Introgression in natural populations of bioindicators: a case study of Carabus splendens and Carabus punctatoauratus
Introgression in natural populations of bioindicators: a case study of Carabus splendens and Carabus punctatoauratus
复制标题
生物指示剂在自然种群中的渗入：以 Carabus splendens 和 Carabus punctatoauratus 为例
作者：
R. Streiff;R. Veyrier;P. Audiot;S. Meusnier;C. Brouat
在过去的十年里，野生动植物杂交在进化上的重要性已得到越来越广泛的认识。在实践中，杂交为保护生物学家提供了一系列异常坚韧的问题。我们说明了这两个步甲科物种的案例研究，广泛用于评估人类活动对生物多样性的影响。这两个物种生活在同域/异域的复杂镶嵌体中，并且已知在受控条件下杂交。由于缺乏一套简单的表型性状来鉴定杂交种，迄今为止，在自然群体中的杂交还没有被量化。因此，我们在自然群体中筛选杂交种，在9个微卫星位点的多位点基因分型。这两个类群之间的遗传分化水平很高，观察到的等位基因频率分布。两个贝叶斯分配程序，没有强制性的纯类群参考，用于推断不同类别的杂种（F1，F2和回交）和两个物种之间的混合比例。低水平的杂交（F1基因型），观察到在自然种群，与在控制条件下获得的结果相比。然而，在12个位点中的3个位点检测到高水平的基因渗入，如回交基因型检测所揭示的。这种种间基因流动是在两个物种共同地理范围的有限区域内检测到的，并且与同域/异地分布模式无关。然后，我们认为这种渗入的起源和影响，基于种内遗传多样性和地理结构。
The evolutionary importance of hybridization in wild plants and animals has become increasingly widely recognized in the last decade. In practical terms, hybridization provides an exceptionally tough set of problems for conservation biologists. We illustrate this in a case study of two Carabidae species widely used to evaluate the impact of human activities on biodiversity. These two species live in a complex mosaic of sympatry/allopatry and are known to hybridize in controlled conditions. Hybridization has not been quantified in natural populations to date due to the lack of a simple set of phenotypic traits for identifying hybrids. We thus screened for hybrids in natural populations, by multilocus genotyping at nine microsatellite loci. A high level of genetic differentiation between these two taxa was observed, as shown by allelic frequency distributions. Two Bayesian assignment procedures without obligatory pure taxon references were used to infer different classes of hybrids (F1, F2 and backcrosses) and mixture proportions between the two species. A low level of hybridization (F1 genotypes) was observed in natural populations, contrasting with results obtained in controlled conditions. A high level of introgression was, however, detected at three of 12 sites, as revealed by the detection of backcrossed genotypes. This interspecific gene flow was detected in a limited zone of the common geographical range of the two species and was not related to the pattern of sympatry/allopatry. We then considered the origin and repercussions of this introgression, based on intraspecific genetic diversity and geographical structure.
DOI：
10.1073/pnas.94.17.9197
发表时间：
1997-08-19
影响因子：
11.1
作者：
Rannala, B;Mountain, JL
通讯作者：
Mountain, JL