Tolerance of genetically characterized <Emphasis Type="Italic">Folsomia candida</Emphasis> strains to phenmedipham exposure     

João Barateiro Diogo  Tiago Natal-da-Luz  José Paulo Sousa  Christian Vogt  Carsten Nowak 《Journal of Soils and Sediments》2007,7(6):388-392

Background, Aims, and Scope  The springtail Folsomia candida is a commonly used model species in ecotoxicological soil testing. The species reproduces parthenogenetically and, thus, laboratories use different clonal lineages. In this study, we investigated if genetic divergence between F. candida strains impacts the reaction to chemical stress and may thus affect the outcome of toxicity tests. Methods  In two exposure assays (life-cycle reproduction test and avoidance behaviour test), three laboratory strains of F. candida from Portugal (PTG), Spain (SPN) and Denmark (DNK) were exposed to different concentrations of the reference chemical phenmedipham. Genetic divergence among strains was estimated based on mitochondrial COI sequence data. Results  No significant differences between tolerance towards phenmedipham exposure were observed in a reproduction test. In contrast, one strain (SPN) showed a decreased susceptibility to phenmedipham compared to the other strains (PTG and DNK) in the avoidance assay. Discussion  A phylogenetic tree based on mitochondrial COI sequences revealed clear genetic differentiation between both ‘reaction types’. Thus, we found a potential lineage dependent stress reaction in avoidance behaviour towards the pesticide. Conclusions  Our findings have implications for the comparability of test results among laboratories. Reproduction tests seem to be more robust towards interclonal genetic differentiation than avoidance tests. Recommendations and Perspectives  We recommend the use of molecular tools for simple and cost effective genetic characterization of F. candida strains used in chemical avoidance tests. Closer investigations concerning the relation between genetic relatedness and chemical response will provide a more detailed and comprehensive picture on the role of intraspecific genetic differentiation in stress tolerance. ESS-Submission Editor: Prof. Dr. Henner Hollert (henner.hollert@bio5.rwth-aachen.de)  相似文献   

Ovarian gene expression in collared peccary (Pecari tajacu Linnaeus, 1758) subjected to gonadotropin stimulation protocols     

Ana Clara N. P. C. S. Viana  Jeferson L. S. Freitas  Lívia C. Magalhães  Lívia B. Campos  Alexandre R. Silva  Moacir F. Oliveira  Vicente J. F. Freitas  Luciana M. Melo 《Reproduction in domestic animals》2021,56(2):351-359

Ovarian response of collared peccaries (Pecari tajacu), after hormonal stimulation with gonadotropin association (eCG/hCG), was accessed by both gene expression and follicular development. Thus, collared peccaries (n = 8) were treated with the dose used for sows (swine dose, SWD) or with dose adjusted for peccary's weight (allometric dose, ALD). The gene expression of receptors was evaluated for both gonadotropins (FSHR and LHCGR) and growth factors (proteins codified by TGFβR-1, BMPR1-A and BMPR2 genes) in antral follicles, cortex and corpora haemorrhagica (CH). Five days after gonadotropin injection, all females presented CH. The ovulation rate was similar (p > .05) between SWD (4.00 ± 1.17) and ALD (2.50 ± 0.43) group. The total number of follicles per animal and amounts of small (<3 mm), medium (3–5 mm) and large (>5 mm) follicles was similar among groups. However, SWD produced large follicles heavier than ALD group, as accessed by weight of follicular wall biopsies. Ovarian follicles expressed both gonadotropin and growth factor receptors at levels which are independent from gonadotropin dose. In conclusion, the two gonadotropin doses (SWD and ALD) can be used for ovarian stimulation of collared peccary. Additionally, FSH and growth factors (TGFβR-1, BMPR1-A and BMPR2) receptors are more expressed in the early follicle development, while LH receptor seems to be more important in the final of follicular growth.  相似文献   

The effect of different grazing heights on carcass and meat quality characteristics of Nellore cattle fattened in pastures of Convert grass     

Biserra  Thiago Trento  Cecato  Ulysses  Galbeiro  Sandra  Bridi  Ana Maria  Fernandes  Henrique Jorge  Duarte  Camila Fernandes Domingues  Da Silva  Diogo Rodrigues  Vicente  João Vitor Rosa  Rogel  Camila Piechnicki 《Tropical animal health and production》2020,52(2):625-635

Carcass characteristic and meat quality from bulls and Nellore steers (n?=?64 total) subjected to different grazing heights (15, 25, 35, and 45 cm) were evaluated isolatedly, under continuous grazing and variable load, in pastures of Convert grass. The experimental period was from May 2015 to June 2017, in an area of 16 ha, divided into 16 paddocks of 1 ha. The experimental design was randomized blocks with four replications. Each paddock was grazed by three animals and regulators, used to adjust grazing heights. The final slaughter weight, hot carcass, and crude protein in the meat of steers were higher when the pastures were managed at 42 cm. When the pasture was managed between 25 and 35 cm in height, greater fat thickness, marbling, muscle:bone and muscle+fat:bone ratio and lower color* of the meat and percentage of bone were found. For the steers, the height of 40 cm provided higher fat thickness and marbling in the meat. The loss during thawing in meat was greater at 28 cm in height. The heights of grazing alter the carcass characteristics and meat of bulls and steers.

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Anisakidae nematodes and Trypanorhyncha cestodes of hygienic importance infecting the king mackerel Scomberomorus cavalla (Osteichthyes: Scombridae) in Brazil     

Dias FJ  São Clemente SC  Pinto RM  Knoff M 《Veterinary parasitology》2011,175(3-4):351-355

From February to October 2007, thirty specimens of the king mackerel, Scomberomorus cavalla (Cuvier, 1829) were purchased from markets in the municipalities of Niterói and Rio de Janeiro. The fishes were measured, filleted and further had their organs investigated for helminths. Ten out of the thirty fish specimens were parasitized with anisakid nematodes represented by Anisakis sp. and Contracaecum sp. with prevalence of 1% and 16%, mean intensity of 2 and 3.31 and mean abundance of 0.02 and 0.53, respectively. The infection range with Contracaecum sp. was 1-9. The sites of infection were the stomach serosa and mesentery. Seventeen fish specimens (53%) out of the 30 investigated were parasitized with Trypanorhyncha metacestodes, identified as Callitetrarhynchus gracilis, Pterobothrium crassicole, Callitetrarhynchus speciosus and Tentacularia coryphaenae in the mesentery, with prevalence of 26, 20, 6, 3%, intensity and mean intensity of 3.25, 3.5, 1, 2 and mean abundance of 0.86, 0.7, 0.06 and 0.06, respectively. The infection range due to C. gracilis and P. crassicole were of 1-5 and 1-20, respectively. Anisakis sp., C. speciosus and P. crassicole are reported in S. cavalla for the first time. Considerations on the zoonotic potential of the parasites and their rules in sanitary inspection are presented.  相似文献   

Hydrolysis influence on phytochemical composition, antioxidant activity, plasma concentration, and tissue distribution of hydroethanolic Ilex paraguariensis extract components     

Rivelli DP  Almeida RL  Ropke CD  Barros SB 《Journal of agricultural and food chemistry》2011,59(16):8901-8907

The infusion of aerial parts of Ilex paraguariensis is widely consumed. Its antioxidant activity suggests an important role of this plant in the treatment/prevention of oxidative stress related diseases. Plant extract active compounds are frequently found in esterified form that may be poorly absorbed. Hydrolysis of the extract is a possible approach to increase its bioavailability. The aim of this study was to perform a phytochemical analysis and evaluate in rats the plasma concentration and tissue distribution of antioxidant compounds in the hydroethanolic extract of Ilex paraguariensis, before and after enzymatic hydrolysis. Both extracts presented high antioxidant activity and phenolic content. Rats given single or repeated doses of the hydrolyzed extract showed increased plasma antioxidant activity and higher plasma levels of caffeic acid. However, no changes of endogenous antioxidants were observed. In conclusion, hydrolysis of the extract of Ilex paraguariensis is a strategy to improve its bioavailability and in vivo antioxidant activity.  相似文献   

A probability-based approach to match species with reserves when data are at different resolutions     

Diogo Alagador  Maria João Martins  Jorge Orestes Cerdeira  Mar Cabeza  Miguel Bastos Araújo 《Biological conservation》2011,(2):811-820

Gap analysis is a protocol for assessing the extent to which valued biodiversity attributes are represented within protected areas. Such analysis involves overlaying the distribution of biodiversity features (e.g. species) with protected areas, but the protocol entails arbitrary assumptions that affect the outcome of the assessments. In particular, since species’ distributions are usually mapped at a coarser resolution than protected areas, rules have to be defined to match the two data layers. Typically, a grid cell is considered protected if a given proportion is covered by protected areas. Because the effectiveness of protected areas is dependent on the definition of such arbitrary proportions (i.e., thresholds), errors of commission and omission in the level of species’ representation are bound to exist. We propose an alternative approach whereby the contribution of a cell for the representation of species is defined as the expected value of a hyper-geometric random variable. We compare the conventional approach based on fixed thresholds with this new probability-based approach for both static and dynamic conservation scenarios, using a virtual dataset and a 100-plant-species’ dataset for Iberian Peninsula. Results support the view that traditional fixed thresholds yield inconsistent results. Because species present different distributional patterns coinciding differently with protected areas, species-specific and time-specific thresholds should be used. Our approach enables to easily obtain these more adequate threshold values, thus offering a promising method for gap analyses. Future studies should seek to evaluate the performance of this method empirically in different conservation planning contexts.  相似文献   

Overweight, asthma symptoms, atopy and pulmonary function in children of 4-12 years of age: findings from the SCAALA cohort in Salvador, Bahia, Brazil     

Matos SM  Jesus SR  Saldiva SR  Prado MS  D'Innocenzo S  Assis AM  Rodrigues LC  Alcantara-Neves NM  Cruz ÁA  Simões Sde M  Barreto ML;SCAALA 《Public health nutrition》2011,14(7):1270-1278

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Ammonium assimilation in rice based on the occurrence of 15N and inhibition of glutamine synthetase activity     

J. R. Magalhães  D.M. Huber  T.C. Lee  C.Y. Tsai 《Journal of plant nutrition》2013,36(9):1861-1873

Assimilation of ammonium (NH₄) into free amino acids and total reduced nitrogen (N) was monitored in both roots and shoots of two‐week old rice seedlings supplied with 5 mM 99% (¹⁵NH₄)₂SO₄ in aerated hydroponic culture with or without a 2 h preincubation with 1 mM methionine sulfoximine (MSX), an inhibitor of glutamine synthetase (GS) activity. ¹⁵NH₄ was not assimilated into amino acids when the GS/GOGAT (glutamate synthase) cycle was inhibited by MSX. Inhibition of glutamine synthetase (GS) activity in roots with MSX increased both the amount of NH₄ and the abundance of ¹⁵N labeled NH₄. In contrast, the amount of Gln and Glu, and their proportions as ¹⁵N, decreased in roots when GS activity was inhibited. This research confirms the importance of GS/GOGAT in NH₄ assimilation in rice roots.

¹⁵N‐labeled studies indicate that NH₄ ions incorporated by roots of rice are transformed primarily into glutamine (Gln) and glutamic acid (Glu) before being converted to other amino acids through transamination (15). The formation of amino acids such as aspartic acid (Asp) and alanine (Ala) directly from free NH₄ in roots also has been reported (4,15). Translocation of free NH₄ to plant shoots, based on the concentration of free NH₄ in xylem exudate, has been reported in tomato (13), although NH₄ in shoots primarily originates from nitrate reduction in the shoot. Photorespiration also can contribute to the accumulation of NH₄ in leaves (7).

The GS/GOGAT cycle appears to be primarily responsible for the assimilation of exogenously supplied NH₄ and NH₄ derived from nitrate reduction in leaves, as well as NH₄ derived from photorespiration (2,3,6,8). Genetic evidence cited to support this conclusion includes the lethal effect of photorespiratory conditions on plant mutants deficient in chloroplast‐localized GS and GOGAT activities (2,3,9), and the rapid accumulation of free NH₄ in GS‐deficient mutants under photorespiratory conditions (2,3,5).

The present study was initiated to quantify the in vivo amino acid synthesis in rice roots and shoots by analysis of ¹⁵N labeling, and should provide a more complete understanding of this important system for NH₄ utilization.  相似文献   

Similarities in response of maize genotypes to water logging and ammonium toxicity 1     

J. R. Magalhães  A. T. Machado  D. M. Huber 《Journal of plant nutrition》2013,36(11):2339-2346

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Nitrate uptake by corn under increasing periods of phosphorus starvation     

J. V. de Magalhães  V. M. C. Alves  R. F. de Novais  P. R. Mosquim  J. R. Magalhães  A. F. C. Bahia Filho 《Journal of plant nutrition》2013,36(8):1753-1763

Single cross seedlings of the male progenitor of the double cross hybrid, BR 201, were grown for seven days in a complete nutrient solution prior to evaluating the kinetics of nitrate uptake under varying periods of phosphorus deficiency. Nitrate uptake decreased 60% after a short period of phosphorus starvation (2 days) and ceased when phosphorus was withheld longer than six days. Nitrate uptake resumed after phosphorus (P) was re‐supplied, but the time required and extent of recovery depended on the length of phosphorus starvation.  相似文献