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1.
Relationship of fatty acid composition to intramuscular fat content in beef from crossbred Wagyu cattle. 总被引：2，自引：0，他引：2
E C Kazala F J Lozeman P S Mir A Laroche D R Bailey R J Weselake 《Journal of animal science》1999,77(7):1717-1725
The deposition of i.m. fat, or marbling, in cattle is recognized as a desirable carcass trait in North American beef grading schemes. In order to investigate the relationship between degree of marbling and fatty acid composition of whole bovine muscle, we extracted the total lipid from pars costalis diaphragmatis (PCD) (n = 23) and longissimus (n = 36) muscles from Wagyu crossbred cattle that were assigned Canadian Grading Agency marbling scores ranging from 1 to 8 on an inverse 10-point scale (i.e., a score of 1 indicated "very abundant" marbling and a score of 10 would be assigned to a carcass "devoid" of marbling). Fatty acid methyl esters (FAME) of the total lipid and triacylglycerol fractions were resolved and quantified through GLC. Marbling scores were negatively associated with total lipid from both PCD (r = -.57, P < .01) and longissimus (r = -.80, P < .001). Differences between PCD and longissimus were found for almost all FAME studied from both lipid fractions, but no differences (P > .05) were seen when the monounsaturated:saturated fatty acid (MUFA/SFA) ratios were compared. Heifers had higher (P < .05) oleic acid content and lower (P < .05) palmitic acid content in lipid extracted from both muscles, resulting in higher (P < .05) MUFA/SFA ratios than those for steers. The relative amount of myristic acid increased as the lipid content (total lipid and triacylglycerol) increased in either longissimus (r values from .48 to .55; n = 36; P < .01) or PCD muscles (r from .67 to .76; n = 23; P < .001). The relative amount of linoleic acid (cis-9, cis-12 isomer) from total lipid was negatively associated with all chemical measurements of lipid from the longissimus (r from -.52 to -.64; n = 36; P < .001) and PCD muscles (r from -.75 to -.85; n = 23; P < .001). This association was not significant (P > .1) for either muscle when linoleic acid from the triacylglycerol fraction was examined, suggesting the negative association between this fatty acid and lipid content was due to a dilution of membrane phospholipids with increasing triacylglycerol. Indices of fatty acid elongase activity, calculated from FAME data, implicated the balance between this enzyme activity and fatty acid synthase as a source of variation between animals displaying various degrees of marbling and worthy of further investigation to better understand the process of marbling fat deposition in beef cattle. 相似文献
2.
Hongjie Li Robert L. Conner Qin Chen Robert J. Graf André Laroche F. Ahmad A. D. Kuzyk 《Genetic Resources and Crop Evolution》2005,51(8):827-835
Wheat streak mosaic virus (WSMV), vectored by the wheat curl mite (WCM),Aceria tosichella Keifer, is one of the most destructive viral diseases of wheat found in many wheat producing areas of the world. Host resistance is the most effective method for controlling this disease and its vector. Symptomatological analysis and enzyme-linked immunosorbent assay (ELISA) were used to characterize WSMV-resistance in wheat-alien partial amphiploid lines and their derivatives. The results showed that most of partial amphiploids derived fromThinopyrum ponticum andTh. intermedium were free of systemic symptoms with very low ELISA readings that were similar to that of the non-inoculated Chinese Spring control. While the partial amphiploid lines 693 and PWM706 were identified as new genetic resources of resistance to WSMV. The present study demonstrated that both symptomatological and ELISA methods efficiently assessed WSMV-resistance in the wheat-alien hybrids and systemic symptom incidence and ELISA absorbance readings were highly correlated (r
2 = 0.8658–0.9323) over time following inoculation. The ELISA results also indicated that the virus did not buildup in the plant tissues of these virus-resistant partial amphiploids. Similar results were observed in chromosome translocation and substitution lines that have the geneWsm1 conferring WSMV resistance. However, the lines containing the geneWsm1 and all the partial amphiploid lines, except Agrotana, were susceptible to the WCM. One line derived from a cross of wheat and Agrotana, was effective in controlling the spread of WSMV and was highly resistant to the WCM. Another line and an accession ofTriticum dicoccoides (Koern.) Schweinf. were highly susceptible to WSMV and WCM. Early disease development was delayed in a new hard red winter cultivar McClintock. The partial WSMV-resistance of McClintock was demonstrated by initially low ELISA readings, and a lower percentage of infected plants than other WSMV-susceptible wheat. The use of the identified promising sources of resistance to WSMV and the WCM in wheat breeding is discussed.LRC Contribution No. 387-01061. 相似文献
3.
Antoine Decamp Orane Michelo Christelle Rabbat Cline Laroche Dominique Grizeau Jrmy Pruvost Olivier Gonalves 《Marine drugs》2021,19(2)
In this work, a new methodological approach, relying on the high specificity of enzymes in a complex mixture, was developed to estimate the composition of bioactive polysaccharides produced by microalgae, directly in algal cultures. The objective was to set up a protocol to target oligomers commonly known to be associated with exopolysaccharides’ (EPS) nutraceutical and pharmaceutical activities (i.e., rhamnose, fucose, acidic sugars, etc.) without the constraints classically associated with chromatographic methods, while maintaining a resolution sufficiently high to enable their monitoring in the culture system. Determination of the monosaccharide content required the application of acid hydrolysis (2 M trifluoroacetic acid) followed by NaOH (2 M) neutralization. Quantification was then carried out directly on the fresh hydrolysate using enzyme kits corresponding to the main monosaccharides in a pre-determined composition of the polysaccharides under analysis. Initial results showed that the enzymes were not sensitive to the presence of TFA and NaOH, so the methodology could be carried out on fresh hydrolysate. The limits of quantification of the method were estimated as being in the order of the log of nanograms of monosaccharides per well, thus positioning it among the chromatographic methods in terms of analytical performance. A comparative analysis of the results obtained by the enzymatic method with a reference method (high-performance anion-exchange chromatography) confirmed good recovery rates, thus validating the closeness of the protocol. Finally, analyses of raw culture media were carried out and compared to the results obtained in miliQ water; no differences were observed. The new approach is a quick, functional analysis method allowing routine monitoring of the quality of bioactive polysaccharides in algal cultures grown in photobioreactors. 相似文献
4.
Nesrine Gargouch Fatma Elleuch Ines Karkouch Olfa Tabbene Chantal Pichon Christine Gardarin Christophe Rihouey Luc Picton Slim Abdelkafi Imen Fendri Cline Laroche 《Marine drugs》2021,19(2)
Exopolysaccharide (EPS) from marine microalgae are promising sources of a new generation of drugs. However, lot of them remain to be discovered and tested. In this study, EPS produced by Porphyridium marinum and its oligomers prepared by High Pressure Homogenizer have been tested for different biological activities, i.e., antibacterial, anti-fungal and antibiofilm activities on Candida albicans, as well as for their effects on the viability of murine breast cancer cells. Results have shown that all EPS samples present some biological activity. For antibacterial and antibiofilm activities, the native EPS exhibited a better efficiency with Minimum Inhibitory Concentration (MIC) from 62.5 µg/mL to 1000 µg/mL depending on the bacterial strain. For Candida albicans, the biofilm formation was reduced by about 90% by using only a 31.3 µg/mL concentration. Concerning breast cancer cells, lower molar masses fractions appeared to be more efficient, with a reduction of viability of up to 55%. Finally, analyses of polymers composition and viscosity measurements were conducted on all samples, in order to propose hypotheses involving the activities caused by the intrinsic properties of polymers. 相似文献
5.
Prevalence and antimicrobial resistance of Campylobacter coli isolated from fattening pigs in France
Campylobacter are a leading cause of human diarrhea. The usual source of infection is contaminated food, particularly poultry but pork has also been described. The veterinary use of antimicrobial drugs has been suggested to be largely responsible for resistance in human isolates of this zoonotic pathogen. A study was carried out to investigate the occurrence and antimicrobial resistance of Campylobacter isolated from French fattening pigs. From March 1998 to June 1999, stomach samples were collected at slaughter from 240 fattening pigs originating from 24 different farms. Half of the pigs were found to be positive for Campylobacter but considerable variation was observed between farms. Isolates all belong to the Campylobacter coli species. Susceptibilities of the strains were determined for five antimicrobial drugs using agar dilution. Resistance to tetracycline and erythromycin was high (79 and 55%, respectively). For nalidixic acid, enrofloxacin and ampicillin, resistance was observed in 34, 15 and 20% of the isolates, respectively. More than one-third of the strains was resistant to at least three antimicrobial drugs. A Thr86Ile modification in GyrA was observed in the enrofloxacin-resistant strains studied. The multiresistant strains analyzed expressed the multidrug transporter CmeB at a high level. Results indicated a high prevalence of C. coli in the stomach of the French pigs examined. In addition, a high proportion of the strains was resistant to antimicrobial drugs, particularly to tetracycline and erythromycin, or were multiresistant. 相似文献
6.
Characterization of wheat-Thinopyrum partial amphiploids for resistance to barley yellow dwarf virus
Resistance to viruses such as wheat streak mosaic virus (WSMV) and barley yellow dwarf virus(BYDV) is lacking in the primary
gene pool of wheat, and therefore resistance is being introgressed from wild relatives such as Thinopyrum species. Resistance to BYDV was found in partial amphiploids (2n = 8x = 56, consisting of 42 wheat and14 alien chromosomes) obtained in hybrids between wheat and both Th. intermedium and Th.ponticum. GISH analysis revealed that the alien genomes of all but one resistant partial amphiploid were heterogeneous consisting
of different ratios of St, Js and J genome chromosomes obtained from theThinopyrum parent. Translocated chromosomes consisting of Robertsonian, interstitial and terminal translocations between the different
genomes were also detected. The tissue blot immunoassay showed that partial amphiploids having resistance could be inoculated
with the virus but both virus multiplication and spread were completely blocked.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
7.
Application of risk analysis to control pork-borne zoonoses on farms is a major aim of the current European food safety legislation. The prevalence, levels of contamination and variations in pig contaminations according to herds and batches must therefore be studied to define relevant methods for control of zoonoses. The aims of this exploratory study were to provide information on the prevalence and levels of infection of finisher/fattening pigs by Campylobacter spp., Clostridium perfringens, Listeria monocytogenes, Salmonella enterica and Staphylococcus aureus, and to quantify the respective effects of batches and herds. One hundred and twenty-seven pooled fresh feces samples and 120 pooled cutaneous swab samples were tested from 37 batches in 14 farrowing-to-finishing farms. Campylobacter spp. was identified in all fecal samples on farms whereas L. monocytogenes was never found. C. perfringens was identified in 48% of samples, Salmonella in 2%, and S. aureus in 48%. The decomposition of variance of on-farm prevalence and levels of contamination and a general linear model showed a systematically significant effect of herd, and an effect of batch only for levels of contamination with Campylobacter and C. perfringens and for prevalence of S. aureus. The contamination status of pigs seems to be mainly explained by herd status linked to poor biosecurity measures. Further studies are needed to explain such correlations in order to define farm indicators for food-borne zoonotic hazards. 相似文献
8.
9.
Context
Forest management and disturbances cause habitat fragmentation for saproxylic species living on old-growth attributes. The degree of habitat spatiotemporal continuity required by these species is a key question for designing biodiversity-friendly forestry, and it strongly depends on species’ dispersal. The “stability–dispersal” model predicts that species using stable habitats should have lower dispersal abilities than species associated with ephemeral habitat and thus respond to habitat availability at smaller scales.
ObjectivesWe aimed at testing the stability–dispersal model by comparing the spatial scales at which saproxylic beetle guilds using substrates with contrasted stability (from stable to ephemeral: cavicolous, fungicolous, saproxylophagous and xylophagous guilds) are affected by landscape structure (i.e. habitat amount and aggregation).
MethodsWe sampled saproxylic beetles using a spatially nested design (plots within landscape windows). We quantified habitat availability (tree cavities, polypores and deadwood) in 1-ha plots, 26-ha buffers around plots and 506-ha windows, and analyzed their effect on the abundance and diversity of associated guilds.
ResultsThe habitat amount within plots and buffers positively affected the abundance of the cavicolous and the fungicolous guilds whereas saproxylophagous and xylophagous did not respond at these scales. The habitat aggregation within windows only positively affected the saproxylophagous species richness within plots and also on the similarity in species composition among plots.
ConclusionsBeetle guilds specialized on more stable habitat were affected by landscape structure at smaller spatial scales, which corroborated the stability–dispersal model. In managed forests, the spatial grain of conservation efforts should therefore be adapted to the target habitat lifetime.
相似文献10.
Tim Xing Xiu-Qing Li Andre Laroche Lining Tian Kipkios Tubei Xiaojing Wang 《European journal of plant pathology / European Foundation for Plant Pathology》2017,149(4):1001-1010
Transient gene expression in protoplasts has been applied to the analysis of gene expression, promoter activity, subcellular localization of proteins, and genome editing. Its advantages have been realized in recent years in various physiological, biochemical, genetic, and molecular biological studies. The omics and systems biology studies of plant development and their interactions with the environment have revitalized this approach. Early plant-pathogen interaction represents one of the most unique signalling research areas. Here, we try to discuss some developments and current applications of the protoplast system. It is for sure that the system will significantly bridge the gap between high throughput approaches and functional analysis in the study of plant-pathogen interactions in the omics era. 相似文献