Origins of endemic stickleback from the Queen Charlotte Islands: Mitochondrial and morphological evidence
Origins of endemic stickleback from the Queen Charlotte Islands: Mitochondrial and morphological evidence
复制标题
DOI：
10.1139/z96-116
复制
发表时间：
1996-06-01
期刊：
影响因子：
--
通讯作者：
Levin, DB
中科院分区：
文献类型：
--
作者：
Deagle, BE;Reimchen, TE;Levin, DB
最近，两个不同的线粒体谱系描述在12个分散的人口的三棘鱼（Gasterosteus aculeatus）的夏洛特女王群岛（QCI），加拿大西部，其中之一，可能是一个孑遗谱系，随后被证明是从日本附近的西太平洋棘鱼的特点。在本研究中，我们分析了985鱼从85 QCI人口的线粒体谱系使用限制性内切酶试验。我们的数据表明，残遗血统在很大程度上是有限的（18 20人口），邻近流域的QCI东北角接近一个可疑的冰川避难所，但我们也发现了血统在两个偏远的湖泊西海岸的QCI，远离任何已知的避难所。我们从太平洋中部获得了33条棘鱼的样本，发现了两个线粒体DNA（mtDNA）谱系，强烈表明这些鱼正在太平洋各地扩散，与以前的建议不一致的一个谱系的残遗状态。形态学衍生的特征，如失去盔甲和失去刺，发生在两个谱系中，但这些在日本谱系中更为普遍。令人惊讶的是，19个地方都有血统，在这些血统和形态之间没有显着的单变量或多变量的关联，这表明很少，如果有不同的mtDNA血统之间的生殖障碍。
Recently, two divergent mitochondrial lineages were described in a survey of 12 scattered populations of the threespine stickleback (Gasterosteus aculeatus) on the Queen Charlotte Islands (QCI), western Canada, one of which, possibly a relict lineage, was subsequently shown to characterize stickleback from the western Pacific near Japan. In the present study, we assayed 985 fish from 85 QCI populations for mitochondrial lineage using a restriction enzyme test. Our data indicate that the relict lineage was largely limited (18 of 20 populations) to adjacent watersheds in the northeast corner of the QCI close to a suspected glacial refugium, but we also found the lineage in two remote lakes on the west coast of the QCI, distant from any known refugia. We obtained a sample of 33 stickleback from the mid-Pacific and found both mitochondrial DNA (mtDNA) lineages, strongly suggesting ongoing dispersal of these fish across the Pacific, and inconsistent with previous suggestions of relict status for one of the lineages. Morphologically derived traits, such as loss of armour and loss of spines, occurred in both lineages, but these were more prevalent in the Japanese lineage. Surprisingly, 19 localities had both lineages, and within each of these there were no significant univariate or multivariate associations between lineages and morphology, suggesting few if any reproductive barriers between the divergent mtDNA lineages.