动物唾液腺功能组分研究进展

动物在长期进化过程中,其唾液腺经过不断演化而分泌具有各种生理活性的功能组分,并对机体产生多重作用.随着生物毒素成为新的研究热点,近年来对动物唾液腺分泌功能组分的研究也越来越深入.在吸血节肢动物、无颌类动物、有毒动物以及吸血蝙蝠的唾液腺分泌物中不断发现大量新的功能组分,其中包括抗凝、抗炎、抗肿瘤和抑菌等多种活性分子.除了...     

昆虫特异蛋白研究进展

蛋白质是昆虫细胞的重要组分.在昆虫细胞内,蛋白质担负着组织形态的构成;调节生长发育的机能;产生抗性,提高免疫力,抵挡病菌入侵,有着非常广泛而积极的作用.在昆虫发育的特定阶段或遇到某些不良的环境条件,体内会产生一些具有特定功能的蛋白,如抗冻蛋白、储存蛋白、荧光蛋白、滞育关联蛋白和病毒增效蛋白等,这对维持昆虫正常的生理生化代谢机能起着非常重要的作用.     

细胞凋亡:昆虫抗病毒感染的重要机制(续)

3.2 细胞凋亡与Cdk_s活性 任何干扰Cdk/cyclin复合体活性的因素都可毫不含糊地导致细胞凋亡。干扰可发生在Cdk_s或其内在抑制因子(如P21、P27、P16)的表达水平上,也可发生在用化学抑制剂对Cdk活性的抑制作用水平上。     

昆虫围食膜的研究进展

围食膜是昆虫特有的,由中肠上皮细胞分泌的一层非细胞结构,主要由几丁质与蛋白质构成,是病原体通过肠道进入昆虫体内的第一道屏障。依据其形成的方式分为Ⅰ型和Ⅱ型围食膜。围食膜在中肠生理中起重要作用,可保护中肠上皮免于机械损伤,防止外源微生物的入侵等。围食膜遭受破坏会影响昆虫的正常生长发育,甚至导致死亡。本文就有关围食膜结构、组分、形成特点、功能等方面的研究进展做一综述。     

昆虫抗菌肽研究进展

本文主要对国外近十年昆虫抗菌肽研究作了一个简单的总结。最近的研究成果包括多种诱异剂包括脂多糖作为诱导产物和抗菌肽基因诱导表达、调控;一些阴离子肽、合成的抗真菌肽,这些抗菌肽遍布昆虫的若干科目,是一类有发展前景的新抗生素。     

昆虫味觉受体研究进展

化学感受受体在昆虫的觅食、食物选择、交配和产卵等行为中发挥着重要作用。随着果蝇、按蚊、蜜蜂、赤拟谷盗和家蚕等昆虫基因组测序的完成。各物种中完整化学感受受体（包括嗅觉受体和味觉受体）得以鉴定,并从中鉴定出与气味识别、食物选择密切相关的受体基因,如果蝇的二氧化碳受体基因DmGr21a和DmGr63a,糖受体DmGr5a,以及冈比亚按蚊识别人类气味的AgOrl等。其中,昆虫的味觉受体功能与昆虫食物选择、大量取食直接相关。本文就目前昆虫基因组中味觉受体的鉴定、进化、表达和功能等方面的研究进展进行了综述。对味觉受体功能的研究,将有助于我们认识昆虫味觉编码的分子基础和神经调控网络,也是研究昆虫与植物相互关系的热点。     

昆虫干细胞研究进展

干细胞是一类具有自我更新和分化潜能的细胞,按照其来源可分为胚胎干细胞和成年干细胞。昆虫中也同样存在多种干细胞。开展昆虫干细胞自我更新、发育命运决定、分化潜能等特性以及其与周围微环境相互关系的研究,对农林害虫的生物防治、经济昆虫的遗传育种以及一些生物反应器材料的利用,甚至对于人类疾病的治疗等都具有重要意义。以模式生物果蝇为主,介绍了昆虫干细胞的相关研究进展,重点集中在果蝇各种组织干细胞的鉴定与识别方面,包括研究较成熟的生殖腺内干细胞、中肠干细胞、马氏管干细胞、神经母细胞和造血干细胞。同时介绍了对干细胞维持起重要调控作用的各种信号途径的研究进展。这些昆虫干细胞的研究成果将为开展家蚕等鳞翅目昆虫的干细胞研究提供启示。     

昆虫抗冻蛋白研究进展

近年来昆虫抗冻蛋白(AFPs)的研究取得了较快的发展。本文综述了昆虫抗冻蛋白的发现过程、结构特点、表达规律、抗冻机制及相关的昆虫基因工程简况。     

五种小型哺乳动物的唾液腺简介

唾液腺(Salivary glangs),亦称涎腺、是分布于动物头部的一组腺体。从前对它的研究主要围绕分泌酌唾液可润湿食物和口腔粘膜,协助消化等方面。近年来随着国内外对动物化学通讯研究的深入发展,揭示出唾液腺又是哺乳动物嗅觉(化学)通讯气味物质——外激素(phermones)重要来源之一。外激素物质随着唾液传播于外环境,寄存于周围物体或基质上,形成气味标记点,再由标记点     

昆虫转基因研究进展、应用和展望

自1982年Spradling和Rubin发现了可作为载体的P转座子并将外源基因成功地转入果蝇胚层系细胞的染色体而得到表达以来,昆虫转基因研究已经取得了长足进步.作为现代昆虫分子生物学中最为基本的技术之一,昆虫转基因技术不仅是分析昆虫基因功能的有力工具,而且在害虫防治、减少人类疾病载体昆虫携带的病原体的传播以及作为生物反应器等方面的作用亦日趋重要.     

Histo-ontogenetic study of the parotid salivary gland of Indian buffalo

The present study was aimed at elucidating the histogenesis of parotid gland of buffalo. The study was carried out on buffalo foetuses (n = 36), during different stages of prenatal life. The foetuses were categorised into three groups based on their curved crown rump length (CVRL). The primordial anlage of parotid salivary gland was evident at 40th day of development whereas the primary ducts, in the form of cords, were first observed at 81st day of prenatal life. The capsule formation as well as the lobulation of the gland was initiated at 127th day. At 141st day, the duct system of gland was completed. The terminal tubules attained the structure of acini at 167th day. The myoepithelial cells first appeared as flattened basal cells initially around the developing acinar cells at 167th day. The typical compound tubulo-acinar nature of the gland was first observed at 185th day. Purely serous acinar cells were seen from 185th day onwards. The micrometrical studies revealed that the mean diameter of acinar cells, intercalated ducts, striated ducts and large ducts increased with the advancement of age. The serous acinar cells were devoid of acidic as well as neutral mucopolysaccharides in prenatal age groups; however, large ducts with goblet cells exhibited positive reaction. Combined PAS-AB method revealed mixed reaction in acinar cells as well as in large ducts. Fine lipid droplets were observed in intralobular as well as interlobular connective tissue; however, phospholipids were observed in the cell membrane of secretory cells and ducts.     

A lectin histochemical study of the zygomatic salivary gland of adult dogs

Seven lectins (PNA, DBA, SBA, UEA I, LTA, WGA and ConA), conjugated with horseradish peroxidase, were used to characterize the glycosidic residues in the zygomatic gland of adult dogs. In some cases (PNA and DBA), lectin staining was preceded by neuraminidase digestion. The acinar and tubular cells produced glycoconjugates with different sugar residues, presenting binding sites for all of the lectins used. The apical surfaces of the cells lining the intra- and interlobular ducts were also stained by all the lectins. In contrast, the demilunar cells only reacted with the Neu-PNA sequence and Con A. Abbreviations: Neu, neuraminidase; see also Table I     

Equine insect bite hypersensitivity: immunoblot analysis of IgE and IgG subclass responses to Culicoides nubeculosus salivary gland extract

Insect bite hypersensitivity (IBH) is an allergic dermatitis of horses caused by IgE-mediated reactions to bites of Culicoides and sometimes Simulium spp. The allergens causing IBH are probably salivary gland proteins from these insects, but they have not yet been identified. The aim of our study was to identify the number and molecular weight of salivary gland extract (SGE) proteins derived from Culicoides nubeculosus which are able to bind IgE antibodies (ab) from the sera of IBH-affected horses. Additionally, we sought to investigate the IgG subclass (IgGa, IgGb and IgGT) reactivity to these proteins. Individual IgE and IgG subclass responses to proteins of C. nubeculosus SGE were evaluated by immunoblot in 42 IBH-affected and 26 healthy horses belonging to different groups (Icelandic horses born in Iceland, Icelandic horses and horses from different breeds born in mainland Europe). Additionally, the specific antibody response was studied before exposure to bites of Culicoides spp. and over a period of 3 years in a cohort of 10 Icelandic horses born in Iceland and imported to Switzerland. Ten IgE-binding protein bands with approximate molecular weights of 75, 66, 52, 48, 47, 32, 22/21, 19, 15, 13/12 kDa were found in the SGE. Five of these bands bound IgE from 50% or more of the horse sera. Thirty-nine of the 42 IBH-affected horses but only 2 of the 26 healthy horses showed IgE-binding to the SGE (p<0.000001). Similarly, more IBH-affected than healthy horses had IgGa ab binding to the Culicoides SGE (19/22 and 9/22, respectively, p<0.01). Sera of IBH-affected horses contained IgE, IgGa and IgGT but not IgGb ab against significantly more protein bands than the sera of the healthy horses. The cohort of 10 Icelandic horses confirmed these results and showed that Culicoides SGE specific IgE correlates with onset of IBH. IBH-affected horses that were born in Iceland had IgGa and IgGT ab (p< or =0.01) as well as IgE ab (p=0.06) against a significantly higher number of SGE proteins than IBH-affected horses born in mainland Europe. The present study shows that Culicoides SGE contains at least 10 potential allergens for IBH and that IBH-affected horses show a large variety of IgE-binding patterns in immunoblots. These findings are important for the future development of a specific immunotherapy with recombinant salivary gland allergens.     

Lipomatous infiltration of the canine salivary gland

Benign connective tumours of the canine salivary glands are rare. This report describes lipomatous infiltration of parotid or submandibular salivary glands in seven dogs in which the glands were enlarged as a result of infiltration by fat cells; they appeared to have been successfully treated by local excision. The precise cause of the lipomatous infiltration in the dogs is unclear but different causes of similar lesions in humans are discussed.     

Idiopathic salivary gland enlargement (sialadenosis) in dogs: a microscopic study

A histological, histochemical and morphometric study was performed on submandibular salivary glands from 13 dogs which had presented with a submandibular mass or swelling that proved to be a portion of non-inflammatory and non-neoplastic submandibular salivary gland. There were no consistent changes in lectin-binding histochemistry or immunohistochemical expression of various cell markers, and, in most cases, there was no measurable difference in acinar size in the affected gland. The possible explanation for the clinical salivary gland enlargement is therefore unclear.     

Sublingual salivary gland sialolithiasis in a dog

A case of sialolithiasis of the sublingual/mandibular salivary gland and duct complex in a dog was reported. Sialoadenectomy of the ipsilateral glands successfully treated the associated sialocele.     

Zygomatic salivary gland mucocele in a ferret

A zygomatic salivary gland mucocele was diagnosed in a 1-year-old female domestic ferret with exophthalmos. A T-shaped incision from near the lateral canthus to the base of the ear and continuing ventrally to the level of the commissure of the mouth was made to expose the mucocele. Surgical removal was complicated by the large open orbit of the ferret, adjacent cellulitis, extension ventromedial to the globe, and difficulty in identifying important motor nerves. Vision was maintained, but slight postoperative enophthalmos and mild upper eyelid paresis developed.     

Selective cloning, characterization, and production of the Culicoides nubeculosus salivary gland allergen repertoire associated with equine insect bite hypersensitivity

Salivary gland proteins of Culicoides spp. have been suggested to be among the main allergens inducing IgE-mediated insect bite hypersensitivity (IBH), an allergic dermatitis of the horse. The aim of our study was to identify, produce and characterize IgE-binding salivary gland proteins of Culicoides nubeculosus relevant for IBH by phage surface display technology. A cDNA library constructed with mRNA derived from C. nubeculosus salivary glands was displayed on the surface of filamentous phage M13 and enriched for clones binding serum IgE of IBH-affected horses. Ten cDNA inserts encoding putative salivary gland allergens were isolated and termed Cul n 2 to Cul n 11. However, nine cDNA sequences coded for truncated proteins as determined by database searches. The cDNA sequences were amplified by PCR, subcloned into high level expression vectors and expressed as hexahistidine-tagged fusion proteins in Escherichia coli. Preliminary ELISA results obtained with these fusions confirmed the specific binding to serum IgE of affected horses. Therefore, the putative complete open reading frames derived from BLAST analyses were isolated by RACE-PCR and subcloned into expression vectors. The full length proteins expressed in Escherichia coli showed molecular masses in the range of 15.5-68.7 kDa in SDS-PAGE in good agreement with the masses calculated from the predicted protein sequences. Western blot analyses of all recombinant allergens with a serum pool of IBH-affected horses showed their ability to specifically bind serum IgE of sensitized horses, and ELISA determinations yielded individual horse recognition patterns with a frequency of sensitization ranging from 13 to 57%, depending on the allergen tested. The in vivo relevance of eight of the recombinant allergens was demonstrated in intradermal skin testing. For the two characterized allergens Cul n 6 and Cul n 11, sensitized horses were not available for intradermal tests. Control horses without clinical signs of IBH did not develop any relevant immediate hypersensitivity reactions to the recombinant allergens. The major contribution of this study was to provide a repertoire of recombinant salivary gland allergens repertoire from C. nubeculosus potentially involved in the pathogenesis of IBH as a starting basis for the development of a component-resolved serologic diagnosis of IBH and, perhaps, for the development of single horse tailored specific immunotherapy depending on their component-resolved sensitization patterns.