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The skeletal system of animals provides the support for a variety of activities and functions. For animals such as mammals, which have endoskeletons, research has shown that skeletal investment (mass) scales with body mass to the 1.1 power. In this study, we ask how exoskeletal investment in insects scales with body mass. We measured the body mass and mass of exoskeletal chitin of 551 adult terrestrial insects of 245 species, with dry masses ranging from 0.0001 to 2.41 g (0.0002–6.13 g wet mass) to assess the allometry of exoskeletal investment. Our results showed that exoskeletal chitin mass scales isometrically with dry body mass across the Insecta as Mchitin = a M, where b = 1.03 ± 0.04, indicating that both large and small terrestrial insects allocate a similar fraction of their body mass to chitin. This isometric chitin‐scaling relationship was also evident at the taxonomic level of order, for all insect orders except Coleoptera. We additionally found that the relative exoskeletal chitin investment, indexed by the coefficient, a, varies with insect life history and phylogeny. Exoskeletal chitin mass tends to be proportionally less and to increase at a lower rate with mass in flying than in nonflying insects (Mflying insect chitin = ?0.56 × M; Mnonflying insect chitin = ?0.55 × M), and to vary with insect order. Isometric scaling (b = 1) of insect exoskeletal chitin suggests that the exoskeleton in insects scales differently than support structures of most other organisms, which have a positive allometry (b > 1) (e.g., vertebrate endoskeleton, tree secondary tissue). The isometric pattern that we document here additionally suggests that exoskeletal investment may not be the primary limit on insect body size. J. Morphol., 2010. © 2010 Wiley‐Liss, Inc. 相似文献
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Monika Ludwig Margarethe Spindler-Barth Klaus-Dieter Spindler 《Archives of insect biochemistry and physiology》1991,18(4):251-263
Homogenates of Chironomus cells synthesize chitin as effectively as intact cells. Chitin is produced in a dose-dependent manner, when GlcN, GlcNAc, or UDP-GlcNAc is used as precursor. Due to the lability of UDP-GlcNAc incorporation of this substrate is underestimated. No allosteric effect is observed when GlcN or GlcNAc is used as a substrate. Chitin synthesis is stimulated by Mg2+ and inhibited by uridine monophosphate (UMP), uridine diphosphate (UDP), and uridine triphosphate (UTP). The apparent temperature optimum is 30°C, the apparent pH optimum is 5.5–6. Addition of the chitinase inhibitor allosamidin does not enhance chitin synthesis significantly. The time course of chitin formation reveals a lag period of about 12 h, which can be overcome by trypsin treatment. Addition of protease inhibitors prevents chitin synthesis. 相似文献
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Edwin P. Marks Jeffrey Balke Harold Klosterman 《Archives of insect biochemistry and physiology》1983,1(3):225-230
Cells from the continuous MRRL-CH line derived from embryos of the tobacco hornworm synthesized chitin. Digestion of the washed pellet from [14C]-N-acetylglucosamine-labeled cells by chitinase yielded a water-soluble labeled compound. The lyophilized residue from the supernatant of the chitin digestion was analyzed by gas-liquid chromatography as its trimethylsilyl derivative. The major component cochromatographed with derivitized chitobiose. The presence of chitobiose was confirmed by gas chro-matography-mass spectrometry. The synthesis of chitin by this cell line is inhibited by diflubenzuron. 相似文献
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抑制真菌细胞壁的合成常作为防治真菌感染的安全有效手段。几丁质是真菌细胞壁及隔膜的重要结构成分,几丁质合酶是催化几丁质合成的关键酶。真菌细胞中几丁质合酶家族的不同成员在调控几丁质的合成中存在着差异,因此产生不同的生物学效应。本文通过综述几丁质合酶在人体三大条件致病真菌白色念珠菌、烟曲霉、新生隐球菌中的研究进展,分析了几丁质合酶对真菌致病性影响的机制,总结了几丁质合酶调控真菌细胞增殖、形态转换、病原菌与宿主的相互作用和细胞壁损伤诱导的补偿效应,展望了抗真菌感染的新策略及关于真菌几丁质合酶的未来研究方向。 相似文献
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Norio Nishi Shin-ichiro Nishimura Akira Ebina Akihiro Tsutsumi Seiichi Tokura 《International journal of biological macromolecules》1984,6(1):53-54
New water-soluble chitin derivatives, chitin phosphate of various degrees of substitution, were successfully prepared by the reaction of chitin with phosphorus pentoxide in methanesulphonic acid. These materials behaved hydrodynamically as typical polyelectrolyte, and showed high ability to adsorb metal ions. 相似文献
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Anti-inflammatory effect of chemically modified chitin 总被引:2,自引:0,他引:2
Katsuyuki Miyatake Yoshiharu Okamoto Yoshihiro Shigemasa Seiichi Tokura Saburo Minami 《Carbohydrate polymers》2003,53(4):417-423
Anti-inflammatory effects of the three types of chitin derivatives namely phosphated chitin (P-chitin), phosphated–sulfated chitin (PS-chitin), and sulfated chitin (S-chitin) were investigated using a canine model of chitosan-induced pneumonia. After simultaneous administration of chitosan with or without each chitin derivative (chitosan alone: n=6, chitosan and P-chitin: n=6, chitosan and PS-chitin: n=1, and chitosan and S-chitin: n=3), hematological examination and X-ray image processing were performed for up to 24 h. Then the lungs were recovered and were evaluated by softex imaging after inflation and fixation. The hematological findings showed that PS-chitin and S-chitin did not prevent the decrease in white blood cell (WBC) count as seen in dogs administered chitosan, while P-chitin prevented such decrease in WBC count. The surface of the inflated and fixed lung specimens was hemorrhagic in the PS- and S-chitin groups as well as in the chitosan group, while the lung looked like normal in the P-chitin group. The pulmonary blood vessels of the chitosan group showed severe change while the P-chitin group showed no changes with softex findings. Furthermore, the pattern of histogram density obtained with image processing of thoracic X-ray in P-chitin group did not change among pre and post administration while chitosan group showed rightward movement and significant changes on parameters. The cause of which is attribured to an attenuation of X-ray permeability by angiectasis of the lung. 相似文献
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Sei-ichi Aiba Norihiko Minoura Yukihiko Fujiwara 《International journal of biological macromolecules》1985,7(2):120-121
Novel graft copolymers have been synthesized by the reaction of N-carboxyanhydrides of amino acids with partially deacetylated chitins. The graft copolymers had different swelling ability from the original chitin. 相似文献
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Extraction of chitin and chitosan from larval exuvium and whole body of edible mealworm,Tenebrio molitor 下载免费PDF全文
Yong‐Su Song Min‐Woo Kim Chaeyeong Moon Dong‐Jun Seo Yeon Soo Han Yong Hun Jo Mi Young Noh Young‐Kyu Park Sun‐Am Kim Young Wook Kim Woo‐Jin Jung 《Entomological Research》2018,48(3):227-233
The purpose of this study was to investigate the production of chitin and chitosan from both the exuvium and whole body of mealworm (Tenebrio molitor) larvae. Chitin from the exuvium and whole body of T. molitor larvae was chemically extracted with acid and alkali solutions to achieve demineralization (DM) and deproteinization (DP), respectively. The average DM (%) and DP (%) on a dry weight (DW) basis was 32.56 and 73.16% from larval exuvium, and 41.68 and 91.53% from whole body, respectively. To obtain chitosan, chitin particles from the exuvium and whole body of T. molitor larva were heated at various temperatures in different concentrations of NaOH. Average chitin yields were 18.01% and 4.92% of DW from the exuvium and whole body, respectively. The relative average yield of chitosan from whole body was 3.65% of DW. On average, over 90% of chitosan derived from whole body was deacetylated. The viscosity of chitosan from whole body was ranged from 48.0 cP to 54.0 cP. The chitin content of dry and wet byproducts from whole body were 17.32% and 16.94% respectively, compared to dry weight. The chitosan contents of byproducts on a DW basis were 14.48% in dry and 13.07% in wet byproduct. These results indicate that the exuvium and whole body of T. molitor larva may serve as a source of chitin and chitosan for use in domestic animal feed. 相似文献
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Most invertebrates, particularly those of marine origin, have relatively high concentrations of free amino acids which are considered an important constituent of their osmoregulatory mechanisms [1]. Very little information is available on the free amino acid distribution in Porifera [2,3]. Common amino acids in some sponges were recognised by paper chromatography by Inskip and Cassidy [4] and Ackermann et al. [5,6] included a few sponges in their survey of the occurence of nitrogen compounds in marine invertebrates. More recently Bergquist and Hartman [7] surveyed semiquantitatively the distribution of free amino acids in several sponges. In the present paper we report on the amino acid composition of 12 species of sponges belonging to the class Demospongiae as a part of a study on the metabolites of Porifera [8]. Fresh sponges were extracted with aqueous ethanol. The organic solvent was removed and the aqueous solution, after removal of the ether soluble compounds, was separated into cationic, anionic and neutral fractions by ion-exchange chromatography. The cation fraction was analysed for amino acids using an automatic amino acid analyser. The results, which are presented in Table 1, show that all species of sponges examined have a similar composition in common amino acids. Glycine almost always appears as the dominant protein amino acid, followed by high concentrations of alanine and glutamic acid, whereas relatively lower concentrations of basic amino acids are present. In Axinella cannabina, Chondrosia reniformis, Chondrilla nucula, Cliona viridis and Hymeniacidon sanguinea, glycine represents more than 77% of the total amino acids. The high percentage of free glycine (90.4%) in Chondrosia reniformis is noteworthy. The anionic and the neutral fractions were examined for sulfur-containing amino acids using PC. Taurine (Table 2) was detected in all the Porifera examined; this is in agreement with previous observations [5–7]. N-Methyltaurine was identified in some of the species examined, whereas neither N,N-dimethyltaurine nor N,N,N-trimethyltaurine were found. 相似文献
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Physiology of microbial degradation of chitin and chitosan 总被引:22,自引:0,他引:22
Graham W. Gooday 《Biodegradation》1990,1(2-3):177-190
Chitin is produced in enormous quantities in the biosphere, chiefly as the major structural component of most fungi and invertebrates. Its degradation is chiefly by bacteria and fungi, by chitinolysis via chitinases, but also via deacetylation to chitosan, which is hydrolysed by chitosanases. Chitinases and chitosanases have a range of roles in the organisms producing them: autolytic, morphogenetic or nutritional. There are increasing examples of their roles in pathogenesis and symbiosis. A range of chitinase genes have been cloned, and the potential use for genetically manipulated organisms over-producing chitinases is being investigated. Chitinases also have a range of uses in processing chitinous material and producing defined oligosaccharides. 相似文献
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Umut Toprak Martin Erlandson Doug Baldwin Lianglu Wan Cathy Coutu Cedric Gillott Dwayne D. Hegedus 《Insect Science》2016,23(5):656-674
The peritrophic matrix (PM) is essential for insect digestive system physiology as it protects the midgut epithelium from damage by food particles, pathogens, and toxins. The PM is also an attractive target for development of new pest control strategies due to its per os accessibility. To understand how the PM performs these functions, the molecular architecture of the PM was examined using genomic and proteomic approaches in Mamestra configurata (Lepidoptera: Noctuidae), a major pest of cruciferous oilseed crops in North America. Liquid chromatography‐tandem mass spectrometry analyses of the PM identified 82 proteins classified as: (i) peritrophins, including a new class with a CBDIII domain; (ii) enzymes involved in chitin modification (chitin deacetylases), digestion (serine proteases, aminopeptidases, carboxypeptidases, lipases and α‐amylase) or other reactions (β‐1,3‐glucanase, alkaline phosphatase, dsRNase, astacin, pantetheinase); (iii) a heterogenous group consisting of polycalin, REPATs, serpin, C‐Type lectin and Lsti99/Lsti201 and 3 novel proteins without known orthologs. The genes encoding PM proteins were expressed predominantly in the midgut. cDNAs encoding chitin synthase‐2 (McCHS‐2), chitinase (McCHI), and β‐N‐acetylglucosaminidase (McNAG) enzymes, involved in PM chitin metabolism, were also identified. McCHS‐2 expression was specific to the midgut indicating that it is responsible for chitin synthesis in the PM, the only chitinous material in the midgut. In contrast, the genes encoding the chitinolytic enzymes were expressed in multiple tissues. McCHS‐2, McCHI, and McNAG were expressed in the midgut of feeding larvae, and NAG activity was present in the PM. This information was used to generate an updated model of the lepidopteran PM architecture. 相似文献
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采用Tecator自动定氮仪和Waters PICO-TAG氨基酸自动分析仪测定了海南螺旋藻粉中蛋白质含量和17种氨基酸含量。结果显示海南螺旋藻粉中蛋白质含量达63.3%,总氨基酸含量达60.88%,其中必需氨基酸含量超过40%,比例平衡,符合FA0标准,可与国外产品媲美。 相似文献
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Chitin synthesis in third-instar Lucilia cuprina larvae cultured at 23 °C was investigated using in vivo and in vitro systems, the latter with whole and with homogenized integuments. Synthesis was at a maximum between 24 and 48h after ecdysis from the second instar. Chitin was deposited in layers, and labeled GlcNAc was rapidly cleared from the hemolymph. In in vitro homogenate systems, the rapid conversion of UDP-([14C]GlcN)Ac to ([14C]GlcN)Ac and its 1-phosphate derivative contributed to the low incorporation of this precursor into chitin. The extent of the conversion was reduced by the addition of KCN or phenylthiourea. In in vivo and in vitro tissue systems the level of incorporation of ([14C]ClcN)Ac was higher than that of UDP-([14C]GlcN)Ac. However, in in vitro homogenate systems there was no difference unless UTP was added when the level of incorporation of only ([14C]GlcN)Ac was increased (by a factor of 9). Incorporation of UDP-([14C]GlcN)Ac, but not that of ([14C]GlcN)Ac, was decreased when larvae were deprived of food. Soluble oligosaccharides were detected in in vitro homogenate systems. They were formed during chitin synthesis and may represent newly initiated chitin chains. A reappraisal of current ideas on chitin synthesis in insects is needed. 相似文献
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Subbaratnam Muthukrishnan Yasuyuki Arakane Qing Yang Chuan‐Xi Zhang Jianzhen Zhang Wenqing Zhang Bernard Moussian 《Archives of insect biochemistry and physiology》2018,98(2)
This microreview stems from the Second Symposium on Insect Molecular Toxicology and Chitin Metabolism held at Shanxi University in Taiyuan, China (June 27 to 30, 2017) at the institute for Applied Biology headed by Professor Enbo Ma and Professor Jianzhen Zhang. 相似文献
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The free amino acid composition and concentration in young and mature leaves of Eucalyptus blakelyi were determined. These data are compared with p 相似文献