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Simple Summary: Annually, the demand for food to supply the world's population is increasing, and the demand for poultry products is constantly increasing. Therefore, to meet these requirements, it is necessary to implement low-cost poultry diets. One way to reduce the cost of production is with the use of feed additives that increase the amount of metabolizable energy, such as guanidinoacetic acid (GAA). In the present study, the effect of GAA in diets with three levels of metabolizable energy (ME) was evaluated. The addition of GAA to low-ME diets maintained egg production and egg mass at similar levels to those of hens fed a high-ME diet, which indicates that adding GAA is a promising nutritional strategy for reducing the level of ME in the diets of laying hens. Different levels of metabolizable energy (ME) and the inclusion of guanidinoacetic acid (GAA) in the diet of 53-week-old Lohmann LSL-CLASSIC hens were used to evaluate its effect on reproductive parameters, egg quality, intestinal morphology, and the immune response. Six diets were used in a 3 × 2 factorial design, with three levels of ME (2850, 2800, and 2750 kcal/kg), and with (0.08%) or without the inclusion of GAA. The addition of GAA to diets with low levels of ME increased (p < 0.05) egg production and egg mass. Moreover, hens fed with 2800 kcal/g without GAA had the highest concentration (p < 0.05) of serum interleukin IL-2, while those fed diets with the same amount of ME but supplemented with 0.08% GAA had the lowest concentration. Finally, the inclusion of 0.08% GAA increased (p < 0.05) the concentration of vascular endothelial growth factor (VEGF), regardless of the ME level in the diet. This study highlights the potential role of GAA in decreasing the energy level of ME (50–100 kcal/g) in the feeding of hens and in the modulation of specific immune responses. Further research is recommended to fully understand the mechanisms of action of GAA on the mechanism target of rapamycin and its relationship with the immune response. [ABSTRACT FROM AUTHOR]

Simple Summary: Alfalfa (Medicago sativa L.) is considered the queen of forages, and hay is an important source of protein and fiber for livestock, while guanidinoacetic acid (GAA) is a feed additive that can improve growth performance and energy metabolism in animals and reduce the population of methanogenic microorganisms. However, the percentage of alfalfa hay (AH) in the diet can cause variations in greenhouse gas (GHG) production, the rumen fermentation profile and methane (CH4) conversion efficiency, which, in turn, influences the effectiveness of GAA. In this regard, this study demonstrates that the percentage of AH in the diet affects the effectiveness of GAA and that the addition of GAA in diets with 25 and 100% AH presents low effectiveness, a diet with 10% AH can improve the mitigation of GHG and the rumen fermentation profile without compromising the CH4 conversion efficiency using a dose of 0.0015 or 0.0020 g GAA g−1 DM in the diet. The objective of this study was to evaluate the effect of different percentages of alfalfa (Medicago sativa L.) hay (AH) and doses of guanidinoacetic acid (GAA) in the diet on the mitigation of greenhouse gas production, the in vitro rumen fermentation profile and methane (CH4) conversion efficiency. AH percentages were defined for the diets of beef and dairy cattle, as well as under grazing conditions (10 (AH10), 25 (AH25) and 100% (AH100)), while the GAA doses were 0 (control), 0.0005, 0.0010, 0.0015, 0.0020, 0.0025 and 0.0030 g g−1 DM diet. With an increased dose of GAA, the total gas production (GP) and methane (CH4) increased (p = 0.0439) in the AH10 diet, while in AH25 diet, no effect was observed (p = 0.1311), and in AH100, GP and CH4 levels decreased (p = 0.0113). In addition, the increase in GAA decreased (p = 0.0042) the proportion of CH4 in the AH25 diet, with no influence (p = 0.1050) on CH4 in the AH10 and AH100 diet groups. Carbon monoxide production decreased (p = 0.0227) in the AH100 diet with most GAA doses, and the other diets did not show an effect (p = 0.0617) on carbon monoxide, while the production of hydrogen sulfide decreased (p = 0.0441) in the AH10 and AH100 diets with the addition of GAA, with no effect observed in association with the AH25 diet (p = 0.3162). The pH level increased (p < 0.0001) and dry matter degradation (DMD) decreased (p < 0.0001) when AH was increased from 10 to 25%, while 25 to 100% AH contents had the opposite effect. In addition, with an increased GAA dose, only the pH in the AH100 diet increased (p = 0.0142 and p = 0.0023) the DMD in the AH10 diet group. Similarly, GAA influenced (p = 0.0002) SCFA, ME and CH4 conversion efficiency but only in the AH10 diet group. In this diet group, it was observed that with an increased dose of GAA, SCFA and ME increased (p = 0.0002), while CH4 per unit of OM decreased (p = 0.0002) only with doses of 0.0010, 0.0015 and 0.0020 g, with no effect on CH4 per unit of SCFA and ME (p = 0.1790 and p = 0.1343). In conclusion, the positive effects of GAA depend on the percentage of AH, and diets with 25 and 100% AH showed very little improvement with the addition of GAA, while the diet with 10% AH presented the best results. [ABSTRACT FROM AUTHOR]

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Copyright of Pasos: Revista de Turismo y Patrimonio Cultural is the property of Universidad de La Laguna, Instituto Universitario de Ciencias Politicas y Sociales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Geográfica is the property of Acta Geografica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background information. MAPKs (mitogen-activated protein kinases) are involved in the transduction of different signals in eukaryotes. They regulate different processes, such as differentiation, proliferation and stress response. MAPKs act through the phosphorylation cascade, being the last element that phosphorylates the final effector of the cell response. They are activated when their threonine and tyrosine residues are phosphorylated. Ntf4, a MAPK with a molecular mass of 45 kDa, has been reported to be expressed in pollen and seeds. Biochemical studies have indicated that the expression and the activation of Ntf4 is regulated during pollen maturation, although an increase of the activation is observed when the pollen is hydrated, just at the beginning of the germination. However, nothing is known about its subcellular localization.Results. In the present study, the in situ expression and subcellular localization of Ntf4 have been analysed during the tobacco pollen developmental pathway. Cryosections, freeze-substitution and cryo-embedding in Lowicryl K4M were used as processing techniques for subsequent immunofluorescence, immunogold labelling and in situ hybridization assays. During pollen maturation, Ntf4 showed an increase in expression, as demonstrated by in situ hybridization, and specific subcellular distributions. We found that the protein was expressed from mid bicellular pollen stage until the pollen was mature. In germinating pollen, the protein increased after the initiation of germination. Translocation of the protein to the nucleus was found at specific stages; the presence of Ntf4 in the nucleus was found in the last stage of the pollen maturation and in germinating pollen. Double immunofluorescence and immunogold labelling with anti-Ntf4 (AbC4) and anti-P-MAPK (phosphorylated MAPK) antibodies revealed the co-localization of both epitopes in the nucleus at late developmental stages.Conclusions. The temporal and spatial pattern of the expression sites of Ntf4 has been characterized during pollen development, indicating that Ntf4 is a ‘late gene’ that is upregulated during maturation and germination, with a possible role in the gametophytic function. The translocation of the Ntf4 protein from the cytoplasm to the nucleus at late pollen developmental stages, and its co-localization with the P-MAPK epitope in several nuclear sites, indicates a relationship between the Ntf4 nuclear translocation and its active state. [ABSTRACT FROM AUTHOR]

Summary. We have performed functional genomics of salt stress by overexpression of gene libraries in yeast and selection for salt tolerance. Thirty halotolerance genes were isolated from yeast, Arabidopsis, and sugar beet. The results indicate that Na + transport (uptake, efflux, and compartmentation), sulfate activation, RNA processing, and protein synthesis are crucial for salt tolerance. [ABSTRACT FROM AUTHOR]

Treatment of tobacco ( Nicotiana tabacum L.) plants with lithium induces the formation of necrotic lesions and leaf curling as in the case of incompatible pathogen interactions. Further similarities at the molecular level include accumulation of ethylene and of salicylic and gentisic acids, and induced expression of pathogenesis-related PR-P, PR5 and PR1 genes. With the exception of PR1 induction, lithium produced the same effects in transgenic tobacco plants that do not accumulate salicylate because of overexpression of the bacterial hydroxylase gene nahG. On the other hand, inhibition of ethylene biosynthesis with aminoethoxyvinylglycine prevented lithium-induced cell death and PR5 expression. These results suggest that lithium triggers a hypersensitive-like response where ethylene signalling is essential. [ABSTRACT FROM AUTHOR]