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111.
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Bicalho HM Pimenta CG Mendes IK Pena HB Queiroz EM Pena SD 《Genetics and molecular research : GMR》2006,5(3):432-437
The International Society of Animal Genetics (ISAG) has chosen nine microsatellites (international marker set) as a standard that should be included in all cattle parentage studies. They are BM1824, BM2113, INRA023, SPS115, TGLA122, TGLA126, TGLA227, ETH10, and ETH225. We decided to ascertain whether this microsatellite set could be used to determine ancestral proportions in individual animals of synthetic breeds produced by crossing zebu and taurine cattle. Since the genotypes of these markers are routinely available, this would constitute a practical and cost-free method to estimate the ancestry of synthetic breed animals. Genotypes of 100 Gir and 100 Holstein animals were examined for this ISAG marker set. As expected, there were very significant allele frequency differences between the two breeds at most loci. We also typed 20 Girolando animals for which there was complete genealogical information. "Structure" software easily distinguished Holstein and Gir animals based on their microsatellite genotypes; it also attributed the genomic proportion of zebu and taurine of each of the 20 Girolando animals. The proportion of Holstein ancestry was then regressed on the genealogical data; there was a highly significant correlation (r = 0.84, P < 0.0001). The nine microsatellites that compose the ISAG international marker set were capable of estimating the ancestral Gir and Holstein genomic proportions in individual Girolando animals within narrow confidence limits. This microsatellite set might also be useful for estimating the proportions of taurine and zebu origins in commercial meat products. 相似文献
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115.
Rivelilson Mendes de Freitas 《Neurochemical research》2010,35(1):162-170
In the present study we investigated the effect of seizures on rat performance in the Morris water maze task, as well as on
choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activities in rat hippocampus. Wistar rats were treated with
0.9% saline (i.p., control group), lipoic acid (20 mg/kg, i.p., LA group), pilocarpine (400 mg/kg, i.p., pilocarpine group),
and the association of LA (20 mg/kg, i.p.) plus pilocarpine (400 mg/kg, i.p.), 30 min before of administration of LA (LA plus
pilocarpine group). After the treatments all groups were observed for 1 h. The effect of lipoic acid administration was observed
on reference and working spatial memory of seized rats. The ChAT and AChE activities were measured using spectrophotometric
methods and the results compared to values obtained from saline and pilocarpine-treated animals. Its activity was also determined
after behavioral task. Results showed that pretreatment with lipoic acid did not alter reference memory when compared to saline-treated
animals. In the working memory task, we observed a significant day’s effect with significant differences between control and
pilocarpine-induced seizures and pretreated animals with lipoic acid. In LA plus pilocarpine group was observed a significantly
increased in ChAT and AChE activities, when compared to pilocarpine group. Results showed that acute administration of lipoic
acid alone did not alter hippocampal ChAT and AChE activities. Our findings suggest that seizures caused cognitive dysfunction
and a decrease of ChAT and AChE activities that might be related, at least in part, to the neurological problems presented
by epileptic patients. Lipoic acid can reverse cognitive dysfunction observed in seized rats as well as increase the ChAT
and AChE activities in hippocampus of rats prior to pilocarpine-induced seizures, suggesting that this antioxidant could be
used in clinic treatment of epilepsy. 相似文献
116.
Deborah Ariza Marcelo M. S. Lima Camila G. Moreira Patrícia A. Dombrowski Thiago V. Avila Alexandra Allemand Daniel A. G. B Mendes Claudio Da Cunha Maria A. B. F. Vital 《Neurochemical research》2010,35(10):1620-1627
The current investigation compared intranigral lipopolysaccharide (LPS), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)
and 6-hydroxydopamine (6-OHDA) administrations, in the light of neurochemical, behavioral and endogenous antioxidant glutathione
alterations. All the results were collected 1, 3 and 7 days after the lesions. LPS produced a delayed reduction of striatal
dopamine, whereas homovanillic acid was drastically increased at the first time-point. Comparatively, MPTP promoted dopamine
reduction 3 and 7 days with increase of homovanillic acid. Whilst, 6-OHDA generated initial increase of dopamine and homovanillic
acid followed by subsequent decrease of this neurotransmitter accompanied by reductions of dopamine metabolites at the same
periods. Furthermore, nigral glutathione demonstrated to be a far more sensitive target for LPS than for MPTP or 6-OHDA. Behavioral
data indicated impairments induced by MPTP, 6-OHDA but not LPS. In conclusion, it is suggested that intranigral LPS can provide
new insights about neuroinflammation, simulating features of the pre-motor phase of Parkinson’s disease. 相似文献
117.
One mechanism by which mammalian cells regulate the uptake of glucose is the number of glucose transporter proteins (GLUT) present at the plasma membrane. In insulin-responsive cells types, GLUT4 is released from intracellular stores through inactivation of the Rab GTPase activating protein Tre-2/USP6-BUB2-Cdc16 domain family member 4 (TBC1D4) (also known as AS160). Here we describe that TBC1D4 forms a protein complex with protein kinase WNK1 in human embryonic kidney (HEK293) cells. We show that WNK1 phosphorylates TBC1D4 in vitro and that the expression levels of WNK1 in these cells regulate surface expression of the constitutive glucose transporter GLUT1. WNK1 was found to increase the binding of TBC1D4 to regulatory 14-3-3 proteins while reducing its interaction with the exocytic small GTPase Rab8A. These effects were dependent on the catalytic activity because expression of a kinase-dead WNK1 mutant had no effect on binding of 14-3-3 and Rab8A, or on surface GLUT1 levels. Together, the data describe a pathway regulating constitutive glucose uptake via GLUT1, the expression level of which is related to several human diseases. 相似文献
118.
Chantal Fernandes Vitor Mendes Joana Costa Nuno Empadinhas Carla Jorge Pedro Lamosa Helena Santos Milton S. da Costa 《Journal of bacteriology》2010,192(6):1624-1633
The compatible solute mannosylglucosylglycerate (MGG), recently identified in Petrotoga miotherma, also accumulates in Petrotoga mobilis in response to hyperosmotic conditions and supraoptimal growth temperatures. Two functionally connected genes encoding a glucosyl-3-phosphoglycerate synthase (GpgS) and an unknown glycosyltransferase (gene Pmob_1143), which we functionally characterized as a mannosylglucosyl-3-phosphoglycerate synthase and designated MggA, were identified in the genome of Ptg. mobilis. This enzyme used the product of GpgS, glucosyl-3-phosphoglycerate (GPG), as well as GDP-mannose to produce mannosylglucosyl-3-phosphoglycerate (MGPG), the phosphorylated precursor of MGG. The MGPG dephosphorylation was determined in cell extracts, and the native enzyme was partially purified and characterized. Surprisingly, a gene encoding a putative glucosylglycerate synthase (Ggs) was also identified in the genome of Ptg. mobilis, and an active Ggs capable of producing glucosylglycerate (GG) from ADP-glucose and d-glycerate was detected in cell extracts and the recombinant enzyme was characterized, as well. Since GG has never been identified in this organism nor was it a substrate for the MggA, we anticipated the existence of a nonphosphorylating pathway for MGG synthesis. We putatively identified the corresponding gene, whose product had some sequence homology with MggA, but it was not possible to recombinantly express a functional enzyme from Ptg. mobilis, which we named mannosylglucosylglycerate synthase (MggS). In turn, a homologous gene from Thermotoga maritima was successfully expressed, and the synthesis of MGG was confirmed from GDP-mannose and GG. Based on the measurements of the relevant enzyme activities in cell extracts and on the functional characterization of the key enzymes, we propose two alternative pathways for the synthesis of the rare compatible solute MGG in Ptg. mobilis.Thermophilic and hyperthermophilic organisms, like the vast majority of other microorganisms, accumulate compatible solutes in response to water stress imposed by salt. In fact, many of the (hyper)thermophiles known were isolated from geothermal areas venting seawater (36). However, the compatible solutes of thermophilic and hyperthermophilic prokaryotes are generally different from those of their mesophilic counterparts and some, namely, di-myo-inositol-phosphate (DIP), mannosyl-di-myo-inositol-phosphate (MDIP), diglycerol phosphate, and mannosylglyceramide, are confined to organisms that grow at extremely high temperatures (19, 22, 34, 38). Mannosylglycerate (2-α-d-mannosylglycerate; MG), for example, is a common compatible solute of thermophiles and hyperhermophiles (23, 27, 38) but has also been found in mesophilic organisms, such as red algae, where it was first identified (6). It should also be noted that there is a growing awareness that compatible solutes are involved in other types of stress; trehalose, for example, plays a role in osmotic stress, heat stress, desiccation, and freezing (9). Some compatible solutes of thermophilic organisms are extremely rare and have been encountered in only one or two, generally closely related, species. Among them are mannosylglyceramide in Rhodothermus marinus, diglycerol phosphate in Archaeoglobus fulgidus, and, more recently, mannosylglucosylglycerate (α-d-1→2-mannopyranosyl-α-d-1→2-glucopyranosylglycerate; MGG) identified in Petrotoga miotherma (16, 19, 38).The species of the genus Petrotoga represent slightly thermophilic members of the generally hyperthermophilic and deep-branching bacteria of the order Thermotogales (2, 3, 31). Organisms of this genus have all been isolated from hot oilfield water (21, 25), and have an optimum temperature for growth of 55 to 60°C in medium containing NaCl in the range of 0.5 to 10% (16). In Ptg. miotherma, the levels of MGG increased during low-level osmotic adaptation, whereas glutamate and proline were used for protection against hyperosmotic stress (16). The hyperthermophilic Thermotoga spp. accumulate primarily di-myo-inositol-phosphate and mannosyl-di-myo-inositol-phosphate during osmotic adjustment or during growth at temperatures above the optimum for growth (37).The novel compatible solute MGG is a derivative of glucosylglycerate (2-α-d-glucosylglycerate; GG) identified in the free form in Erwinia chrysanthemi, in the marine cyanobacteria Prochlorococcus marinus and Synechococcus sp. PCC7002, and in the thermophilic bacterium Persephonella marina, the latter of which possesses two alternative pathways for its synthesis (8, 13, 14, 18, 37). Glucosylglycerate has also been detected in trace amounts in Mycobacterium smegmatis, where it probably is the precursor of a polysaccharide involved in the regulation of fatty acid synthesis, as well as in the polar head group of a glycolipid from Nocardia otitidiscaviarum (17, 30).Two alternative pathways for the synthesis of GG have been identified and characterized. In the two-step reaction scheme, the synthesis of GG involves the condensation of nucleoside diphosphate (NDP)-glucose and d-3-phosphoglycerate (3-PGA) into glucosyl-3-phosphoglycerate (GPG), which in turn is dephosphorylated to yield GG. Yet, in a single-step pathway, the synthesis of GG occurs via the condensation of ADP-glucose with d-glycerate (13). Similar routes to those described above also lead to the synthesis of mannosylglycerate in Rhodothermus marinus (4).Two functionally connected genes encoding an “actinobacterial”-type glucosyl-3-phosphoglycerate synthase (GpgS) and an unknown glycosyltransferase were detected in the genome of Petrotoga mobilis (12). In this study, we examine the synthesis of MGG through a phosphorylating pathway (with a phosphorylated intermediate) from 3-phosphoglycerate and UDP-glucose to the final compatible solute, in cell extracts and by functional characterization of recombinant enzymes. We also examine a second nonphosphorylating pathway (no phosphorylated intermediates) that could represent an alternative route for the synthesis of MGG in Ptg. mobilis that could lead to the direct conversion of GG and GDP-mannose to MGG. Pathway multiplicity likely reflects a crucial role for MGG in the physiology of Ptg. mobilis during stress adaptation. 相似文献
119.
Tiago I Mendes V Pires C Morais PV Veríssimo A 《Systematic and applied microbiology》2006,29(2):100-108
A Gram-negative bacterium designated AC-74(T) was isolated from a highly alkaline groundwater environment (pH 11.4). This organism formed rod-shaped cells, is strictly aerobic, catalase and oxidase positive, tolerates up to 3.0% NaCl, has an optimum growth temperature of 30 degrees C, but no growth occurs at 10 or 40 degrees C, and an optimum pH value of 8.0, but no growth occurs at pH 7.0 or 11.3. The predominant fatty acids are iso-15:0, iso-17:1 omega9c and 16:1 omega7c and or iso-15:2OH. The G+C content of DNA was 43.5mol%. The phylogenetic analyses of the sequences of the 16s RNA genes indicated that strain AC-74(T) belongs to the family "Flexibacteriaceae" and is phylogenetically equidistant ( approximately 94.5%) from the majority of the species of the genus Algoriphagus and from the genus Hongiella. Based on the phylogenetic analyses and distinct phenotypic characteristics, we are of the opinion that strain AC-74(T), represents a new species of the novel genus for which we propose the name Chimaereicella alkaliphila gen. nov., sp. nov. 相似文献
120.
F. A. Azevedo F. A. A. Mourão Filho B. M. J. Mendes W. A. B. Almeida E. H. Schinor R. Pio J. M. Barbosa S Guidetti-Gonzalez H. Carrer E. Lam 《Plant Molecular Biology Reporter》2006,24(2):185-196
Transgenic plants expressing the bacterio-opsin (bO) gene can spontaneously activate programmed cell death (ped) and may enhance broad-spectrum pathogen resistance by activating
an intrinsic defense pathway in plant species such as tobacco and potato. In this work, we produced transgenic Rangpur lime
plants with thebO gene, viaAgrobacterium tumefaciens-mediated transformation, and evaluated these plants forPhytophthora nicotianae resistance. Two transgenic lines were successfully regenerated and transformation was confirmed by GUS activity assay, PCR
analysis, Southern, Northern and Western blot analyses, in addition to detecting the expressed bO protein by an immunological
approach. Evaluation forPhytophthora nicotianae resistance was carried out by plant inoculations with the pathogen and quantification of the affected area. One of the two
transgenic lines showed greater tolerance to the fungal pathogen as compared to the control, with significantly smaller stem
lesions after pathogen challenge. This increase in pathogen tolerance is correlated with a significantly higher level of transgene
expression in this line when compared with the other transgenic line. This is the first report of the introduction of a potentially
important gene into Rangpur lime to provide novel pathogen tolerance. 相似文献