Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115, Berlin, Germany.
Sci Rep. 2017 Aug 18;7(1):8845. doi: 10.1038/s41598-017-09195-0.
Investigating samples of the cancellothyridid brachiopod Terebratulina collected during the IceAGE (Me85/3) expedition of RV METEOR at the continental shelf around Iceland with both morphometrical and molecular methods, we were for the first time able to detect a hybridization event between brachiopod sister species, which are thought to have separated 60 MYA. Terebratulina retusa and T. septentrionalis can clearly be distinguished on the basis of consistent species-specific molecular signatures in both mitochondrial and nuclear markers, whereas morphometrical analyses proved to be less reliable for species determination than previously thought. Two out of 28 specimens were identified as offspring of a one-way hybridization event between T. retusa eggs and T. septentrionalis sperm. Whereas the fossil record of Terebratulina in the North Atlantic region is too fragmentary to reconstruct the history of the hybridization event, the different life history traits of the two species and current oceanographic conditions around Iceland offer plausible explanations for the occurrence of crossbreeds in this common brachiopod genus.
利用形态计量学和分子方法，对在冰岛大陆架上 RV METEOR 号在冰期（Me85/3）考察期间采集的 cancellothyridid 腕足动物 Terebratulina 样本进行研究，我们首次能够检测到腕足动物姐妹种之间的杂交事件，据认为这两个种已经分离了 6000 万年。Terebratulina retusa 和 T. septentrionalis 可以基于线粒体和核标记中一致的种特异性分子特征清楚地区分，而形态计量学分析在种的确定方面比以前认为的要不可靠。在 28 个样本中，有两个被鉴定为 T. retusa 卵子与 T. septentrionalis 精子单向杂交事件的后代。尽管北大西洋地区 Terebratulina 的化石记录过于零碎，无法重建杂交事件的历史，但两个物种的不同生活史特征和冰岛周围当前的海洋状况为这种常见腕足动物属中出现杂交种提供了合理的解释。
