Nondestructive DNA extraction from blackflies (Diptera: Simuliidae): retaining voucher specimens for DNA barcoding projects

A nondestructive, chemical-free method is presented for the extraction of DNA from small insects. Blackflies were submerged in sterile, distilled water and sonicated for varying lengths of time to provide DNA which was assessed in terms of quantity, purity and amplification efficiency. A verified DNA barcode was produced from DNA extracted from blackfly larvae, pupae and adult specimens. A 60-second sonication period was found to release the highest quality and quantity of DNA although the amplification efficiency was found to be similar regardless of sonication time. Overall, a 66% amplification efficiency was observed. Examination of post-sonicated material confirmed retention of morphological characters. Sonication was found to be a reliable DNA extraction approach for barcoding, providing sufficient quality template for polymerase chain reaction amplification as well as retaining the voucher specimen for post-barcoding morphological evaluation.     

湖北神农架自然保护区一新特蚋种(双翅目,蚋科)(英文)

描记采自湖北神农架自然保护区一蚋属蚋亚属新种,齿端蚋Simulium(Simulium)dentastylum sp.nov..模式标本存于贵阳医学院生物学教研室.     

DNA metabarcoding and the cytochrome c oxidase subunit I marker: not a perfect match

DNA metabarcoding enables efficient characterization of species composition in environmental DNA or bulk biodiversity samples, and this approach is making significant and unique contributions in the field of ecology. In metabarcoding of animals, the cytochrome c oxidase subunit I (COI) gene is frequently used as the marker of choice because no other genetic region can be found in taxonomically verified databases with sequences covering so many taxa. However, the accuracy of metabarcoding datasets is dependent on recovery of the targeted taxa using conserved amplification primers. We argue that COI does not contain suitably conserved regions for most amplicon-based metabarcoding applications. Marker selection deserves increased scrutiny and available marker choices should be broadened in order to maximize potential in this exciting field of research.     

DNA barcoding in Tardigrada: the first case study on Macrobiotus macrocalix Bertolani & Rebecchi 1993 (Eutardigrada, Macrobiotidae)

Morphological and molecular studies on a tardigrade species have been carried out to verify the possibility of using a DNA barcoding approach for species identification in this phylum. Macrobiotus macrocalix Bertolani & Rebecchi, 1993 was chosen as the test species since it belongs to a group of species in which the taxonomy is quite problematic. Animals and eggs belonging to three Italian and one Swedish populations have been investigated. Both morphological and molecular analyses show that all the populations belong to the same species. The low genetic distances recorded among the studied populations (0.3-1.0%) and the high genetic distance (15.9-16.3%) between these populations and a closely related species confirm the possibility of identifying a specimen of this species by its cytochrome oxidase subunit I sequence. Data from other authors support our results indicating that DNA barcoding can be applied to tardigrades. With our protocols, we have obtained voucher specimens that enable us to show a correspondence between morphology and molecular data.     

Study of COI sequences from endemic New Zealand aphids highlights high mitochondrial DNA diversity in Rhopalosiphina (Hemiptera: Aphididae)

Focussed searches were made across New Zealand between 2013 and 2016, for endemic aphids from the Schizaphis (Rhopalosiphina) genus, which is currently represented by two putative, undescribed species from the endemic host plants Aciphylla and Dracophyllum. Cytochrome c oxidase I (COI) gene sequences (48 in total) from the Schizaphis were analysed together with those from a broader collection of New Zealand endemic aphids that has been assembled since the year 2000. The bulk of the Schizaphis belonged to two clusters corresponding to the host plant genera. Two aphids from central North Island Dracophyllum represented a much diverged lineage without clear affiliations to other New Zealand Schizaphis. Inter-population variation in the New Zealand Schizaphis was high compared with that seen in international studies of Aphidinae and among populations of other endemic New Zealand Aphidina. Within Schizaphis from Dracophyllum, geography played an apparent role in genetic structuring, with populations from Taranaki (North Island) and especially Mt Lyford (South Island) being divergent from those on the South Island main divide. Two distinct lineages of Schizaphis, which co-occurred at some sites, were found on Aciphylla. Our sequence comparisons, including GMYC analyses, indicated up to five New Zealand Schizaphis lineages, and two newly discovered endemic Aphis species from the host plants Clematis and Hebe.     

DNA barcoding of Caenogastropoda along coast of China based on the COI gene

DNA barcoding provides an efficient method for species-level identifications. In this study, we have amplified partial sequences of mitochondrial cytochrome c oxidase I (COI) gene from 110 specimens of 45 species of Caenogastropoda collected from the coast along China to evaluate whether DNA barcodes can distinguish these species accurately. The average Kimura 2-parameter (K2P) distances within species, genera and families were 0.44%, 13.96% and 22.27%, respectively. Both the neighbour-joining tree and the Bayesian tree showed a clear discrimination of all the species in our study with highly supported clades. These results proved that the species of Caenogastropoda can be efficiently and accurately identified by DNA barcoding based on the COI gene.     

Identifying fern gametophytes using DNA sequences

Identification of fern gametophytes is generally hampered by low morphological complexity. Here we explore an alternative: DNA‐based identification. We obtained a plastid rbcL sequence from a sterile gametophyte of unknown origin (cultivated for more than 30 years) and employed blast to determine its affinities. Using this approach, we identified the gametophyte as Osmunda regalis. To evaluate the robustness of this determination, and the usefulness of rbcL in differentiating among species, we conducted a phylogenetic analysis of osmundaceous fern sequences. Based on our results, it is evident that DNA‐based identification has considerable potential in exploring the ecology of fern gametophytes.     

贵州蚋科一新种 (双翅目:蚋科)(英文)

本文记述采自贵州雷公山的蚋属一新种 ,以产地命名为黔蚋Simulium (Simulium )qianensesp .nov。新种隶属于杂色蚋组S .variegatumspecies group ,与台湾蚋S .taiwanicum最近似 ,但可依其特殊的盾饰、足的颜色、雄尾中骨端裂和幼虫后颊裂深并在后腹部具附骨等特征与其他近缘种相区别。模式标本存放于贵阳医学院生物教研室。     

中国贵州梵净山蚋属一新种(双翅目:蚋科)

本文记述采自贵州梵净山的蚋属一新种,鞍阳蚋Ｓｉｍｕｌｉｕｍ（Ｓｉｍｕｌｉｕｍ）ｅｐｈｉｐｐｉｏｉｄｕｍ,新种隶属于多叉蚋组Ｓｉｍｕｌｉｕｍ ｍｕｌｔｉｓｔｒｉａｔｕｍ－ｇｒｏｕｐ。,其两性尾器形态特殊,茧具前侧窗,幼虫后腹节具叶状毛等特征,可与其它已知近缘种相区别。     

贵州蚋属一新种 (双翅目：蚋科)

 记述采自贵州雷公山的蚋属一新种, 显著蚋Simulium (Simulium) prominentum, 新种 。根据其蛹和幼虫的特征显著而命名, 对其幼期形态进行描述并与其近缘种作分类讨论。