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11.
Amanda McGrosky Carlo Meloro Ana Navarrete Sandra A. Heldstab Andrew C. Kitchener Karin Isler Marcus Clauss 《American journal of primatology》2019,81(8)
Although it is generally assumed that among mammals and within mammal groups, those species that rely on diets consisting of greater amounts of plant fiber have larger gastrointestinal tracts (GIT), statistical evidence for this simple claim is largely lacking. We compiled a dataset on the length of the small intestine, caecum, and colon in 42 strepsirrhine, platyrrhine, and catarrhine primate species, using specimens with known body mass (BM). We tested the scaling of intestine length with BM, and whether dietary proxies (percentage of leaves and a diet quality index) were significant covariates in these scaling relationships, using two sets of models: one that did not account for the phylogenetic structure of the data, and one that did. Intestine length mainly scaled geometrically at exponents that included 0.33 in the confidence interval; Strepsirrhini exhibited particularly long caeca, while those of Catarrhini were comparatively short. Diet proxies were only significant for the colon and the total large intestine (but not for the small intestine or the caecum), and only in conventional statistics (but not when accounting for phylogeny), indicating the pattern occurred across but not within clades. Compared to terrestrial Carnivora, primates have similar small intestine lengths, but longer large intestines. The data on intestine lengths presented here corroborate recent results on GIT complexity, suggesting that diet, as currently described, does not exhaustively explain GIT anatomy within primate clades. 相似文献
12.
《Fungal biology》2020,124(1):65-72
This review deals with characteristics of peptidases of fungi whose life cycles are associated with insects to varying degrees. The review examines the characteristic features of the extracellular peptidases of entomopathogenic fungi, the dependence of the specificity of these peptidases on the ecological characteristics of the fungi, and the role of peptidases in the development of the pathogenesis. Data on the properties and physiological role of hydrolytic enzymes of symbiotic fungi in “fungal gardens” are also considered in detail. For the development of representations about mechanisms of control over populations of insect pests, special attention is given to analysis of possibilities of genetic engineering for the creation of entomopathogens with enhanced virulence. Clarification of the role of fungi and their secreted enzymes and careful environmental studies are still required to explain their significance in the composition of the biota and to ensure widespread adoption of these organisms as effective biological control agents. The systematization and comparative analysis of the existing data on extracellular peptidases of insect-associated fungi will help in the planning of further work and the search for markers of pathogenesis and symbiosis. 相似文献
13.
Preparation of chloroplast DNA from pea plastids isolated in a medium of high ionic strength 总被引:8,自引:0,他引:8
A simple, rapid, and inexpensive method for the preparation and purification of chloroplast DNA (cpDNA) from pea has been developed. The crucial step is the isolation of chloroplasts in a medium of high ionic strength (I congruent equal to 1.40 M). CpDNA from pea prepared according to this method has successfully been used for restriction enzyme mapping, Southern transfers, and cloning. 相似文献
14.
15.
Acid proteinases with an optimum around pH 3 were demontrated in various tissues of 12 molluscan species. Enzymes strongly inhibited by pepstatin were predominant and the molecular weights of those from two species were in the region of 38,000–68,000, suggesting that they were cathepsin D-type proteinases. 相似文献
16.
Satiation and the functional response: a test of a new model 总被引:1,自引:0,他引:1
N. J. MILLS 《Ecological Entomology》1982,7(3):305-315
Abstract. 1. A model of the functional response to prey density is derived to include the reduction in time available for search, Ts , resulting from predator satiation.
2. For larger prey items predator satiation occurs at each prey capture and Ts is reduced by the attack time and digestive pause of a series of attack cycles. For small prey items predator foraging is continuous at low densities with Ts reduced solely by attack time. At higher densities predator satiation occurs after the capture of several small prey items and Ts is reduced by the attack time and digestive pause of a series of foraging cycles.
3. A comparison of the predicted asymptotic level of prey capture using experimentally estimated parameter values, with the maximum consumption of aphids by larval and adult coccinellids provides a test of the satiation model.
4. The limitation of prey capture by predator satiation is discussed with reference to handling time and the success of coccinellids in biological control. 相似文献
2. For larger prey items predator satiation occurs at each prey capture and T
3. A comparison of the predicted asymptotic level of prey capture using experimentally estimated parameter values, with the maximum consumption of aphids by larval and adult coccinellids provides a test of the satiation model.
4. The limitation of prey capture by predator satiation is discussed with reference to handling time and the success of coccinellids in biological control. 相似文献
17.
Free radical mechanisms in enzyme reactions 总被引:1,自引:0,他引:1
Isao Yamazaki 《Free radical biology & medicine》1987,3(6):397-404
Free radicals are formed in prosthetic groups or amino acid residues of certain enzymes. These free radicals are closely related to the activation process in enzyme catalysis, but their formation does not always result in the formation of substrate free radicals as a product of the enzyme reactions. The role of free radicals in enzyme catalysis is discussed. 相似文献
18.
Thiol redox state (TRS) reduced and oxidized components form profiles characteristic of each of the four main types of differentiation in the sclerotiogenic phytopathogenic fungi: loose, terminal, lateral-chained, and lateral-simple, represented by Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotium rolfsii, and Sclerotinia minor, respectively. A common feature of these fungi is that as their undifferentiated mycelium enters the differentiated state, it is accompanied by a decrease in the low oxidative stress-associated total reduced thiols and/or by an increase of the high oxidative stress-associated total oxidized thiols either in the sclerotial mycelial substrate or in its corresponding sclerotium, indicating a relationship between TRS-related oxidative stress and sclerotial differentiation. Moreover, the four studied sclerotium types exhibit high activities of TRS-related antioxidant enzymes, indicating the existence of antioxidant protection of the hyphae of the sclerotium medulla until conditions become appropriate for sclerotium germination. 相似文献
19.
《Journal of Plant Interactions》2013,8(2):91-99
Abstract The present research work focused on the metal translocation in the soil-plant system and subsequent metal stress on biochemical response of aquatic macrophytes growing along an industrial waste discharge channel. The bottom sediment of the effluent channel is highly contaminated with metals. High transfer factor (TF) for most of the metals indicated higher metal uptake by aquatic macrophytes of which Typha sp. was found to be the most suitable. Average TF was in the order of Fe (4.82) > Mn (3.91) > Cu (3.59) > Cd (2.29) > Zn (2.22) > Cr (1.83) > Pb (1.80). Hyper accumulation of metals within plants resulted in significant reductions in total chlorophyll, soluble sugar with an increase in protein and proline content. The investigation also demonstrated that exposure to high concentrations on metals resulted in enhanced activity of catalase (61.82–90.91%) and peroxidase (37.08–70.23%) in all examined macrophytes with a reduced (27.58–43.4%) or unchanged ascorbate peroxidase activity depending on plant species. 相似文献
20.
Robert P. Hausinger 《Journal of biological inorganic chemistry》1997,2(3):279-286
The five known nickel-dependent enzymes include urease, hydrogenase, carbon monoxide dehydrogenase (and CO dehydrogenase/acetyl-coenzyme
A synthase), methyl-S–coenzyme M reductase, and one class of superoxide dismutase. Consistent with their disparate functions, these Ni enzymes
have distinct metallocenter structures that vary in Ni coordination geometry, number and types of metals, and the presence
of additional components. Sophisticated cellular Ni processing systems have been devised to allow for specific and functional
incorporation of Ni into these proteins. This review highlights several themes that are common to the enzyme activation processes
and summarizes current concepts related to the enzyme-specific Ni assembly pathways.
Received, accepted: 3 April 1997 相似文献