Primary structure of the beta subunit of the DHP-sensitive calcium channel from skeletal muscle

Complementary DNAs for the beta subunit of the dihydropyridine-sensitive calcium channel of rabbit skeletal muscle were isolated on the basis of peptide sequences derived from the purified protein. The deduced primary structure is without homology to other known protein sequences and is consistent with the beta subunit being a peripheral membrane protein associated with the cytoplasmic aspect of the sarcolemma. The protein contains sites that might be expected to be preferentially phosphorylated by protein kinase C and guanosine 3',5'-monophosphate-dependent protein kinase. A messenger RNA for this protein appears to be expressed in brain.     

冠菌素诱导冬小麦幼苗抗旱性的初步研究

为研究不同冠菌素浓度对冬小麦抗旱性的诱导效应,以两个冬小麦品种为材料,研究了不同浓度冠菌素对20%PEG-6000模拟干旱条件下幼苗生长及其抗旱性指标的影响.结果表明,无论是抗旱性品种长武134还是水分敏感型品种陕253均表现相同的趋势,即:0.01 μmol·L-1和0.1 μmol·L-1的冠菌素预处理有利于幼苗叶片维持相对含水量,提高可溶性糖、脯氨酸和可溶性蛋白含量;对增加幼苗干重和根系长度、提高根冠比、扩大根表面积、特剐是提高根系活力有显著效应.由此说明,冠菌素能诱导小麦幼苗提高抗旱能力.     

湘华鲮引种驯养及繁育技术研究

2007～2009年,从沅江、资江采用三种不同捕捞方法,共获得野生湘华鲮Sinilabeo decorus tungting (Nichols) 252尾,分别在三种不同水域中进行驯养,结果成活率为,池塘驯养27%,水泥池水流驯养78.8%,江河网箱驯养77.5%,三种不同捕捞方法驯养成活率分别是,电捕93.8%,刺网捕60.8%,电打+鹭鸶捕42.6%。人工繁殖所获亲鱼,在18批次催产中有16批次为野生亲本,2批次为人工驯养亲本。18批次共催产亲鱼37尾,有19尾产卵,催产率为51.4%,其中人工驯养鱼催产5尾,产4尾,催产率为80%,催产共计产卵35.6万粒,受精率在51%～88%,孵化出苗17.68万尾。在四种催产药物中,通过多种组合试验,结果为（LRH-A2 (5 μg/kg)+HCG (1000 IU/kg)+PG (1.5个/kg)）、（LRH-A2 (5 μg/kg)+HCG (1000 IU/kg)）和（LRH-A2 (6 μg/kg)+HCG (800 IU/kg) + DOM (3 μg/kg)）3种药物组合效果较好。苗种培育,经三种不同培育模式试验,其水泥池成活率为25.8%,江河网箱68.4%,土池21.7%;起水均重为,池塘7.8g/尾,江河网箱5.1g/尾,水泥池6.0g/尾,各池湘华鲮苗种起水总重量,水泥池1550g,江河网箱3500g,池塘1700g。     

小麦和玉米对舞毒蛾幼虫取食的诱导抗性研究

通过幼虫取食供试作物叶片,检测舞毒蛾幼虫取食小麦和玉米叶片后几种抗性酶的活性,以探讨舞毒蛾幼虫取食对小麦和玉米的诱导抗性。结果表明:舞毒蛾取食后的小麦和玉米叶片CAT、PPO、POD活性较取食前显著升高;受害小麦叶片的PAL活性较取食前显著升高,玉米无显著变化;结果提示舞毒蛾幼虫取食能够诱导小麦和玉米在生理生化方面的抗虫性。     

日粮粗蛋白质水平对鹅组织IGF-ImRNA表达的影响

为了探明不同粗蛋白质(CP)水平日粮对鹅组织中胰岛素样生长因子-I基因(IGF-I)mRNA表达量的影响,为科学配制肉鹅饲料提供理论依据,采用半定量RT-PCR方法检测分别饲喂粗蛋白质水平为16％、18％、20％日粮的28日龄苏牧白鹅的肝脏、腿肌和胸肌组织的胰IGF-I mRNA表达量差异.结果表明:在不同粗蛋白质水平下鹅的肝脏和胸肌组织中均能检测到IGF-I mRNA表达,而在腿肌中未能检测到该基因mRNA表达.在肝脏组织中,18％CP组IGF-I mRNA表达量低于16％CP组和20％CP组,后两者之间无显著差异.在母鹅胸肌组织中,各组IGF-ImRNA表达量无显著差异;但20％CP组公鹅的IGF-I mRNA表达量显著高于16％CP组.20％CP组公鹅IGF-I mRNA表达量显著高于母鹅,18％CP组、20％CP组公鹅肝脏组织IGF-I mRNA表达量极显著低于母鹅,其他组公母间差异均不显著.不同粗蛋白质水平能影响鹅组织中IGF-I mRNA表达;在相同粗蛋白质水平的日粮和同性别条件下,IGF-I mRNA相对表达量肝脏大于胸肌,腿肌中未检出.     

植物生长调节剂灌根对菠菜的作用效果研究

评价了胺鲜酯(DA-6)、复硝酚钠(CSN)、萘乙酸(NAA)和吲哚丁酸(IBA)灌根对菠菜的作用效果和生理调节机制.研究发现当灌根作用浓度为0.2 ～2.0 mg/kg(土)时,4种植物生长调节剂均能够促进菠菜根系生长、提高菠菜产量.在作用浓度为0.2 mg/kg(土)时,DA-6、CSN、NAA和IBA对菠菜的增产幅度分别为34.7％、37.4％、21.5％和17.0％.与空白对照相比,DA-6和CSN灌根可提高菠菜的根系活力,而NAA和IBA则对菠菜的根系活力无提高作用.除CSN可提高菠菜的谷胱甘肽还原酶(GR)、过氧化物酶(POD)和过氧化氢酶(CAT)活性外,DA-6、NAA和IBA均对菠菜的抗氧化系统酶活性无调节作用;另外,菠菜的叶绿素含量在植物生长调节剂处理与对照之间无显著差异.     

杂交苏丹草中CN-含量的测定

对传统的异烟酸－吡唑啉酮比色法测定CN^-的条件进行了优化，并用于测定杂交苏丹草体内CN^-的含量。结果表明，苏丹草在苗期体内CN^-含量较高，达163mg/kg，以后呈逐渐下降的趋势。     

甜菜碱对热应激肉鸡生长性能、十二指肠消化酶活性及盲肠微生物区系的影响

本试验通过在饲粮中添加不同剂量的甜菜碱研究其对热应激肉鸡生长性能、十二指肠消化酶活性及盲肠微生物区系的影响。选取270只14日龄爱拔益加(AA)肉鸡随机分成6组:常温组、热应激组,常温+0.1%甜菜碱组、热应激+0.1%甜菜碱组、热应激+0.2%甜菜碱、热应激+0.4%甜菜碱组。热应激肉鸡饲养在(32±1)℃的高温环境中。每组3个重复,每个重复15只。预试期7 d,正试期21 d。结果表明:1)饲粮添加甜菜碱可极显著增加28~42日龄热应激肉鸡的体重(P<0.01),极显著降低22~35日龄肉鸡料重比(P<0.01);2)除添加0.1%和0.2%甜菜碱饲粮对28日龄热应激肉鸡胰蛋白酶活性无显著影响(P>0.05)和添加0.1%甜菜碱对35日龄热应激肉鸡淀粉酶活性无显著影响(P>0.05)外,不同浓度的甜菜碱均能显著或极显著增加28、35、42日龄热应激肉鸡十二指肠胰蛋白酶、淀粉酶和胰脂肪酶活性(P<0.05或P<0.01);3)饲粮添加甜菜碱极显著提高了28、35、42日龄热应激肉鸡盲肠内乳酸杆菌的数量(P<0.01),极显著降低了产气荚膜梭菌的数量(P<0.01)。由此可见,热应激状态下,在基础饲粮中添加甜菜碱可改善AA肉鸡生长性能,提高十二指肠消化酶的活性,维持盲肠内微生物区系平衡,从而减轻热应激对肉鸡的危害。     

Mutants in the lipopolysaccharide of Brucella ovis are attenuated and protect against B. ovis infection in mice

Brucella spp. are Gram-negative bacteria that behave as facultative intracellular parasites of a variety of mammals. This genus includes smooth (S) and rough (R) species that carry S and R lipopolysaccharides (LPS), respectively. S-LPS is a virulence factor, and mutants affected in the S-LPS O-polysaccharide (R mutants), core oligosaccharide or both show attenuation. However, B. ovis is naturally R and is virulent in sheep. We studied the role of B. ovis LPS in virulence by mutating the orthologues of wadA, wadB and wadC, three genes known to encode LPS core glycosyltransferases in S brucellae. When mapped with antibodies to outer membrane proteins (Omps) and R-LPS, wadB and wadC mutants displayed defects in LPS structure and outer membrane topology but inactivation of wadA had little or no effect. Consistent with these observations, the wadB and wadC but not the wadA mutants were attenuated in mice. When tested as vaccines, the wadB and wadC mutants protected mice against B. ovis challenge. The results demonstrate that the LPS core is a structure essential for survival in vivo not only of S brucellae but also of a naturally R Brucella pathogenic species, and they confirm our previous hypothesis that the Brucella LPS core is a target for vaccine development. Since vaccine B. melitensis Rev 1 is S and thus interferes in serological testing for S brucellae, wadB mutant represents a candidate vaccine to be evaluated against B. ovis infection of sheep suitable for areas free of B. melitensis.