceptor trigger zone (causing emesis) and mu-receptors in the vomiting centre (producing anti-emesis) therefore results, leading to a self-limiting emesis. Blockade of the mu-receptors by naloxone increased and prolonged the effect of apomorphine. A relatively narrow range of apomorphine concentrations on s.c. administration is then effective to stimulate the chemoreceptor trigger zone, but can hardly inhibit the vomiting centre, and must therefore be considered the most suitable route for administration of apomorphine.     

Chemoreceptor Tumors Diagnosed at the Western College of Veterinary Medicine 1967-1979

Twenty-nine chemoreceptor tumors submitted to the Western College of Veterinary Medicine, Saskatoon, Saskatchewan between 1967 and 1979 were compared with those previously reported. The prevalence was low, with 28 cases occurring in dogs while only one was diagnosed in a cat. Old male dogs and the Boxer, Boston bull terrier and Collie breeds were affected most commonly. The prevalence in Collies (five of 28 dogs) was unexpected but may have been coincidental in this size of sample. The chemoreceptor tumor was often of clinical significance because in two-thirds of the cases it was either the presenting complaint or considered at necropsy to have caused illness or death.     

昆虫抗菌肽基因表达调控机理

昆虫先天免疫应答主要通过模式识别受体识别入侵微生物,激活Toll和Imd信号途径,通过NF-κB样转录因子调控抗微生物肽基因的表达,合成高效广谱的抗微生物多肽,杀灭外源微生物.本文以果蝇的两个信号途径为例,通过与哺乳动物的TLR (Toll-like receptor)和TNFR (tumour-necrosis factor receptor)信号途径的比较,我们综述了昆虫免疫应答的激活机理的新近研究成果,并讨论了Toll和Imd信号途径的进化关系和昆虫模式识别受体的功能分类.     

味觉的细胞生物学研究进展

味蕾是咪感觉器官。在哺乳动物中味蕾主要分布在舌上皮中。味蕾中存在基细胞、亮细胞、暗细胞和中间细胞四种类型,蕾内神经纤维和蕾周神经纤维共同支配味蕾。利用免疫组织化学技术,能在功能上对味细胞和味觉神经纤维进行分类和鉴定。味蕾组织染色方法在舌面拓扑学和味觉系统发育研究中起着重要作用。分离出单个的味蕾细胞是研究受体细胞传导味觉机理的手段。味蕾组织培养对于研究味觉神经支配提供了有效的模型。文章介绍了味觉细胞生物学研究中的两个热点争议问题：味蕾细胞分化路线和味感觉细胞的鉴定,并探讨了形成分歧的原因。     

The occurrence of taste buds in adults of the terrestrial ceacilian Boulengerula boulengeri Tornier, 1898 (Lissamphibia: Gymnophiona: Herpelidae)

Two generations of gustatory organs occur during amphibian ontogeny in frogs and salamanders (Anura and Caudata), and are classified as taste buds or taste discs. Taste buds are present in larval forms, whereas taste discs are typical for adults. The little research done on Gymnophiona suggests that only taste buds are present in aquatic forms (larvae and adults), and adults of the only terrestrial species studied had taste buds. Here we investigate the nature of gustatory organs in a terrestrial caecilian, Boulengerula boulengeri (Herpelidae), from Tanzania using standard light and scanning electron microscopy. We found only taste bud type organs to be present in B. boulengeri. These occur mainly in the mucosa of the front part of the oral cavity, usually near the teeth. Our results suggest that B. boulengeri possesses only one type of gustatory organ during its ontogeny.     

家蚕胰岛素受体类似基因挖掘及在限食模型中的表达特征

家蚕素是家蚕胰岛素相关肽,与其受体(IR)结合激活胰岛素信号转导(IIS)途径。利用生物信息学方法,挖掘出具有胰岛素受体类似结构域的家蚕基因Ir-lp,其ORF长2 658 bp,编码885个氨基酸残基,蛋白质分子质量100.3 kD,pI为6.93,与果蝇等昆虫的同源蛋白保守区域高度一致,NJ法分子进化分析显示家蚕IR-LP与昆虫胰岛素受体相关蛋白同源,但是家蚕Ir-lp编码蛋白缺少胰岛素受体酪氨酸激酶催化结构域,基因表达特征也与已知的家蚕Ir有显著差异。建立家蚕限食模型,调查限食后家蚕8个组织中Ir-lp与Ir表达变化的差异,探讨Ir-lp基因与IIS途径的关系,结果显示长期限食使得Ir-lp与Ir在脂肪体、性腺和表皮中上调表达,在马氏管中下调表达,其中Ir-lp的表达量变化幅度较大。综合分析,IR-LP可能在家蚕胚胎期、蛹期、蛾期等特定发育时期通过与IR竞争结合家蚕素来有效调控能量利用效率。     

Proteomics analysis of porcine serum proteins by LC-MS/MS after foot-and-mouth disease virus (FMDV) infection

To analyze serum proteomics differences between normal and foot and mouth disease virus (FMDV)-infected piglets, an analytical method based on liquid chromatography with tandem mass spectrometry (LC-MS/MS) was used. Samples of venous blood were collected before and after FMDV infection and high abundance serum albumin was removed using a commercial kit. After trypsin digestion, serum samples were processed with LC-MS/MS. Proteins were identified by peptide mass fingerprinting. We found that apolipoprotein A-IV precursor, haptoglobin and probable chemoreceptor glutamine deamidase cheD appeared after FMDV infection in the same piglet. This is believed to be the first time that serum proteomics analysis by LC-MS/MS after FMDV infection has been performed, and our results may provide further information about biomarkers for early diagnosis of FMD in piglets.     

家蚕卵巢肿瘤基因Bmotu及其可变剪接

已知卵巢肿瘤基因(ovarian tumor gene,otu)在果蝇(Drosophila melanogaster)卵巢发育过程中发挥极其重要的作用,该基因突变会扰乱卵子形成的正常过程。为探究家蚕(Bombyx mori)是否具有类似果蝇生殖发育相关基因otu的同源基因,以及基因存在的可变剪接形式,在电子克隆的基础上,应用RT-PCR从家蚕精巢组织中获得了4条不同长度的Bmotu cDNA片段(GenBank登录号:HQ831341,HQ831342,HQ999998,HQ831343),其中3条由于无义突变导致翻译提前终止;而从卵巢组织中仅获得了1条Bmotu cDNA片段,该片段序列与精巢中扩增的登录号为HQ831343片段序列的5'端相同。结果表明Bmotu基因存在可变剪接,且雌、雄之间的剪接方式可能存在差异。生物信息学分析发现Bmotu基因编码蛋白与果蝇Otu的结构类似,含有半胱氨酸蛋白酶结构域(Otu结构域)、Tudor结构域、脯氨酸基序。研究结果有助于进一步探讨家蚕生殖发育机制。     

Ultrastructural Changes in Nervous Elements associated with the Granular Cells of the Common Carotid Artery of the Domestic Fowl after Distal Vagal Ganglionectomy

Intramural granular cells of the left and right common carotid artery of the domestic fowl were examined with the electron microscope after left distal vagal ganglionectomy. The vast majority of the nerve fibers and endings associated with the granular cells of the left common carotid artery degenerated rapidly after ispilateral ganglionectomy, indicating that they are derived from the left vagus. On the other hand, left distal vagal ganglionectomy resulted in transformation of the intramural granular cells of the right common carotid artery and the few nervous elements associated with them, into a typical chemoreceptor tissue. This tissue was made up of small granule (60 -120 nm) containing cells associated with many nerve fibers, nerve endings and fenestrated capillaries. The nerve endings were of two types; presumptive afferent endings and adrenergic efferent endings. Both types of endings made synaptic junctions with the granular cells.