Cimmaruta R, Bondanelli P, Nascetti G
Department of Ecology and Economic Sustainable Development, Tuscia University of Viterbo, Via San Giovanni Decollato, 1, I-01100 Viterbo, Italy.
Mol Ecol. 2005 Jul;14(8):2577-91. doi: 10.1111/j.1365-294X.2005.02595.x.
This study aimed at assessing the genetic structure and the state of the stocks of the European hake (Merluccius merluccius). To this end, 15 samples were taken from the whole range of the species and analysed using allozymes. Since 11 samples were taken from the poorly studied Mediterranean Sea, the results obtained provided a complete picture of the hake's genetic structure and an initial insight into its relationships with environmental features. Atlantic and Mediterranean hake populations are separated by the Almeria-Oran front. This area has been proved to be the boundary between Atlantic and Mediterranean stocks of many marine organisms, but some doubt exists concerning the efficaciousness of the local gyres as barriers to the gene flow. Our data have evidenced a latitudinal cline at loci Gapdh and Gpi-2 within the Mediterranean Sea, with a further steep change across the Almeria-Oran front. The genetic pattern showed a strong correlation with the values of the salinity both at the surface and at -320 m and of the salinity + temperature at the surface, suggesting a role for these parameters in maintaining the genetic differentiation among the two population groups through selective processes. Finally, the levels of genetic variability were found to be slightly lower in the depleted Atlantic stock than in the Mediterranean one.
本研究旨在评估欧洲无须鳕（Merluccius merluccius）的遗传结构和种群状况。为此，从该物种的整个分布范围内采集了15个样本，并使用同工酶进行分析。由于11个样本取自研究较少的地中海，所获得的结果提供了无须鳕遗传结构的完整图景，并初步洞察了其与环境特征的关系。大西洋和地中海无须鳕种群被阿尔梅里亚-奥兰锋分隔开。该区域已被证明是许多海洋生物大西洋种群和地中海种群之间的边界，但对于当地环流作为基因流动障碍的有效性存在一些疑问。我们的数据表明，地中海内Gapdh和Gpi - 2位点存在纬度渐变，且在阿尔梅里亚-奥兰锋两侧有进一步急剧变化。遗传模式显示，其与表层及-320米深处的盐度值以及表层盐度加温度值具有很强的相关性，这表明这些参数在通过选择过程维持两个种群组之间的遗传分化中发挥了作用。最后，发现枯竭的大西洋种群的遗传变异性水平略低于地中海种群。
