DNA polymorphism and species composition of plankton in an artificial lake for breeding transgenic fish

Abstract

采用RAPD和PCR-DGGE指纹技术对转基因鱼试验湖的浮游生物群落DNA多态性进行了研究,并探讨了DNA多态性与物种组成的关系.结果显示:(1)形态学分类共鉴定到44种/类浮游生物:其中藻类13种,原生动物11种,轮虫16种,枝角类和桡足类各2种.多甲藻(Peridinium sp.)、球形砂壳虫(Difflugia globulosa)、螺形龟甲轮虫(Keratella cochlearis)和针簇多肢轮虫(Polyarthra trigla)4个物种在各个站丰度相对较高.(2)RAPD扩增共获得128条长度在200-1200bp的谱带,多态率为61.7%,特异性谱带占总谱带的19.5%.(3)PCR-DGGE指纹分析共获得87条扩增谱带,其中原核生物谱带相对较多(50条),真核生物谱带较少(37条),多态率分别为86%和64.9%.尽管形态学鉴定和DNA指纹分析都表现出较高物种多样性,但其相似性聚类却有差别:物种组成聚类中B、C站聚为一类,D、E站聚为一类,A站独为一类;两种DNA指纹分析聚类结果显示C、D、E三站聚为一类,A、B聚为一类.综上所述,在对浮游生物群落的研究中,形态学方法与DNA指纹技术不显著对应,后者能揭示更丰富的物种多样性,但毫无疑问三种方法可以从不同方面表征群落结构.这将为进一步研究湖泊浮游生物群落结构和功能关系奠定坚实的基础.;The present study was designed to explore relationship between DNA polymorphism, as revealed by RAPD and PCR-DGGE fingerprintings, and species composition of plankton community in an artificial lake for breeding transgenic fish. Planktonic samples were collected from five sampling sites in the artificial lake, and their similarity was assessed with cluster analysis. The results were: (1) a total of 44 planktonic taxa were identified, among which there were 13 algae, 11 protozoa, 16 rotifer, 2 Cladocera and Copepoda, respectively; (2) 128 observable bands were totally amplified by the 9 random primers screened in RAPD analysis, among which 61.7% and 19.5% were polymorphic bands and specific bands, respectively; (3) there were 87 distinct bands identified by the method of PCR-DGGE, among which 50 were 16S rRNA bands and 37 were 18S rRNA bands. Despite the analysis of morphological identification and DNA fingerprintings had shown a higher species diversity, the cluster of similarity was different: based on species composition, group 1 consisted of B, C sites, group 2 contained D, E sites, and group 3 only comprised of A site. However, according to the DNA fingerprint analysis, the plankton community of C, D, E were similar, and another two sites-A and B were similar. In summary, our results suggested that the species composition was not closely related to the DNA polymorphism of plankton community, and the latter can describe more species. However, the characteristics of biodiversity revealed from different ), 2009, 21(3) 376 a