Genetic characterization of a collection of chayote, <Emphasis Type="Italic">Sechium edule</Emphasis> (Jacq.) Swartz,in Costa Rica by using isozyme markers     

Ana Abdelnour  Oscar J. Rocha 《Genetic Resources and Crop Evolution》2008,55(1):163-170

We established protocols for the analysis of genetic diversity in chayote (Sechium edule) by using isozyme markers, thereby determining the level of genetic diversity present in 42 accessions of chayote from Costa Rica. We obtained clear and reproducible zymograms for eight enzyme staining systems: PGM, 6-PGD, PGI, IDH, MDH, SOD, SKD, and EST, and were able to score 14 putative loci. Eight of the 14 loci examined were polymorphic. We found 35 distinct multilocus genotypes among these accessions. Five of these multilocus genotypes were homozygous for all loci. In addition, our data also revealed that most of the multilocus genotypes (24) were heterozygous for only one of the eight loci, and the rest were heterozygous for two or three loci (9 and 4 accessions, respectively). Seven multilocus genotypes were found in two different accessions. Dice similarity coefficient was used to study the relationship between accessions. This analysis, based on the presence and absence of alleles, revealed that accessions collected in the same location seldom shared the same multilocus genotype. The value of isozyme polymorphisms as tools to continue studies on the characterization of chayote is discussed.  相似文献   

Potential of advanced breeding lines of bread‐making wheat to accumulate grain minerals (Ca,Fe, Mg and Zn) and low phytates under Mediterranean conditions     

Francisco Gomez‐Coronado  Ana S. Almeida  Oscar Santamaria  Ismail Cakmak  Maria J. Poblaciones 《Journal of Agronomy and Crop Science》2019,205(3):341-352

About 3 billion people may suffer from micronutrient deficiency such as Ca, Fe, Mg or Zn, caused not only by a mineral deficiency in staple food but also by a high content of phytates which bind those minerals and inhibit their absorption. With the aim of evaluating the potential of new cultivars of bread‐making wheat to accumulate those minerals and low phytates, nine advanced breeding lines from an ongoing Portuguese breeding program were studied during 2 years in a field experiment. A wide genetic variability was found between the studied genotypes in all the parameters studied, especially grain yield (ranging on average between 2,027 and 3,209 kg/ha) and grain Mg and Zn concentrations (ranging on average between 1,070 and 1,336 mg/kg, and 23.4 and 30.7 mg/kg, respectively). In global terms, the cultivars with best performance, and therefore, the most potentially suitable to be used in a breeding program, were the Cultivars 3 and 4. However, such a potential varied depending on the analysed trait, and it was clearly influenced by the climatic conditions. The consumption of 100 g of Cultivar‐4 produced under the most favourable conditions might provide a 5.2% of Ca, 26.4% of Fe, 38.9% of Mg and 31.9% of Zn of the recommended daily intakes, with a very good bioavailability for Fe and Ca, but low for Mg and Zn.  相似文献   

Perturbations in the uterine luminal fluid composition are detrimental to pregnancy establishment in cattle     

Thiago Martins  Guilherme Pugliesi  Mariana Sponchiado  Angela M.Gonella-Diaza  Oscar A.Ojeda-Rojas  Frederich D.Rodriguez  Roney S.Ramos  Andrea C.Basso  Mario Binelli 《畜牧与生物技术杂志(英文版)》2019,(1)

Background: A major,unresolved issue is how the uterine microenvironment determines pregnancy success in cattle.Before implantation,conceptus development depends on the uterine secretome(i.e.,histotroph).Despite its pivotal role,little is known about the dynamics of histotroph synthesis and changes in composition throughout the early diestrus and the relevance to pregnancy establishment.We hypothesize that disturbances on histotroph composition affect the establishment of pregnancy.Aim was to disturb histotroph composition at early diestrus and verify the effects on:(Exp.1) timing to restore its composition; and(Exp.2) pregnancy rate after multiple-embryo transfer.Estrous cycle of multiparous Nelore cows were synchronized and estrus was considered d 0(D0) of the experiments.Disturbance was through flushing each uterine horn with 30 m L of DMPBS and collecting the resulting uterine luminal flushing(ULF) on D1; D4; D7; D1 + D4 + D7.Control group remained not-collected.In Exp.1,ULF was collected on D7.5 from all animals and used for quantification of total protein concentration and abundance of albumin.In Exp.2,three in vitro-produced embryos were transferred to the uterine horn ipsilateral to the ovary containing the CL on D7.5 and pregnancy was checked on D25 by ultrasound.Results: In Exp.1,ULF collection on D4 or D7 increased(1.5-to 2.2-folds) the total protein concentration and albumin abundance.ULF collection on D1 did not alter(P 0.10) these endpoints.In Exp.2,ULF collected on D4 or D7 decreased pregnancy rates to approximately half of that measured in the remaining groups.Conclusions: Subtle perturbations imposed to the native intrauterine milieu,such as those caused by a single,low-volume collection of ULF,profoundly disturbs intrauterine composition and pregnancy success.At least 4 d were necessary for the uterus to recover its composition and the functional capacity to carry post-implantation gestation.  相似文献   

Evaluation of comparative advantages in the profitability and competitiveness of the small-scale dairy system of Tulancingo Valley,Mexico     

Rodolfo Rogelio Posadas-Domínguez  Oscar Enrique Del Razo-Rodríguez  Isaac Almaraz-Buendía  Armando Pelaez-Acero  Verónica Espinosa-Muñoz  Samuel Rebollar-Rebollar  Jesús Armando Salinas-Martínez 《Tropical animal health and production》2018,50(5):947-956

This article combines a Policy Analysis Matrix with a sensitivity and poverty line analysis with the objective of evaluating the economic contribution of comparative advantages to the private profitability and competitiveness of small-scale dairy systems. For 1 year, socioeconomic data were collected from 82 farms selected from four strata via statistical sampling. Two scenarios were established to determine the quantitative contribution of comparative advantages: (1) a simulated scenario, which accounted for the cost of purchasing the total food and the opportunity cost of the family labour force (FLF), and (2) an actual production scenario, which accounted for the cost of producing food and eliminating the payment of the FLF and included other income. The E3 and E4 producers were the most profitable and competitive in the simulated scenario and actual production scenario. Of the four scales evaluated, the E2 and E1 producers were the most efficient in taking advantage of the economic contribution provided by the comparative advantages in their own production of food and employment of the FLF, in addition to accounting for other income, a condition that increased their profitability by 171 and 144% and competitiveness by 346 and 273%, respectively. The poverty results indicated that only E3 and E4 producers were non-vulnerable in the simulated scenario and actual production scenario. The purchase of food was the comparative advantage with the greatest sensitivity to cost increases in the two scenarios analysed, which exacerbated the effect on the E1 and E2 producers.  相似文献   

Expected consequences of including methane footprint into the breeding goals in beef cattle. A Spanish Blonde d'Aquitaine population as a case of study          下载免费PDF全文

Javier López‐Paredes  Rafael Alenda  Oscar González‐Recio 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2018,135(5):366-377

This study evaluates two potential scenarios for including methane (CH₄) emissions in the breeding objectives of beef cattle, using the Spanish population of Blonde d′Aquitaine as a case of study. First, CH₄ emissions were included as a cost using a shadow carbon price of 1.22€/CH₄ kg (0.044€/CO₂ kg) (carbon tax scenario). In the other scenario, a CH₄ quota was applied, optimizing emissions per unit of product. The current production system was used as benchmark scenario (Scenario 1). The economic value of CH₄ was calculated under all scenarios using a bioeconomic model that translated the production system into a mathematical function. Then, CH₄ emissions were included with proper relative weight in the selection index under each scenario. The economic value of CH₄ production from cows was ?0.54€/year and ?0.16€/year in a carbon tax and in a CH₄ quota scenario, respectively. Economic values for CH₄ production from fattening calves were ?1.22€/year and ?0.34€/year in a carbon tax and a quota scenario, respectively. The relative weights of total CH₄ traits in the indices were 4.9% and 1.8% in a carbon tax and quota scenario. The carbon tax scenario led to smaller cows (?7.59 kg of mature weight) and a decrease in carcass weight gain of calves (?4.78 g/day) involving a reduction in emissions in comparison with Scenario 1 (?0.76 CH₄ kg/slaughtered calf/year). However, it also led to a lower expected gain in profit per unit of product (?7.86 €/slaughtered calf/year). A carbon quota scenario would select slightly smaller cows (?0.48 kg) with similar responses in maternal abilities (age at first calving, calving interval, maternal weaning weight, and calving ease) and growth, and lower emissions (?0.22 CH₄ kg/slaughtered calf/year) regarding the benchmark scenario. Profit per cow would increase by +1.52€/slaughtered calf/year although this scenario implies a reduction in the number of cows per herd. In a carbon tax scenario, higher reduction in emissions implied a reduction of profitability per animal.  相似文献   

Occurrence of a CGRP-like molecule in siki (Centroscymnus coelolepsis) hydrolysate of industrial origin     

Martínez-Alvarez O  Guimas L  Delannoy C  Fouchereau-Peron M 《Journal of agricultural and food chemistry》2007,55(14):5469-5475

Fish protein hydrolysates (FPH) may have potential as bioactive components in functional foods as nutraceuticals. This study focused on the identification of calcitonin gene-related peptide (CGRP) molecules in FPH. CGRP is a neuropeptide belonging to the calcitonin/CGRP family and is known as potent arterial and venous vasodilator in humans. Hydrolysates of industrial origin were prepared from siki (Centroscymnus coelolepsis) heads and were analyzed for the presence of CGRP-like molecules using specific radioimmunoassays and radioreceptorassays. The biological activity of the CGRP-related molecules was assessed by their ability to stimulate the adenylate cyclase activity in rat liver membranes. They were finally purified using gel exclusion chromatography and high-performance liquid chromatography (HPLC). These molecules presented a molecular weight around 1500-2500 Da and were obtained with a purification factor of 79. The incorporation of FPH with CGRP-like molecules in functional foods could lead to the development of new useful products for health and nutrition markets.  相似文献   

Validity and reproducibility of two semi-quantitative alcohol frequency questionnaires for the Colombian population     

Herrán OF  Ardila MF 《Public health nutrition》2006,9(6):763-770

OBJECTIVE: To determine the relative validity and reproducibility of two alcohol intake frequency questionnaires (AFQ-A; AFQ-B), designed to classify subjects according to their alcohol intake level, in Bucaramanga, Colombia. METHOD: One hundred and nine randomly selected subjects, aged between 20 and 60 years, completed three 30-day semi-quantitative alcohol intake records (30-DR). The AFQs were applied three months after the last 30-DR. AFQ-A contained 53 items; AFQ-B contained five items, with the alcoholic drinks for AFQ-B selected by Max_r. The correlation and agreement between alcohol intake assessed with the AFQs and the 30-DR were obtained using Pearson's correlation coefficient (r), Lin's concordance correlation coefficient (rhoC), Spearman's rank correlation coefficient (rS), Bland and Altman's limits of agreement (LOA) and Cohen's weighted kappa statistic (Kw). RESULTS: The reproducibility of the 30-DR was poor; rS ranged from 0.33 to 0.41. The reproducibility of the AFQs was higher, with rS between 0.50 and 0.73. The agreement (Kw) of the 30-DR and the AFQs was 0.40. The lower and upper LOA were between -56.4% and -11.0%. The AFQs and 30-DR were well correlated. Assessment of relative validity between the two methods yielded r values for alcohol between 0.52 and 0.60, which reduced to 0.20-0.29 after energy adjustment. CONCLUSIONS: These AFQs may be useful to rank subjects according to their alcohol intake. The AFQ-B is easy and quick to apply, and is also highly cost-effective.  相似文献   

New neurons follow the flow of cerebrospinal fluid in the adult brain   总被引：1，自引：0，他引：1  

Sawamoto K  Wichterle H  Gonzalez-Perez O  Cholfin JA  Yamada M  Spassky N  Murcia NS  Garcia-Verdugo JM  Marin O  Rubenstein JL  Tessier-Lavigne M  Okano H  Alvarez-Buylla A 《Science (New York, N.Y.)》2006,311(5761):629-632

In the adult brain, neuroblasts born in the subventricular zone migrate from the walls of the lateral ventricles to the olfactory bulb. How do these cells orient over such a long distance and through complex territories? Here we show that neuroblast migration parallels cerebrospinal fluid (CSF) flow. Beating of ependymal cilia is required for normal CSF flow, concentration gradient formation of CSF guidance molecules, and directional migration of neuroblasts. Results suggest that polarized epithelial cells contribute important vectorial information for guidance of young, migrating neurons.  相似文献   

Evaluation of modified vaccinia virus Ankara expressing VP2 protein of infectious bursal disease virus as an immunogen in chickens     

Flavia Adriana Zanetti  Mar��a Paula Del M��dico Zajac  Oscar Alberto Taboga  Gabriela Calamante 《Journal of veterinary science (Suw?n-si, Korea)》2012,13(2):199-201

A recombinant modified vaccinia Ankara (MVA) virus expressing mature viral protein 2 (VP2) of the infectious bursal disease virus (IBDV) was constructed to develop MVA-based vaccines for poultry. We demonstrated that this recombinant virus was able to induce a specific immune response by observing the production of anti-IBDV-seroneutralizing antibodies in specific pathogen-free chickens. Besides, as the epitopes of VP2 responsible to induce IBDV-neutralizing antibodies are discontinuous, our results suggest that VP2 protein expressed from MVA-VP2 maintained the correct conformational structure. To our knowledge, this is the first report on the usefulness of MVA-based vectors for developing recombinant vaccines for poultry.  相似文献   

Seroprevalence of Toxoplasma gondii and Neospora caninum in feral cats (Felis silvestris catus) in Majorca, Balearic Islands, Spain     

Javier Milln  Oscar Cabezn  Marcela Pabn  J.P. Dubey  Sonia Almería 《Veterinary parasitology》2009,165(3-4):323-326

Cryptosporidium spp. are common intestinal protozoan parasites that infect a wide range of hosts, including humans and livestock, worldwide. The objective of this study was to determine the prevalence of Cryptosporidium spp. in dairy calves in Prince Edward Island, Canada, and the potential for transmission of this parasite between dairy calves and humans. Fecal samples were collected from 183 dairy calves from 11 farms in Prince Edward Island. The prevalence of Cryptosporidium spp. infections in these animals was determined by examining for the presence of oocysts in the fecal samples, using immunofluorescence microscopy. Molecular characterization was done using a nested-PCR protocol to amplify fragments of the Cryptosporidium heat-shock protein 70 gene, followed by DNA sequencing. Ten calves (6.2%), representing 4 out of 11 farms tested, were positive for Cryptosporidium spp. DNA sequence analysis on five PCR positive samples demonstrated that Cryptosporidium parvum was the only species present in the calves tested, suggesting that there is a potential risk of zoonotic transmission between dairy calves and humans in this region.  相似文献