Myosotella myosotis (Mollusca: Ellobiidae) — an overlooked,but well-established introduced species in South Africa

Myosotella myosotis is shown to be a well-established alien species in South Africa. Discovered in Port Elizabeth more than 100 years ago, it was initially thought to be indigenous and was described under two different names, but subsequent taxonomic work has demonstrated that these are synonyms of the variable and widely introduced European M. myosotis. This information, published in a revision of western Atlantic Ellobiidae, has escaped the attention of the South African marine science community. There has been no recent mention of M. myosotis or its two pseudoindigenous synonyms in the literature pertaining to either the estuaries or the malacofauna of South Africa, or to marine bioinvasions in the region. This example serves to demonstrate that invasion biology has a global context and that taxonomic literature is an important source of pertinent data. The fact that a species, which evidently occurs in abundance, can be overlooked for so long is both surprising and sobering.     

生物结皮中优势蓝藻胞外多糖对几种荒漠草本植物种子萌发的影响

蓝藻是荒漠生物结皮的重要组成。选取生物结皮中的优势蓝藻(具鞘微鞘藻(Microcoleus vaginatus)、眼点伪枝藻(Scytonema ocellatum)、地木耳(Nostoc commune)),通过提取其胞外多糖,研究了不同蓝藻胞外多糖对荒漠植物种子萌发的影响。结果表明:具鞘微鞘藻、眼点伪枝藻的胞外多糖对粗枝猪毛菜(Salsola subcrassa)的种子萌发表现为低浓度抑制、高浓度促进作用,地木耳的胞外多糖仅在高浓度时对粗枝猪毛菜的种子萌发具有促进作用(p<0.05);具鞘微鞘藻胞外多糖对小花荆芥(Nepeta micrantha)种子萌发无明显的影响作用,但眼点伪枝藻和地木耳对小花荆芥种子萌发具有抑制作用。具鞘微鞘藻、眼点伪枝藻和地木耳胞外多糖对琉苞菊(Hyalea pulchella)种子萌发具有明显的抑制作用。藻种胞外多糖组分的差异和不同种子的生物学特性差异可能是造成不同藻种胞外多糖对种子萌发产生不同影响的主要原因。     

Identification of Prorocentrum minimum and Takayama pulchella by fluorescence in situ hybridization through epifluorescence microscopy and flow cytometry

Partial rDNA sequences of Prorocentrum minimum and Takayama pulchella were amplified, cloned and sequenced, and these sequence data were deposited in the GenBank. Eight oligonucleotide probes (DNA probes) were designed based on the sequence analysis. The probes were employed to detect and identify P. minimum and T. pulchella in unialgal and mixed algal samples with a fluorescence in situ hybridization method using flow cytometry. Epifluorescence micrographs showed that these specific probes labeled with flu...     

Identification of Prorocentrum minimum and Takayama pulchella by fluorescence in situ hybridization through epifluorescence microscopy and flow cytometry

Partial rDNA sequences of Prorocentrum minimum and Takayama pulchella were amplified,cloned and sequenced,and these sequence data were deposited in the GenBank.Eight oligonucleotide probes(DNA probes)were designed based on the sequence analysis.The probes were employed to detect and identify P.minimum and T. pulchella in unialgal and mixed algal samples with a fuorescence in situ hybridization method using flow cytometry.Epifluorescence micrographs showed that these specific probes labeled with fluorescein isothiocyanate entered the algal cells and bound to target sequences,and the fluorescence signal resulting from whole-cell hybridization varied from probe to probe.These DNA probes and the hybridization protocol we developed were specific and effective for P.minimum and T. pulchella,without any specific binding to other algal species.The hyrbridization efficiency of difierent probes specific to P.minimum was in the order:PMl8S02＞PM28S02＞PM28S01＞PM18S01,and that of the probes specific to T. pulchella was TP18S02＞TP28S01＞TP28S02＞TP18S01.The djfferent hybridization efficiency of the DNA probes could also be shown in the fuorescent signals between the labeled and unlabeled cells demonstrated using flow cytometry.The DNA probes PM18S02,PM28S02,TPl8S02 and TP28S01,and the protocol,were also useful for the detection of algae in natural samples.     

鬼手海葵(Aiptasia pulchella)白化恢复后的基因表达差异

海葵白化是由于海葵失去体内共生的虫黄藻和(或)共生的虫黄藻失去体内色素而导致海葵变白的生态现象。为探究鬼手海葵(Aiptasia pulchella)白化和白化恢复后相关的分子机制, 本研究对海葵进行慢性热胁迫处理, 以白化海葵和白化恢复后的海葵为研究对象, 采用2代IIlumina Hi-seq测序技术进行转录组测序, 探究两者在基因表达水平方面的差异变化, 分别获得50109686和43163786条Clean reads, 注释后获得24565和24157个Unigene。比较转录组分析结果显示, 白化海葵与白化恢复后的海葵之间存在214个差异表达基因, 其中白化海葵的高表达基因有101个, 白化恢复后海葵的高表达基因有113个, 这些差异表达基因主要与DNA复制、新陈代谢、离子转运和胶原蛋白有关。对不同处理所涉及的全部28050个表达基因进行基因集富集分析(gene set enrichment analysis, GSEA), 结果发现, 白化海葵在胶原蛋白和离子转运方面显著富集表达, 白化恢复后的海葵在核酸修复方面显著富集表达, 推测这些生物学过程在海葵白化和白化后修复过程中发挥重要作用。本研究获得的转录组数据和研究结果初步揭示了海葵共生体系在共生失衡后进行适应性调节的分子机制, 为海葵及珊瑚共生体系应对环境变化的适应性机制研究提供了理论依据。     

Identification of Provocentrum minimum and Takayama pulchella by fluorescence in situ hybridization through epifluorescence microscopy and flow cytometry

Partial rDNA sequences of Prorocentrum minimum and Takayama pulchella were amplified,cloned and sequenced,and these sequence data were deposited in the GenBank.Eight oligonucleotide probes(DNA probes)were designed based on the sequence analysis.The probes were employed to detect and identify P.minimum and T. pulchella in unialgal and mixed algal samples with a fuorescence in situ hybridization method using flow cytometry.Epifluorescence micrographs showed that these specific probes labeled with fluorescein isothiocyanate entered the algal cells and bound to target sequences,and the fluorescence signal resulting from whole-cell hybridization varied from probe to probe.These DNA probes and the hybridization protocol we developed were specific and effective for P.minimum and T. pulchella,without any specific binding to other algal species.The hyrbridization efficiency of difierent probes specific to P.minimum was in the order:PMl8S02＞PM28S02＞PM28S01＞PM18S01,and that of the probes specific to T. pulchella was TP18S02＞TP28S01＞TP28S02＞TP18S01.The djfferent hybridization efficiency of the DNA probes could also be shown in the fuorescent signals between the labeled and unlabeled cells demonstrated using flow cytometry.The DNA probes PM18S02,PM28S02,TPl8S02 and TP28S01,and the protocol,were also useful for the detection of algae in natural samples.