Condensin complex and Molecular Motor KIF4A, new players in CRC under WNT signalling regulation = Papel del Complejo Condensina y el Motor Molecular KIF4A en el Cáncer Colorrectal como nuevas dianas de la vía de señalización Wnt

[spa] Durante la división celular, el ADN debe estructurarse en cromosomas para asegurar un correcto reparto de la información genética a las dos células hijas. El complejo condensina, junto con el motor molecular KIF4A, son los encargados de dar estructura y estabilidad a los cromosomas. En este estudio hemos demostrado que estas proteínas se encuentran frecuentemente sobre-expresadas en el cáncer colorrectal y que esta sobre-activación se debe a que están bajo la regulación de la vía Wnt. Esta vía de señalización, fundamental para el mantenimiento de a homeóstasis del epitelio intestina, está íntimamente ligada a la tumorogénesis colorrectal, ya que su hiperactivación aberrante está presente en un 85% de casos de cáncer colorectal. Hemos estudiado además la posible implicación de KIF4A en el proceso tumorogénico y hemos visto que está asociada a proliferación, invasión, mecanismos de diferenciación celular y respuesta a daño al ADN. Por último, se han identificado los niveles altos de expresión de KIF4A como marcador de mal pronóstico en casos avanzados de cáncer colorrectal

Box 2. The EU economies’ natural gas inventories in 2022 and 2023 under two hypothetical scenarios

Artículo de revistaThis early-release box was published on 16 Septembe

Nutritional contribution of torula yeast and fish meal to the growth of shrimp Litopenaeus vannamei as indicated by natural nitrogen stable isotopes

Torula yeast (Candida utilis) and fish meal were used to formulate six experimental diets for Pacific white shrimp Litopenaeus vannamei. The dietary nitrogen supplied by fish meal was replaced by increasing dietary proportions of torula yeast (0, 7.5, 15, 30, 60 and 100%). Nitrogen stable isotope values (δ15N) were measured in ingredients, diets and muscle tissue of experimental animals in order to estimate the relative contributions of dietary nitrogen and dry matter supplied by both ingredients. At the end of a 29 d bioassay, there were no significant differences in survival rate among treatments. Shrimps fed on all diets containing torula yeast and fish meal had higher growth rates (k = 0.059-0.064) than animals fed on diets containing only fish meal or only torula yeast (k = 0.041-0.054). Incorporation of δ15N values of ingredients and muscle tissue into an isotopic mixing model indicated that the relative incorporation of dietary nitrogen and total dry matter from torula yeast to growth consistently increased in relation to increasing proportions of this ingredient in the experimental diets. The only exception was the diet formulated with the highest yeast content (60%, diet 40F/60T) where fish meal contributed a higher proportion of dietary nitrogen to growth. Dietary nitrogen from torula yeast available in diets 93F/7T, 85F/15T, 70F/30T and 40F/60T was incorporated in muscle tissue at proportions of 6.5, 13.7, 27.1 and 50.5 %, respectively. Estimated nitrogen residency time in tissue (t50) was relatively shorter in shrimps fed on diets 85F/15T and 70F/30T (3 d), indicating higher metabolic turnover rates in these animals than those fed on diet containing only fish meal. Growth and survival rates were statistically similar in shrimp fed on all mixed diets, therefore indicating the suitability of this single cell protein as dietary ingredient in diets containing up to 60% of torula yeast

Simultaneous estimation of the nutritional contribution of fish meal, soy protein isolate and corn gluten to the growth of Pacific white shrimp (Litopenaeus vannamei) using dual stable isotope analysis

The nutritional contribution of the dietary nitrogen, carbon and total dry matter supplied by fish meal (FM), soy protein isolate (SP) and corn gluten (CG) to the growth of Pacific white shrimp Litopenaeus vannamei was assessed by means of isotopic analyses. As SP and CG are ingredients derived from plants having different photosynthetic pathways which imprint specific carbon isotope values to plant tissues, their isotopic values were contrasting. FM is isotopically different to these plant meals in regards to both, carbon and nitrogen. Such natural isotopic differences were used to design experimental diets having contrasting isotopic signatures. Seven isoproteic (36% crude protein), isoenergetic (4.7 Kcal gr-1) diets were formulated; three diets consisted in isotopic controls manufactured with only one main ingredient supplying dietary nitrogen and carbon: 100 % FM (diet 100F), 100% SP (diet 100S) and 100% CG (diet 100G). Four more diets were formulated with varying mixtures of these three ingredients, one included 33% of each ingredient on a dietary nitrogen basis (diet 33FSG) and the other three included a proportion 50:25:25 for each of the three ingredients (diets 50FSG, 50SGF and 50GFS). At the end of the bioassay there were no significant differences in growth rate in shrimps fed on the four mixed diets and diet 100F (k = 0.215-0.224). Growth rates were significantly lower (k = 0.163-0.201) in shrimps grown on diets containing only plant meals. Carbon and nitrogen stable isotope values (δ13C and δ15N) were measured in experimental diets and shrimp muscle tissue and results were incorporated into a three-source, two-isotope mixing model. The relative contributions of dietary nitrogen, carbon and total dry matter from FM, SP and CG to growth were statistically similar to the proportions established in most of the diets after correcting for the apparent digestibility coefficients of the ingredients. Dietary nitrogen available in diet 33FSG was incorporated in muscle tissue at proportions representing 24, 35 and 41% of the respective ingredients. Diet 50GSF contributed significantly higher amounts of dietary nitrogen from CG than from FM. When the level of dietary nitrogen derived from FM was increased in diet 50FSG, nutrient contributions were more comparable to the available dietary proportions as there was an incorporation of 44, 29 and 27% from FM, SP and CG, respectively. Nutritional contributions from SP were very consistent to the dietary proportions established in the experimental diets

Incorporation of dietary nitrogen from fish meal and pea meal (Pisum sativum) in muscle tissue of Pacific white shrimp (Litopenaeus vannamei) fed low protein compound diets

Stable isotope analyses were applied to explore the relative dietary nitrogen contributions from fish meal and pea meal (Pisum sativum) to muscle tissue of Pacific white shrimp postlarvae (141 ± 31 mg) fed low protein diets having different proportions of both ingredients as the sole dietary protein sources. A negative control diet was formulated to contain 100% pea meal and six more isoproteic diets to have decreasing levels of pea meal-derived nitrogen: 95, 85, 70, 55, 40 and 0 % of the initial level. Growth rates were negatively correlated to dietary pea protein inclusion due to progressive essential amino acid deficiencies (sulfur amino acids, threonine, lysine, histidine). The nitrogen turnover rate significantly increased in muscle tissue of shrimps fed diets having high levels of pea meal; however, contrary to observations from a previous study using soy protein , the relative contributions of dietary nitrogen from pea meal to shrimp muscle tissue were equal or higher than expected contributions established by the dietary formulations. Results highlight the effectiveness of stable isotope analysis in assessing the nutritional contributions of alternative ingredients for aquaculture feeds and the potential suitability of pea as a source of protein (provided the diets are nutritionally balanced)

Isotopic Evaluation of the Nutritional Contribution of Poultry By-product Meal and Fish Meal to the Growth of Pacific White Shrimp, Litopenaeus vannamei

The nutritional contribution of the dietary nitrogen supplied by poultry by-product meal (PBM) and fish meal (FM) to the somatic growth of Pacific white shrimp, Litopenaeus vannamei was assessed by means of stable isotope analysis. Seven experimental diets were formulated with different proportions of PBM replacing FM. Mixed diets were formulated to replace 0, 35, 50, 65, 80, 95 and 100 % of FM with PBM, on a dietary nitrogen basis. At the end of the experiment, there were no significant differences in survival among dietary treatments (89±5 %); however, significant differences in final wet weights were observed. Diets having FM replacement levels of 35 and 50% with PBM, promoted mean final weights (708-789 mg) similar to those observed in shrimps fed on diet containing 100% FM (874 mg). Shrimp final mean weight significantly decreased as a function of PBM inclusion (r= -0.98) due to the use of only two dietary nitrogen sources and by possible nutritional restrictions as PBM levels increased. The relative proportions of dietary nitrogen supplied by PBM and FM were incorporated in muscle tissue at proportions that were statistically similar to those established in the dietary formulations

Digestibility of different wheat products in white shrimp Litopenaeus vannamei juveniles

Dry matter, energy, crude protein and amino acid apparent digestibility coefficients (ADCs) were determined in white shrimp juveniles for six wheat products: hard red winter whole grain meal (HWG), Rayon whole grain meal (RWG), Durum whole grain meal (DWG), hard red winter clear flour (HCF), mixed wheat 2nd clear flour (MCF) and semolina (S). The test diets included 30% of the test ingredients and 70% of a ground commercial diet supplemented with 1% chromic oxide and 1% sodium alginate. Amino acid contents in the ingredients, diets and feces were analyzed, and digestibility was determined by difference in order to minimize the impact of endogenous amino acid losses; crude protein and amino acids ADCswere adjusted for dietary preprandial losses in seawater. In general, nutrients digestibility was far higher in the wheat products than in the fish meal-based reference diet. Drymatter and crude proteinADCswere not statistically different amongwheat products (from84 to 96% and from88 to 107% respectively). Energy ADCs were significantly higher for clear flours (96% for HCF and MCF) than forwhole grainmeals and S (from83 to 86%). Total amino acids (TAA) and essentialamino acids (EAA) ADCs, once adjusted for preprandial leaching fromthe experimental diets, ranged from81 to 89% and from 58 to 81% respectively, and were statistically comparable among wheat products. Low Thr ADCs appear as a common feature of the amino acids digestibility profiles for whole grain meals, clear flours, or semolina

Comparing the assimilation of dietary nitrogen supplied by animal-, plant- and microbial-derived ingredients in Pacific white shrimp Litopenaeus vannamei: A stable isotope study

In order to become a more profitable and sustainable industry, the aquaculture sector is constantly exploring alternative nutrient sources. In the present study, the natural stable isotope signatures of different animal-, plantand microbial-derived ingredients were determined to evaluate the assimilation of dietary nitrogen in Pacific white shrimp. Experimental diets were manufactured to replace fish meal and squid meal with microbial- and plant- derived ingredients (48 and 66 % dietary inclusion) and were also used as additives (4%). Ingredients were also used as additives to study their effects on growth performance and assimilation. Corn gluten, soy protein isolate, Arthrospira (Spirulina) biomass and a bacterial meal (ProFloc™) were used to formulate six, isotopic control diets containing one source of dietary nitrogen, while six combined diets had varying proportions of ingredients. At the end of the trial, survival rates were similar among treatments (88 ± 9%) but there were significant differences in mean final weight. Microbial and animal proteins promoted similar final weight when combined (1080−1537 mg), while plant ingredients and Arthrospira caused lower growth when used alone (420−970 mg). Isotopic values indicated significant differences in the assimilation proportions of dietary nitrogen, mainly attributed to the ingredients’ different amino acid profiles. The dietary nitrogen contained in microbial-derived ingredients was assimilated at similar, or even higher proportions than fish meal and squid meal. Diet formulated with 33 % fish meal, Arthrospira and corn gluten, contributed 31, 36 and 33 % of dietary nitrogen to muscle growth, respectively. The second 33 % combination supplied 42, 34 and 24 % from squid meal, bacterial meal and soy protein. When ingredients were used at 4%, additive levels, they also contributed structural nitrogen to shrimp muscle tissue despite low dietary inclusions. Results demonstrated the viable use of stable isotopes to evaluate the assimilation of dietary nitrogen supplied by emerging alternative ingredient

Uso de secuestrantes para disminuir la toxicidad de micotoxinas en alimentos para acuacultura.

La presencia de micotoxinas en alimentos para animales terrestres y acuáticos puede llegar a reducir significativamente el crecimiento, consumo de alimento, sobrevivencia e incrementar la tasa de conversión alimenticia así como causar afeccciones en el sistema inmune, por lo que pueden ser responsables de pérdidas económicas considerables. Para prevenir la contaminación de los ingredientes con micotoxinas durante su cultivo, cosecha y almacenamiento se han utilizado un sin número de procedimientos como buenas prácticas agrícolas, selección de semillas resistentes al ataque de hongos y a la formación de micotoxinas, uso de compuestos químicos durante el almacenamiento, remoción de micotoxinas por procesos físicos, etc., no obstante, en algunas ocasiones no se logra impedir la generación de estas toxinas. La inclusión de remediadores como: secuestrantes, biotransformadores y compuestos protectores son otras alternativas que permiten reducir al máximo la presencia de estas sustancias en los alimentos terminados o disminuir los estragos cuando los animales consumen alimentos contaminados con micotoxinas. En este trabajo se presenta una revisión general del uso de estos productos en alimentos para animales terrestres y acuáticos, incluyendo estudios de su efectividad in vivo así como consideraciones importantes al momento de incluirse en alimentos terminados