低温胁迫对草地早熟禾抗性生理生化指标的影响

研究低温胁迫对草地早熟禾生理生化指标的影响。结果表明,在5℃下,超氧化物岐化酶(SOD)和过氧化氢酶(CAT)的活性随着胁迫时间的延长而增加,当4h时出现最大值,之后活性逐渐下降。当温度为0℃与-6℃时,两种酶的活性随着胁迫时间的延长而急剧下降,接近于零,温度越低,下降越快。叶绿素和类胡萝卜素含量随着肋迫时间的延长而下降,温度越低下降越快。5℃对脯氨酸含量无明显影响,在0℃与-6℃时,随着时间的延长,含量则明显增加。5℃和0℃低温胁迫对质膜相对透性无明显影响,-6℃时,质膜相对透性明显增大。供试指标对低温胁迫敏感性的顺序是:超氧化物岐化酶、过氧化氢酶>类胡萝卜素>脯氨酸>叶绿素>质膜相对透性。     

波尔山羊与睢宁白山羊杂交羔羊生长性能研究

研究波尔山羊与睢宁白山羊F1 代、F2 代的生长发育情况 ,结果从出生到 3个月不同日龄羔羊的体重体尺均高于纯种睢宁白山羊 ,杂交优势显著 ,F1 代体重的杂种优势率为 18 96 % ,杂种后代生长性能比睢宁白山羊好     

DNA Barcoding:An Effective Tool for Species Identification of Lepidopteran Oak Pests

[Objective] The paper was to improve the efficiency and accuracy of early forecast of Lepidopteran oak-infesting pests.[Method] DNA barcoding technique was established for quick species identification using mitochondrial cytochrome C oxidase subunit Ⅰ(COⅠ) as the standard gene.This barcoding technique was used to amplify and sequence genomic DNA samples from eggs and pupae of 11 species of Lepidopteran pests collected from oak.[Result] The DNA barcoding standard genes of 594-708 bp were determined from eggs and pupae of Lepidopteran insects.There were differences of 0-2 bases in DNA barcode sequences between conspecific eggs and pupae,with the sequence identity of 99.7%-100%.The average content of A,T,G and C of DNA barcode sequences from Lepidopteran insects were 30.7%,38.5%,14.9% and 15.9%,respectively.The obtained DNA barcode sequences had 91.4%-100% identity and 0-8.6% difference degree with GenBank-deposited DNA barcode sequences from organisms of the genetically-closest relationship.Among them,DNA barcode sequences from egg and pupa samples of 10 Lepidopteran insects(No.1-20) had 99%-100% identity and 0-1.0% difference degree with homologous sequences in GenBank database,while the remaining samples(No.21-22) had high difference degree(8.6%) with homologous sequences.[Conclusion] The established DNA barcoding technique is an effeetive tool for species identification of Lepidopteran pests using genomic DNA from eggs and pupae of Lepidopteran insects.     

封闭群实验小鼠的生产管理要点

实验小鼠来源于野生小家鼠,大约在19世纪开始用于遗传学研究,经过长期人工饲养、选育,目前已培育成500多个独立的近交系和远交群,是当今世界上研究最详尽、用量最大、用途最广、品种最多的一种实验动物。由于小鼠体型小,易于控制,生长繁殖快,产仔多,易饲养管理,质量标准明确,品种、品系多,在生物医学研究的各个领域中得到了广泛的应用     

福建省牛病毒性腹泻病的血清学调查

为了了解福建省牛感染牛病毒性腹泻(BVDV)的情况,本中心对福建省9个地区2006-2008年的15个非免疫牛场和56个散养户共计511份样品进行了该病的检测。结果规模场BVDV血清学阳性一直保持在较高的水平,年平均阳性率维持在80%以上,散养户BVDV血清学阳性,2006、2007、2008年的血清学阳性分别为12.3%,21.4%和18.5%。调查表明,我省规模牛场感染BVDV较为严重,散养户感染BVDV的数量在逐年增加。     

短期禁牧对天山北坡蒿类荒漠群落特征及其稳定性的影响

本研究以天山北坡蒿类荒漠为研究对象,采用野外调查取样的方法,探讨不同区域荒漠围栏内外群落特征和物种多样性对禁牧的响应规律,分析禁牧对生态系统稳定性的影响。结果表明,1)禁牧能改变荒漠植被功能群结构,禁牧后不同生态经济类群群落盖度和生物量分别上升40.2%~57.0%和44.4%~81.0%;2)荒漠群落物种多样性指数对短期禁牧的响应较小,但从区域上看,玛纳斯荒漠放牧区Patrick丰富度指数、Shannon-Wiener多样性指数比博乐和奇台显著高16.7%~20.0%,而禁牧区Simpson优势度指数、Shannon-Wiener多样性指数、Pielou均匀度指数高了8.6%~17.7%;3)短期禁牧有利于荒漠群落稳定性的维持,且稳定性可能与禁牧年限和生态环境的变化均有一定的关系。因此,短期禁牧能显著提高荒漠草地生产力,有利于群落物种多样性和群落稳定性的维持。     

High‐level exogenous trans10, cis12 conjugated linoleic acid plays an anti‐lipogenesis role in bovine mammary epithelial cells

Primary bovine mammary epithelial cells (BMECs) were treated by 0, 37.5, 75, 112.5, 150 μmol/L trans10, cis12 conjugated linoleic acid (CLA) to evaluate the effects of different level trans10, cis12 CLA on lipogenesis in BMEC. Addition of 75–150 μmol/L trans10, cis12 CLA reduced significantly the triacylglycerol (TAG) content (P < 0.05), but did not have inhibiting action on cell proliferation (P > 0.05). Treatment with 150 μmol/L trans10, cis12 CLA for 48 h resulted in a 17.1% reduction (P < 0.0001) of medium chain fatty acids (MCFA, C14 < C < C16), a 26.5% reduction (P < 0.0001) of unsaturated fatty acids (UFA) and a corresponding reduction of the mRNA abundance of acetyl coenzyme A (acetylCoA) carboxylase (ACC) (P = 0.046), fatty acid synthase (FAS) (P = 0.017) and stearoylCoA desaturase1 (SCD1) (P = 0.002). Another finding was that trans10, cis12 CLA elevated expression of diacylglycerol acyltransferase2 (DGAT2) (P = 0.020) and long chain acylCoA synthetases (ACSL) (P = 0.032). In conclusion, higher trans10, cis12 CLA, not low trans10, cis12 CLA, inhibited milk fat synthesis and changed fatty acid composition by regulating the expression of FAS, ACC, SCD1, DGAT2 and ACSL.     

Influence of recombinant duck follistatin protein on embryonic muscle development and gene expressions

Follistatin (FST) acts as a positive regulator of muscle development by inhibiting the activities and expression of myostatin. The recombinant duck FST protein was injected into hatching eggs and was also added to the medium of duck myoblast to study its role on duck embryonic muscle development and gene expressions. Duck embryo weight increased 3.49% (p > 0.05) in FST treatment group as compared with control group, but minor effects were found on leg or breast muscle weights of ducklings at 2 days post‐hatching (p > 0.05). Relative expression of Pax7 was upregulated in both leg and breast muscle tissues (p < 0.05), while MyoD was only upregulated in leg muscle (p < 0.05), and Myf5 was only upregulated in breast muscle (p < 0.05). Relative expression of myostatin was downregulated in both muscle tissues researched (p < 0.05). In vitro studies also showed some maker genes relevant to protein synthesis and degradation, cells’ proliferation and differentiation had significant changes in myoblasts after treated with FST. These results suggested that in ovo feeding of recombinant FST protein to duck hatching eggs had an effect on duck embryo development but have less roles on the duck embryonic muscle development.     

Experimental studies with foot-and-mouth disease virus type Asia-1, responsible for the 2005 epidemic in China

This study was carried out to investigate the biological characteristics of the foot-and-mouth disease (FMD) virus strain Asia-1 China/2005, which is responsible for the 2005 epidemic in China. The result showed that this strain is not host restricted, and could not only cause FMD in cattle and sheep but also in pigs by either inoculation or direct contact.     

Acaricidal activity of extracts of neem (Azadirachta indica) oil against the larvae of the rabbit mite Sarcoptes scabiei var. cuniculi in vitro

The acaricidal activity of the petroleum ether extract, the chloroform extract and the acetic ether extract of neem (Azadirachta indica) oil against Sarcoptes scabiei var. cuniculi larvae was tested in vitro. A complementary log-log (CLL) model was used to analyze the data of the toxicity tests. The results showed that at all test time points, the petroleum ether extract demonstrated the highest activity against the larvae of S. scabiei var. cuniculi, while the activities of the chloroform extract and the acetic ether extract were similar. The activities of both the petroleum ether extract and the chloroform extract against the larvae showed the relation of time and concentration dependent. The median lethal concentration (LC(50)) of the petroleum ether extract (1.3muL/mL) was about three times that of the chloroform extract (4.1muL/mL) at 24h post-treatment. At the concentrations of 500.0muL/mL, the median lethal time (LT(50)) of the petroleum ether extract and the chloroform extract was 8.4 and 9.6h, respectively.