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1.
Itacir P. Ubert Cristiano M. Zimmer Kelly Pellizzaro Luiz C. Federizzi Itamar Cristiano Nava 《Euphytica》2017,213(2):41
Avena sativa L. subsp. nudisativa has the ability to produce naked grains. Genetic studies on the naked trait of oat began over a century ago, but the genetic and molecular factors associated with the expression of this trait have not been fully clarified. The objectives of this study were to evaluate the naked trait in two oat populations of recombinant inbred lines (RILs), to determine the number of genes, to estimate the heritability, and to map genomic regions associated with the naked trait in hexaploid oat. Parental lines and RILs of each population were screened for the naked trait from plants grown in the field over a 2 year period. Based on the phenotypic data, the oat RILs were classed as naked, partially naked, partially hulled and hulled. In both populations and years, a great number of RILs showed variable expressivity for the naked trait. The genetic analysis indicated the action of a major gene (N1) with the action of modifying genes controlling the formation of naked grains. The results of the estimate of heritability show that environmental conditions do not have a great influence in determining the naked trait. The quantitative trait loci analysis detected a genomic region with a large effect on the naked trait that explained more than 50% of the phenotypic variation. Further studies are needed to validate the use of these molecular markers to assist breeding programs to select high quality and stable naked oat cultivars. 相似文献
2.
Mira Fine Edna Sakal Dorit Vashdi Nava Chapnik-Cohen Violet Daniel Avigdor Levanon Orli Lipshitz Arieh Gertler 《Fish physiology and biochemistry》1993,11(1-6):353-361
Carp growth hormone (cGH) cDNA, in which Cys-123 was mutated to Ala, was prepared, transferred to the expression vector, expressed
in Escherichia coli and the mutant was purified to homogeneity. The mutation only slightly improved yield of the monomeric fraction, indicating
that Cys-123 is not involved in improper refolding. As compared to cGH, the mutant (cGH-C123A) exhibited lower binding affinity
toward homologous liver receptors and lower bioactivity in a 3T3-F442A preadipocyte bioassay despite the fact that both hormones
exhibited almost identical cross-reactivity with anti-cGH antibodies. These results, along with those of a structural comparison
to hGH, suggest that Cys-123 is located in the hydrophobic core of the hormone, and is most likely affecting the conformation
of the binding site. Dimeric forms of the hormone and its mutant were less active than their respective monomers. Homologous
binding experiments using a carp liver microsomal fraction revealed a single receptor population with Kd = 0.77 nM and Bmax = 241 fmol/mg microsomal protein.
Résumé Un ADN complémentaire (cDNA) de l'hormone de croissance de carpe (cGH), dans lequel l'acide aminé Cys-123 a été muté en Ala, a été préparé, inséré dans un vecteur d'expression, et exprimé dans Escherichia coli. Le mutant a ensuite été purifié jusqu'à homogénéité. La mutation améliore seulement faiblement la production de la fraction monomérique, indiquant que le Cys-123 n'est pas impliqué dans un repliement erroné. Comparé à la cGH, sa forme mutée (cGH-C123A) montre une plus faible affinité de liaison vis à vis de récepteurs hépatiques homologues, et une plus faible activité biologique dans un test réalisé sur des préadipocytes 3T3-F442A; cela en dépit du fait que les deux hormones présentent des réactions croisées presque identiques avec un anticorps anti-cGH polyclonale. Ces résultats, associés à une comparaison à la structure de l'hGH, suggèrent que le Cys-123 est localisé dans la partie hydrophobique de l'hormone, et affecte, le plus vraisemblablement, la conformation du site de liaison. Les formes dimériques de l'hormone et de sa forme mutée sont moins actives que leurs monomères respectifs. Les études de liaison homologue, réalisées avec des fractions microsomales de foie, révèlent une population unique de récepteurs de Kd = 0,77 nM et de Bmax = 241 fmol/mg de proteine microsomale.相似文献
3.
Itamar Cristiano Nava Carla Andréa Delatorre Ismael T. de Lima Duarte Marcelo Teixeira Pacheco Luiz Carlos Federizzi 《Euphytica》2006,148(3):353-358
Summary Aluminum toxicity due to the cation Al+3 is a major factor limiting yields in acid soils. Wide genetic variability to aluminum tolerance is found in oat genotypes. The objectives of this study were to determine the number of genes controlling aluminum tolerance in oats and to verify if any detrimental effects were present of the aluminum tolerance genes on grain yield and grain quality in Al+3free soils. Aluminum tolerance was estimated as the average regrowth of the main root after exposure to toxic levels of Al+3 in a hydroponic solution under controlled conditions. The number of genes controlling that trait was estimated from the distribution of the average root regrowth frequencies in a population of 333 recombinant inbred lines (RIL's) in generations F5:6 and F5:7. The effects on grain yield and grain quality were assessed in a subpopulation of 162 RIL's chosen based on their aluminum tolerance response. Aluminum tolerance in the evaluated population was controlled by one dominant major gene with the tolerant genotypes carying Al
a
Al
a
and the sensitive ones al
a
al
a
alleles. No detrimental effects of the Al
a
allele on grain yield or grain quality were detected.Part of the Master of Science dissertation of the first author 相似文献
4.
Jose A Morales Ligbel Sanchez Harvi Velasquez Beatriz De Borrego Marlene De Nava Denis Portillo Yulixis Cano Angel Morillo Ana Albornoz Elsa Socorro 《Water, air, and soil pollution》2001,130(1-4):511-516
Nutrient content and pH of rain samples collected at nine sites during 1988-1996 were studied to determine the amounts of N, P and S added by precipitation over Maracaibo Lake basin. The basin is a wide depression occupied by Lake Maracaibo and extensive alluvial plains and delimited by a mountainous zone of variable physiolgraphic characteristics with different cattle ranching and industrial activities. Rain pHs averaged ≈ 4 to 6, individual samples occasionally reached as low as pH 3 in the south basin. NH4 + levels were significantly higher (up to 2.6 mg/l NH4-N) than NO3 ? plus NO2 ?. Phosphorus levels were low, ranging from undetectable to 1.5 mg/l. The amounts of inorganic N/ha/yr added ranged from ≈ 5.4 Kg in the north to ≈ 8 Kg in the south basin; around the lakeshore, it was estimated that ≈ 9.8–16.8 Kg TN/ha (≈ 55 % as organic-N) are annually deposited. The annual amounts of SO4-S/ha added range from ≈ 10 to 13 Kg. The contribution of precipitation to P in the ecosystem is very small; ≈ 0.02 – 0.8 Kg of PO4-P/ha/yr was added in basin. The results of this study show that precipitation represents a significant factor for the total nitrogen and sulfur loading to Maracaibo Lake Basin. 相似文献
5.
Schnetzler CC Philpotts JA Nava DF Schuhmann S Thomas HH 《Science (New York, N.Y.)》1972,175(4020):426-428
Major and trace element concentrations have been determined by atomic absorption spectrophotometry, colorimetry, and isotope dilution in Apollo 15 mare basalt 15555 from the Hadley Rille area; trace element concentrations have also been determined in plagioclase and pyroxene separates from basalt 15555 and in soil 15531 from the same area. Basalt 15555 most closely resembles in composition the Apollo 12 olivine-rich basalts. The concentrations of lithium, potassium, rubidium, barium, rare-earth elements, and zirconium in basalt 15555 are the lowest, and the negative europium anomaly is the smallest, reported for lunar basalts; this basalt might be the least differentiated material yet returned from the moon. Crystallization and removal of about 6 percent of plagioclase similar to that contained in the basalt would account for the observed europium anomaly; if plagioclase is not on the liquidus of this basalt, a multistage origin is indicated. Mineral data indicate that plagioclase and pyroxene approached quasi-equilibrium. Most of the chemical differences between basalt 15555 and soil 15531 would be accounted for if the soil were a mixture of 88 percent basalt, 6 percent KREEP (a component, identified in other Apollo soils, rich in potassium, rare-earth elements, and phosphorus) and 6 percent plagioclase (anorthosite?). 相似文献
6.
Martinez MF de Nava G Demmers KJ Tutt D Rodriguez Sabarrós M Smaill B Corti M Juengel J 《Reproduction in domestic animals》2012,47(2):230-237
Two experiments were designed to investigate the administration of intravaginal progesterone in protocols for oestrus and ovulation synchronization in beef heifers. In Experiment 1, cyclic Black Angus heifers (n = 20) received an Ovsynch protocol and were randomly assigned to receive (CIDR‐Ovsynch) or not (Ovsynch) a progesterone device between Days 0 and 7. Treatment with a controlled internal drug release (CIDR) device significantly increased the size of the dominant follicle prior to ovulation (12.8 ± 0.4 CIDR‐Ovsynch vs 11.4 ± 0.4 Ovsynch) (p < 0.02). Plasma progesterone concentrations throughout the experiment were affected by the interaction between group and day effects (p < 0.004). In Experiment 2, cyclic Polled Hereford heifers (n = 382) were randomly assigned to one of the six treatment groups (3 × 2 factorial design) to receive a CIDR, a used bovine intravaginal device (DIB), or a medroxiprogesterone acetate (MAP) sponge and GnRH analogues (lecirelin or buserelin). All heifers received oestradiol benzoate plus one of the devices on Day 0 and PGF on Day 7 pm (device withdrawal). Heifers were detected in oestrus 36 h after PGF and inseminated 8–12 h later, while the remainder received GnRH 48 h after PGF and were inseminated on Day 10 (60 h). The number of heifers detected in oestrus on Day 8 and conception rate to AI on Day 9 were higher (p < 0.01) in the used‐DIB than in the CIDR or MAP groups, while the opposite occurred with the pregnancy rate to FTAI on Day 10 (p < 0.01). There was no effect of progesterone source, GnRH analogue or their interaction on overall pregnancy rates (64.9%). Progesterone treatment of heifers during an Ovsynch protocol resulted in a larger pre‐ovulatory follicle in beef heifers. Progesterone content of intravaginal devices in synchronization protocols is important for the timing of AI, as the use of low‐progesterone devices can shorten the interval to oestrus. 相似文献
7.
Angel Rolando Endara Agramont Sergio Franco Maass Gabino Nava Bernal Juan Ignacio Valdez Hernández Todd S. Fredericksen 《林业研究》2012,23(1):39-44
Sample plots were established in the principal forest types in the the Nevado de Toluca National Park, Mexico including those dominated by Pinus hartwegii, Abies religiosa, Quercus laurina and Alnus jorullensis. The vertical structure was defined by three strata in the coniferous forests and two strata in the broadleaved forests. Timber harvesting in Abies religiosa and Quercus laurina forests and fires generated by humans in Pinus hartwegii forests impeded the recruitment of saplings. Mature trees were also heavily impacted by logging in Pinus hartwegii forests. On the contrary, Alnus jorullensis forests were increasing due to the disturbance of Pinus and Quercus forests, as well abandoned crop lands within the park. A combination of logging, uncontrolled fire, and grazing appears to be compromising the recruitment of important tree species in this national park. These factors, together with human settlements, have also increased the proportion of early successional species. Changes in forest structure from human disturbance indicate a need to control these activities if conservation goals are not to be compromised. 相似文献
8.
Histological alterations in gills of shrimp Litopenaeus vannamei in low‐salinity waters under different stocking densities: Potential relationship with nitrogen compounds 
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下载免费PDF全文 Marcela G. Fregoso‐López María S. Morales‐Covarrubias Miguel A Franco‐Nava Javier Ramírez‐Rochín Juan F Fierro‐Sañudo Jesús T Ponce‐Palafox Federico Páez‐Osuna 《Aquaculture Research》2017,48(12):5854-5863
Two experimental modules with different stocking densities (M1 = 70 and M2 = 120 shrimp /m2) were examined weekly over a culture cycle in tanks with low‐salinity water (1.9 g/L) and zero water exchange. Results showed survival rates of 87.7 and 11.9% in M1 and M2, respectively. Water temperature, pH, dissolved oxygen, electrical conductivity and chlorophyll a were not significantly (p > .05) different between modules. In contrast, the concentrations of nitrogen compounds were significantly (p < .05) different between modules, except nitrite‐N (M2 were 2.31 ± 1.38 mg/L N‐TAN, 0.18 ± 0.49 mg/L N‐NO2? and 6.83 ± 6.52 mg/L N‐NO3?; in M1: 0.97 ± 0.73 mg/L N‐TAN, 0.05 ± 0.21 mg/L N‐NO2? and 0.63 ± 0.70 mg/L N‐NO3?). When waters of both modules reached higher levels of ammonia and nitrite, histological alterations were observed in gills. The histological alterations index (HAI) was higher in M2 (5‐112) than in M1 (2‐22). 相似文献
9.
In order to describe the normal bacterial flora in vaginas of Criollo Limonero cows, 51 healthy multiparous cows, at least
90-day postpartum, were selected. Duplicated swabs (N = 102) were taken from the vaginal fornix of cows to perform aerobic and anaerobic cultures as well as conventional biochemical
tests. Out of 102 swabs, bacterial growth was obtained in 55 (53.9%) while the remaining 47 (46.1%) did not exhibited any
bacterial growth. Of the 55 bacterial growths, 23 (41.8%) were aerobic whereas 32 (58.1%) were anaerobic. Likewise, 29 (52.72%)
of bacterial growths were pure and 26 (47.27%) were mixed. Under both aerobic and anaerobic conditions, Gram positive bacteria
were predominant (81.82% and 73.08%, respectively) over Gram negative bacteria (18.18% and 26.92%, respectively). Isolated
bacteria were Arcanobacterium pyogenes (22.92%), Staphylococcus aureus (15.63%), Staphylococcus coagulase negative (17.71%), Erysipelothrix rhusiopathiae (6.25%), Bacteroides spp. (13.54%), and Peptostreptococcus spp. (7.29%). In conclusion, normal vaginal bacterial flora of Criollo Limonero cows was predominantly Gram positive and included
A. pyogenes, S. aureus, coagulase negative Staphylococcus, E. rhusiopathiae, Bacteroides spp., and Peptostreptococcus spp. In Criollo Limonero cattle, adaptive aspects such as development of humoral and physical mechanisms for defense, and bacterial
adaptation to host deserve research attention. 相似文献
10.
G. Alfaro C. Lomeli R. Ocadiz V. Ortega R. Barrera M. Ramirez G. Nava 《Veterinary immunology and immunopathology》1992,30(4):385-398
Some of the immunologic and genetic properties of the cell line S180 have been examined. These cells grew without restrictions in the peritoneal cavity of different inbred strains of mice and invariably killed the animals. With Northern blots it was demonstrated that S180 cells contained class I mRNAs but failed to transcribe B2m genes. However, under experimental conditions, a protective humoral immune response mediated by cytotoxic antibodies and complement against S180 cells was obtained through non-H-2 antigens in C57BL/6J mice. 相似文献