Canadian polar bear population structure using genome-wide markers

Predicting the consequences of environmental changes, including
human-mediated climate change on species, requires that we quantify
range-wide patterns of genetic diversity and identify the ecological,
environmental, and historical factors that have contributed to it. Here,
we generate baseline data on polar bear population structure across most
Canadian subpopulations (n=358) using 13,488 genome-wide single nucleotide
polymorphisms (SNPs) identified with double digest restriction
site-associated DNA sequencing (ddRAD). Our ddRAD dataset showed three
genetic clusters in the sampled Canadian range, congruent with previous
studies based on microsatellites across the same regions; however due to a
lack of sampling in Norwegian Bay, we were unable to confirm the existence
of a unique cluster in that subpopulation. These data on the genetic
structure of polar bears using SNPs provide a detailed baseline against
which future shifts in population structure can be assessed, and
opportunities to develop new non-invasive tools for monitoring polar bears
across their range.

预测环境变化（包括人类活动介导的气候变化）对物种的影响，需要我们量化物种全分布范围内的遗传多样性模式，并明确促成该模式的生态、环境与历史因素。本研究针对加拿大境内绝大多数北极熊亚种群（样本量n=358），利用双酶切限制性位点相关DNA测序（double digest restriction site-associated DNA sequencing, ddRAD）鉴定得到的13488个全基因组单核苷酸多态性（single nucleotide polymorphisms, SNPs）位点，生成了北极熊种群结构的基线数据。我们的ddRAD数据集在采样覆盖的加拿大分布区内鉴定出三个遗传聚类群，该结果与此前针对相同区域开展的微卫星标记研究结论一致；但由于挪威湾区域采样缺失，我们无法验证该亚种群存在独特遗传聚类群的推测。本研究基于SNPs位点解析北极熊遗传结构的数据，为评估未来种群结构变迁提供了详实的基线参考，同时也为开发用于全球北极熊分布区监测的新型非侵入式工具提供了契机。