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1.
A trial was conducted to study the effect of sire line (Duroc (DU) and Pietrain (PI)) on carcass, meat and fat quality of pigs reared outdoor and destined to dry-cured meat production. No differences between sire genotypes were detected in carcass fat thickness (P > 0.10) but carcasses from DU-sired pigs were longer (P < 0.05) and tended to have a higher yield of trimmed shoulders (P = 0.07) and hams (P = 0.06) than carcasses from PI-sired pigs. Loins from DU-sired genotype showed higher (P < 0.05) L* value and lower (P < 0.01) a* value than loins from PI-sired genotype. Pork from DU-sired offspring tended to have higher (P = 0.09) intramuscular fat (IMF) percentage and lower (P < 0.05) moisture proportion than meat from PI-sired offspring. Also, loins from DU-sired pigs had lower (P < 0.001) thawing losses than loins from PI-sired pigs. The subcutaneous fat from the DU-sired line tended to show lower (P = 0.08) percentage of total polyunsaturated fatty acids (PUFAs) than that from the PI-sire line, mostly due to the higher proportion of C18:2 (P = 0.09) and C20:3 (P < 0.01). However, no effect of crossbreed was detected on the total proportion of saturated, monounsaturated fatty acid (MUFAs) or PUFAs of IMF (P > 0.10). We conclude that both sire lines can be used successfully under outdoor conditions but DU boars are more adequate than PI boars for the production of heavy pigs intended for the dry-cured meat industry.  相似文献   

2.
The objectives were to: (1) develop an enzyme immunoassay (EIA) for insulin-like peptide 3 (INSL3) or relaxin-like factor (RLF) in bovine plasma; (2) investigate changes of plasma INSL3 concentrations from birth to pubertal age of beef bulls; and (3) compare changes in plasma concentrations of INSL3, testosterone, and LH. Plasma samples were collected from beef bull calves (n = 15) at birth (0 d) and at 28, 56, and 84 d after birth. Furthermore, in beef bulls around pubertal age (n = 26; age range 3 to 22 mo), plasma samples were collected at 1 to 4 mo intervals. Plasma INSL3 concentrations increased (P < 0.05) from 0 to 28, 28 to 56, and from 56 to 84 d of age. Plasma testosterone concentrations increased (P < 0.001) from 0 to 28 d, and from 28 to 56 d, but did not change from 56 to 84 d. For bulls around pubertal age, plasma INSL3 concentrations did not change from the prepubertal phase (3 to 6 mo) to the early pubertal phase (6 to 12 mo), but increased (P < 0.05) from the early to late pubertal phases (12 to 18 mo), and from the late pubertal to postpubertal phases (18 to 22 mo). Plasma testosterone concentrations increased from the prepubertal to early pubertal phases (P < 0.001), but did not change thereafter. Plasma LH concentrations did not change from 0 d to 84 d, but decreased (P < 0.001) from prepubertal to early pubertal phase, with no significant change thereafter. Plasma INSL3 concentrations increased during the first 3 mo of life and throughout the pubertal age in beef bulls. There were similar dynamic patterns for INSL3 and testosterone during the first 3 mo of life, but patterns subsequently diverged in bulls around pubertal ages.  相似文献   

3.
The phosphoinositolglycan(-peptide) (PIG-P) portion of glycosylphosphatidylinositol-anchored plasma membrane (GPI) proteins or synthetic PIG(-P) molecules interact with proteinaceous binding sites which are located in high-cholesterol-containing detergent/carbonate-insoluble glycolipid-enriched raft domains (hcDIGs) of the plasma membrane. In isolated rat adipocytes, PIG(-P) induce the redistribution of GPI proteins from hcDIGs to low-cholesterol-containing DIGs (lcDIGs) and concomitantly provoke insulin-mimetic signaling and metabolic action. Using a set of synthetic PIG(-P) derivatives we demonstrate here that their specific binding to hcDIGs and their insulin-mimetic signaling/metabolic activity strictly correlate with respect to (i) translocation of the GPI proteins, Gce1 and 5(')-nucleotidase, from hcDIGs to lcDIGs, (ii) dissociation of the nonreceptor tyrosine kinase, pp59(Lyn), from caveolin residing at hcDIGs, (iii) translocation of pp59(Lyn) from hcDIGs to lcDIGs, (iv) activation of pp59(Lyn), (v) tyrosine phosphorylation of insulin receptor substrate proteins-1/2, and finally (vi) stimulation of glucose transport. The natural PIG(-P) derived from the carboxy-terminal tripeptide of Gce1, YCN-PIG, exhibits the highest potency followed by a combination of the separate peptidylethanolamidyl and PIG constituents. We conclude that efficient positive cross-talk of PIG(-P) to the insulin signaling cascade requires their interaction with hcDIGs. We suggest that PIG(-P) thereby displace GPI proteins from binding to hcDIGs leading to their release from hcDIGs for lateral movement to lcDIGs which initiates signal transduction from DIGs via caveolin and pp59(Lyn) to the insulin receptor substrate proteins of the insulin signaling pathway.  相似文献   

4.
In order to understand the epidemiology of Newcastle disease (ND) outbreaks in double-crested cormorants (Phalacrocorax auritus), a study was conducted on wintering migratory cormorants (P. a. auritus) in Alabama and Mississippi (USA) and non-migratory cormorants (P. a. floridanus) that breed in Florida (USA). Antibodies against ND virus were detected by the hemagglutination-inhibition method in sera from 86 of 183 (47%) migratory cormorants over-wintering in eight roosting sites in Alabama and Mississippi between November, 1997 and April, 1999. Titers ranged from 5 to 40. Antibody prevalences in sera collected from females in early winter (November and December) (26%) and late winter (February and March) (56%) were significantly different (P = 0.0007). None of 45 serum samples from 1- to 7-wk-old nestlings from 11 colonies in Florida during the 1997-98 and 1998-99 breeding seasons was positive. However, antibodies were detected in yolk samples from 98 of 126 (78%) eggs collected in these same colonies. Titers ranged from 4 to 256. The prevalence of antibodies in eggs collected from fresh-water colonies (63% prevalence, n = 30) and salt-water colonies (82% prevalence, n = 96) was significantly different (P = 0.041). ND virus was not isolated from tissues of 18 cormorants and cloacal and tracheal swabs from 202 cormorants collected in Alabama and Mississippi; virus was also not isolated from cloacal and tracheal swabs from 51 nestlings from Florida.  相似文献   

5.
为了揭示12周高强度循环训练(high-intensity circuit training, HICT)对于超重肥胖男性的身体组成、心肺功能及代谢症候指标的影响,本研究将23位中年超重男性随机分配至HICT组((45.7±4.0) yrs,(172.1±5.1) cm,(76.6±10.2) kg, n=13)和控制组((47.8±4.8) yrs,(173.5±4.8) cm,(76.6±8.5) kg, n=10)。运动干预前、后分别测量受试者的各项指标。HICT组进行每周6次,为期12周(共72次)的高强度循环训练,即最大努力完成12个动作,运动30 s,休息15 s;控制组则维持日常身体活动。研究显示,相较于控制组,HICT组的体脂肪百分比由(25.1±5.1)%降至(23.2±4.1)%、体脂肪重由(19.5±5.7) kg降至(17.5±4.4) kg;体力指数由63.9±14.1升至72.4±16.9,腰围由(88.2±8.6) cm降至(84.2±8.1) cm、臀围由(99.5±5.1) cm降至(96.7±4.1) cm、收缩压由(136.1±11.8) mmHg降至(120.9±9.4) mmHg、舒张压由(88.9±9.3) mmHg降至(80.6±8.1) mmHg、空腹血糖由(105.9±25.0) mg/d L降至(97.1±22.1) mg/dL、血浆甘油三脂(triglyceride, TG)浓度由(101.5±61.7) mg/dL降至(117.5±50.3) mg/dL、胆固醇(total cholesterol, TC)浓度(161.9±20.0) mg/dL降至(117.5±50.3) mg/dL、高密度脂蛋白(high-density lipoproteincholesterol, HDL-C)浓度由(161.9±20.0) mg/dL升至(148.9±21.8) mg/dL,低密度脂蛋白胆固醇(low-density lipoprotein cholesterol, LDL-C)浓度由(105.1±25.0) mg/dL降至(97.2±23.5) mg/dL,实验前后,HITC组与控制组后测数值具有显著差异(p<0.05)。本研究表明,每周运动时间约60 min,为期12周共72次的高强度循环训练可有效改善中年超重肥胖男性的身体成分、心肺功能和代谢症候指标。  相似文献   

6.
AIMS: To describe the occurrence and virulence gene pattern of shiga toxin-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) in healthy goats of Jammu and Kashmir, India. METHODS AND RESULTS: A total of 220 E. coli strains belonging to 60 different 'O' serogroups was isolated from 206 local (nonmigratory) and 69 migratory goats. All the 220 strains were screened for the presence of stx(1), stx(2), eaeA and hlyA genes. Twenty-eight E. coli (75.6%) strains from local and nine (24.3%) strains from migratory goats belonging to 18 different serogroups showed at least presence of one virulence gene studied. Twenty-eight strains (16.47%) (belonging to 13 different serogroups) from local goats carried stx(1) gene alone or in combination with stx(2) gene, while as only one strain (2%) from migratory goats possessed stx(2) gene alone. Interestingly in the present study none of the STEC strains carried eaeA gene. Similarly, none of the strains from local goats possessed eaeA and none of the migratory goats possessed stx(1) gene. Eight strains (16%) (belonging to four different serogroups) from migratory goats carried eaeA gene. Twenty-five (14.7%) and seven (14%) strains from local and migratory goats harboured hlyA gene respectively. CONCLUSIONS: Healthy goats of Jammu and Kashmir state serve as a reservoir of STEC and EPEC. Further studies in this direction are needed to work out whether or not they are transmitted to humans in this part of world. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first report of isolation of STEC and EPEC strains from healthy goats in Jammu and Kashmir State of India, which could be a source of infection to humans.  相似文献   

7.
The range and stability of expression of the transgenic CryIA(b) protein was examined in Ciba Seeds Bt maize plants derived from Event 176. Specifically, CryIA(b) levels were determined for: (1) various plant tissues and developmental stages in three maize lines from 1993 field tests; (2) pollen and leaves from plants representing four backcross generations of two genotypes; (3) leaves of 6 precommercial hybrids; and (4) silage from one Bt maize hybrid. Significant levels were found only in pollen and leaves. Genetic background did not greatly impact the level seen in either tissue. CryIA(b) expression in maize plants derived from transformation Event 176 was stable over at least four successive generations. On a per acre basis, the highest amount of CryIA(b) protein (estimated to be 2-4 g CryIA(b) protein/acre) was found to occur at anthesis, consistent with the stage at which maximum plant vegetative biomass is reached. CryIA(b) was not detected in silage prepared from CryIA(b)-expression plants. The maize-expressed CryIA(b) protein was found to have the expected size and to be immunoreactive with antibodies prepared against crystals from Bacillus thuringiensis subsp. kurstaki.  相似文献   

8.
A domain of epiglucan was synthesized by beta-glucosidases. Two beta-glucosidases, an extracellular beta-glucosidase derived from Sclerotinia sclerotiorum grown on xylose, and a commercial lyophilized preparation of beta-glucosidase from Aspergillus niger, were used to synthesize gluco-oligosaccharides from cellobiose and, specially, beta-(1-6) branched beta-(1-3) gluco-oligosaccharides, corresponding to the structure of epiglucan. Gentiobiose, cellotriose, cellotetraose, beta-Glc-(1-3)-beta-Glc-(1-4)-Glc, beta-Glc-(1-6)-beta-Glc-(1-4)-Glc and beta-Glc-(1-6)-beta-Glc-(1-3)-Glc were synthesized from cellobiose by both enzymes. The latter compound was preferentially synthesized by the beta-glycosidase from Sclerotinia sclerotiorum. Under the best conditions, only 7 g l(-1) of beta-Glc-(1-6)-beta-Glc-(1-3)-Glc was synthesized by the beta-glycosidase from Aspergillus niger compared to 20 g l(-1) synthesized with beta-glycosidase from Sclerotinia sclerotiorum.  相似文献   

9.
The results of studies on the content of the nitrogen basic compounds, viz. quinolizidine alkaloids, biogenic polyamines and basic amino acids in lupin seeds are presented. The investigations concerned three lupin species (Lupinus angustifolius L., Lupinus albus L. and Lupinus luteus L.) and 10 bitter and sweet cultivated varieties. Content of quinolizidine alkaloids in L. angustifolus ranged from 11.4 to 19.6 microg mg(-1) dw (bitter cultivars), from 0.18 to 0.47 microg mg(-1) dw (sweet), in L. albus from 0.58 microg mg(-1) dw (sweet) to 29.6 microg mg(-1) dw (bitter) and in L. luteus from 0.59 (sweet) to 14.7 microg mg(-1) dw (bitter). Total biogenic polyamine content ranged in L. angustifolius from 2,773.9 to 3,180.2 pmol mg(-1) dw (bitter) and from 315.0 to 599.0 pmol mg(-1) dw (sweet), in L. albus from 432.6 pmol mg(-1) dw (sweet) to 1,832.0 pmol mg(-1) dw (bitter) and in L. luteus from 506.9 pmol mg(-1) dw (sweet) to 2,091.8 pmol mg(-1) dw (bitter). Total basic amino acids varied in L. angustifolus from 1,034.3 to 1,704.6 pmol mg(-1) dw (bitter) and from 1,761.9 to 2,101.9 pmol mg(-1) dw (sweet), in L. albus from 696.9 pmol mg(-1) dw (bitter) to 1,269.2 pmol mg(-1) dw (sweet) and in L. luteus from 927.6 pmol mg(-1) dw (bitter) to 1,598.3 pmol mg(-1) dw (sweet). We found a close dependence between alkaloid content and level of biogenic polyamines and basic amino acids in all three lupin species tested. All bitter lupin seeds also contain high level of biogenic polyamines but a low content of basic amino acids. The reverse relationship in sweet lupin seeds was found. The findings demonstrate that lupin nitrogen basic compounds are in steady equilibrium and that change of content in one compound leads to corresponding change in the content of another.  相似文献   

10.
The objective of this study was to quantify the genetic variation in carcass cuts predicted using digital image analysis in commercial cross-bred cattle. The data set comprised 38,404 steers and 14,318 heifers from commercial Irish herds. The traits investigated included the weights of lower value cuts (LVC), medium value cuts (MVC), high value cuts (HVC), very high value cuts (VHVC) and total meat weight. In addition, the weights of total fat and total bones were available on the steers. Heritability of carcass cut weights, within gender, was estimated using an animal linear model, whereas genetic and phenotypic correlations among cuts were estimated using a sire linear model. Carcass weight was included as a covariate in all models. In the steers, heritability ranged from 0.13 (s.e. = 0.02) for VHVC to 0.49 (s.e. = 0.03) for total bone weight, and in the heifers heritability ranged from 0.15 (s.e. = 0.04) for MVC to 0.72 (s.e. = 0.06) for total meat weight. The coefficient of genetic variation for the different cuts varied from 1.4% to 3.6%. Genetic correlations between the different cut weights were all positive and ranged from 0.45 (s.e. = 0.08) to 0.89 (s.e. = 0.03) in the steers, and from 0.47 (s.e. = 0.14) to 0.82 (s.e. = 0.06) in the heifers. Genetic correlations between the wholesale cut weights and carcass conformation ranged from 0.32 (s.e. = 0.06) to 0.45 (s.e. = 0.07) in the steers, and from 0.10 (s.e. = 0.12) to 0.38 (s.e. = 0.09) in the heifers. Genetic correlations between the same wholesale cut traits in steers and heifers ranged from 0.54 (s.e. = 0.14) for MVC to 0.79 (s.e. = 0.06) for total meat weight; genetic correlations between carcass weight and carcass classification for conformation and fat score in both genders varied from 0.80 to 0.87. The existence of genetic variation in carcass cut traits, coupled with the routine availability of predicted cut weights from digital image analysis, clearly shows the potential to genetically improve carcass value.  相似文献   

11.
Muscle specific maximal voluntary isometric contractions (MVIC) are commonly used to elicit reference amplitudes to normalize electromyographic signals (EMG). It has been questioned whether this is appropriate for normalizing EMG from dynamic contractions. This study compares EMG amplitude when shoulder muscle activity from dynamic contractions is normalized to isometric and isokinetic maximal excitation as well as a hybrid approach currently used in our laboratory. Anterior, middle and posterior deltoid, upper and lower trapezius, pectoralis major, latissimus dorsi and infraspinatus were monitored during (1) manually resisted MVICs, and (2) maximum voluntary dynamic concentric contractions (MVDC) on an isokinetic dynamometer. Dynamic contractions were performed (a) at 30°/s about the longitudinal, frontal and sagittal axes of the shoulder, and (b) during manual bi-rotation of a tilted wheel at 120°/s. EMG from the wheel task was normalized to the maximum excitation from (i) the muscle specific MVIC, (ii) from any MVIC (MVICALL), (iii) for any MVDC, (iv) from any exertion (maximum experimental excitation, MEE). Mean EMG from the wheel task was up to 45% greater when normalized to muscle specific isometric contractions (method i) than when normalized to MEE (method iv). Seventy-five percent of MEE’s occurred during MVDCs. This study presents an 20 useful and effective process for obtaining the greatest excitation from the shoulder muscles when normalizing dynamic efforts.  相似文献   

12.
13.
Phosphodiesterase activity is estimated in extracts and partially purified preparations from functionally different parts of bovine tongue. The enzyme activity varied from 4.0 to 10.4 nmole/mg of protein/min. Properties of phosphodiesterase from circumvallate papillae are studied, the pH optimum being 8.0--8.5, Km for cAMP--1.5.10(-4) M and for cGMP--6.5.10(-5) M. The enzyme activity did not change after the treatment with trypsin, protamine sulphate (0.01--1.0%), heparin (0.01--1.0) and taste agents: L-leucine (from 1.10(-2) M to 1.10(-5) M), quinine (from 4.10(-3) M to 4.10(-8) M) and D-glucose (from 1.10(-1) M to 1.10(-4) M). The protein inhibitor of the enzyme, isolated from retina external rod-cell segments considerably suppressed phosphodiesterase activity, and the protein activator from brain tissue stimulated it insignificantly. Thermostable protein modulators, which inhibit or activate (depending on experimental conditions) phosphodiesterase activity, are isolated from circumvallate papillae.  相似文献   

14.
Ovine tubal (n = 87) and ovarian in vitro matured oocytes (n = 99) were fertilized in vitro with ejaculated spermatozoa capacitated for 8 h in modified defined medium buffered with Hepes. High levels of fertilization were obtained as assessed by development to two-to six-cell stage within 40 h (75. 8% for ovulated and 62. 6% for in vitro matured oocytes). Electron microscope analysis of oocytes 20–22 h after insemination indicated that in vitro fertilization approximated the in vivo events. Embryos (two- to six-cell) were transferred surgically to the oviducts of pseudopregnant rabbits. Three days later, 42 (from ovulated oocytes) and 15 (from in vitro matured oocytes) embryos were recovered; 26 (61. 9%) and 10 (66. 6%), respectively, had cleaved at least once. Embryos incubated in vivo (n = 20 from ovulated oocytes; n = 9 from in vitro matured oocytes) were transferred surgically to the uteri of seven and four recipient ewes resulting in four and two pregnancies, respectively, from which three and one, respectively, have been maintained ( > 3 months). The first lamb resulting from the in vitro fertilization of an ovulated oocyte was born. In addition, six embryos (two- to four-cell) from tubal oocytes and ten embryos (two- to six-cell) from in vitro matured oocytes were directly transferred to the oviducts of two and three ewes, respectively. Two pregnancies resulting from in vitro matured fertilized oocytes are in progress ( > 3 months).  相似文献   

15.
Summary Mineral nitrogen and potassium lost from the Eastern Flevoland polder and from the North Eastern polder were estimated at regular intervals by determining the amounts of soluble nitrogen and potassium in the water which had been admitted by locks and inlets and discharged by pumping stations and subtracting nitrogen and potassium added in the rain. From 1959 to 1966 the nett annual losses of nitrogen in the discharged water from various pumping stations in Eastern Flevoland ranged from 18.9 to 33.2 (average 25.2) kg N per ha. Similarly in the North Eastern polder from 1963 to 1966 the nett annual losses ranged from 16.7 to 33.2 (average 22.1) kg N per ha. Rainfall added annually between 4.8 and 11.8 (average 8.6) kg N per ha to both polders. Nett losses from Eastern Flevoland ranged from 9.2 to 21.9 (average 15.8) kg per ha and from the North Eastern polder from 10.1 to 24.0 (average 14.9) kg N per ha, annually. Drainage water contained principally nitrate nitrogen, whereas the discharged water in many cases contained both ammonium and nitrate nitrogen, and often more ammonium than nitrate, presumably because the composition of the mineral nitrogen in the waterways is changed by the growth and death of algae. From 1962 to 1966 the discharged water removed potassium from the Eastern Flevoland polder in amounts ranging from 105 to 226 (average 162) kg K per ha annually. During 1963–1964, amounts lost from the North Eastern polder ranged from 47 to 71 (average 59) kg K per ha each year. The rain added from 4.5 to 10.7 (average 6.9) kg K per ha annually to both polders. Nett losses from Eastern Flevoland ranged from 99 tot 219 (average 156) kg K per ha and from the North Eastern polder from 41 to 67 (average 54) kg K per ha annually.  相似文献   

16.
Interactions of bovine follicular fluid glycosaminoglycans (GAGs) with extracellular matrix (ECM) components fibronectin and laminin and with low-density lipoproteins (LDL) were examined using affinity chromatography. Glycosaminoglycans from small (diameter less than 5 mm) and large (diameter 11-20 mm) follicles were isolated from follicular fluid. The dermatan sulphate or heparan sulphate from small or large follicles was applied to Fn-, Lm- or LDL-Sepharose columns. Portions of each fraction of the bound or unbound GAG were then subjected to gel filtration h.p.l.c. for quantification. The binding interaction between dermatan sulphate and fibronectin was significantly greater than between heparan sulphate and fibronectin (P less than 0.05); the binding interaction between GAGs from small follicles and fibronectin was significantly greater than between GAGs from large follicles (P less than 0.05). The binding interaction between GAGs from small follicles and laminin was significantly greater than for GAGs from large follicles (P less than 0.05). Dermatan sulphate from small follicles bound to fibronectin (42%), laminin (36%) and LDL (14%) and that from large follicles bound to fibronectin (14%), laminin (23%) and LDL (14%). Heparan sulphate from small follicles bound to fibronectin (17%), laminin (15%) and that from large follicles bound to fibronectin (13%), laminin (10%) and LDL (6%). These results suggest that dermatan sulphate, but not heparan sulphate, from follicles at different stages of development exhibit a varied ability to interact with components of the ECM. Both substances bound to LDL comparably in small amounts.  相似文献   

17.
The aim of our current study was to investigate the effect of acute exposure to electric tail shock stress (ES) and to a stress witnessing procedure (SW), as models for physical and psychological stress paradigms, respectively, on phagocytosis and H(2)O(2) production in peritoneal macrophages isolated from Albino Oxford (AO) and Dark Agouti (DA) rats. In addition, we studied the in vitro effects of methionine-enkephalin (ME) on phagocytosis and H(2)O(2) production in peritoneal macrophages isolated from both AO and DA rats that had been exposed to ES and SW procedures. The results showed that peritoneal macrophages isolated from DA rats were less sensitive to the suppressive effects of ES and SW than macrophages isolated from AO rats. In vitro treatment of macrophages isolated from AO rats with ME mimicked to some extent the suppressive effects of ES and SW on phagocytosis and H(2)O(2) production and additionally diminished H(2)O(2) release in macrophages isolated from AO rats previously exposed to ES or SW. ME did not have any effect on phagocytosis in macrophages isolated from DA rats, but changed H(2)O(2) production in a concentration-dependent manner. In macrophages isolated from DA rats previously exposed to stress the effect of ME was dependent on the macrophage function tested and the particular stress paradigm employed. Our results emphasise the fact that both beneficial and detrimental effects of stress on immune system functions could be attributed to the individual variations in the macrophage's response to stress mediators.  相似文献   

18.
Yeoh HH  Badger MR  Watson L 《Plant physiology》1981,67(6):1151-1155
Studies of ribulose-1,5-bisphosphate (RuBP) carboxylase from taxonomically diverse plants show that the enzyme from C(3) and crassulacean acid metabolism pathway species exhibits lower K(m)(CO(2)) values (12-25 micromolar) than does that from C(4) species (28-34 micromolar). RuBP carboxylase from aquatic angiosperms, an aquatic bryophyte, fresh water and marine algae has yielded consistently high K(m)(CO(2)) values (30-70 micromolar), similar in range to that of the enzyme from C(4) terrestrial plants. This variation in K(m)(CO(2)) is discussed in relation to the correlation between the existence of CO(2)-concentrating mechanisms for photosynthesis and the affinity of the enzyme for CO(2). The K(m)(RuBP) of the enzyme from various sources ranges from 10 to 136 micromolar; mean +/- sd = 36 +/- 20 micromolar. This variation in K(m)(RuBP) does not correlate with different photosynthetic pathways, but shows taxonomic patterns. Among the dicotyledons, the enzyme from crassinucellate species exhibits lower K(m)(RuBP) (18 +/- 4 micromolar) than does that from tenuinucellate species (25 +/- 7 micromolar). Among the Poaceae, RuBP carboxylase from Triticeae, chloridoids, andropogonoids, Microlaena, and Tetrarrhena has yielded lower K(m)(RuBP) values (29 +/- 11 micromolar) than has that from other members of the grass family (46 +/- 10 micromolar).  相似文献   

19.
A dinucleotide-enriched genomic library was obtained from mandarin orange (Citrus reticulata Blanco). A subset of 101 positive clones was sequenced and primers were designed. The loci were screened for levels of variation using 26-29 wild mandarin oranges collected in Vietnam. Forty-three loci were polymorphic with the number of alleles ranging from two to 18. The observed heterozygosity (H(O) ) and expected heterozygosity (H(E) ) were from 0.03 to 0.96 and from 0.03 to 0.92, respectively.  相似文献   

20.
Dean B  Pavey G  Scarr E  Goeringer K  Copolov DL 《Life sciences》2004,74(25):3115-3131
In situ radioligand binding with autoradiography and anti-human dopamine D(2) receptor antibodies with Western blots have been used to measure the density of dopamine D(2)-like receptors in the caudate-putamen and pituitary from schizophrenic subjects who did or did not have residual antipsychotic drugs in their tissue at death. There was a significant decrease in the Ki for haloperidol displaceable [(125)I]iodosulpride binding in the pituitary (p < 0.01) and caudate-putamen (p < 0.05) from subjects with schizophrenia with residual drugs in their tissue. There was a significant decrease in the density of [(125)I]iodosulpride in the pituitary (p < 0.001) and a strong trend to a decrease in binding in the caudate-putamen (p = 0.055) from subjects with schizophrenia. By contrast, [(3)H]spiperone binding was decreased in the caudate-putamen (p < 0.05) with a trend to decreased binding in the pituitary (p = 0.07) from subjects with schizophrenia. There was no difference in the density of dopamine D(2) receptors in the caudate-putamen from subjects with schizophrenia (p = 0.31). All the findings on receptor densities were independent of drug status. [(125)I]iodosulpride binds to the dopamine D(2&3) receptors. We have shown that there is no change in the dopamine D(2) receptor in the caudate-putamen from subjects with schizophrenia and therefore, these data would be consistent with there being a decrease in the dopamine D(3) in the caudate-putamen from subjects with schizophrenia. Since dopamine D(3) receptors are absent or present at low concentrations in the pituitary, our data would suggest the dopamine D(2) receptor is decreased in that tissue from schizophrenic subjects.  相似文献   

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