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331.
懒猴属的核糖体DNA变异及其种间分化关系 总被引:3,自引:2,他引:3
用15种限制性内切酶和人28S、18SrDNA探针构建了懒猴属各物种核糖体DNA重复单位的限制性内切酶图谱。在进化速率较高的非转录间隔区,在大、中、小懒猴中分别定位了23、24、24个酶切位点。大懒猴与中懒猴有12个位点不同,与小懒猴有14个位点不同,而中、小懒猴间则只有一个位点的差异。经过计算,大懒猴与中懒猴的遗传距离值为12.65%,与小懒猴的差异为14.24%,中、小懒猴间的差异则仅为0.7 相似文献
332.
家鸡和原鸡的线粒体DNA多态性比较 总被引:17,自引:0,他引:17
本文运用11种限制性内切酶分析了家鸡(茶花鸡、尼西鸡、大理漾濞黄鸡)和原鸡共10只个体的线粒体DNA限制性片段长度多态性(RFLP),平均每个个检测到的片段为40条左右。但仅发现3种变异的限制性片制性格局,即StuI-B,Eca-I-b和RI-B.其中StuI-B和ScaI-B为首次报道,而且均为原鸡所物有,EcoRI-B则为大理漾濞黄鸡所特有。茶花鸡和尼西鸡拥有完全相同的限制性格局。经过计算,原 相似文献
333.
Phylum-Level Archaeal Distributions in the Sediments of Chinese Lakes With a Large Range of Salinity
Uncovering microbial diversity and their influencing factors is a primary goal for microbial ecology. In comparison with studies on bacterial diversity, limited is known about archaeal diversity and its response to influencing factors in lakes. Here, we investigated the archaeal community compositions (ACCs) and their correlation with spatial/environmental factors in the sediments from 38 Chinese lakes with a large range of salinity (0.2–363.1 g/l) and pairwise geographic distance (3–3656 km). Illumina-Miseq sequencing was employed to characterize the ACCs in the lakes samples. The results showed that Euryarchaeota, Bathyarchaeota, Thaumarchaeota, and Woesearchaeota were the dominant archaeal phyla in the studied samples, and they each can occur in the samples with a wide range of salinity (0.2–363.1 g/l) although their abundance was relatively low (<1%) in certain samples. The Thaumarchaeota and Woesearchaeota phyla dominated (up to 90% of total sequences) some lake sediments. Mantel test indicated that compositions of total archaeal community and the Euryarchaeota and Woesearchaeota populations were significantly (p < 0.05) correlated with geographic distance in the studied lake sediments. Salinity was the most important environmental factor influencing the compositions of the total archaeal community and the Euryarchaeota population, while it did not show significant influence on the distribution of the Woesearchaeota and Thaumarchaeota populations. Taken together, this survey expands our current knowledge on the ecology of lacustrine archaea and give clues for studying the archael role in biogeochemical cycles in lakes. 相似文献
334.
Zhihua Liu John S. Kimball Nicholas C. Parazoo Ashley P. Ballantyne Wen J. Wang Nima Madani Caleb G. Pan Jennifer D. Watts Rolf H. Reichle Oliver Sonnentag Philip Marsh Miriam Hurkuck Manuel Helbig William L. Quinton Donatella Zona Masahito Ueyama Hideki Kobayashi Eugnie S. Euskirchen 《Global Change Biology》2020,26(2):682-696
Arctic and boreal ecosystems play an important role in the global carbon (C) budget, and whether they act as a future net C sink or source depends on climate and environmental change. Here, we used complementary in situ measurements, model simulations, and satellite observations to investigate the net carbon dioxide (CO2) seasonal cycle and its climatic and environmental controls across Alaska and northwestern Canada during the anomalously warm winter to spring conditions of 2015 and 2016 (relative to 2010–2014). In the warm spring, we found that photosynthesis was enhanced more than respiration, leading to greater CO2 uptake. However, photosynthetic enhancement from spring warming was partially offset by greater ecosystem respiration during the preceding anomalously warm winter, resulting in nearly neutral effects on the annual net CO2 balance. Eddy covariance CO2 flux measurements showed that air temperature has a primary influence on net CO2 exchange in winter and spring, while soil moisture has a primary control on net CO2 exchange in the fall. The net CO2 exchange was generally more moisture limited in the boreal region than in the Arctic tundra. Our analysis indicates complex seasonal interactions of underlying C cycle processes in response to changing climate and hydrology that may not manifest in changes in net annual CO2 exchange. Therefore, a better understanding of the seasonal response of C cycle processes may provide important insights for predicting future carbon–climate feedbacks and their consequences on atmospheric CO2 dynamics in the northern high latitudes. 相似文献
335.
Pyrosequencing analysis of bacterial diversity in 14 wastewater treatment systems in china 总被引:2,自引:0,他引:2
To determine if there is a core microbial community in the microbial populations of different wastewater treatment plants (WWTPs) and to investigate the effects of wastewater characteristics, operational parameters, and geographic locations on microbial communities, activated sludge samples were collected from 14 wastewater treatment systems located in 4 cities in China. High-throughput pyrosequencing was used to examine the 16S rRNA genes of bacteria in the wastewater treatment systems. Our results showed that there were 60 genera of bacterial populations commonly shared by all 14 samples, including Ferruginibacter, Prosthecobacter, Zoogloea, Subdivision 3 genera incertae sedis, Gp4, Gp6, etc., indicating that there is a core microbial community in the microbial populations of WWTPs at different geographic locations. The canonical correspondence analysis (CCA) results showed that the bacterial community variance correlated most strongly with water temperature, conductivity, pH, and dissolved oxygen (DO) content. Variance partitioning analyses suggested that wastewater characteristics had the greatest contribution to the bacterial community variance, explaining 25.7% of the variance of bacterial communities independently, followed by operational parameters (23.9%) and geographic location (14.7%). Results of this study provided insights into the bacterial community structure and diversity in geographically distributed WWTPs and discerned the relationships between bacterial community and environmental variables in WWTPs. 相似文献
336.
Gergely Losonczy Attila Vajas Lili Takács Erika Dzsudzsák ágnes Fekete éva Márhoffer László Kardos éva Ajzner Bego?a Hurtado Pablo Garcia de Frutos András Berta István Balogh 《PloS one》2012,7(11)
Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly in the developed world. Numerous genetic factors contribute to the development of the multifactorial disease. We performed a case-control study to assess the risk conferred by known and candidate genetic polymorphisms on the development of AMD. We searched for genetic interactions and for differences in dry and wet AMD etiology. We enrolled 213 patients with exudative, 67 patients with dry AMD and 106 age and ethnically matched controls. Altogether 12 polymorphisms in Apolipoprotein E, complement factor H, complement factor I, complement component 3, blood coagulation factor XIII, HTRA1, LOC387715, Gas6 and MerTK genes were tested. No association was found between either the exudative or the dry form and the polymorphisms in the Apolipoprotein E, complement factor I, FXIII and MerTK genes. Gas6 c.834+7G>A polymorphism was found to be significantly protective irrespective of other genotypes, reducing the odds of wet type AMD by a half (OR = 0.50, 95%CI: 0.26–0.97, p = 0.04). Multiple regression models revealed an interesting genetic interaction in the dry AMD subgroup. In the absence of C3 risk allele, mutant genotypes of both CFH and HTRA1 behaved as strongly significant risk factors (OR = 7.96, 95%CI: 2.39 = 26.50, p = 0.0007, and OR = 36.02, 95%CI: 3.30–393.02, p = 0.0033, respectively), but reduced to neutrality otherwise. The risk allele of C3 was observed to carry a significant risk in the simultaneous absence of homozygous CFH and HTRA1 polymorphisms only, in which case it was associated with a near-five-fold relative increase in the odds of dry type AMD (OR = 4.93, 95%CI: 1.98–12.25, p = 0.0006). Our results suggest a protective role of Gas6 c.834+7G>A polymorphism in exudative AMD development. In addition, novel genetic interactions were revealed between CFH, HTRA1 and C3 polymorphisms that might contribute to the pathogenesis of dry AMD. 相似文献
337.
植酸对稻米品质影响的研究(Ⅰ) 总被引:2,自引:0,他引:2
本文报道在水稻生长的抽穗期、齐穗期、灌浆期和蜡熟期喷施不同浓度植酸改良稻米品质的研究。结果表明,在水稻生长的不同阶段,控制喷施植酸浓度可提高糙米率,降低稻米垩白。 相似文献
338.
A phylogenetic analysis was carried out to clarify the systematic position of Gyrocheilos and Didymocarpus, particularly the species placed in Didymocarpus sect.Heteroboea by Wang et al. Based on sequencing the internal transcribed spacer and the chloroplast spacer trnL-F, parsimony and Bayesian inference analyses were carried out using separate nuclear and chloroplast datasets, as well as a combined dataset. Our results showed that the two sections of Didymocarpus in China andGyrocheilos did not form separate monophyletic subclades, but turned up in three different places in the phylogenetic trees. In the frame of the present study, the pollen morphology of the species included in the analysis was studied. It proved inconsistent with the delimitation between Didymocarpus and Gyrocheilos. Furthermore, pollen and other morphological characters indicate that Gyrocheilos and some taxa of Didymocarpus should be placed within Didymocarpus. 相似文献
339.
Transcriptome‐wide sequencing provides insights into geocarpy in peanut (Arachis hypogaea L.) 下载免费PDF全文
Xiaoping Chen Qingli Yang Haifen Li Heying Li Yanbin Hong Lijuan Pan Na Chen Fanghe Zhu Xiaoyuan Chi Wei Zhu Mingna Chen Haiyan Liu Zhen Yang Erhua Zhang Tong Wang Ni Zhong Mian Wang Hong Liu Shijie Wen Xingyu Li Guiyuan Zhou Shaoxiong Li Hong Wu Rajeev Varshney Xuanqiang Liang Shanlin Yu 《Plant biotechnology journal》2016,14(5):1215-1224
340.
利用鱼肝中视黄化合物和α—生育酚指示水污染毒性的探讨 总被引:1,自引:0,他引:1
利用高效反相液相色谱法检测了夏冬两季受有机氯污染的典型湖泊--鸭儿湖严家湖区鲢肝中的视黄醇,软脂酸视黄酯及α-生育酚的含量。结果表明,两种营养素在鱼体内的代谢转换明显受环境温度的影响,夏季外界温度较高,肝脏内维生素主要以其生理活性形式存在,表现出视黄醇及α-生育酚含量较高;而冬季外界温度较低,肝脏内维生素主要以其储存形式存在,表现出软脂酸视黄酯含量高。鱼肝中视黄化合物的浓度随氧化塘中污染物浓度的增加而呈现出有规律下降的显著剂量/效应关系,表现在有机氯污染水域中鲢肝中的视黄化合物可作为一种生物标志物指示其污染毒性。 相似文献