Louisiana Universities Marine Consortium, Chauvin, Louisiana, United States of America.
PLoS One. 2012;7(4):e30144. doi: 10.1371/journal.pone.0030144. Epub 2012 Apr 30.
The 3,000 oil/gas structures currently deployed in the northern Gulf of Mexico (GOM) provide hard substratum for marine organisms in a region where such has been rare since the Holocene. The major exception to this are the Flower Garden Banks (FGB). Corals are known to have colonized oil/gas platforms around the FGB, facilitating biogeographic expansion. We ask the question, what are the patterns of genetic affinity in these coral populations. We sampled coral tissue from populations of two species occurring on oil and gas platforms: Madracis decactis (hermatype) and Tubastraea coccinea (invasive ahermatype). We sampled 28 platforms along four transects from 20 km offshore to the continental shelf edge off 1) Matagorda Island, TX; 2) Lake Sabine, TX; 3) Terrebonne Bay, LA; and 4) Mobile, AL. The entire population of M. decactis was sampled between depths of 5 m and 37 m. T. coccinea populations were sub-sampled. Genetic variation was assessed using the PCR-based Amplified Fragment Length Polymorphisms (AFLPs). Data were analyzed via AFLPOP and STRUCTURE. Genetic connectivity among M. decactis platform populations was highest near the FGB and decreased to the east. Connectivity increased again in the eastern sector, indicating isolation between the populations from different sides of the Mississippi River (Transects 3 and 4). A point-drop in genetic affinity (relatedness) at the shelf edge south of Terrebonne Bay, LA indicated a population differing from all others in the northern GOM. Genetic affinities among T. coccinea were highest in the west and decreased to the east. Very low genetic affinities off Mobile, AL indicated a dramatic difference between those populations and those west of the Mississippi River, apparently a formidable barrier to larval dispersal.
目前在墨西哥湾北部（GOM）部署了 3000 个石油/天然气结构，为该地区自全新世以来罕见的海洋生物提供了硬底质。主要的例外是花坛银行（FGB）。众所周知，珊瑚已经在 FGB 周围的石油/天然气平台上定居，促进了生物地理扩张。我们要问的问题是，这些珊瑚种群的遗传亲和力模式是什么。我们从两种在石油和天然气平台上出现的物种的种群中采集了珊瑚组织：Madracis decactis（hermatype）和 Tubastraea coccinea（入侵 ahermatype）。我们沿着四条测线从 20 公里的近海到 1）德克萨斯州马塔哥达岛、2）德克萨斯州萨宾湖、3）路易斯安那州特伦布尔湾和 4）阿拉巴马州莫比尔的大陆架边缘对 28 个平台进行了采样。在 5 米至 37 米的深度之间对整个 M. decactis 种群进行了采样。T. coccinea 种群进行了亚采样。使用基于 PCR 的扩增片段长度多态性（AFLPs）评估遗传变异。通过 AFLPOP 和 STRUCTURE 分析数据。M. decactis 平台种群之间的遗传连通性在靠近 FGB 的地方最高，向东逐渐降低。在东部区域再次增加，表明密西西比河两岸的种群之间存在隔离（第 3 和第 4 条测线）。在路易斯安那州特伦布尔湾以南的大陆架边缘处，遗传亲和力（相关性）的急剧下降表明，该种群与 GOM 北部的所有其他种群不同。T. coccinea 之间的遗传亲和力在西部最高，向东逐渐降低。莫比尔附近的遗传亲和力非常低，表明这些种群与密西西比河以西的种群之间存在明显差异，这显然是幼虫扩散的巨大障碍。
