不同生物素水平对3T3-L1脂肪细胞脂肪合成相关基因转录表达的影响

【目的】诱导3T3-L1细胞分化为3T3-L1脂肪细胞,研究不同生物素水平对3T3-L1脂肪细胞脂肪合成相关基因转录表达的影响。【方法】利用三联诱导法将3T3-L1细胞经诱导分化为3T3-L1脂肪细胞。当3T3-L1脂肪细胞密集后分别采用0(对照组)、0.2、0.5、1 μmol/L生物素处理,分别在12 h、24 h与48 h时检测细胞上清液中PK mRNA、GLUT-4 mRNA、FAS mRNA及ACC1 mRNA相对表达量。【结果】在试验12 h时:各试验组GLUT-4、PK、ACC1 mRNA相对表达量均极显著(P＜0.01)高于对照组,1 μmol/L组与0.5 μmol/L组FAS mRNA相对表达量极显著(P＜0.01)高于对照组与0.2 μmol/L组;在试验24 h时:1 μmol/L组GLUT-4 mRNA与PK mRNA相对表达量显著(P＜0.05)高于对照组,1 μmol/L组ACC1 mRNA相对表达量极显著(P＜0.01)高于对照组,0.2 μmol/L组与0.5 μmol/L组ACC1 mRNA相对表达量显著(P＜0.05)高于对照组;在试验48 h时:1 μmol/L组GLUT-4 mRNA相对表达量显著(P＜0.05)高于对照组,1 μmol/L 组PK mRNA相对表达量极显著(P＜0.01)高于对照组,0.5 μmol/L组FAS mRNA相对表达量极显著(P＜0.05)高于1 μmol/L组,1 μmol/L组FAS mRNA相对表达量显著(P＜0.05)高于对照组,1 μmol/L组ACC1 mRNA相对表达量极显著(P＜0.01)高于其它组。【结论】生物素的添加可以提升脂肪细胞GLUT-4、PK、FAS与ACC1 mRNA相对表达量,且当以1 μmol/L浓度作用时对GLUT-4、PK与ACC1提升效果最佳,以0.5 μmol/L浓度作用时对FAS提升效果最佳。     

小麦－簇毛麦杂种染色体的DNA原位杂交研究

以生物素标记的簇毛麦基因组ＤＮＡ作探针与小麦－簇毛麦杂种双二倍体及异附加系染色体进行原位杂交,旨在探索一种鉴定小麦中簇毛麦染色质的分子细胞遗传学方法。首先试验了标记的簇毛麦ＤＮＡ与小麦ＤＮＡ之含量比对原位杂交效果的影响,发现探针混合液中不加未标记的小麦ＤＮＡ时,获得的原位杂交结果较理想。在八倍体小麦－簇毛麦双二倍体（２ｎ＝５６）中,１４对簇毛麦染色体出现明显的棕褐色原位杂交信号,而小麦染色体不显标记,使这２个物种的染色体很易相互区分开来。进一步用生物素标记的簇毛麦ＤＮＡ与小麦－簇毛麦６Ｖ染色体附加系体细胞杂交,也可检测出其中１对附加的６Ｖ染色体。由于该方法标记的簇毛麦ＤＮＡ覆盖各簇毛麦染色体的整个染色体臂,由此,用其鉴定小片段小麦－簇毛麦染色体易位是有效的。     

生物素营养生理作用及其应用研究进展

生物素是一种水溶性的含硫维生素,与机体的碳水化合物、脂肪酸、蛋白质和核酸代谢有着密切的关系。本文主要从生物素的化学特性、生理功能及其在畜禽生产中的应用进行了综述。     

过瘤胃生物素对舍饲辽宁绒山羊血清指标的影响

选择20只健康(未发生肢体病)舍饲辽宁绒山羊母羊,随机分成5组,其中1组为对照组,2组至5组为试验组,每羊只日补饲过瘤胃生物素依次0、200、250、300、320 mg(折算为生物素分别是0、2、2.5、3、3.2 mg)。饲养60 d后,采集静脉血测定代谢指标、抗氧化指标和骨关节损伤生物学标志物。结果表明:随着过瘤胃生物素补饲量的增加,血糖和血清胰岛素含量均呈现降低趋势,胰高血糖素含量呈增加趋势;血清尿酸和尿素氮含量呈降低趋势;血清GSH-PX、SOD、CAT活性呈增加趋势,其中试验4组和5组GSH-PX、SOD的活性显著(P<0.05)高于对照组;血清MDA含量呈降低趋势,试验3组、4组和5组的MDA含量显著(P<0.05)低于对照组;血清COMP、CTX-Ⅱ和PⅡANP含量呈一定程度的降低趋势,但均差异不显著(P>0.05)。在舍饲健康辽宁绒山羊日粮中按每天每只羊添加250~300 mg过瘤胃生物素可明显提高机体抗氧化能力,对于维护骨关节的健康和预防肢蹄病局有较好作用。     

Physiological Changes in the Concentrations of Biotin in the Serum and Milk and in the Physical Properties of the Claw Horn in Holstein Cows

Physiological changes in the concentrations of biotin in the serum and milk and in the physical properties of the claw horn were examined in Holstein cows. A lower concentration of biotin in the serum and a higher concentration of biotin in milk were found during early and late lactation and during the dry period, and a significant (p<0.05) inverse correlation was found between serum and milk biotin concentrations. A high moisture content and a low level of hardness of the claw horn were found during mid-lactation. Our results indicate that change in the serum biotin concentration probably results from the loss of biotin in the milk of cows during each stage of lactation and also confirm that the moisture content and hardness of the claw horn undergo physiological changes.     

生物素的应用研究概况

本文对生物素在提高胴体质量、改善肉质,提高家畜的繁殖性能、生产性能及饲料利用率,标记核酸探针以及发酵工业中的应用进行了概述。     

Influences of increased levels of biotin, zinc or mannan-oligosaccharides in the diet on foot pad dermatitis in growing turkeys housed on dry and wet litter

Foot pad dermatitis (FPD) is very common in turkeys and it is an animal health and welfare issue affecting not only performance and walking ability but also the carcass quality. Thus, there is a great need to find out the preventive measures against this problem. The potential roles of extra dietary biotin, Zn and mannan-oligosaccharides (MOS) in preventing the development of FPD were assessed in this study which was conducted on 2-week-old female turkeys over a period of 4 weeks. The birds were allotted to four groups, with 29 each, and housed on dry wood shavings in floor pens. The turkeys were fed a control (300 μg biotin and 50 mg Zn/kg), high biotin (2000 μg/kg), high Zn (150 mg/kg) or MOS (1%) diet. Half of the turkeys in each group were additionally exposed to wet litter (27% DM) for 8 h daily in adjacent separate boxes. Foot pads of the birds were examined on days 0, 7, 14, 21 and 28 and assessed macroscopically and histopathologically for foot pad lesions. High dietary levels of biotin or Zn significantly reduced the severity of FPD on dry litter (score 1 vs. 2 in control) but not on wet litter. However, MOS did not affect the severity of foot pad lesions either on dry or wet litter. In addition, the severity was overall substantially higher on wet (approximately three times) than on dry litter. The present results suggest that adding high levels of biotin or Zn to the diet could reduce the development and severity of FPD on dry litter but without having any preventive effects on wet litter. Finally, the high litter moisture appears to be the major factor resulting in FPD. Therefore, the litter should be maintained dry to minimize the prevalence and severity of FPD in turkeys.     

口蹄疫病毒核酸试纸条检测方法的建立

本研究通过核酸探针与免疫层析相结合的方法,建立了一种简单、敏感、特异的检测口蹄疫病毒的方法。试验利用RT-PCR方法获得口蹄疫病毒3D核苷酸片段,在引物中设计了灵敏度高、特异性好的核酸探针--生物素和地高辛,使扩增产物结合探针。利用胶体金的放大原理将链霉亲和素与金颗粒形成胶体金混合物,从而与RT-PCR产物中的生物素探针结合。硝酸纤维素膜上端标记生物素化山羊抗兔IgG作为指控条带,下端标记抗地高辛抗体以捕获RT-PCR产物中的地高辛探针。组装金标试纸条,检测RT-PCR产物,结果表明该核酸试纸条可以检测到 0.3×10^-3~3×10^-3 μg/μL,敏感性高于琼脂糖凝胶电泳,两种方法的符合率高,核酸试纸条检测方法是一种敏感性高、成本低且费时短的新型检测方法。该方法为口蹄疫病毒检测提供了一种新的思路。     

不同生物素添加水平对肉仔鸡免疫器官发育和免疫功能的影响

将400只1日龄艾维茵肉仔鸡随机分成4个处理,每处理5个重复,每重复20只鸡(公母各半);在 基础日粮——小麦-酪蛋白-鱼粉型日粮中分别添加0．3,0．9和2．7 mg／kg生物素,以基础日粮为对照,系统研究了 生物素对肉仔鸡免疫器官发育、机体免疫反应和神经内分泌激素的影响。结果表明:(1)生物素缺乏可抑制免疫器 官的发育,降低其重量指数;添加生物素可促进免疫器官发育,提高其重量指数。(2)添加生物素可促进细胞免疫反 应和体液免疫反应,提高血清中球蛋白水平及新城疫抗体滴度和IgG水平,极显著提高血液中T、B淋巴细胞转化 率。(3)添加生物素后,血清甲状腺素T4、三碘甲状原氨酸T3、生长激素和皮质醇水平均呈上升趋势。