饲料不同钙磷比对三疣梭子蟹幼蟹生长性能、矿物质沉积和能量代谢的影响

为研究饲料中不同钙磷比对三疣梭子蟹幼蟹生长性能、血清生化、矿物质沉积和能量代谢的影响,配制5种等氮等脂(46%粗蛋白和7%粗脂肪)钙磷比分别为1.00∶2.00、1.00∶1.50、1.00∶1.00、1.00∶0.75和1.00∶0.50的实验饲料。选择初始体质量为(12.82±0.37) g的梭子蟹150只,随机分成5组(每组3个重复,每个重复10只),进行为期8周的养殖实验。结果显示,钙磷比为1.00∶1.00和1.00∶0.75的饲料,其特定生长率(SGR)和饲料效率(FER)显著高于其他组。钙磷比为1.00∶0.50饲料组幼蟹血淋巴的谷草转氨酶(GOT)显著高于其他组,碱性磷酸酶(AKP)和谷丙转氨酶(GPT)活性随着饲料钙磷比的增加呈上升的趋势。幼蟹肝胰腺、肌肉和甲壳中的磷含量随着钙磷比的升高呈下降的趋势,且钙磷比1.00∶2.00组幼蟹磷含量显著高于1.00∶0.50组。钙磷比1.00∶1.50和1.00∶1.00组幼蟹肝胰腺ATP含量显著高于其他饲料组。幼蟹肝胰腺己糖激酶(HK)和琥珀酸脱氢酶(SDH)的活性随饲料钙磷比的升高呈先升高后下降的趋势,当钙磷比为1时,梭子蟹肝胰腺的HK和SDH酶活性最高。此外,钙磷比1.00∶1.00组显著上调了梭子蟹肝胰腺电子传递链相关基因(nd1、sdhc、cytb和coxⅡ)的表达水平,当钙磷比为1.00∶0.75时,显著上调了幼蟹肝胰腺线粒体能量代谢相关基因(ATPase6、sirt3和nrf1)的表达量。研究表明,本实验条件下,以增重率为评价指标,通过回归模型得到梭子蟹最适钙磷比为1.06～1.26,在此范围内能促进三疣梭子蟹幼蟹的生长、维持组织的最适磷沉积以及很好地促进能量的产生。     

合成氨基酸对肉鸡肠道功能的改善作用

鸡球虫病、坏死性肠炎等肠道感染可能对消化道内源性氨基酸损失产生较大影响。虽然对这一课题的了解不多，但相关文献报道了这些疾病对氨基酸表观回肠消化率的影响。在确定肠内氨基酸流动时必须考虑多种因素，包括肉鸡的年龄、是否有病原体、肠内氨基酸代谢等。胃肠道和肝脏共同承担向外周血释放氨基酸的任务，这些氨基酸是支持蛋白质合成所必需的。一般来说，肠道是氨基酸代谢反应的一个非常活跃的器官系统，它首先会满足自身对氨基酸的需求，然后才会将氨基酸输送到机体其他部分。因此，本综述旨在讨论影响肠内氨基酸流动的因素及日粮氨基酸和肠道感染对氨基酸利用和代谢的影响。     

滞绿突变对大豆叶片蔗糖代谢相关基因表达的影响

为研究大豆滞绿突变对叶片衰老过程中蔗糖代谢相关基因表达产生的影响，以晋大滞绿1号及其亲本晋大74号为试验材料，测定了大豆开花后至成熟期间叶片可溶性糖含量的变化趋势，并对比了不同基因型大豆品种叶片衰老过程中蔗糖代谢相关基因的表达差异。结果表明:1)花后至成熟期间，2个供试大豆品种可溶性总糖含量均呈波动升高然后降低的变化趋势。花后14至42天，晋大滞绿1号可溶性总糖含量高于晋大74号；2)花后29至42天，晋大滞绿1号蔗糖磷酸合成酶基因SPS4，转化酶基因CInv、CWInv2以及蔗糖合酶基因SS1、SS2-2表达水平显著高于非滞绿品种晋大74号；己糖激酶和果糖激酶基因Hxk和Frk表达量也高于非滞绿品种晋大74号；3)除 SUT4-1外，其余6个蔗糖转运体基因SUTs的表达模式具有明显的品种特异性。花后29至42天，晋大滞绿1号叶片SUTs表达水平较高。综上，滞绿突变对于大豆蔗糖代谢相关基因的表达产生了明显的影响，特别是在鼓粒初期和中期等大豆籽粒形成的关键时期，滞绿品种晋大滞绿1号蔗糖代谢相关基因的表达更加活跃。     

不同体质量中华倒刺鲃的静止代谢率和生长性能

为了探讨不同体质量中华倒刺鲃能量代谢和生长能力的差异,在25°C条件下分别测定不同体质量大小(10、20、40、100和180 g组)中华倒刺鲃的静止代谢率(RMR);经过为期28 d投喂养殖实验,测定各实验组的特定生长率(SGR)、摄食率(FR)和饲料转化效率(FE);并测定不同体质量大小(10.4～248.1 g)实验鱼的生长激素(GH)水平。随体质量的增加,中华倒刺鲃个体RMR显著增加,单位体质量RMR显著下降;SGR和FR均显著增加;体质量对FE影响不显著;GH水平与体质量间呈显著负相关(r=-0.753,n=30)。单位体质量RMR与SGR(r=0.586,n=51)和FR(r=0.640,n=51)均呈显著正相关,与FE(r=0.100,n=51)关系不显著;SGR与FR(r=0.956,n=51)和FE(r=0.447,n=30)均呈显著正相关;FR与FE(r=0.245,n=30)关系不显著。研究表明,小体质量中华倒刺鲃具有相对更高的维持能量的消耗和生长潜能,归因于小体质量鱼具有更高的摄食消化及同化能力。     

Effects of dietary fish oil replacements with three vegetable oils on growth,fatty acid composition,antioxidant capacity,serum parameters and expression of lipid metabolism related genes in juvenile Onychostoma macrolepis

Five isonitrogenous and isoenergetic diets with soybean oil (SO), linseed oil (LO), algae oil from Schizochytrium sp. (AO), mixed oil (MO, SO:LO:AO = 1:1:1) and fish oil (FO; control group) were selected to feed juvenile Onychostoma macrolepis (initial weight 1.86 ± 0.07 g) for eight weeks. The results showed that in the LO and FO groups fish grew best. There was no significant difference in specific growth rate (SGR) and feed efficiency (FE) between the MO and FO groups (p > .05). The highest contents of 18:2n‐6, 18:3n‐3 and 22:6n‐3 in liver and muscle were found with the SO, LO and AO groups, respectively (p < .05). There appeared the highest malondialdehyde (MDA) content and the lowest superoxide dismutase (SOD) activity in the fish liver of the AO group. There appeared the highest concentrations of serum glucose (GLU), cholesterol (CHOL) and triglycerides (TG) in the SO group. The expressions of lipid anabolism genes were significantly up‐regulated by dietary SO and LO (p < .05). The expressions of lipid catabolism genes were significantly higher with the AO, MO and FO groups (p < .05). This study recommended that LO or MO as a better vegetable oil source for juvenile O. macrolepis.     

外源褪黑素对干旱胁迫下大豆鼓粒期生理和产量的影响

干旱胁迫降低大豆产量,探究提高大豆耐旱能力和降低产量损失的机制对大豆生产具有重要意义。施褪黑素能缓解干旱胁迫对植株生长的抑制和氧化损伤。本试验于2017—2018年研究叶面喷施褪黑素对干旱胁迫下大豆鼓粒期叶片光合、抗逆、碳氮代谢和产量的影响表明,外源褪黑素提高干旱胁迫下大豆叶片抗氧化酶活性,抑制活性氧的产生和细胞膜损伤,缓解干旱胁迫对光合能力的抑制,提高碳氮同化能力,最终缓解干旱胁迫造成的产量损失。与干旱胁迫相比,褪黑素处理下单株荚数、单株粒数和百粒重两年平均提高了2.9%、0.8%和17.2%,产量(单株粒重)平均提高了14.7%。     

Comparison of effects of dietary‐specific fatty acids on growth and lipid metabolism in Nile tilapia

The dominant fatty acids (FAs) in oils are often used to explain different nutritional effects of dietary oils in fish. However, the amounts of dominant FAs among oils are different, and the nutritional roles of these important FAs in fish have not been precisely compared at similar levels in feeding trials. In the present study, different amounts of palmitic acid were added to safflower oil (SO), olive oil (OO) and fish oil (FO) to obtain comparable amounts (about 550 g/kg of total FAs) of 18:2n‐6, 18:1n‐9 and 20:5n‐3 + 22:6n‐3 and subsequently fed to Nile tilapia (11.1 ± 0.01 g) for 8 weeks. The results showed similar growth among groups but FO group obtained lower fat deposition, serum ALT and AST activities, compared to OO. Lipogenesis‐related gene expressions were higher in OO group than FO group in liver, muscle and adipose tissue, but there were only few differences in these genes between SO and FO groups. Lipid catabolism genes in FO group were higher than OO and SO groups in adipose tissue, but not in muscle, and the significantly higher expressions of CPT1b and PPARα were only observed in liver. Overall, dietary 18:2n‐6, 20:5n‐3 and 22:6n‐3 were beneficial to normal growth and lipid metabolism, whereas high amount of 18:1n‐9 induced lipid deposition and liver damage in Nile tilapia.     

Effects of different active constituents of Gynostemma pentaphyllum on mitochondrial energy metabolism-related proteins in endothelial cells induced by ox-LDL

AIM To investigate the effects of different components of Gynostemma pentaphyllum ［gypenosides (Gps), gypenoside XLIX (GpXLIX) and ginsenoside Rb3 (GRb3)］ on mitochondrial energy metabolism-related proteins in endothelial cells induced by oxidized low-density lipoprotein (ox-LDL). METHODS EA.hy926 cells were divided into control group, model group, Gps group, GpXLIX group and GRb3 group. The cells in control group were cultured only in DMEM complete medium. The cells in model group were treated with 100 mg/L ox-LDL for 48 h. The cells in Gps group, GpXLIX group and GRb3 group were treated with 100 mg/L ox-LDL for 24 h, and then treated with Gps, GpXLIX and GRb3 at 100 mg/L for another 24 h, respectively. The ATP content in each group was detected by ELISA. The expression levels of mitochondrial energy metabolism-related proteins, cytochrome C oxidase subunit 5a （Cox5a）, NADH:ubiquinone oxidoreductase core subunit S1 （Ndufs1）, ATP synthase F1 subunit alpha (ATP5a) and cytochrome C (Cyt C）, were determined by Wes automatic Western blot quantitative analysis system and Western blot. RESULTS Compared with control group, the ATP content in model group was decreased (P<0.01). After drug intervention, the ATP content increased to different degrees in Gps group, GpXLIX group and GRb3 group (P<0.01). The results of Wes automatic Western blot quantitative analysis system were consistent with those of Western blot. These results showed that compared with control group, the protein expression of Cox5a, Ndufs1 and ATP5a in model group was decreased, and the protein expression of Cyt C was increased (P<0.01). After intervention, the protein expression of Cox5a, Ndufs1 and ATP5a was increased and the protein expression of Cyt C was decreased in Gps group, GpXLIX group and GRb3 group (P<0.05 or P<0.01). Among them, the effect of Gps on the protein expression of Cox5a, Ndufs1 and Cyt C was significantly stronger than those of the 2 monomer components, and the effect of GRb3 was found to be superior in the 2 monomer components. The effect of GpXLIX on ATP5a protein was superior to the other 2 components. CONCLUSION Gynostemma total saponins and related active ingredients protect ox-LDL-induced endothelial cells by affecting mitochondrial energy metabolism-related proteins, thereby preventing and treating atherosclerosis.     

饲料脂肪源和碘酸钾对中华鳖稚鳖生长、存活率、肝肠组织形态和脂类代谢的影响

为了比较饲料中添加鱼油、茶籽油、亚麻籽油以及碘酸钾对中华鳖（）稚鳖生长和脂类代谢的影响，本研究配制了4种油脂含量为10%的饲料，分别为鱼油料（FO，对照组）、鱼油+碘酸钾料（FO+PI，碘酸钾添加量为75 mg/kg）、茶籽油料（TO）和亚麻籽油料（LO），饲喂初重为（5.06±0.05）g的中华鳖66 d。FO+PI组和LO组中华鳖稚鳖的存活率显著低于FO组（<0.05）。各组中华鳖稚鳖血浆中葡萄糖、总胆固醇和甘油三酯水平无显著差异（ACACA）的表达水平，上调了中华鳖-499的表达水平（-23b的表达水平（<0.05）。FO+PI组和TO组的稚鳖肝脏细胞内脂滴空泡较少，同时TO显著影响了肠道组织的黏膜褶。结论认为，相比于鱼油组，在饲料中添加10%茶籽油、亚麻籽油和添加75 mg/kg碘酸钾不会引起稚鳖生长差异，但是亚麻籽油和碘酸钾降低了稚鳖的存活率，茶籽油和碘酸钾影响肝脏的脂类代谢。     

H2S的信号分子作用及其对果蔬采后生理代谢的调控研究进展

硫化氢（H2S）作为气体信号分子，参与调控植物体的一系列生命活动，并在果蔬采后生理代谢过程中发挥着重要作用。本文综述了H2S的理化性质、发展应用历史及其在果蔬采后生理调控机制中的信号分子作用，讨论了H2S对果蔬生理代谢的调控作用，包括对果蔬采后抗逆性和品质的影响，以期为采后果蔬的贮藏保鲜提供理论参考。