Transmission electron microscopy for characterization of acrosomal damage after Percoll gradient centrifugation of cryopreserved bovine spermatozoa     

Letícia Z. Oliveira  Vera F. M. Hossepian de Lima  Marcelo A. Levenhagen  Ricarda M. dos Santos  Terezinha I. Assump??o  José O. Jacomini  André F. C. de Andrade  Rubens P. de Arruda  Marcelo E. Beletti 《Journal of veterinary science (Suw?n-si, Korea)》2011,12(3):267-272

The objective of this study was to characterize acrosomal ultrastructure following discontinuous Percoll gradient centrifugation of cryopreserved bovine sperm. Semen was collected from six bulls of different breeds and three ejaculates per bull were evaluated. Frozen semen samples were thawed and the acrosomal region of sperm cells was evaluated by transmission electron microscopy (TEM) before (n = 18) and after (n = 18) Percoll centrifugation. The evaluation of 20 sperm heads from each of the 36 samples analyzed ensured that a large number of cells were investigated. The data were subjected to analysis of variance at a level of significance of 5%. Percoll centrifugation reduced the percentage of sperm exhibiting normal acrosomes (from 61.77 to 30.24%), reduced the percentage of sperm presenting atypical acrosome reactions (from 28.38 to 4.84%) and increased the percentage of sperm exhibiting damage in the acrosome (from 6.14 to 64.26%). The percentage of sperm with typical acrosome reactions was not significantly different before (3.70%) and after (0.67%) centrifugation. TEM distinguished four different types of acrosomal status and enabled ultrastructural characterization of acrosomal injuries. The percentage of sperm exhibiting normal acrosomes decreased and damage in the acrosome was the most frequent acrosomal injury with the Percoll gradient centrifugation protocol utilized.  相似文献   

Convergence of developmental mutants into a single tomato model system: 'Micro-Tom' as an effective toolkit for plant development research     

Carvalho RF  Campos ML  Pino LE  Crestana SL  Zsögön A  Lima JE  Benedito VA  Peres LE 《Plant methods》2011,7(1):18-14

Background

The tomato (Solanum lycopersicum L.) plant is both an economically important food crop and an ideal dicot model to investigate various physiological phenomena not possible in Arabidopsis thaliana. Due to the great diversity of tomato cultivars used by the research community, it is often difficult to reliably compare phenotypes. The lack of tomato developmental mutants in a single genetic background prevents the stacking of mutations to facilitate analysis of double and multiple mutants, often required for elucidating developmental pathways.

Results

We took advantage of the small size and rapid life cycle of the tomato cultivar Micro-Tom (MT) to create near-isogenic lines (NILs) by introgressing a suite of hormonal and photomorphogenetic mutations (altered sensitivity or endogenous levels of auxin, ethylene, abscisic acid, gibberellin, brassinosteroid, and light response) into this genetic background. To demonstrate the usefulness of this collection, we compared developmental traits between the produced NILs. All expected mutant phenotypes were expressed in the NILs. We also created NILs harboring the wild type alleles for dwarf, self-pruning and uniform fruit, which are mutations characteristic of MT. This amplified both the applications of the mutant collection presented here and of MT as a genetic model system.

Conclusions

The community resource presented here is a useful toolkit for plant research, particularly for future studies in plant development, which will require the simultaneous observation of the effect of various hormones, signaling pathways and crosstalk.  相似文献   

Subsoil retention of organic and inorganic nitrogen in a Brazilian savanna Oxisol   总被引：1，自引：0，他引：1  

J. Lehmann  J. Lilienfein  K. Rebel  S. do  Carmo Lima W. Wilcke 《Soil Use and Management》2004,20(2):163-172

Abstract. Nitrogen (N) loss by leaching poses great challenges for N availability to crops as well as nitrate pollution of groundwater. Few studies address this issue with respect to the role of the subsoil in the deep and highly weathered savanna soils of the tropics, which exhibit different adsorption and drainage patterns to soils in temperate environments. In an Anionic Acrustox of the Brazilian savanna, the Cerrado, dynamics and budgets of applied N were studied in organic and inorganic soil pools of two maize (Zea mays L.) – soybean (Glycine max (L.) Merr.) rotations using ¹⁵N tracing. Labelled ammonium sulphate was applied at 10 kg N ha^?1 (with 10 atom%¹⁵N excess) to both maize and soybean at the beginning of the cropping season. Amounts and isotopic composition of N were determined in above‐ground biomass, soil, adsorbed mineral N, and in soil solution at 0.15, 0.3, 0.8, 1.2 and 2 m depths using suction lysimeters throughout one cropping season. The applied ammonium was rapidly nitrified or immobilized in soil organic matter, and recovery of applied ammonium in soil 2 weeks after application was negligible. Large amounts of nitrate were adsorbed in the subsoil (150–300 kg NO₃^?‐N ha^?1 per 2 m) matching total N uptake by the crops (130–400 kg N ha^?1). Throughout one cropping season, more applied N (49–77%; determined by ¹⁵N tracers) was immobilized in soil organic matter than was present as adsorbed nitrate (2–3%). Most of the applied N (71–96% of ¹⁵N recovery) was found in the subsoil at 0.15–2 m depth. This coincided with an increase with depth of dissolved organic N as a proportion of total dissolved N (39–63%). Hydrophilic organic N was the dominant fraction of dissolved organic N and was, together with nitrate, the most important carrier for applied N. Most of this N (>80%) was leached from the topsoil (0–0.15 m) during the first 30 days after application. Subsoil N retention as both adsorbed inorganic N, and especially soil organic N, was found to be of great importance in determining N losses, soil N depletion and the potential of nitrate contamination of groundwater.  相似文献   

Stabilization of soybean oil with heated quercetin and 5-caffeoylquinic acid in the presence of ferric ion     

Bastos De Maria CA  Moreira Santos MC  José De Lima Dias U  Marana M 《Journal of agricultural and food chemistry》2000,48(9):3935-3938

The effect of heated quercetin (400 mg/kg of oil) or 5-caffeoylquinic acid (5-CQA) and the presence of ferric ion (2.2 mg/kg of oil) on the stability of soya oil oxidized in an oxidative stability index (OSI) instrument was investigated. After heating the phenolic at 100 degrees C or 150 degrees C, the OSI values of treated oils were not significantly (p < 0.001) different, whereas, at 200 degrees C, the values decreased significantly with addition of quercetin, but not with 5-CQA. However, the antioxidative activity of quercetin remained significantly greater than that of 5-CQA. The antioxidative potency of quercetin was reduced significantly by addition of ferric palmitate (FP), but that of 5-CQA was not. Reaction between the ortho-dihydroxy groups of the quercetin and ferric ion may reduce the number of hydroxyls available to react with free radicals. Chelating action of 5-CQA might be provided by ortho-dihydroxy grouping of the quinic acid moiety.  相似文献   

Pseudopregnancy in Saanen Goats (Capra hircus) Raised in Northeast Brazil     

Lopes Júnior ES  Cruz JF  Teixeira DI  Lima Verde JB  Paula NR  Rondina D  Freitas VJ 《Veterinary research communications》2004,28(2):119-125

The prevalence of pseudopregnancy over 44 months was investigated in 23 Saanen goats raised in Northeast Brazil during continuous oestrous cycling (cyclic group) or after synchronization of oestrus (synchronized group). The goats were monitored by ultrasonography and their plasma progesterone profile. The overall prevalence of pseudopregnancy was 30.4% (7/23). In the cyclic group, 28.6% (4/14) of goats showed pseudopregnancy, while in the synchronized group the prevalence was 33.3% (3/9). There was no significant difference between the groups (p>0.05). The mean (+/- SD) length of pseudopregnancy, as shown by the progesterone profile, was 121.6 +/- 33.5 days, ranging from 70 to 155 days. The study defined the prevalence of pseudopregnancy in Saanen goats raised in Northeast Brazil for the first time. This finding identified a major problem for this breed, as without treatment such animals remain unproductive until the spontaneous resolution of the condition. More research seems desirable to ascertain the prevalence of this condition in other breeds in this region of Brazil.  相似文献   

Kinetic enzymatic determination of glycerol in wine and beer using a sequential injection system with spectrophotometric detection     

Oliveira HM  Segundo MA  Lima JL  Grassi V  Zagatto EA 《Journal of agricultural and food chemistry》2006,54(12):4136-4140

A sequential injection system for the automatic determination of glycerol in wine and beer was developed. The method is based on the rate of formation of NADH from the reaction of glycerol and NAD+ catalyzed by the enzyme glycerol dehydrogenase in solution. The determination of glycerol was performed between 0.3 and 3.0 mmol L(-1) (0.028 and 0.276 g L(-1)), and good repeatability was attained (rsd < 3.6%, n = 5) for all samples tested. The determination rate was 54 h(-1), the reagent consumption was only 0.75 micromol of NAD+ and 5.4 ng of enzyme per assay, and the waste production was 2.12 mL per assay. Results obtained for samples were in agreement with those obtained with the batch enzymatic method.  相似文献   

Characterization of extraintestinal Escherichia coli isolated from a peacock (Pavo cristatus) with colisepticemia     

Barbieri NL  Tejkowski TM  de Oliveira AL  de Brito BG  Horn F 《Avian diseases》2012,56(2):436-440

Extraintestinal infections by avian pathogenic strains of Escherichia coli (APEC) are commonly reported in poultry, but there is little information on infections by APEC in other bird species. Here we report on the characterization of extraintestinal E. coli isolated from a domesticated peacock, from the south of Brazil, that died of colisepticemia. Necropsy examination revealed congested liver, hypertrophied kidneys, peritonitis, severe typhlitis suggestive of coligranuloma, pneumonia, and airsacculitis--typical signs of colisepticemia. The isolates from lungs, kidney, heart, intestine, liver, and bone marrow all harbored the same virulence-associated factors (iucD, colV, iss, mat, fimC, ompA, traT crl, csgA vgrG, and hcp), yielded the same band pattern in amplified ribosomal DNA restriction analysis, and were allocated to the Escherichia coli Reference Collection group B1. The isolates were resistant to bacitracin, trimethoprim, and tetracycline, but displayed slight differences in their resistance to other antimicrobials. The isolates also differed in their virulence in 1-day-old chickens, but none displayed high virulence in vivo. We conclude that the peacock died of colisepticemia after it was infected with an extraintestinal E. coli strain of low virulence that nevertheless harbored virulence factors generally associated with APEC. This study represents the first characterization of an APEC isolated from a nonpoultry bird species.  相似文献   

Effect of organic acids and mannanoligosaccharide on excretion of Salmonella typhimurium in experimentally infected growing pigs     

Calveyra JC  Nogueira MG  Kich JD  Biesus LL  Vizzotto R  Berno L  Coldebella A  Lopes L  Morés N  Lima GJ  Cardoso M 《Research in veterinary science》2012,93(1):46-47

The effect of organic acids and mannanoligosaccharide addition to the diet was assessed in pigs orally inoculated with Salmonella typhimurium. Forty-six growers were distributed among four treatments: Basal Diet (BD); BD+encapsulated organic acids; BD+free organic acids; BD+mannanoligosaccharide. Seroconversion was monitored, and feces and tissue samples were tested for Salmonella isolation. No treatment prevented the carrier state, but a tendency of lower fecal excretion was observed in the group treated with mannanoligosaccharide.  相似文献   

Influence of different supplements and sugarcane (Saccharum officinarum L.) cultivars on intake, digestible variables and methane production of dairy heifers under tropical conditions     

Dos Santos Pedreira M  Berchelli TT  Primavesi O  de Oliveira SG  Frighetto R  de Lima MA 《Tropical animal health and production》2012,44(7):1773-1778

The sulphur hexafluoride (SF(6)) gas tracer method was used to measure methane (CH(4)) production of crossbred (3/4 Holstein x Zebu) dairy heifers fed two types of sugarcane (Saccharum officinarum L.; cultivar IAC-862480 (CC1) or cultivar IAC-873184 (CC2)) and supplemented with urea or concentrate. The study was performed at Embrapa Southeast Cattle, S?o Carlos, SP, Brazil, using a completely randomised design. Differences between treatments were significant for digestibility of dry matter, organic matter and energy. When animals were supplemented with urea differences between sugarcane cultivars did occur for NDF consumption, but not for daily methane production. This suggest that variation in chemical composition of sugarcane did not affect bovine ruminal CH(4) emissions. Concentrate inclusion in animal diet increased digestible organic matter intake, improving the nutrient intake by animals, but did not reduce CH(4) production expressed as a percentage of gross energy intake.  相似文献   

Transcription of pattern recognition receptors and abortive agents induced chemokines in the bovine pregnant uterus     

Silva AP  Costa EA  Macêdo AA  Martins Tda M  Borges AM  Paixão TA  Santos RL 《Veterinary immunology and immunopathology》2012,145(1-2):248-256

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