Kannan Adrian, Rama Rao Suganiya, Ratnayeke Shyamala, Yow Yoon-Yen
Department of Biological Sciences, School of Science & Technology, Sunway University, Selangor Darul Ehsan, Malaysia.
PeerJ. 2020 Apr 1;8:e8755. doi: 10.7717/peerj.8755. eCollection 2020.
Invasive apple snails, and , have a widespread distribution globally and are regarded as devastating pests of agricultural wetlands. The two species are morphologically similar, which hinders species identification via morphological approaches and species-specific management efforts. Advances in molecular genetics may contribute effective diagnostic tools to potentially resolve morphological ambiguity. DNA barcoding has revolutionized the field of taxonomy by providing an alternative, simple approach for species discrimination, where short sections of DNA, the cytochrome c oxidase subunit I (COI) gene in particular, are used as 'barcodes' to delineate species boundaries. In our study, we aimed to assess the effectiveness of two mitochondrial markers, the COI and 16S ribosomal deoxyribonucleic acid (16S rDNA) markers for DNA barcoding of and . The COI and 16S rDNA sequences of 40 specimens collected from six localities in Peninsular Malaysia were analyzed to assess their barcoding performance using phylogenetic methods and distance-based assessments. The results confirmed both markers were suitable for barcoding and . The phylogenies of the COI and 16S rDNA markers demonstrated species-specific monophyly and were largely congruent with the exception of one individual. The COI marker exhibited a larger barcoding gap (6.06-6.58%) than the 16S rDNA marker (1.54%); however, the magnitude of barcoding gap generated within the barcoding region of the 16S rDNA marker (12-fold) was bigger than the COI counterpart (approximately 9-fold). Both markers were generally successful in identifying and in the similarity-based DNA identifications. The COI + 16S rDNA concatenated dataset successfully recovered monophylies of and but concatenation did not improve individual datasets in distance-based analyses. Overall, although both markers were successful for the identification of apple snails, the COI molecular marker is a better barcoding marker and could be utilized in various population genetic studies of and .
入侵苹果螺Pomacea canaliculata和Pomacea maculata在全球分布广泛，被视为农业湿地的毁灭性害虫。这两个物种在形态上相似，这阻碍了通过形态学方法进行物种鉴定以及针对性的管理工作。分子遗传学的进展可能有助于提供有效的诊断工具，以潜在地解决形态学上的模糊性。DNA条形码技术通过提供一种替代的、简单的物种鉴别方法，彻底改变了分类学领域，其中短片段的DNA，特别是细胞色素c氧化酶亚基I（COI）基因，被用作“条形码”来划定物种界限。在我们的研究中，我们旨在评估两种线粒体标记，即COI和16S核糖体脱氧核糖核酸（16S rDNA）标记对Pomacea canaliculata和Pomacea maculata进行DNA条形码分析的有效性。对从马来西亚半岛六个地点采集的40个Pomacea canaliculata标本的COI和16S rDNA序列进行了分析，使用系统发育方法和基于距离的评估来评估它们的条形码性能。结果证实这两种标记都适用于Pomacea canaliculata和Pomacea maculata的条形码分析。COI和16S rDNA标记的系统发育显示出物种特异性的单系性，除了一个个体外，在很大程度上是一致的。COI标记显示出比16S rDNA标记（1.54%）更大的条形码间隙（6.06 - 6.58%）；然而，16S rDNA标记条形码区域内产生的条形码间隙大小（12倍）比COI对应物（约9倍）更大。在基于相似性的DNA鉴定中，这两种标记通常都能成功鉴定Pomacea canaliculata和Pomacea maculata。COI + 16S rDNA串联数据集成功恢复了Pomacea canaliculata和Pomacea maculata的单系性，但在基于距离的分析中，串联并没有改善单个数据集。总体而言，尽管这两种标记都成功用于苹果螺的鉴定，但COI分子标记是更好的条形码标记，可用于Pomacea canaliculata和Pomacea maculata的各种群体遗传学研究。
