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2.
RNA interference (RNAi) technology using small interfering RNAs (siRNA) has been widely used as a powerful tool to knock down gene expression in various organisms. In pig preimplantation embryos, no attempt to suppress the target gene expression with such technology has been made. The purpose of this study is to demonstrate that the RNAi technology is useful for suppression of endogenous target gene expression at an early stage of development in pigs. Alpha-1,3-Galactosyltransferase (α-GalT) is an enzyme that creates the Galα1-3Gal (α-Gal) epitope on the cell surface in some mammalian species, and removal of the epitope is considered to be a prerequisite for pig-to-human xenotransplantation. We decided to suppress the endogenous α-GalT mRNA expression in pig early embryos, since reduction of α-GalT synthesis is easily monitored by cytochemical staining with Bandeiraea simplicifolia isolectin-B(4), a lectin that specifically binds to the α-Gal epitope, and by RT-PCR analysis. Cytoplasmic microinjection of double-stranded RNA and pronuclear injection of an siRNA expression vector into the embryos generated in vitro resulted in a significant reduction in expression of the α-GalT gene and α-Gal epitope in blastocysts, at which stage the α-Gal epitope is abundantly expressed. Somatic cell nuclear transfer of embryonic fibroblasts stably transfected with an siRNA expression vector also led to a significant reduction in the level of α-GalT mRNA synthesis together with decreased amounts of the α-Gal epitope at the blastocyst stage. These results indicate that the RNAi technology is useful for efficient suppression of a target gene expression during embryogenesis in pigs and suggest the possibility of production of siRNA-expressing pigs for use in xenotransplantation. 相似文献
3.
1. The present study was aimed to investigate the effect of adding ascorbic acid or α-lipoic acid to to the diet of broilers exposed to heat stress on performance and meat quality. 2. Heat stress caused a decrease in final body weight and feed consumption, whilst ascorbic acid (AA) and α-lipoic acid (ALA) partly prevented the decrease in final body weight of males. 3. While heat stress increased the pH values of broiler drumsticks and breast meat, AA and ALA partly reduced this increase. For meat quality, AA and ALA reduced the adverse effects on the relative yellowness value, particularly on d 14 of storage. 4. It was determined that heat stress affected the microbiological quality of meat adversely, and that AA and ALA alleviated this effect to a certain extent. 5. In conclusion, while heat stress affected body weight gain and meat quality adversely, the supplementation of the ration with AA and ALA partly alleviated these adverse effects. 相似文献
4.
The neonatal pig is susceptible to stress and infection, conditions which favor tumor necrosis factor α (TNFα) secretion. This study examined whether TNFα can alter metabolic activity and cytokine gene expression within neonatal pig adipose tissue. Cell cultures were prepared from neonatal subcutaneous adipose tissue using standard procedures. Cultures (5 experiments) were incubated with medium containing 14C-glucose for 4 h to measure glucose conversion to lipid in the presence of combinations of TNFα (10 ng), insulin (10 nM) and an anti-pig TNFα antibody (5 μg). Basal lipogenesis was not affected by TNFα treatment ( P?>?0.05). However, insulin stimulated lipogenesis was reduced by TNFα ( P?<?0.02). For gene expression studies, cultures were incubated with 0, 2.5, 5.0 or 10 ng TNFα for 2, 4 or 24 h ( n?=?4 experiments). Interleukin 6 and TNFα gene expression were acutely (2–4 h) stimulated by exogenous TNFα treatment ( P?<?0.05), as analyzed by real-time PCR. Adiponectin mRNA abundance was reduced ( P?<?0.001) while monocyte chemotactic gene expression was increased by TNFα treatment at all time points ( P?<?0.001). Chronic treatment (24 h) was required to increase monocyte multiplication inhibitory factor or suppress lipoprotein lipase gene expression ( P?<?0.02). These data suggest conditions which increase serum TNFα, like sepsis, could suppress lipid accumulation within adipose tissue at a time of critical need in the neonate and induce a variety of adipose derived cytokines which may function to alter adipose physiology. 相似文献
5.
The Exaltation of Newcastle disease virus (END) phenomenon is induced by the
inhibition of type I interferon in pestivirus-infected cells in vitro,
via proteasomal degradation of cellular interferon regulatory factor (IRF)-3 with the
property of the viral autoprotease protein N pro. Reportedly, the amino acid
residues in the zinc-binding TRASH motif of N pro determine the difference in
characteristics between END-phenomenon-positive (END +) and
END-phenomenon-negative (END −) classical swine fever viruses (CSFVs). However,
the basic mechanism underlying this function in bovine viral diarrhea virus (BVDV) has not
been elucidated from the genomic differences between END + and END −
viruses using reverse genetics till date. In the present study, comparison of complete
genome sequences of a pair of END + and END − viruses isolated from
the same virus stock revealed that there were only four amino acid substitutions (D136G,
I2623V, D3148G and D3502Y) between two viruses. Based on these differences, viruses with
and without mutations at these positions were generated using reverse genetics. The END
assay, measurements of induced type I interferon and IRF-3 detection in cells infected
with these viruses revealed that the aspartic acid at position 136 in the zinc-binding
TRASH motif of N pro was required to inhibit the production of type I interferon
via the degradation of cellular IRF-3, consistently with CSFV. 相似文献
6.
Indispensable AA are involved in the control of feed intake. When a diet deficient in Val is offered to pigs, feed intake is typically reduced. This effect is aggravated when dietary Leu is supplied in excess of the requirement. If an unbalanced supply of branched-chain AA (BCAA) is harmful, an anorectic response may serve as a mechanism to prevent this situation. We verified this hypothesis by measuring the voluntary feed intake of a balanced diet offered during the 30-min period 1 h after ingestion of a test meal deficient or not in Val (Val- and Val+) with an excess of Leu. Twelve and four 6-wk-old crossbred female pigs were used in Exp. 1 and 2, respectively. Prior ingestion of the Val- test meal resulted in a 14% reduction in feed intake compared with that observed after ingestion of the Val+ test meal (P = 0.06) in Exp. 1, indicating that the signal to reduce feed intake occurred within 1 h. It is possible that the plasma concentration of the limiting AA serves as a signal for the dietary AA deficiency. We therefore determined the postprandial plasma concentrations of BCAA and their α-keto acids after ingestion of Val- and Val+ in 4 pigs in Exp. 2. After ingestion of the Val- diet, plasma concentrations of Val and its keto acid were reduced compared with values observed after ingestion of the Val+ diet. The peak concentration occurred earlier after ingestion of the Val- diet compared with that of the Val+ diet. Although the plasma concentration increased after the meal, it declined rapidly in pigs offered Val-, and the Val concentration 4 h after ingestion of the meal was even less than that observed in the fasted state. In conclusion, it appears that the pig is able to detect a deficient supply of Val within 1 h after ingestion. The plasma concentration of Val or its concentration relative to the other BCAA during the postprandial period may act as a signal indicating the AA deficiency. 相似文献
7.
The present study was conducted to determine the effects of α-lipoic acid supplementation on post-mortem changes in the fatty acid profile and concentrations of nucleotide-related substances, especially those of a taste-active compound, inosine 5?-monophosphate, in chicken meat. Mixed-sex broiler chicks aged 14 d were divided into three groups of 16 birds each and were fed on diets supplemented with α-lipoic acid at levels of 0, 100 or 200 mg/kg for 4 weeks. Blood and breast muscle samples were taken at 42 d of age under the fed condition and then after fasting for 18 h. The breast muscle obtained from fasted chickens was subsequently refrigerated at 2°C for one and 3 d. α-Lipoic acid supplementation did not affect any plasma metabolite concentration independently of feeding condition, while a slight increase in plasma glucose concentration was shown with both administration levels of α-lipoic acid. In early post-mortem breast muscle under the fed condition, α-lipoic acid had no effect on concentrations of fatty acids or nucleotides of ATP, ADP, and AMP. In post-mortem breast tissues obtained from fasted chickens, total fatty acid concentrations were markedly increased by α-lipoic acid feeding at 200 mg/kg irrespective of length of refrigeration. This effect was dependent on stearic acid, oleic acid, linoleic acid and linolenic acid. However, among fatty acids, the only predominantly increased unsaturated fatty acid was oleic acid. Dietary supplementation with α-lipoic acid at 200 mg/kg increased the inosine 5?-monophosphate concentration in breast meat and, in contrast, reduced the subsequent catabolites, inosine and xanthine, regardless of the length of refrigeration. Therefore, the present study suggests that α-lipoic acid administration altered the fatty acid profile and improved meat quality by increasing taste-active substances in the post-mortem meat obtained from fasted chickens. 相似文献
8.
Antioxidant vitamins are commonly used as colorant, preventive, sweetener, nutritive and antioxidant materials in food industry. Thus, many studies have been conducted in recent years. We have performed the present study to understand the effects of α-lipoic acid (ALA), vitamin C and E, added into rations of Japanese quails, on chronic heat stress. This study was carried out in five groups as: control, stress, ALA, vitamin E and vitamin C groups. Heat stress is applied to all groups except the control group. Superficial pectoral muscles tissues were used for biochemical determinations. During the research, it is found that heat stress exerted undesired effects such as increasing lipid peroxidation (LPO) level indicating oxidative stress in Japanese quails. In addition, superoxide dismutase (SOD) and catalase (CAT) enzyme activities and glutathione (GSH) amounts were studied to understand the behaviour of defence mechanism. While stress increased LPO ratio, it was determined that all antioxidant added into the ration decreases LPO significantly (p < 0.05). In addition, it was determined that all of antioxidants added into ration effectively restored SOD activity and LPO ratio which heat stress affected negatively. Interestingly, vitamin C did not adjust GSH ratio in contrast to vitamin E and ALA, where vitamin E and C did not perform any positive effect on heat stress decreased CAT activity. Finally, it can be thought that antioxidant vitamins relatively ameliorated these undesired affects caused by stress factors given. 相似文献
9.
This is the first paper describing the cloning of pigeon IFN-γ gene (PiIFN-γ) and the analysis of the in vitro expressed recombinant protein. The PiIFN-γ gene was identified by RT-PCR as a 498 bp, fragment coding for a precursor protein of 165 amino acids instead of 164 amino acids, as observed in the other avian species. The recombinant protein was expressed in vitro by an eukaryotic system and the biological properties of the cytokine were tested using a chicken macrophage cell line. The high degree of amino acid and nucleotide identity, shared with the ChIFN-γ, and the fact that the pigeon protein was functional on chicken cells, indicates a cross-reactivity between pigeon and chicken IFN-γ. The detection of the PiIFN-γ could represent an useful instrument in understanding the role played by this cytokine in immune response related to vaccinations and infectious diseases in the pigeon. 相似文献
10.
Dietary fibers (DF) contain an abundant amount of energy, although the mammalian genome does not encode most of the enzymes required to degrade them. However, a mutual dependence is developed between the host and symbiotic microbes, which has the potential to extract the energy present in these DF. Dietary fibers escape digestion in the foregut and are fermented in the hindgut, producing short-chain fatty acids (SCFA) that alter the microbial ecology in the gastrointestinal tract (GIT) of pigs. Most of the carbohydrates are fermented in the proximal part, allowing protein fermentation in the distal part, resulting in colonic diseases. The structures of resistant starch (RS), arabinoxylan (AX), and β-glucan (βG) are complex; hence, makes their way into the hindgut where these are fermented and provide energy substrates for the colonic epithelial cells. Different microbes have different preferences of binding to different substrates. The RS, AX and βG act as a unique substrate for the microbes and modify the relative composition of the gut microbial community. The granule dimension and surface area of each substrate are different, which influences the penetration capacity of microbes. Arabinose and xylan are 2 different hemicelluloses, but arabinose is substituted on the xylan backbone and occurs in the form of AX. Fermentation of xylan produces butyrate primarily in the small intestine, whereas arabinose produces butyrate in the large intestine. Types of RS and forms of βG also exert beneficial effects by producing different metabolites and modulating the intestinal microbiota. Therefore, it is important to have information of different types of RS, AX and βG and their roles in microbial modulation to get the optimum benefits of fiber fermentation in the gut. This review provides relevant information on the similarities and differences that exist in the way RS, AX, and βG are fermented, and their positive and negative effects on SCFA production and gut microbial ecology of pigs. These insights will help nutritionists to develop dietary strategies that can modulate specific SCFA production and promote beneficial microbiota in the GIT of swine. 相似文献
11.
γ-Aminobutyric acid (GABA) is a natural nonprotein amino acid distributed in animals, plants and microbes. GABA is an inhibiting neurotransmitter which takes great effect in mammalian central nervous system. We carried out the research to study the influence of GABA on blood hormone concentrations, antioxidant status and meat quality in fattening pigs after transportation. The 72 pigs with a starting weight of approximately 32.67 ± 0.62 kg were randomly allocated to 2 groups based on dietary treatments, containing 6 replicates with 6 pigs in each. The pigs were fed dietary supplementation of GABA (0 or 30 mg/kg of diets) for 74 days. Twelve pigs were randomly selected from each group and assigned to the either 1 hr of transport (T group) or no transport (N group), resulting in two-factor factorial design. Compared to the control, GABA supplementation increased average daily gain (ADG) ( p < .01) and decreased feed–gain ratio (F/G) ( p < .05). The pH 45 min was lower and drip loss was greater in the longissimus muscles (LM) of post-slaughter of transported pigs ( p < .05). The pH 45 min of 0/T group (group with 0 mg/kg GABA and transport) was significantly lower than the pH 45 min of the 30/T group (diet × transport; p < .05). GABA supplementation significantly increased serum glutathione peroxidase (GSH-Px) concentration ( p < .05) before transportation. Following transport, pigs fed GABA had decreased concentrations of serum malonaldehyde (MDA), adrenal cortical hormone and cortisol ( p < .05). The results indicate that feeding GABA significantly increased the growth performance of growing-finishing pigs. The transportation model negatively impacted meat quality, antioxidant indexes and hormone parameters, but dietary supplementation of GABA could suppress the rise of drip loss of LM, ACTH and COR and suppress the drop of pH 45 min of LM after transportation stress in growing-finishing pigs. Feeding GABA alleviated transportation stress in pigs. 相似文献
12.
The present study was conducted to test whether the dietary supplementation of β-mannanase affects amino acids (AA) digestibility, metabolizable energy (ME) contents of corn, wheat, soybean meal, distillers dried grains with solubles, and palm kernel meal (PKM), nutrient digestibility, and growth performance of pigs. In Exp. 1, 22 cannulated pigs were used for 10 dietary treatments including 5 feed ingredients and 2 β-mannanase concentrations (0 and 0.5 g/kg of the diet) in 6 periods in an incomplete Latin square design to determine the AA and energy digestibility. In Exp. 2, 200 growing pigs were randomly allotted to 4 treatments with 2 nutrient levels (high and low) and 2 concentrations of β-mannanase (2 × 2 factorial arrangement) in 2 phases (phase 1, d 0 to 21; and phase 2, d 22 to 42). In Exp. 1, β-mannanase increased the mean standardized ileal digestibility (SID) of AA in all feed ingredients. The amount of digestible energy was increased ( P < 0.05) in β-mannanase-treated PKM. Pigs fed β-mannanase showed a greater ( P < 0.05) digestibility of gross energy (GE). The feed-to-gain (F:G) ratio was improved ( P < 0.01) in pigs fed high-nutrient diets. Pigs fed β-mannanase in the diets had greater ( P < 0.05) average daily gain and F:G. In phase 2, the concentration of fecal ammonia was decreased ( P < 0.05) in pigs fed β-mannanase. Considering the 2 experiments, it can be concluded that β-mannanase increases the SID of AA, which has to be considered in balancing the rations. 相似文献
13.
Worldwide, only a few “fatty” pig breeds exist with different and/or regional
utilization. Using the Hungarian Mangalica, which almost went extinct in Europe and the
Lao Moo Lat pig, which still has a large population in South-East Asia as exemples, we
wanted to demonstrate that indigenous (fatty) pig breeds may represent both national value
and tremendous economic potential. Since these less prolific and less productive breeds
cannot contribute to mass production, new market roles and methods should be established
for them in the premium segment of pork trading. Thus their preservation and propagation
needs the comprehensive collaboration of commercial, governmental actors and researchers.
Briefly summarizing the history, we report the current results of reproductive physiology
research. The commercial renaissance of Mangalica pigs is indebted to the enthusiastic
efforts of basic scientists, pig breeding experts and dedicated Mangalica producers.
Scientific achievements were applied to practical breeding and production of delicious
pork and processed products, which ultimately made the economic success in the Mangalica
sector possible. Both, research on and utilization of endangered (pig) breeds maintain not
only breed diversities, but also may improve the livelihood of farmers worldwide. 相似文献
14.
-Adrenoceptors were identified and characterized by [ 3H]dihydroalprenolol ([ 3H]DHA) binding experiments in muscle membrane preparations from piglets. The [ 3H]DHA binding was rapid, reversible and stereoselective. Catecholamines competed for specific binding with a rank order of potency (-)-isopropylnoradrenaline > (-)-epinephrine » (-)-norepinephrine, indicating a -subtype of adrenoceptor. Saturation binding experiments with [ 3H]DHA showed no significant difference for either the number of binding sites or the equilibrium dissociation constants in normal and splayleg pigs.Adenylate cyclase assays indicated that the basal adenylate cyclase activity and the prostaglandin E 1 (PGE 1)-, (-)-isopropylnoradrenaline (ISO)-, 5-guanylyl-imidodiphosphate (GppNHp)- and sodium fluoride (NaF)-stimulated values were not significantly different in normal and splayleg pigs. In both groups, PGE 1 did not affect basal activity, whereas ISO and GppNHp stimulated adenylate cyclase activity significantly ( p<0.001) to about 40% above basal level. NaF induced a significant ( p<0.001) increase of cAMP in normal and splayleg pigs amounting to 48% and 61% respectively. Significant correlations between absolute adenylate cyclase responses to ISO ( r=0.83 ***), NaF ( r=0.72 **) and GppNHp ( r=0.61 *) and basal activity in the splayleg pigs were the most striking findings. In contrast, these correlations could not be detected in the normal pigs. Whether or not this observation reflects an alteration in the signal transduction system needs to be further investigated.To the best of our knowledge this is the first biochemical study which relates an altered -adrenoceptor function and porcine splayleg. 相似文献
15.
Steroid hormones are produced by the porcine uterus. We hypothesized that the uterus in
pigs possesses active 3β-hydroxysteroid dehydrogenase/Δ 5-Δ 4
isomerase (3β-HSD) responsible for progesterone and androstenedione production, that
uterine steroids may supplement the amount of steroid hormones produced by embryos and
corpus luteum and that these steroids are necessary for maintenance of pregnancy. In this
study, we examined 1) endometrial and myometrial expression of 3β-HSD
mRNA, 2) uterine 3β-HSD protein activity and 3) in vitro production of
A 4 and P 4 by uterine slices harvested from pigs on days 10 to 11,
12 to 13 and 15 to 16 of pregnancy and the estrous cycle. The expression of
3β-HSD and the presence and activity of 3β-HSD protein were different
in the endometrium and the myometrium during the examined periods of pregnancy and the
estrous cycle. Production of A 4 by the endometrium and myometrium was highest
on days 12 to 13 of pregnancy and the estrous cycle. Endometrial secretion of
P 4 did not differ in the course of early pregnancy and on the respective days
of the estrous cycle. The gravid myometrium was the highest source of P 4 in
pregnant pigs on days 12 to 13. The release of P 4 by the cyclic myometrium rose
during the examined days of the estrous cycle. The steroidogenic activity of the uterus,
as described in this study, may support early pregnancy or the luteal phase of the estrous
cycle in pigs. 相似文献
17.
1. The aim of this study was to evaluate the effect of supplementation of the layer diet with olive leaves ( Olea europea L.) on lipid oxidation and fatty acid profile of α-linolenic acid enriched eggs during refrigerated storage, and to compare this effect with α-tocopheryl acetate supplementation. 2. A total of 72 brown Lohmann laying hens, equally allocated to 3 groups, were fed on diets supplemented with 40?g/kg linseed oil, or linseed oil and olive leaves at 10?g/kg or linseed oil and α-tocopheryl acetate at 200?mg/kg. Collected eggs were analysed for fatty acid profile and lipid oxidation either fresh or following 60?d storage at 4°C. 3. Results showed that olive leaves or α-tocopheryl acetate supplementation reduced lipid hydroperoxide concentration in fresh eggs but had no effect on their fatty acid profile and malondialdehyde (MDA) content compared to controls. 4. Refrigerated storage for 60?d decreased the proportions of PUFAs but increased those of MUFAs in eggs from the control diet, whilst it had no effect on the fatty acid composition of eggs from the diets supplemented with olive leaves or α-tocopheryl acetate, which in turn showed decreased concentrations of lipid hydroperoxides and MDA. 相似文献
18.
The fermented feed has been identified as a potential alternative to antibiotics in feeds that markedly affects gut health and growth performance of pigs. Two recent studies performed in our laboratory investigated that the fermented corn–soybean meal (fermented feed, FF) improved the gut health of pigs. This study was conducted to determine the effect of a FF on the carcass, meat quality, muscle fatty acids profile, muscle amino acid and antioxidant ability of grower-finisher pigs. In this study, a total of 48 crossbred barrows (Duroc × Landrace × Large White) were randomly divided into 2 treatments with unfermented corn–soybean diet (Ctrl) and FF diet. Compared with control pigs fed a standard diet, the results showed that FF significantly increased the muscle colour of redness and significantly reduced muscle moisture loss rate. Furthermore, FF significantly increased the content of aromatic amino acids such as aspartic acid, glutamic acid and alanine. More importantly, FF increased monounsaturated fatty acid and polyunsaturated fatty acid content. Collectively, FF could be a promising feed strategy in improving meat quality and nutritional value in grower-finisher pig. 相似文献
19.
Taking into account the beneficial effects of antioxidants in reducing morbidity and mortality in calves, the aim of this study was to evaluate the effects of vitamins E and C on the development of the inflammation process and on selected defence mechanisms against infections induced by M. haemolytica.The study was carried out on 30 Simmentaler calves weighing about 100 kg, which received s.c.vitamin E (750 UI) or vitamin C (2.5 g/calf). In leukocytes obtained from the calves, sensitivity to the cytotoxic effect of M. haemolytica Lkt was evaluated using the MTT assay, expression of β 2-integrin receptors on leukocyte surfaces was assessed, and metabolic activity was measured by the nitrotetrazolium blue test (NBT). Concentration of haptoglobin (Hp) and serum amyloid A (SAA) was estimated in the sera obtained.Analysis of the intracellular metabolism of the leukocytes showed no statistically significant differences compared to the control. A difference (p ≤ 0.05) was observed in the sensitivity of the leukocytes to the cytotoxic effect of Lkt in comparison with the control group. No differences were found in the percentage of cells sensitive to Lkt between the group given vitamin E and the calves which received vitamin C. The percentage of expression of β 2-integrin receptors reached its lowest values on leukocytes isolated from the calves given vitamin E. The correlation between expression of β 2-integrins and sensitivity of leukocytes to Lkt showed the greatest correlation on day 14 in calves given vitamin E, and on day 21 in calves given vitamin C.Analysis of Hp concentration in the sera showed no differences between the two groups of calves tested, but revealed differences (p ≤ 0.05) in absorbance values compared to the control on particular days of experiment. SAA concentration in the sera of calves from the group that received vitamin E was similar to that of the control on days 14 and 21 of the experiment. On days 3 and 7 of the experiment a significant (p ≤ 0.05) decrease was observed in SAA in the sera obtained from calves from the group given vitamin E compared to the control and the group given vitamin C. 相似文献
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