Frequency of bovine Nramp1 (Slc11a1) alleles in Holstein and Zebu breeds   总被引：1，自引：0，他引：1  

Paixão TA  Ferreira C  Borges AM  Oliveira DA  Lage AP  Santos RL 《Veterinary immunology and immunopathology》2006,109(1-2):37-42

Natural resistance against brucellosis in cattle is linked to the Nramp1 gene, which encodes a divalent cation transporter that localizes in the phagolysosome membrane in macrophages. Nramp1 gene in mouse plays a critical role in innate immunity favoring bacterial killing by macrophages in addition to its influence on adaptative immunity. Polymorphisms at the bovine Nramp1 3' untranslated region (3'UTR), detectable by Single Strand Conformational Analysis (SSCA), are associated with natural resistance against brucellosis. Such polymorphisms are associated with variation in the number of GT repeats. This study compared the frequency of Nramp1 3'UTR polymorphisms between Zebu and European bovine breeds. Eighty-one Holsteins (Bos taurus taurus) and 167 Zebu (Bos taurus indicus), including the following breeds: Nelore (n=95), Guzerá (n=37), and Gir (n=35), totaling 248 pure breed cattle studied. DNA extraction was performed using the guanidium protocol and genotyping was performed by SSCA. DNA from cattle considered genotypically resistant to brucellosis resulted in a single band (homozygous) with 175bp, corresponding to the 3'UTR with 13 GT pairs (GT13), whereas DNA from genotypically susceptible cattle generated one single band with 177bp (homozygous GT14) or double bands with both 175 and 177bp, or 175 and 179bp (heterozygous GT13/GT14 or GT13/GT15, respectively). A marked difference in the frequency of alleles was detected between the Zebu and Holstein cattle. Holsteins had an extremely homogeneous genotype, with 100% of the individuals with a GT13 genotype. In sharp contrast the Nelore breed had the most heterogeneous genotype with four allelic combinations, namely, homozygous GT13, homozygous GT14, heterozygous GT13/GT14, and heterozygous GT13/GT15. When the Zebu breeds were compared to each other, the only significant difference observed was the frequencies of the genotypes GT13 and GT14 between the Nelore and Guzerá breeds. The knowledge of allelic frequencies in different breeds of cattle may prove to be very useful in the future for planning breeding strategies for selection of resistant cattle.  相似文献   

Early settlement and growth of stocked European glass eels in a fragmented watercourse     

Pedro M. Félix  José Lino Costa  Bernardo R. Quintella  Pedro R. Almeida  Rui Monteiro  Joana Santos  Teresa Portela  Isabel Domingos 《Fisheries Management and Ecology》2021,28(1):91-100

One of the actions that has been implemented to support the recovery of the panmictic population of European eel is stocking of waterbodies where natural recruitment is low or null. However, growth conditions of the stocked eels can vary greatly. This circumstance emphasises the importance to determine ideal habitat conditions to contribute to the success of stocking actions and, consequently, to increase the production of silver eels. This study aims to evaluate the early settlement and growth of stocked glass eels in the upper reaches of a fragmented river. Stocking was carried out, in 2014, at three sites of an inland tributary of the Mondego river basin (Central Portugal), and its monitoring was conducted during the following two years, until 2016, along with the collection of environmental and hydromorphological parameters. The results showed a successful dispersion throughout the study area. Growth varied spatially, although environmental parameters have not clearly explained this variation, but overall with high growth rates and a positive allometric growth in this early stage of stocking, suggesting a good condition of the stocked individuals. This study showed that these upper reaches of fragmented watercourses, a shared feature amongst most European rivers that are currently inaccessible for natural recruitment, may be suitable habitats for eel stocking.  相似文献   

Dietary intake and nutritional adequacy prior to conception and during pregnancy: a follow-up study in the north of Portugal     

Pinto E  Barros H  dos Santos Silva I 《Public health nutrition》2009,12(7):922-931

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Habitat suitability, threats and conservation of isolated populations of the smooth snake (Coronella austriaca) in the southern Iberian Peninsula     

Xavier Santos  José C. Brito  Antonio J. Abril  Neftalí Sillero 《Biological conservation》2009,142(2):344-352

During the Pleistocene, climatic fluctuations due to glacial and interglacial periods greatly modified the distribution of boreal organisms. One direct effect of these distribution shifts is that, along the southern edge of the range of some boreal species, populations persist only in isolated patches of suitable habitats, surrounded by less suitable areas. Isolated populations in marginal habitat are vulnerable to several threats, including climate change, anthropogenic threats, and stochastic events. We developed habitat-suitability models using Ecological Niche Factor Analysis for populations of the smooth snake, Coronella austriaca, at the southernmost limit of the species range. These models were based on historical and current records of occurrence, coupled with remote sensing data including elevation, slope, and climatic variables. Our results indicated that C. austriaca in the Iberian Peninsula occurred in areas associated with high slope and precipitation, low temperatures, and low variation in seasonal temperature and precipitation compared to areas of non-occurrence. At a broad scale, the areas classified as highly suitable for the species in the southern Iberian Peninsula were small and fragmented. At a local scale, extensive field work demonstrated that C. austriaca occurs in low densities in these areas. In addition, we detected several human-induced threats like habitat loss, favoured by temperature increase and rainfall reduction. Several life-history traits, such as dietary specialization and low frequency reproduction, also may contribute to the vulnerability of these populations to local extinctions. Although the most suitable southernmost areas are included in protected reserves, specific guidelines for management are needed to assess conservation needs.  相似文献   

Vermicompost for Tinted Organic Cationic Dyes Retention     

Madson de Godoi Pereira  Mauro Korn  Bruno Barros Santos  Marcia Guia Ramos 《Water, air, and soil pollution》2009,200(1-4):227-235

The use of vermicompost was expanded as natural adsorbent for cationic dyes retention. The adsorption profiles in batch and flow modes for crystal violet and methylene blue on vermicompost material were evaluated. In batch mode, a retention index higher than 97% was obtained for both compounds, while in flow condition, 40 g of dried adsorbent material were enough to remove 100 mg of crystal violet or methylene blue at column flow rates of 5 and 20 mL min^?1. Adsorption isotherms showed adsorptive maximum capacities for vermicompost of 0.78 and 5.47 mg g^?1, respectively, which were compatible with the literature. Due to this good efficiency capacity, incineration steps can be considered as acceptable disposal procedures for enriched vermicompost. From these characteristics, economical and environmental advantages of the proposed material for the evaluated cationic dyes retention were evidenced.  相似文献   

An engineered microbial platform for direct biofuel production from brown macroalgae     

Wargacki AJ  Leonard E  Win MN  Regitsky DD  Santos CN  Kim PB  Cooper SR  Raisner RM  Herman A  Sivitz AB  Lakshmanaswamy A  Kashiyama Y  Baker D  Yoshikuni Y 《Science (New York, N.Y.)》2012,335(6066):308-313

Prospecting macroalgae (seaweeds) as feedstocks for bioconversion into biofuels and commodity chemical compounds is limited primarily by the availability of tractable microorganisms that can metabolize alginate polysaccharides. Here, we present the discovery of a 36-kilo-base pair DNA fragment from Vibrio splendidus encoding enzymes for alginate transport and metabolism. The genomic integration of this ensemble, together with an engineered system for extracellular alginate depolymerization, generated a microbial platform that can simultaneously degrade, uptake, and metabolize alginate. When further engineered for ethanol synthesis, this platform enables bioethanol production directly from macroalgae via a consolidated process, achieving a titer of 4.7% volume/volume and a yield of 0.281 weight ethanol/weight dry macroalgae (equivalent to ~80% of the maximum theoretical yield from the sugar composition in macroalgae).  相似文献   

Genetic analysis of kernel oil content in tropical maize with design III and QTL mapping     

Gustavo Vitti Môro  Mateus Figueiredo Santos  Dyeme Antônio Vieira Bento  Aurélio Mendes Aguiar  Cláudio Lopes de SouzaJr. 《Euphytica》2012,185(3):419-428

Oil content and grain yield in maize are negatively correlated, and so far the development of high-oil high-yielding hybrids has not been accomplished. Then a fully understand of the inheritance of the kernel oil content is necessary to implement a breeding program to improve both traits simultaneously. Conventional and molecular marker analyses of the design III were carried out from a reference population developed from two tropical inbred lines divergent for kernel oil content. The results showed that additive variance was quite larger than the dominance variance, and the heritability coefficient was very high. Sixteen QTL were mapped, they were not evenly distributed along the chromosomes, and accounted for 30.91% of the genetic variance. The average level of dominance computed from both conventional and QTL analysis was partial dominance. The overall results indicated that the additive effects were more important than the dominance effects, the latter were not unidirectional and then heterosis could not be exploited in crosses. Most of the favorable alleles of the QTL were in the high-oil parental inbred, which could be transferred to other inbreds via marker-assisted backcross selection. Our results coupled with reported information indicated that the development of high-oil hybrids with acceptable yields could be accomplished by using marker-assisted selection involving oil content, grain yield and its components. Finally, to exploit the xenia effect to increase even more the oil content, these hybrids should be used in the Top Cross^™ procedure.  相似文献   

Effect of intramuscular injection of butaphosphan and vitamin B12 on the quality of fresh and cooled stallion semen     

N. Cazales  G.O. Santos  M. Farias  H.B.A. Bastos  G.H.Z. Winter  I.C. Bustamante-Filho  R.C. Mattos 《Journal of Equine Veterinary Science》2012

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Seasonal effects on behavioral traits of stabled Criollo stallions during semen collection     

D.C. de Souza  S.D. Schiavo  M.A. Peres Maciel  N.M. Fajardo Campos  S.I. dos Santos  I.C. Bustamante-Filho  L.S. Van der Linden  S.F. Rechsteiner  A. Pires Neves 《Journal of Equine Veterinary Science》2012

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Mycoplasma haemocanis – the canine hemoplasma and its feline counterpart in the genomic era     

Naíla C do Nascimento  Andrea P Santos  Ana MS Guimaraes  Phillip J SanMiguel  Joanne B Messick 《Veterinary research》2012,43(1):66

Mycoplasma haemocanis is a hemotrophic mycoplasma (hemoplasma), blood pathogen that may cause acute disease in immunosuppressed or splenectomized dogs. The genome of the strain Illinois, isolated from blood of a naturally infected dog, has been entirely sequenced and annotated to gain a better understanding of the biology of M. haemocanis. Its single circular chromosome has 919 992 bp and a low G + C content (35%), representing a typical mycoplasmal genome. A gene-by-gene comparison against its feline counterpart, M. haemofelis, reveals a very similar composition and architecture with most of the genes having conserved synteny extending over their entire chromosomes and differing only by a small set of unique protein coding sequences. As in M. haemofelis, M. haemocanis metabolic pathways are reduced and apparently rely heavily on the nutrients afforded by its host environment. The presence of a major percentage of its genome dedicated to paralogous genes (63.7%) suggests that this bacterium might use antigenic variation as a mechanism to evade the host’s immune system as also observed in M. haemofelis genome. Phylogenomic comparisons based on average nucleotide identity (ANI) and tetranucleotide signature suggest that these two pathogens are different species of mycoplasmas, with M. haemocanis infecting dogs and M. haemofelis infecting cats.  相似文献