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21.
22.
John Butterworth Grant R. Sutherland David M. Broadhead A.Douglas Bain 《Life sciences》1973,13(6):713-722
A number of factors which may correlate with the levels of α-glucosidase and β-glucosidase in cultured amniotic fluid cells have been investigated. Fluctuations in enzyme activity occurred as passage numbers increased. Whereas α-glucosidase showed a consistently lower activity in the earlier passages compared to the later ones, the results for β-glucosidase were equivocal. Both enzymes showed an increase in activity correlated with the time taken by the cells to reach confluency in the third passage. When replicate cultures were assayed daily after subculture, neither enzyme showed any change correlated with time. When cultures were grown in parallel in Ham's F10 and Eagle's M.E.M. tissue culture media, the activity of both enzymes was unaffected. Cell strains cultured from serial samples of amniotic fluid from the same woman had differing enzyme levels unrelated to gestational age. 相似文献
23.
The tibial nerve transection model is a well-tolerated, validated, and reproducible model of denervation-induced skeletal muscle atrophy in rodents. Although originally developed and used extensively in the rat due to its larger size, the tibial nerve in mice is big enough that it can be easily manipulated with either crush or transection, leaving the peroneal and sural nerve branches of the sciatic nerve intact and thereby preserving their target muscles. Thus, this model offers the advantages of inducing less morbidity and impediment of ambulation than the sciatic nerve transection model and also allows investigators to study the physiologic, cellular and molecular biologic mechanisms regulating the process of muscle atrophy in genetically engineered mice. The tibial nerve supplies the gastrocnemius, soleus and plantaris muscles, so its transection permits the study of denervated skeletal muscle composed of fast twitch type II fibers and/or slow twitch type I fibers. Here we demonstrate the tibial nerve transection model in the C57Black6 mouse. We assess the atrophy of the gastrocnemius muscle, as a representative muscle, at 1, 2, and 4 weeks post-denervation by measuring muscle weights and fiber type specific cross-sectional area on paraffin-embedded histologic sections immunostained for fast twitch myosin. 相似文献
24.
Enhancing the egg's natural defence against bacterial penetration by increasing cuticle deposition 总被引:1,自引:0,他引:1
M. M. Bain K. Mcdade R. Burchmore A. Law P. W. Wilson M. Schmutz R. Preisinger I. C. Dunn 《Animal genetics》2013,44(6):661-668
The cuticle is a proteinaceous layer covering the avian egg and is believed to form a defence to microorganism ingress. In birds that lay eggs in challenging environments, the cuticle is thicker, suggesting evolutionary pressure; however, in poultry, selection pressure for this trait has been removed because of artificial incubation. This study aimed to quantify cuticle deposition and to estimate its genetic parameters and its role on trans‐shell penetration of bacteria. Additionally, cuticle proteins were characterised to establish whether alleles for these genes explained variation in deposition. A novel and reliable quantification was achieved using the difference in reflectance of the egg at 650 nm before and after staining with a specific dye. The heritability of this novel measurement was moderate (0.27), and bacteria penetration was dependent on the natural variation in cuticle deposition. Eggs with the best cuticle were never penetrated by bacteria (P < 0.001). The cuticle proteome consisted of six major proteins. A significant association was found between alleles of one of these protein genes, ovocleidin‐116 (MEPE), and cuticle deposition (P = 0.015) and also between alleles of estrogen receptor 1 (ESR1) gene and cuticle deposition (P = 0.008). With the heritability observed, genetic selection should be possible to increase cuticle deposition in commercial poultry, so reducing trans‐generational transmission of microorganisms and reversing the lack of selection pressure for this trait during recent domestication. 相似文献
25.
JULIE DUBOSCQ JÉRÔME MICHELETTA MUHAMMAD AGIL KEITH HODGES BERNARD THIERRY ANTJE ENGELHARDT 《American journal of primatology》2013,75(4):361-375
In primates, females typically drive the evolution of the social system and present a wide diversity of social structures. To understand this diversity, it is necessary to document the consistency and/or flexibility of female social structures across and within species, contexts, and environments. Macaques (Macaca sp.) are an ideal taxon for such comparative study, showing both consistency and variation in their social relations. Their social styles, constituting robust sets of social traits, can be classified in four grades, from despotic to tolerant. However, tolerant species are still understudied, especially in the wild. To foster our understanding of tolerant societies and to assess the validity of the concept of social style, we studied female crested macaques, Macaca nigra, under entirely natural conditions. We assessed their degree of social tolerance by analyzing the frequency, intensity, and distribution of agonistic and affiliative behaviors, their dominance gradient, their bared‐teeth display, and their level of conciliatory tendency. We also analyzed previously undocumented behavioral patterns in grade 4 macaques: reaction upon approach and distribution of affiliative behavior across partners. We compared the observed patterns to data from other populations of grade 4 macaques and from species of other grades. Overall, female crested macaques expressed a tolerant social style, with low intensity, frequently bidirectional, and reconciled conflicts. Dominance asymmetry was moderate, associated with an affiliative bared‐teeth display. Females greatly tolerated one another in close proximity. The observed patterns matched the profile of other tolerant macaques and were outside the range of patterns of more despotic species. This study is the first comprehensive analysis of females’ social behavior in a tolerant macaque species under natural conditions and as such, contributes to a better understanding of macaque societies. It also highlights the relevance of the social style concept in the assessment of the degree of tolerance/despotism in social systems. Am. J. Primatol. 75:361‐375, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
26.
VIVIANE LANQUAR ASTRID AGORIO JÉRÔME GIRAUDAT THOMAS ROACH ANJA KRIEGER‐LISZKAY SÉBASTIEN THOMINE 《Plant, cell & environment》2013,36(4):804-817
Cadmium (Cd) is highly toxic to plants causing growth reduction and chlorosis. It binds thiols and competes with essential transition metals. It affects major biochemical processes such as photosynthesis and the redox balance, but the connection between cadmium effects at the biochemical level and its deleterious effect on growth has seldom been established. In this study, two Cd hypersensitive mutants, cad1‐3 impaired in phytochelatin synthase (PCS1), and nramp3nramp4 impaired in release of vacuolar metal stores, have been compared. The analysis combines genetics with measurements of photosynthetic and antioxidant functions. Loss of AtNRAMP3 and AtNRAMP4 function or of PCS1 function leads to comparable Cd sensitivity. Root Cd hypersensitivities conferred by cad1‐3 and nramp3nramp4 are cumulative. The two mutants contrast in their tolerance to oxidative stress. In nramp3nramp4, the photosynthetic apparatus is severely affected by Cd, whereas it is much less affected in cad1‐3. In agreement with chloroplast being a prime target for Cd toxicity in nramp3nramp4, the Cd hypersensitivity of this mutant is alleviated in the dark. The Cd hypersensitivity of nramp3nramp4 mutant highlights the critical role of vacuolar metal stores to supply essential metals to plastids and maintain photosynthetic function under Cd and oxidative stresses. 相似文献
27.
Tian Zhang Pier-Luc Tremblay Akhilesh Kumar Chaurasia Jessica A. Smith Timothy S. Bain Derek R. Lovley 《Applied and environmental microbiology》2013,79(24):7800-7806
Anaerobic activation of benzene is expected to represent a novel biochemistry of environmental significance. Therefore, benzene metabolism was investigated in Geobacter metallireducens, the only genetically tractable organism known to anaerobically degrade benzene. Trace amounts (<0.5 μM) of phenol accumulated in cultures of Geobacter metallireducens anaerobically oxidizing benzene to carbon dioxide with the reduction of Fe(III). Phenol was not detected in cell-free controls or in Fe(II)- and benzene-containing cultures of Geobacter sulfurreducens, a Geobacter species that cannot metabolize benzene. The phenol produced in G. metallireducens cultures was labeled with 18O during growth in H218O, as expected for anaerobic conversion of benzene to phenol. Analysis of whole-genome gene expression patterns indicated that genes for phenol metabolism were upregulated during growth on benzene but that genes for benzoate or toluene metabolism were not, further suggesting that phenol was an intermediate in benzene metabolism. Deletion of the genes for PpsA or PpcB, subunits of two enzymes specifically required for the metabolism of phenol, removed the capacity for benzene metabolism. These results demonstrate that benzene hydroxylation to phenol is an alternative to carboxylation for anaerobic benzene activation and suggest that this may be an important metabolic route for benzene removal in petroleum-contaminated groundwaters, in which Geobacter species are considered to play an important role in anaerobic benzene degradation. 相似文献
28.
Sclerotia produced by a single isolate of Rhizoctonia solani AG3PT were buried in small plot experiments to investigate the effects of sclerotial production method, soil type and burial depth on sclerotial viability in field soil. The factor with the greatest effect on sclerotial viability, defined as the percentage of sclerotia germinating on agar following retrieval, in all experiments was the duration of burial. After 18 months, on average across all experiments, 20% of retrieved sclerotia were viable. A comparison between sclerotia produced in vitro on malt yeast extract agar and in vivo using micropropagated tubers in field soil found no significant differences between the two production methods on sclerotial viability. Burial in field soil at 20‐cm depth was found to significantly reduce sclerotial viability to 50% compared to 60% at 5 cm. In two pot experiments, amending the growing medium and soil with increasing inoculum densities of R. solani was found to increase stem number, stem canker and black scurf severity regardless of whether this soil‐borne inoculum was derived from mycelium or sclerotia. Black scurf incidence and severity were assessed 30–32 days posthaulm destruction and found to be similar for a range of sclerotial soil‐borne inoculum densities (1.0 × 10?1 g/kg d.w. soil to 6 × 10?3 g/kg d.w. soil). The significance of these findings in relation to pathogen survival, detection in soil and disease development is discussed. 相似文献
29.
G Cuce S Cetinkaya N Isitez S Kuccukturk ME Sozen S Kalkan 《Biotechnic & histochemistry》2016,91(2):122-127
Methylmethane sulfonate (MMS) is an alkylating agent that may react with DNA and damage it. We investigated histological changes and apoptosis caused by MMS and the effects of curcumin on MMS treated mouse kidneys. Twenty-four mice were divided into four equal groups: controls injected with saline, a group injected with 40 mg/kg MMS, a group injected with 40 mg/kg MMS and given 100 mg/kg curcumin by gavage, and a group given 100 mg/kg curcumin by gavage. MMS caused congestion and vacuole formation, and elevated the apoptotic index significantly, but had no other effect on kidney tissue. Curcumin improved the congestion and vacuole formation caused by MMS and decreased the apoptotic index. Curcumin administered with MMS appears to decrease the deleterious effects of MMS on the kidney. 相似文献
30.