关键词:
conservation genetics
fecal sampling
mitogenome
mito-nuclear discordance
Qinghai-Tibet Plateau
snow leopard
保护遗传学
粪便采样
线粒体基因组
核质冲突
青藏高原
雪豹
摘要:
Fecal samples are commonly used in conservation genetics for endangered and elusive species such as the snow leopard ( Panthera uncia ). However, the limited quantity and low quality of endogenous DNA in these samples present a challenge for acquiring genetic and genomic data. Previous studies of snow leopard mitochondrial DNA (mtDNA) phylogeography have produced inconsistent results, likely due to the limited sequencing length of PCR-based methods. To address this limitation, we performed Next-Generation Sequencing (NGS) on 19 fecal samples obtained from the eastern Qinghai-Tibet Plateau, resulting in 6.51–12.72 Gb of raw data per sample. We successfully assembled 17 complete mitogenome sequences (~16,720 bp) and identified 67 SNPs. Phylogeographic analysis revealed two divergent mtDNA lineages with a patristic distance of 0.31%, comparable to the divergence observed between major lineages of lions (0.38%–0.82%) and tigers (0.24%–0.56%). One lineage was predominantly found in the Qilian Mountains, while the other was more broadly distributed across the Sanjiangyuan Region and the Hengduan Mountains. These results reveal a considerable level of mtDNA diversity at a local scale, which was missed in a previous study focusing on short mtDNA segments. Our study demonstrates the promising applicability of mitogenome assembly via NGS of fecal DNA, and we anticipate that it may advance global snow leopard conservation genetics by alleviating technical hurdles and enhancing data sharing. 粪便样本因其非侵入式采样的优点, 在雪豹 ( Panthera uncia ) 等濒危且难以观测物种的保护遗传学研究中被广泛应用。然而, 粪便中内源DNA含量低且降解严重, 给获取高质量的遗传或基因组数据带来了显著挑战。此前关于雪豹线粒体DNA (mtDNA) 谱系地理的研究结果存在一定争议, 可能受限于传统PCR方法所获取的短序列片段。为突破这一局限, 本研究对来自青藏高原东部的19份粪便样本进行了二代测序 (NGS), 每个样本获得6.51至12.72 Gb的原始数据。我们成功组装了17条完整线粒体基因组序列 (约16,720 bp), 共鉴定出67个位点的单核苷酸多态性 (SNP) 。谱系地理分析显示, 雪豹存在两个明显分化的mtDNA支系, 其谱系距离达0.31%, 与狮 (0.38%–0.82%) 和虎 (0.24%–0.56%) 主要谱系之间的差异相当。其中一个支系主要分布于祁连山地区, 另一个则广泛分布于三江源和横断山脉地区。该结果揭示了雪豹在以往基于短片段的研究中被忽视的局域尺度上显著的mtDNA多样性。本研究验证了通过二代测序粪便DNA组装线粒体基因组的可行