七种抑制剂对两种白蚁谷胱甘肽S-转移酶活性抑制作用的比较

利用分光光度酶动力学方法,确定了白蚁谷胱甘肽S-转移酶（GSTs）的最适反应条件,并进一步研究了7种抑制剂对黑翅土白蚁Odontotermes formosanus (Shiraki)和黑胸散白蚁Reticulitermes chinensis Snyder GSTs活性的体外影响。结果表明：白蚁GSTs测定的最适反应条件为pH 6.5,温度25℃,最适反应时间2 min。黑翅土白蚁GSTs的米氏常数(K_mCDNB和K_mGSH)分别为0.11±0.02 mmol/L和0.81±0.16 mmol/L,最大反应速度(V_maxCDNB和V_maxGSH)分别为425.92±19.67 nmol/(min·mg)和534.86±39.05 nmol/(min·mg)。黑胸散白蚁GSTs的米氏常数(K_mCDNB和K_mGSH)分别为0.12±0.03 mmol/L和1.03±0.31 mmol/L,最大反应速度(V_maxCDNB和V_maxGSH)分别为544.39±37.19 nmol/(min·mg)和715.45±83.68 nmol/(min·mg)。浓度为2×10^-5 mol/L时,槲皮素和辛硫磷对黑胸散白蚁GSTs活性的抑制作用要强于黑翅土白蚁,对黑胸散白蚁GSTs活性的抑制作用分别为62.28％和44.89％,对黑翅土白蚁GSTs活性的抑制作用分别为54.96％和28.36％。高效氯氰菊酯、甲氰菊酯、啶虫脒和单宁酸对黑翅土白蚁GSTs活性的抑制作用要强于黑胸散白蚁,对黑翅土白蚁GSTs活性的抑制作用分别为39.43％,72.07％,52.24％和82.19％;对黑胸散白蚁GSTs活性的抑制作用分别为14.96％,40.23％,39.96％和57.80％。阿维菌素对黑翅土白蚁和黑胸散白蚁GSTs活性的抑制作用没有显著差异,对黑翅土白蚁和黑胸散白蚁GSTs活性的抑制作用分别为76.21％和76.88％。这表明两种白蚁对药剂的敏感性完全不同。实验结果还表明,在3.2×10^-8～2×10^-5 mol/L内,上述植物次生物质和杀虫剂对两种白蚁GSTs活性的抑制率存在明显的剂量-效应关系。     

The GH26 β-mannanase RsMan26H from a symbiotic protist of the termite Reticulitermes speratus is an endo-processive mannobiohydrolase: Heterologous expression and characterization

Symbiotic protists in the gut of termites are prominent natural resources for enzymes involved in lignocellulose degradation. Here we report expression, purification, and biochemical characterization of a glycoside hydrolase family 26 mannanase RsMan26H from the symbiotic protist of the lower termite, Reticulitermes speratus. Biochemical analysis of RsMan26H demonstrates that this enzyme is an endo-processive mannobiohydrolase producing mannobiose from oligo- and polysaccharides, followed by a minor accumulation of oligosaccharides larger than mannobiose. To our knowledge, this is the first report describing the unique mannobiohydrolase enzyme from the eukaryotic origin.     

雌激素受体在白蚁卵发生过程中的免疫细胞化学定位(简报)

雌激素受体(Estrogen receptor,ER)是一种与性腺发育和精、卵成熟有直接重要关系的性激素受体,不仅在哺乳动物中已经证实与卵子的发生有关系,近年来还发现雌激素受体也存在于雌性文昌鱼早期卵原细胞、卵黄生成期卵母细胞和成熟期卵母细胞中;Osada等在扇贝的卵巢中发现有ER免疫阳性物质存在于卵黄形成期的卵母细胞中,认为ER是基本的类固醇激素受体,有着     

Polymorphic microsatellite loci in the European subterranean termite,Reticulitermes santonensis Feytaud

We report on the identification and characterization of two dinucleotide, two trinucleotide and eight tetranucleotide microsatellite DNA loci isolated from the European subterranean termite Reticulitermes santonensis. We tested the loci on 51–92 individuals from 46 colonies from different regions of France. Eleven loci were polymorphic with 2–8 alleles per locus and low observed heterozygosities (0.10–0.48). We also tested the loci on 17–20 individuals from 10 colonies in the closely related North American species R. flavipes and found significantly more alleles (2–9 alleles per locus) and higher observed heterozygosities (0.15–0.80) than in R. santonensis. The lower observed heterozygosities in R. santonensis are consistent with higher levels of inbreeding in these colonies due to the presence of numerous inbred replacement reproductives.     

Microsatellite loci in the Japanese subterranean termite,Reticulitermes speratus

Reticulitermes termites have such a cryptic life style and complex colony structure that polymorphic microsatellite markers are desired to investigate their population and colony structures. We successfully isolated seven microsatellite loci in R. speratus , the Japanese subterranean termite, five of which were polymorphic. These polymorphic loci had 2–8 alleles per locus and their observed heterozygosities ranged from 0.059 to 0.438. These five loci were also polymorphic in R . kanmonensis , distributed sympatrically with R. speratus in the Kanmon Region, western Japan; the number of alleles per locus was 2–5, and observed heterozygosity was 0.176–0.625.