DNA barcode assessment of Ceramiales (Rhodophyta) in the intertidal zone of the northwestern Yellow Sea

A total of 142 specimens of Ceramiales(Rhodophyta) were collected each month from October 2011 to November 2012 in the intertidal zone of the northwestern Yellow Sea. These specimens covered 21 species,14 genera,and four families. Cluster analyses show that the specimens had a high diversity for the three DNA markers,namely,partial large subunit r RNA gene(LSU),universal plastid amplicon(UPA),and partial mitochondrial cytochrome c oxidase subunit I gene(COI). No intraspecific divergence was found in our collection for these markers,except for a 1–3 bp divergence in the COI of Ceramium kondoi,Symphyocladia latiuscula,and Neosiphonia japonica. Because short DNA markers were used,the phylogenetic relationships of higher taxonomic levels were hard to evaluate with poor branch support. More than half species of our collection failed to find their matched sequences owing to shortage information of DNA barcodes for macroalgae in Gen Bank or BOLD(Barcode of Life Data) Systems. Three specimens were presumed as H eterosiphonia crispella by cluster analyses on DNA barcodes assisted by morphological identification,which was the first record in the investigated area,implying that it might be a cryptic or invasive species in the coastal area of northwestern Yellow Sea. In the neighbor-joining trees of all three DNA markers,H eterosiphonia japonica converged with D asya spp. and was distant from the other Heterosiphonia spp.,implying that H. japonica had affinities to the genus Dasya. The LSU and UPA markers amplified and sequenced easier than the COI marker across the Ceramiales species,but the COI had a higher ability to discriminate between species.     

红藻DNA条形码分析技术研究进展

DNA条形码是指利用一段相对较短的标准DNA片段,对物种进行识别和鉴定。目前该技术在动物、植物物种鉴定领域已经得到了广泛的研究和应用。在藻类的研究中,尚未确定一条统一的标准条形码基因,现阶段都是使用2条或2条以上基因序列来完成物种鉴定。对于形态多样、种类繁多的海洋红藻,常用的DNA条形码基因有COI基因(Partial cytochrome c oxidase I gene)、UPA基因(Partial 23SrRNA gene,universal plastid amplicon)、LSU基因(Partial 28SrRNA gene)和rbcL基因(The large subunit of ribulose-1,5-bisphosphate carboxylase)等,这些基因中2个或3个基因的互补运用准确有效地提高了红藻的鉴定准确率,尤其是COI基因的种间差异大足够区分相近物种。本文在概述条形码的原理及其标准的基础上,阐述了红藻DNA条形码鉴定研究的新进展以及常用几种基因片段的优缺点,并对条形码在红藻鉴定中存在的问题进行了分析,对其应用前景进行了展望。     

武汉大学主校区情绪与压力时空分布特征研究

基于微博数据,针对大学生心理亚健康问题,从宏观的角度分析了微博用户的情绪与压力在时空上的变化规律.利用基于词典匹配的情感分类方法,借助GIS分析手段,以武汉大学主校区为例进行了分析.研究结果表明,情绪与压力在不同时空下呈现不同的特征,能为高校管理人员更好地理解学生心理、调整教学方法提供参考.     

卫星之眼|百里丹霞风景道

百里丹霞风景道位于新疆昌吉回族自治州,横跨昌吉市、呼图壁县、玛纳斯县南部山区,沿省道101,东起昌吉市硫磺沟镇头屯河桥,西至玛纳斯县肯斯瓦特水库,全长146千米.这里的丹霞地貌形成于7000万年前的喜马拉雅造山运动,陡崖坡、石峰、石柱、石墙等奇特的地貌形态都有体现,有着\"一日看四季、百里不同天\"的壮美景象.