LDL受体基因cDNA的RT－PCR分离、克隆及其在RFLP中的应用

利用ＲＴ－ＰＣＲ技术分离低密度脂蛋白受体基因ｃＤＮＡ,将长为２６０５ｂｐ的ｃＤＮＡ插入质粒ｐＪＮ６,并经全序列测定证实,该序列与已报道序列相比,存在两个变异碱基,即第７５４位Ｃ→Ｔ,和１６５４位的Ｇ→Ａ,这两个变异碱基并不改变编码的氨基酸,利用ＬＤＬ受体基因ｃＤＮＡ中的ＣｌａⅠ片段作为探针,检测到ＬＤＬ受体基因上外显子８的ＳｔｕⅠ位点是个限制性片段长度多态性位点。所克隆的ｃＤＮＡ含有可译框架的全部密码,因此可作为基因表达材料。     

Synergistic effects of TAL1 over-expression and PHO13 deletion on the weak acid inhibition of xylose fermentation by industrial Saccharomyces cerevisiae strain

In the industrial production of bioethanol from lignocellulosic biomass, a strain of Saccharomyces cerevisiae that can ferment xylose in the presence of inhibitors is of utmost importance. The recombinant, industrial-flocculating S. cerevisiae strain NAPX37, which can ferment xylose, was used as the parent to delete the gene encoding p-nitrophenylphosphatase (PHO13) and overexpress the gene encoding transaldolase (TAL1) to evaluate the synergistic effects of these two genes on xylose fermentation in the presence of weak acid inhibitors, including formic, acetic, or levulinic acids. TAL1 over-expression or PHO13 deletion improved xylose fermentation as well as the tolerance of NAPX37 to all three weak acids. The simultaneous deletion of PHO13 and the over-expression of TAL1 had synergistic effects and improved ethanol production and reduction of xylitol accumulation in the absence and presence of weak acid inhibitors.     

双委夜蛾气味结合蛋白AdisOBP6的原核表达抗体制备及表达谱分析

【目的】本研究旨在对双委夜蛾Athetis dissimilis气味结合蛋白OBP6进行原核表达、抗体制备以及表达谱分析,便于今后对AdisOBP6功能展开研究。【方法】利用生物信息学软件分析AdisOBP6蛋白结构特征;利用通过原核表达获得的重组蛋白4次免疫新西兰大白兔,制备AdisOBP6抗体;采用荧光定量PCR和Western blot技术检测AdisOBP6在双委夜蛾雌雄成虫触角、不同时期精巢以及受精卵和未受精卵中的表达情况。【结果】同源建模预测显示,AdisOBP6具有6个保守半胱氨酸残基和7个α-螺旋结构,并 折叠成一个结合口袋。原核表达结果显示,在20℃下0.5 mmol/L IPTG诱导重组蛋白表达量最多、最稳定。4次免疫重复中,抗体效价分别超过1∶512 000, 1∶512 000, 1∶512 000和1∶64 000。Westernblot检测获得的抗体与AdisOBP6蛋白能够特异性结合。荧光定量PCR结果显示,AdisOBP6在双委夜蛾精巢中的表达量远高于在触角中的,在幼虫期精巢中AdisOBP6就已经开始表达,在蛹期精巢中表达量低于在幼虫期的, 成虫羽化后精巢中的表达量逐渐进入高峰,在未受精卵和受精卵中几乎不表达或表达量极低。Western blot分析发现,AdisOBP6蛋白也主要在精巢中表达,在雌雄成虫触角、受精卵和未受精卵中表达量很低。【结论】本研究实现了AdisOBP6的原核表达,成功地制备了抗体;并证实AdisOBP6在双委夜蛾精巢中大量表达,成虫羽化后表达量达到高峰,推测AdisOBP6可能参与了授精过程。本研究结果为今后进一步研究AdisOBP6的功能奠定了基础。     

微卫星技术在大耳白黑眼兔近交系培育中的监测分析

利用微卫星技术监测大耳白黑眼兔(white hair black eyes rabbits,WHBE兔)近交培育中第五代(F5)、第六代(F6)和第七代(F7)的遗传多样性.选取21个微卫譬座位,筛选出扩增产物稳定并且具有多态性的11对微卫星引物用于本研究.结果表明,F5代WHBE兔在每个座位上的等位基因数(Na)为3～9个不等,11个座位的平均有效等位基因数(Ne)为1.81个,平均观察杂合度(Ho)和平均多态信息含量(PIC)分别为0.381和0.524,累积个体识别率(CDP)达到100%,累积非父排除概率(CPE)在双亲信息都是未知情况下的为0.926,而在得知任一亲本信息的情况F,CPE值为0.993.F6代WHBE兔在每个座位上的Na为3～8个不等,11个座位的平均Ne为1.68个,平均Ho和PIC值分别为0.356和0.548,CDP达到100%,CPE在双亲信息都是未知情况下的为0.931,而在得知任一亲本信息的情况下,CPE值为0.994.F7代WHBE兔在每个座位上的Na为2～6个不等,11个座位的Ne为1.51个,平均Ho和PIC值分别为0.287和0.498,CDP达到100%,CPE在双亲信息都是未知情况下的为0.891,而在得知任一亲本信息的情况下,CPE值为0.986.在近交系培育过程中,从F5代到F7代,WHBE兔的平均Ne和平均Ho 都呈下降趋势,提示随着近交代数的增加,WHBE兔的基因纯合度越来越高.     

Development and characterization of microsatellite loci in Taihangia rupestris (Rosaceae), a rare cliff herb

? Premise of the study: Microsatellite primers were developed for the rare Taihangia rupestris (Rosaceae) to evaluate genetic diversity, population genetic structure, mating system, and demographic events of this species. ? Methods and Results: Ten primer sets were developed using an enriched genomic library and were successfully amplified in T. rupestris var. ciliata and T. rupestris var. rupestris. The number of alleles per locus ranged from 2 to 21; the observed and expected heterozygosities ranged from 0.300 to 0.950 and from 0.328 to 0.956, respectively, in the two varieties. ? Conclusions: The markers described here will be useful for studies of genetic variation, genetic structure, and mating systems of T. rupestris, which are important for the future conservation of this rare species.     

绢蒿属8种植物果实微形态特征及其分类学意义

为寻找绢蒿属系统学的新证据,应用解剖镜和扫描电镜对我国8种绢蒿属植物的果实微形态特征进行了比较观察。结果表明,绢蒿属8种植物果实形状相似性较高,呈倒卵形或长倒卵形,直或稍弯曲;果脐圆形,常偏向一侧;顶端中央均可见花柱残留物,边缘具衣领状环;果实表面纹饰为搓板状和不规则皱褶纹饰。这些果实微形态特征中,果实的表面纹饰具有一定的差异,特别是次级结构,可作为绢蒿属植物区分种的参考性状之一。