Proportion of prey consumed can be determined from faecal DNA using real-time PCR
Proportion of prey consumed can be determined from faecal DNA using real-time PCR
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DOI：
10.1111/j.1755-0998.2010.02974.x
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发表时间：
2011-05-01
影响因子：
7.7
通讯作者：
Trites, Andrew W.
中科院分区：
文献类型：
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作者：
Bowles, Ella;Schulte, Patricia M.;Trites, Andrew W.
重建鳍足类的饮食视觉识别猎物仍然回收粪便样本是具有挑战性的，因为消化和通过率的硬部分的差异。使用DNA为基础的技术分析粪便材料的软矩阵是一种替代手段，以确定猎物的物种消耗，但公布的技术在很大程度上是非定量的，这限制了它们的实用性，为某些应用程序。我们进一步开发和验证了一种实时PCR技术，使用物种特异性线粒体DNA引物，以量化的比例猎物的饮食中的斯特勒海狮（Eumetopias jubatus），鳍足类物种被认为是面临重大的饮食相关的挑战，在北太平洋。我们首先证明，从四个猎物物种中分离的DNA混合物中的猎物组织DNA的比例可以估计在一个类似于12%的混合物中的百分比的保证金。这些被捕食物种包括鲱鱼Clupea palasii，Eulachon Thaleichthyes pacificus，鱿鱼Loligo opalescens和玫瑰刺岩鱼Apricotes helvomaculatus。然后，我们应用实时PCR的粪便样本中提取的DNA从斯特勒海狮在人工饲养的鲱鱼，eulachon，鱿鱼和太平洋鲈鱼岩鱼（alutus），范围从7%到75%的贡献每餐（湿重）的11种不同的组合。通过实时PCR估计的平均百分比与所消耗的猎物百分比之间的差异对于所有喂食的饮食通常< 12%。我们的研究结果表明，粪便DNA的实时PCR可以检测到猎物消耗的近似相对数量的复杂的饮食和猎物物种，包括头足类和鱼类。
Reconstructing the diets of pinnipeds by visually identifying prey remains recovered in faecal samples is challenging because of differences in digestion and passage rates of hard parts. Analysing the soft-matrix of faecal material using DNA-based techniques is an alternative means to identify prey species consumed, but published techniques are largely nonquantitative, which limits their usefulness for some applications. We further developed and validated a real-time PCR technique using species-specific mitochondrial DNA primers to quantify the proportion of prey in the diets of Steller sea lions (Eumetopias jubatus), a pinniped species thought to be facing significant diet related challenges in the North Pacific. We first demonstrated that the proportions of prey tissue DNA in mixtures of DNA isolated from four prey species could be estimated within a margin of similar to 12% of the percent in the mix. These prey species included herring Clupea palasii, eulachon Thaleichthyes pacificus, squid Loligo opalescens and rosethorn rockfish Sebastes helvomaculatus. We then applied real-time PCR to DNA extracted from faecal samples obtained from Steller sea lions in captivity that were fed 11 different combinations of herring, eulachon, squid and Pacific ocean perch rockfish (Sebastes alutus), ranging from 7% to 75% contributions per meal (by wet weight). The difference between the average percentage estimated by real-time PCR and the percentage of prey consumed was generally < 12% for all diets fed. Our findings indicate that real-time PCR of faecal DNA can detect the approximate relative quantity of prey consumed for complex diets and prey species, including cephalopods and fish.