甘肃莲花山黑冠山雀繁殖生态的初步研究

2017和2018年每年的4至8月在甘肃莲花山国家级自然保护区,对人工巢箱中黑冠山雀（Periparus rubidiventris）的繁殖生态进行了研究。共悬挂100个巢箱,两年共计招引到15巢黑冠山雀。此外,还记录到4个自然巢,分别位于干枯的糙皮桦（Betula utilise）树洞（1巢）、土坡的缝隙（1巢）和路边水泥护坡的出水管中（2巢）。黑冠山雀雌雄亲鸟共同筑巢,巢内壁为兽毛夹杂少量绒羽,外壁为草茎须根和苔藓。5月中下旬为黑冠山雀的产卵高峰期,清晨产卵,日产1枚,产下最后1枚卵后开始孵卵。平均窝卵数为6枚（4 ~ 7 枚,n = 15）,平均卵重（1.12 ± 0.02）g,卵长径（15.30 ± 0.10）mm,卵短径（12.09 ± 0.11）mm（n = 86）。孵卵由雌鸟承担,孵卵期为15 d（14 ~ 16 d,n = 5）。产卵期,雌鸟离巢时有用巢材盖卵的行为,开始孵卵后则不再盖卵。双亲共同育雏,育雏期为16 d和17 d（n = 2）。所记录的18巢黑冠山雀的繁殖成功率为83.3%,人工巢箱（15巢）中繁殖成功率为86.7%,巢捕食者主要为鼠类。     

适应性突变的遗传学特征

基于大肠杆菌FC40菌株的研究结果表明,适应性突变依赖RecBCD重组途径的酶,要求SOS反应的部分基因功能,lac+回复突变序列都是在单核苷酸短重复序列处的一个碱基缺失。有证据表明有的适应性突变来自一个或多个暂时性的超突变的细胞亚群,它们的基因组发生大量的突变,转座子高频丢失。产生这种暂时性的超突变的增变子可能是因为细胞的MMR活性暂时不足,或是因错误翻译产生丧失了校读活性的DNA聚合酶III。其他一些研究系统虽然得到了一些同FC40菌株不一致的结论,但所有实验证据都表明,在饥饿等环境胁迫因子作用下,非生长或缓慢生长的细胞可以产生突变,这种突变具有生长依赖的自发突变所不同的一些遗传学特征。 Abstract:The research based on the Escherichia coli FC40 showed that adaptive mutations required the enzymes of RecBCD recombination pathway and some unknown proteins of SOS response,and the mutation spectrum of lac+ revertants is single-base deletions in the small mononucleotide repeats.Some evidence showed that the revertants with adaptive mutations partly come from one (or some) subset of transient hypermutable subpopulation of cells,in which high frequently losing of transposons and genome-wide mutations were observed.It was suggested that this kind of transient hypermutability may be due to the transient deficient activity of mismatch repair (MMR) system,or a defective epsilon unit of DNA polymerase III generated by mistranslation.Although other systems demonstrated some different mechanisms from FC40,all research works suggested that,adaptive mutations occurred in nondividing or nongrowing cells under environmental stresses,for example,starvation,displayed different genetic features from growth-dependent spontaneous mutation.     

Effect of hexavalent chromium on the growth and physiological and biochemical parameters on Brassica oleracea L. var. acephala DC

In order to determine the toxic effect of chromium Cr(VI) on the seed germination, the root and shoot length, the root-cotyledonary leaves, the fresh and dry weight in eight-day-old seedlings Brassica oleracea L. var. acephala DC (kale) were treated with various concentrations of Cr in the growth medium. The accumulation of chromium in the tissues was determined in the cotyledons and the roots of the kale seedlings. High rate of Cr uptake was observed in the roots. But the organs could not accumulate large amount Cr. The effect of Cr on B. oleracea var. acephala was evaluated by changes in chlorophyll a, b, lipid peroxidation, proline, ascorbate, protein carbonyl groups, non-protein thiols and peroxidase activity. There were significant decreases in chlorophylls a, b content of the plants treated with Cr. Chromium treated kale seedlings had higher lipid peroxidation and the protein carbonyl groups in cotyledonary leaves than the roots. The changes refer to toxic effects of Cr. There were increases in the non-protein thiol, the total ascorbate, and proline content in the cotyledons and the roots of the seedlings grown on the media containing 0.1 and 0.15 mM Cr. The guaiacol peroxidase activity was higher in the roots of the seedlings than their cotyledons.     

Mitochondrial DNA Diversity of Modern,Ancient and Wild Sheep (Ovis gmelinii anatolica) from Turkey: New Insights on the Evolutionary History of Sheep

In the present study, to contribute to the understanding of the evolutionary history of sheep, the mitochondrial (mt) DNA polymorphisms occurring in modern Turkish native domestic (n = 628), modern wild (Ovis gmelinii anatolica) (n = 30) and ancient domestic sheep from Oylum Höyük in Kilis (n = 33) were examined comparatively with the accumulated data in the literature. The lengths (75 bp/76 bp) of the second and subsequent repeat units of the mtDNA control region (CR) sequences differentiated the five haplogroups (HPGs) observed in the domestic sheep into two genetic clusters as was already implied by other mtDNA markers: the first cluster being composed of HPGs A, B, D and the second cluster harboring HPGs C, E.To manifest genetic relatedness between wild Ovis gmelinii and domestic sheep haplogroups, their partial cytochrome B sequences were examined together on a median-joining network. The two parallel but wider aforementioned clusters were observed also on the network of Ovis gmelenii individuals, within which domestic haplogroups were embedded. The Ovis gmelinii wilds of the present day appeared to be distributed on two partially overlapping geographic areas parallel to the genetic clusters that they belong to (the first cluster being in the western part of the overall distribution). Thus, the analyses suggested that the domestic sheep may be the products of two maternally distinct ancestral Ovis gmelinii populations.Furthermore, Ovis gmelinii anatolica individuals exhibited a haplotype of HPG A (n = 22) and another haplotype (n = 8) from the second cluster which was not observed among the modern domestic sheep. HPG E, with the newly observed members (n = 11), showed signs of expansion. Studies of ancient and modern mtDNA suggest that HPG C frequency increased in the Southeast Anatolia from 6% to 22% some time after the beginning of the Hellenistic period, 500 years Before Common Era (BCE).     

植被生化组分光谱模型抗土壤背景能力分析

应用LOPEX'93(Leaf Optical Properties Experiment)数据,分析了统计回归模型在进行植被叶绿素和水分反演中抗土壤背景影响的能力,模型参数分别使用了:反射率及其变化形式、光谱位置变量、植被指数。在LOPEX'93数据库的植被波谱中分别加入10%-90%的实测土壤光谱信息,得到植被与土壤的混合光谱,并分析混合光谱对植被生化组分的响应。结果表明:应用反射率及其变化形式进行植被叶绿素反演时,以730nm和400nm组合的反射率和反射率倒数的对数为参数的模型具有最高的抗土壤背景能力,在土壤背景所占比例从低到高的变化过程中,以二者反射率组合为参数的模型与叶绿素的相关系数,始终保持在0.645附近,以二者反射率倒数的对数为参数的模型与植被叶绿素的相关系数保持在0.650附近;应用反射率及其变化形式进行植被含水量反演时,以1100,1170,1000,1040,1080nm组合的反射率为参数的模型以及以1170,960,1210,1090,1080,950,1220,1210nm反射率倒数的对数组合为参数的模型具有较高的稳定性,在土壤组分变化的过程中,以上模型与植被含水量的相关系数均稳定的高于0.99;对于光谱位置变量的分析中,以红边-绿峰-红谷组合的模型与植被叶绿素含量具有较高、而且稳定的相关系数,在土壤背景所占比例变化的情况下,相关系数稳定在0.53附近;在应用植被指数进行叶绿素的反演过程中,植被指数与叶绿素的相关系数在土壤背景所占比例变化的情况下变化较大,抗土壤背景的能力均较差;在应用植被指数进行植被水分含量的反演时,以水分指数Ratio975和Ratio1200相关系数最高,且在不同比例土壤背景变化下稳定,相关系数分别分布在0.980附近和0.960附近。该结果可用于指导不同植被覆盖条件下植被冠层参数的反演,提高反演的稳定性和准确性。     

Target-specific delivery of doxorubicin to human glioblastoma cell line via ssDNA aptamer

Targeted drug delivery approaches have been implementing significant therapeutic gain for cancer treatment since last decades. Aptamers are one of the mostly used and highly selective targeting agents for cancer cells. Herein, we address a nano-sized targeted drug delivery approach adorned with A-172 glioblastoma cell-line-specific single stranded DNA (ssDNA) aptamer in which the chemotherapeutic agent Doxorubicin (DOX) had been conjugated. DNA aptamer, GMT-3, was previously selected for specific recognition of glioblastoma and represented many advantageous characteristics for drug targeting purposes. Flow cytometry analysis proved the binding efficiency of the specific aptamer to tumour cell lines. Cell-type-specific toxicity of GMT-3:DOX complex was showed by XTT assay and terminated cytotoxic effects were screened for both target cell and a control breast cancer cell line. The result of this contribution demonstrated the potential utility of GMT-3 aptamer-mediated therapeutic drug transportation in the treatment of gliomas specifically. It was concluded that aptamer-mediated drug delivery can be applied successfully for clinical use.     

Effect of salinity on antioxidant responses of chickpea seedlings

The changes in the activity of antioxidant enzymes, like superoxide dismutase, ascorbate peroxidase, catalase and glutathione reductase, and growth parameters such as length, fresh and dry weight, proline and H₂O₂ contents, chlorophyll fluorescence (Fv/Fm), quantum yield of PSII and the rate of lipid peroxidation in terms of malondialdehyde in leaf and root tissues of a chickpea cultivar (Cicer arietinum L. cv. Gökçe) under salt treatment were investigated. Plants were subjected to 0.1, 0.2 and 0.5 M NaCl treatments for 2 and 4 days. Compared to controls, salinity resulted in the reduction of length and of the fresh and dry weights of shoot and root tissues. Salinity caused significant (P < 0.05) changes in proline and MDA levels in leaf tissue. In general, a dose-dependent decrease was observed in H₂O₂ content, Fv/Fm and quantum yield of photosynthesis under salt stress. Leaf tissue extracts exhibited three activity bands, of which the higher band was identified as MnSOD and the others as FeSOD and Cu/ZnSOD. A significant enhancement was detected in the activities of Cu/ZnSOD and MnSOD isozymes in both tissues. APX and GR activities exhibited significant increases (P < 0.05) in leaf tissue under all stress treatments, whereas no significant change was observed in root tissue. The activity of CAT was significantly increased under 0.5 M NaCl stress in root tissue, while its activity was decreased in leaf tissue under 0.5 M NaCl stress for 4 days. These results suggest that CAT and SOD activities play an essential protective role against salt stress in chickpea seedlings.     

小花琉璃草精油成分的研究

用气相色谱－质谱联用法分析了小花琉璃草精油的化学成分,鉴定了茴香脑、爱草醚、小茴香酮、对－甲氧基－苯甲醚等６４个化合物,并用气相色谱测定了精油中各成分的相对含量