Centre for Ecology and Evolution in Microbial Model Systems, EEMiS, Department of Biology and Environmental Science, Linnaeus University, SE-392 31, Kalmar, Sweden.
BMC Genom Data. 2021 Jun 28;22(1):22. doi: 10.1186/s12863-021-00974-3.
Fitness consequences of intraspecific genetic admixture can vary from positive to negative depending on the genetic composition of the populations and environmental conditions. Because admixture has potential to influence the success of management and conservation efforts, genetic similarity has been suggested to be used as a proxy to predict the outcome. Studies utilizing microsatellites (a neutral marker) to investigate associations between genetic distance and admixture effects show conflicting results. Marker types that yield information on genome-wide and/or adaptive variation might be more useful for predicting responses to inter-population hybridization. In this study we utilized published data for three populations of pike (Esox lucius) to investigate associations between offspring performance (hatching success) and parental genetic similarity in experimentally purebred and admixed families, based on neutral (microsatellites), genome-wide neutral (RADseq SNPs), and adaptive (SNPs under selection) markers.
Estimated similarity varied among the markers, likely reflecting differences in their inherent properties, but was consistently higher in purebred than admixed families. A significant interaction between marker type and admixture treatment reflected that neutral SNPs yielded higher estimates than adaptive SNPs for admixed families whereas no difference was found for purebred families, which indicates that neutral similarity was not reflective of adaptive similarity. When all samples were pooled, no association between similarity and performance was found for any marker. For microsatellites, similarity was positively correlated with hatching success in purebred families, whereas no association was found in admixed families; however, the direction of the effect differed between the population combinations.
The results strengthen the notion that, as of today, there is no proxy that can reliably predicted the outcome of admixture. This emphasizes the need of further studies to advance knowledge that can shed light on how to safeguard against negative consequences of admixture, and thereby inform management and promote conservation of biological diversity.
由于种群的遗传组成和环境条件的不同，种内遗传混合的健身后果可能从积极变为消极。由于混合有影响管理和保护工作成功的潜力，因此遗传相似性已被建议用作预测结果的替代指标。利用微卫星（中性标记）研究遗传距离与混合效应之间的关联的研究显示出相互矛盾的结果。产生有关全基因组和/或适应性变异信息的标记类型可能更有助于预测对种群间杂交的反应。在这项研究中，我们利用已发表的数据，对三个梭子鱼种群（Esox lucius）进行了研究，基于中性（微卫星）、全基因组中性（RADseq SNPs）和适应性（受选择的 SNPs）标记，调查了纯系和混合系后代表现（孵化成功率）与亲本遗传相似性之间的关联。
估计的相似性因标记而异，这可能反映了其固有特性的差异，但在纯系中比在混合系中始终更高。标记类型和混合处理之间的显著相互作用反映了在混合系中，中性 SNP 比适应性 SNP 产生更高的估计值，而在纯系中则没有差异，这表明中性相似性不能反映适应性相似性。当所有样本混合在一起时，任何标记都没有发现相似性与表现之间的关联。对于微卫星，相似性与纯系中的孵化成功率呈正相关，而在混合系中则没有关联；然而，这种效应的方向在种群组合之间有所不同。
这些结果强化了这样一种观点，即目前还没有可靠的替代指标可以预测混合的结果。这强调了需要进一步研究，以提高知识水平，阐明如何防范混合的负面后果，并为管理和促进生物多样性保护提供信息。
