Anthropogenic activities may facilitate undesirable hybridization and genomic introgression between fish species. Walleye (Sander vitreus) and sauger (Sander canadensis) are economically valuable freshwater species that can spontaneously hybridize in areas of sympatry. Levels of genomic introgression between walleye and sauger may be increased by modifications to waterbodies (e.g., reservoir development) and inadvertent propagation of hybrids in stocking programs. We used genotyping by sequencing (GBS) to examine 217 fish from two large reservoirs with mixed populations of walleye and sauger in Saskatchewan, Canada (Lake Diefenbaker, Tobin Lake). Analyses with 20,038 (r90) and 478 (r100) single nucleotide polymorphisms clearly resolved walleye and sauger, and classified hybrids with high confidence. F₁, F₂, and multigeneration hybrids were detected in Lake Diefenbaker, indicating potentially high levels of genomic introgression. In contrast, only F₁ hybrids were detected in Tobin Lake. Field classification of fish was unreliable; 7% of fish were misidentified based on broad species categories. Important for activities such as brood stock selection, 12 of 173 (7%) fish field identified as pure walleye, and one of 24 (4%) identified as pure sauger were actually hybrids. In addition, two of 15 (13%) field‐identified hybrids were actually pure walleye or sauger. We conclude that hybridization and introgression are occurring in Saskatchewan reservoirs and that caution is warranted when using these populations in stocking programs. GBS offers a powerful and flexible tool for examining hybridization without preidentification of informative loci, eliminating some of the key challenges associated with other marker types.

中文翻译：

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两个大型水库中白斑眼斑眼鱼 (Sander vitreus) 和萨格斑眼斑眼斑眼鱼 (Sander canadensis) 之间的自发杂交和基因渗入：通过测序进行基因分型的见解


人类活动可能会促进鱼类之间不良的杂交和基因组渗入。 Walleye ( Sander vitreus ) 和sauger ( Sander canadensis ) 是具有经济价值的淡水物种，可以在同源地区自发杂交。通过对水体的改造（例如，水库开发）和放养计划中杂种的无意繁殖，可能会增加白眼鱼和索格鱼之间的基因组渗入水平。我们使用测序基因分型 (GBS) 检测了加拿大萨斯喀彻温省两个大型水库（迪芬贝克湖和托宾湖）的 217 条鱼，其中有白眼鱼和索格鱼的混合种群。对 20,038 (r90) 和 478 (r100) 个单核苷酸多态性的分析清楚地解析了白眼鱼和索格鱼，并以高置信度对杂交种进行分类。在迪芬贝克湖中检测到 F ₁ 、F ₂和多代杂种，表明潜在的高水平基因组渗入。相比之下，在托宾湖中仅检测到F ₁杂种。鱼类的现场分类不可靠；根据广泛的物种类别，7% 的鱼类被错误识别。对于亲鱼选择等活动非常重要，173 个鱼场中的 12 个（7%）被确定为纯白眼鱼，24 个被确定为纯索格鱼的鱼场中有一个（4%）实际上是杂交鱼。此外，在现场鉴定的 15 个杂交品种中，有两个 (13%) 实际上是纯白眼鱼或索格鱼。我们的结论是，萨斯喀彻温省水库中正在发生杂交和基因渗入，因此在放养计划中使用这些群体时需要谨慎。 GBS 提供了强大而灵活的工具来检查杂交，无需预先识别信息基因座，从而消除了与其他标记类型相关的一些关键挑战。