Feeding ecology of Xenoturbella bocki (phylum Xenoturbellida) revealed by genetic barcoding
Feeding ecology of Xenoturbella bocki (phylum Xenoturbellida) revealed by genetic barcoding
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DOI：
10.1111/j.1471-8286.2007.01959.x
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发表时间：
2008-01-01
影响因子：
7.7
通讯作者：
Obst, Matthias
中科院分区：
文献类型：
--
作者：
Bourlat, Sarah J.;Nakano, Hiroaki;Obst, Matthias
底栖海洋蠕虫 Xenoturbella 经常受到软体动物 DNA 的污染，这在早些时候曾引起混乱，导致人们认为存在双壳类动物的关系。为了找到污染物的来源，我们使用了来自 Xenoturbella 的软体动物序列，并将它们与从与 Xenoturbella 共享相同环境的几个非显微软体动物个体获得的条形码进行了比较。使用细胞色素氧化酶 1，我们发现污染序列与双壳类 Ennucula tenuis 相似度达到 98%。利用 Xenoturbella 大核糖体亚基的高度可变的 D1-D2 区域，我们发现了三种不同的污染性软体动物物种，其中一种与双壳类 Abra nitida（发现 Xenoturbella 的古尔马斯峡湾中最丰富的双壳类之一）有 99% 的相似性，另一种与双壳类 Nucula sulcata 99% 相似。这些数据清楚地表明，Xenoturbella 只含有源自生活在同一环境中的双壳类动物的软体动物 DNA，驳斥了之前关于双壳类动物关系的假设。此外，这些数据表明异涡虫专门以多种物种的双壳类猎物为食，可能以卵和幼虫的形式存在。
The benthic marine worm Xenoturbella is frequently contaminated with molluscan DNA, which had earlier caused confusion resulting in a suggested bivalve relationship. In order to find the source of the contaminant, we have used molluscan sequences derived from Xenoturbella and compared them to barcodes obtained from several individuals of the nonmicroscopic molluscs sharing the same environment as Xenoturbella. Using cytochrome oxidase 1, we found the contaminating sequences to be 98% similar to the bivalve Ennucula tenuis. Using the highly variable D1-D2 region of the large ribosomal subunit in Xenoturbella, we found three distinct species of contaminating molluscs, one of which is 99% similar to the bivalve Abra nitida, one of the most abundant bivalves in the Gullmarsfjord where Xenoturbella was found, and another 99% similar to the bivalve Nucula sulcata. These data clearly show that Xenoturbella only contains molluscan DNA originating from bivalves living in the same environment, refuting former hypotheses of a bivalve relationship. In addition, these data suggest that Xenoturbella feeds specifically on bivalve prey from multiple species, possibly in the form of eggs and larvae.