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1.
Sensillae of the tarsal receptor complex, palpal organ, and body chaetom were examined by means of scanning electron microscopy in three endoparasitic gamasid mites: Rhinonyssus rhinolethrum, Rh. subrhinolethrum and Ptilonyssus motacillae, the parasites of Anser albifrons, Anas crecca, and Motacilla alba, respectively. In the tarsal sensory complex, the scale of reduction of the olfactory sensilla reflects the adaptation of gamasid mites to cavernous parasitism. The topography of this sensilla is specific at generic and species taxonomic levels. In the palpal sensory organ, the number and scale of reduction of two main sensilla types depend on peculiarities of places of blood-sucking.  相似文献   

2.
The main complication sensory organs (the palpal organ and the tarsal sensory complex) of several species of gamasid mites were studied in scanning electron microscope. The species examined included permanent ectoparasites (Laelaps agilis, Laelaptidae), parasites of the nasal cavity and respiratory tract of birds (Sternostoma tracheocolum and Ptilonyssus reguli, Rhinonyssidae), dwellers of the sea littoral zone (Parasitus kempersi, Parasitus immanis, Parasitidae), and mites found on soil and on plants (Amblyseius barkeri, Parasitidae). Similar sensillar types, including olfactory SW-WP sensilla, contact chemo-mechanosensory (SW-UP and DW-UP) sensilla, termo-chemo-mechanosensitive (DW-WP) sensilla of two types, and tactile (NP) sensilla were found in all these species, excluding endoparasites, where some sensillar types (in particular, DW-WP sensilla with slit-like pores) are absent. It was shown that the topography of olfactory SW-WP sensilla of the tarsal complex reflects taxonomic position and phylogenetic history of mite genera, whereas the number of certain sensillar types and the degree of their development reflect ecological specialization of species. The palpal organ is characterized by rather uniform structure in mites of different families, dwellers of different environments, except for the endoparasites of the family Rhinonyssidae, where this organ is strongly reduced.  相似文献   

3.
Adult nymphalid butterflies possess sensilla trichodea (ST) that perceive taste in their walking legs. We examined whether the gustatory responses to mid-leg tarsal stimulation were different between Vanessa indica (rotting-food feeder) and Argyreus hyperbius (flower-nectar feeder). Sucrose, fructose, and glucose elicited behavioral responses (proboscis extension reflex: PER) and electrophysiological responses (spikes) from ST. Sugar responsiveness was similar in both species, where sucrose was the most stimulatory. Two fermentation products, ethanol and acetic acid, never induced PERs but elicited large-amplitude spikes at a concentration of >1% (w/v). The two species significantly differed in responsiveness to the binary mixtures of sucrose and the fermentation products. Ethanol enhanced the sugar responses of V. indica but slightly inhibited those of A. hyperbius. Although acetic acid suppressed the sugar responses of both species, V. indica was less susceptible than A. hyperbius. When concentration of the fermentation products increased, binary mixtures evoked large spikes together with small ones regarded as the sucrose responses. Unlike the proboscal sensilla in our previous study, the tarsal ST of both species unambiguously responded to fermentation products. These results demonstrate that the tarsal gustatory sense of V. indica is adaptive to the use of rotting foods.  相似文献   

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6.
Ants are able to climb effortlessly on vertical and inverted smooth surfaces. When climbing, their feet touch the substrate not only with their pretarsal adhesive pads but also with dense arrays of fine hairs on the ventral side of the 3rd and 4th tarsal segments. To understand what role these different attachment structures play during locomotion, we analysed leg kinematics and recorded single-leg ground reaction forces in Weaver ants (Oecophylla smaragdina) climbing vertically on a smooth glass substrate. We found that the ants engaged different attachment structures depending on whether their feet were above or below their Centre of Mass (CoM). Legs above the CoM pulled and engaged the arolia (‘toes’), whereas legs below the CoM pushed with the 3rd and 4th tarsomeres (‘heels’) in surface contact. Legs above the CoM carried a significantly larger proportion of the body weight than legs below the CoM. Force measurements on individual ant tarsi showed that friction increased with normal load as a result of the bending and increasing side contact of the tarsal hairs. On a rough sandpaper substrate, the tarsal hairs generated higher friction forces in the pushing than in the pulling direction, whereas the reverse effect was found on the smooth substrate. When the tarsal hairs were pushed, buckling was observed for forces exceeding the shear forces found in climbing ants. Adhesion forces were small but not negligible, and higher on the smooth substrate. Our results indicate that the dense tarsal hair arrays produce friction forces when pressed against the substrate, and help the ants to push outwards during horizontal and vertical walking.  相似文献   

7.
The mechanisms by which air pollution has multiple systemic effects in humans are not fully elucidated, but appear to include inflammation and thrombosis. This study examines whether concentrations of ozone and components of fine particle mass are associated with changes in methylation on tissue factor (F3), interferon gamma (IFN-γ), interleukin 6 (IL-6), toll-like receptor 2 (TLR-2), and intercellular adhesion molecule 1 (ICAM-1). We investigated associations between air pollution exposure and gene-specific methylation in 777 elderly men participating in the Normative Aging Study (1999–2009). We repeatedly measured methylation at multiple CpG sites within each gene’s promoter region and calculated the mean of the position-specific measurements. We examined intermediate-term associations between primary and secondary air pollutants and mean methylation and methylation at each position with distributed-lag models. Increase in air pollutants concentrations was significantly associated with F3, ICAM-1, and TLR-2 hypomethylation, and IFN-γ and IL-6 hypermethylation. An interquartile range increase in black carbon concentration averaged over the four weeks prior to assessment was associated with a 12% reduction in F3 methylation (95% CI: -17% to -6%). For some genes, the change in methylation was observed only at specific locations within the promoter region. DNA methylation may reflect biological impact of air pollution. We found some significant mediated effects of black carbon on fibrinogen through a decrease in F3 methylation, and of sulfate and ozone on ICAM-1 protein through a decrease in ICAM-1 methylation.  相似文献   

8.
Some common legumes and weeds indigenous to peach orchards in South Carolina were tested in greenhouse experiments to determine their host suitability for Criconemella xenoplax. Legumes that were hosts for the nematode were dwarf English trefoil (Lotus corniculatus var. arvensis), big trefoil (L. uliginosis), birdsfoot trefoil (L. corniculatus), narrowleaf birdsfoot trefoil (L. tenuis), ball clover (Trifolium nigrescens), rose clover (T. hirtum), subterranean clover (T. subterraneum), striate lespedeza (Lespedeza striata), and partridge pea (Cassiafasciculata). Most nonleguminous plants tested did not support population increases, but small increases were observed on orchardgrass (Dactylis glomerata), broadleaf signalgrass (Brachiaria platyphylla), purslane (Portulaca oleracea), and Carolina geranium (Geranium carolinianum). Results indicate that leguminous plants probably should not be used as ground cover or rotation crops for plants that are injured by C. xenopax.  相似文献   

9.
Cembrane-type diterpenoids, 13,18,20-epi-iso-chandonanthone (1) and (8E)-4α-acetoxy-12α,13α-epoxycembra-1(15),8-diene (2), two fusicoccane-type diterpenoids, fusicoauritone 6α-methyl ether (3) and 6β,10β-epoxy-5β-hydroxyfusicocc-2-ene (4) and a zierane sesquiterpene γ-lactone, chandolide (5) were isolated from the Tahitian liverwort Chandonanthus hirtellus (Web.) Mitt., together with eight known diterpenoids, chandonanthine (6), fusicogigantone A (7), fusicogigantone B (8), fusicogigantepoxide (9), anadensin (10), fusicoauritone (11), ent-verticillol (12) and ent-epi-verticillol (13). Their structures were established by a combination of extensive NMR spectroscopy and/or X-ray crystallographic analyses. Compounds 1, 5 and 10 showed weak cytotoxic activity against HL-60. Compound 3 also indicated weak cytotoxic activity against KB cell lines.  相似文献   

10.
庞泉沟自然保护区森林群落优势种群分布格局研究   总被引:1,自引:0,他引:1  
在野外调查的基础上,运用扩散系数等5种指数、聚集强度、Poisson分布和负二项分布的χ2拟合检验等方法对山西庞泉沟自然保护区森林群落优势种群的分布格局进行了研究,并用相关分析比较了6个指数间的关系。结果表明:(1)乔木层中华北落叶松、白桦、青杄、辽东栎及山杨具有较强的竞争能力和较宽的生态位而呈聚集分布,且聚集强度大;白杄和油松也呈聚集分布,但聚集程度小;红桦则表现出随机分布的趋势。(2)林下层中金银忍冬、东方草莓、披针叶苔草和中亚苔草表现出较强的聚集强度,而土庄绣线菊、美蔷薇、小红菊和糙苏等聚集强度较小;灰栒子、东北茶藨子、北方拉拉藤、山马兰等由于相对较弱的竞争能力和较窄的生态位而呈随机分布。(3)扩散系数(DI)、聚集指数(CI)、平均拥挤度(m*)、聚块性指数(PAL)、Green指数(GI)之间存在着显著的正相关性,且在判定物种分布格局时应以方差/均值比率为主要依据,Poisson分布和负二项分布的χ2拟合检验为辅共同判定,这样能够更准确的反映出物种的格局分布。  相似文献   

11.
Chen X  Wang L  Wang H  Chen H  Zhou M  Chen T  Shaw C 《Peptides》2011,32(1):26-30
Extensive studies on bradykinin-related peptides (BRPs) generated from plasma kininogens in representative species of various vertebrate taxa, have confirmed that many amphibian skin BRPs reflect those present in putative vertebrate predators. For example, the (Val1, Thr6)-bradykinin, present in the defensive skin secretions of many ranids and phyllomedusines, can be generated from plasma kininogens in colubrid snakes—common predators of these frogs. Here, we report the presence of (Arg0, Trp5, Leu8)-bradykinin in the skin secretion of the European edible frog, Pelophylax kl. esculentus, and have found it to be encoded in single copy by a kininogen with an open-reading frame of 68 amino acid residues. This peptide is the archetypal bony fish bradykinin that has been generated from plasma kininogens of the bowfin (Amia calva), the long-nosed gar (Lepisosteus oseus) and the rainbow trout (Onchorhynchus mykiss). More recently, this peptide has been shown to be encoded within cloned kininogens of the Atlantic cod (Gadus morhua) spotted wolf-fish (Anarichas minor), zebrafish (Danio rerio), pufferfish (Tetraodon nigroviridis) and Northern pike (Esox lucius). The latter species is regarded as a major predator of P. kl. esculentus. Synthetic (Arg0, Trp5, Leu8)-bradykinin was previously reported as having multiphasic effects on arterial blood pressure in conscious trout and here we have demonstrated that it can antagonize the relaxation in rat arterial smooth muscle induced by canonical mammalian bradykinin. The discovery of (Arg0, Trp5, Leu8)-bradykinin in the defensive skin secretion of this amphibian completes the spectrum of vertebrate taxon-specific BRPs identified from this source.  相似文献   

12.
One new bithiophenes, 5-(but-3-yne-1,2-diol)-5′-hydroxy-methyl-2,2′-bithiophene (2), two new polyacetylenic glucosides, 3-O-β-d-glucopyranosyloxy-1-hydroxy-4E,6E-tetradecene-8,10,12-triyne (8), (5E)-trideca-1,5-dien-7,9,11-triyne-3,4-diol-4-O-β-d-glucopyranoside (9), six new terpenoid glycosides, rel-(1S,2S,3S,4R,6R)-1,6-epoxy-menthane-2,3-diol-3-O-β-d-glucopyranoside (10), rel-(1S,2S,3S,4R,6R)-3-O-(6-O-caffeoyl-β-d-glucopyranosyl)-1,6-epoxy menthane-2,3-diol (11), (2E,6E)-2,6,10-trimethyl-2,6,11-dodecatriene-1,10-diol-1-O-β-d-glucopyranoside (12), 3β,16β,29-trihydroxy oleanane-12-ene-3-O-β-d-glucopyranoside (13), 3,28-di-O-β-d-glucopyranosyl-3β,16β-dihydroxy oleanane-12-ene-28-oleanlic acid (14), 3-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl oleanlic-18-ene acid-28-O-β-d-glucopyranoside (15), along with fifteen known compounds (1, 37, and 1624), were isolated from the aerial parts of Eclipta prostrata. Their structures were established by analysis of the spectroscopic data. The isolated compounds 19 were tested for activities against dipeptidyl peptidase IV (DPP-IV), compound 7 showed significant antihyperglycemic activities by inhibitory effects on DPP-IV in human plasma in vitro, with IC50 value of 0.51 μM. Compounds 1024 were tested in vitro against NF-κB-luc 293 cell line induced by LPS. Compounds 12, 15, 16, 19, 21, and 23 exhibited moderate anti-inflammatory activities.  相似文献   

13.
A new yellow carotenoid, named 5,6-dihydrocrustaxanthin (6), was isolated together with five yellow xanthophylls: isoastaxanthin (1), 5,6-dihydropenaeusxanthin (2), penaeusxanthin (3), tetrahydroxypirardixanthin (4), and crustaxanthin (5) from three species of prawns: Marsupenaeus japonicus, Litopenaeus vannamei, and Metapenaeus joyneri, belonging to Penaeidae. The structure of (6) was determined to be (3R,4S,5R,6R,3′R,4′S)-5,6-dihydro-β,β-carotene-3,4,3′,4′-tetrol by UV-VIS, MS, 1H NMR, and CD spectral data. Distributions of yellow xanthophylls (16) in ten species of shrimps were investigated from a chemo-systematic point of view. Yellow xanthophylls (16) were present in only three species of prawns described above, among the ten species of shrimps investigated. Instead of 16, luteins and tunxanthins, having the 3-hydroxy-ε-end group, were present in other species of shrimps belonging to Penaeidae, Pandalidae, and Palaemonidae.  相似文献   

14.
One new β-hydroxychalcone, 4-acetoxy-5,2′,4′,6′,β-pentahydroxy-3-methoxychalcone (1), one new flavanone, 7,3′-dihydroxy-5,4′-dimethoxyflavanone (2) and seven known compounds, 2R, 3R-trans-aromadendrin (3), naringenin-7-O-methylether (4), myricetin (5), quercetin-3-O-rutinoside (6), ursolic acid (7), gallic acid (8) and d-glucose (9) were isolated from the methanolic fruit extract of Cornus mas L. (=Cornus mascula L.), Cornaceae. The structures of the new compounds were elucidated on the basis of extensive spectroscopic methods, including 2D NMR experiments and of known compounds by comparison of physical and spectral data with literature.  相似文献   

15.
The phytochemical investigation of the roots of Triosteum himalayanum Wall. led to the isolation of eleven iridoids (16 and 812), one monoterpene diglycoside (7), and four flavonoids (1316), of which 4′,6′-di-O-isopropylidene sweroside (1) and secologanin diethylacetal (2) were new iridoid glucosides. The existence of iridoids and flavonoids provided further confirmation of the typical profile of the secondary metabolites found in the genus Triosteum, suggesting a close relationship among the species of Caprifoliaceae.  相似文献   

16.
Glutathione S-transferase (GST) inhibition-directed fractionations on the ethanolic extract of Artocarpus nobilis of Sri Lankan origin yielded four known triterpenoids, cyclolaudenyl acetate (1), lupeol acetate (2), β-amyrine acetate (3), and zizphursolic acid (4), along with five known flavonoids, artonins E (5), artobiloxanthone (6) artoindonesianin U (7), cyclocommunol (8) and multiflorins A (9). Our recent chemical studies on the methanolic extract of Matricaria chamomilla, collected from Manitoba, afforded one new compound, matriisobenzofuran (10), and six known natural products, fraxidin (11), scopoletin (12), apigenin (13), apigenin 7-O-β-glucopyranoside (14), palmatoside A (15) and p-hydroxyacetophenone (16). Compounds 116 were identified with the aid of extensive NMR and MS spectral data. Compounds 116 exhibited a wide range of GST inhibition activity. Compounds 59 exhibited significant anti-oxidant activity in DPPH free radical scavenging assay. Compounds 10 and 11 were also moderately active in anti-leishmanial assay.  相似文献   

17.
Paleogene mammal localities of North China are particularly well represented in the Erlian Basin, Inner Mongolia. Among them, the locality of Bayan Ulan is most famous for its late Paleocene Gashatan fauna. However, the younger Arshantan fauna of the same site is not well known, since no extensive study has been done so far. Here, we present a small mammal assemblage based on dental and tarsal material from a new Arshantan collection retrieved from the red beds of the late early to early middle Eocene Arshanto Formation at Bayan Ulan. It consists of at least six different taxa: the basal lagomorph Dawsonolagus antiquus, the large pantodont Pantolambdodon sp., the tapiroid Schlosseria magister, and the rhinocerotoids Hyrachyus crista and Rhodopagus guoi nov. sp. The assemblage is dominated by perissodactyls, especially Lophialetidae and Hyracodontidae. For the first time, p4-m1 of Dawsonolagus antiquus, tarsal material from Pantolambdodon sp., and lower dentition and tarsals of Hyrachyus crista are described and illustrated. Unlike other described Arshantan faunas, the Bayan Ulan Arshantan mammal assemblage has been collected exclusively from a single locality, which contributes to the reassessment of the misunderstood Arshantan Asian Land Mammal Age.  相似文献   

18.
We revise the relationships of the spider genus Cryptothele after reexamination of the morphology of the spinnerets, leg tarsal claws and maxillae with scanning electron microscopy. Cryptothele species have a particular conformation of the spinning field of the anterior lateral spigots that is typical of zodariids and close relatives: the field of major ampullate gland spigots, together with their strain sensilla, are invaginated within the field of piriform gland spigots. The implantation of the teeth on the inner side of the leg tarsal claws is also consistent with its placement among zodariids. We added Cryptothele to a morphological dataset of zodariid genera, together with the outgroups Homalonychus (Homalonychidae) and Penestomus (Penestomidae). The phylogenetic analysis concludes that the genus Cryptothele is a member of the subfamily Cydrelinae, which by priority is here considered a junior synonym of Cryptothelinae. Cryptothele specimens cover most of their body with soil particles which become consolidated as mud, and the debris is probably held in place by curved setae covered by long barbs. The spinnerets, which can be retracted and hidden, as well as the booklungs, are surrounded by a crown of thick setae that are densely covered by short barbs, protecting those areas against soil particles. Cryptothele are probably specialized to prey on termites, and their phylogenetic placement indicates that this diet specificity evolved two times independently in zodariids.  相似文献   

19.
In this study, the SAPT (DFT) method is used to determine the components of the electronic interaction energies (electrostatic (Eele), exchange (Eex), induction (Eind), exchange-induction (Eex-ind), dispersion (Edisp), and exchange-dispersion (Eex-disp)) between the several selected flavonoids and the important residues of the active site of Escherichia coli DNA Gyr determined by molecular docking. A significant linear correlation between the calculated SAPT (DFT) interaction energies of flavonoids and their experimental pIC50 values is found, which is not observed for the free binding energies (ΔGb) of flavonoids obtained from molecular docking. The variation of the interaction energy components of flavonoids with their structural differences is investigated to find the relation between the flavonoids structures and their biological activity based on the interaction energy components.  相似文献   

20.
Here we report glycan structures and their position of attachment to a carrier protein, uridine 5′-diphosphate-glucose: glycoprotein glucosyltransferase (UGGT1), as detected using tandem mass spectrometry. UGGT1 acts as a folding sensor of newly synthesized glycosylated polypeptides in the endoplasmic reticulum, and the transferase itself is known to be glycosylated. The structure of glycan attached to UGGT1, however, has not been investigated. In this study, we reveal the site of glycosylation (N269) and the glycan structures (Hex5–8HexNAc2) in UGGT1 obtained from rat (Rattus norvegicus), pig (Sus scrofa), cow (Bos taurus), and human (Homo sapiens).  相似文献   

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