Variation in Bufadienolide Composition of Parotoid Gland Secretion From Three Taxa of Japanese Toads
Variation in Bufadienolide Composition of Parotoid Gland Secretion From Three Taxa of Japanese Toads
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DOI：
10.1007/s10886-020-01217-y
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发表时间：
2020-09-30
影响因子：
2.3
通讯作者：
Mori, Naoki
中科院分区：
文献类型：
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作者：
Inoue, Takato;Nakata, Ryu;Mori, Naoki
蟾蜍在它们的抛物线腺中合成和积累蟾酥二烯内酯(BDS)。BDS是一种强心类固醇，在防御蟾蜍捕食者方面发挥着重要作用。在日本大陆发现了三个蟾酥类群，它们分别是中华大蟾蜍、日本大蟾蜍和日本大蟾蜍。托伦蒂科拉。对分离自B.的BDS的化学结构进行了初步研究。几十年前就被研究过了，但关于日本蟾蜍的有毒成分及其新陈代谢还没有进一步的信息。在这项研究中，我们分析了来自日本各地的蟾蜍的BDS，并用液相色谱/质谱仪(LC/MS)和层次聚类分析(HCA)比较了BD的特征。我们在三个分类群中观察到了BDS，并通过核磁共振(NMR)分析鉴定了其中五个最常见的BDS。在五种BDS中，只在所有个体中检测到蟾酥。个体BD剖面的HCA将三个分类群划分为五个初级类群和几个亚类群。这一结果表明，BD剖面在分类群之间和分类群内都不同。BDS的聚类模式与由日本蟾蜍线粒体细胞色素基因构建的系统发育树基本一致。我们的结果表明，日本蟾蜍的BDS已经多样化，不是因为特定的选择压力，而是因为随着进化时间的推移，种群结构的变化。
Toads of the genusBufosynthesize and accumulate bufadienolides (BDs) in their parotoid glands. BDs are cardiotonic steroids that play an important role in defense against the toads' predators. Three bufonid taxa occur in mainland Japan,Bufo japonicus formosus,B. j. japonicus, andB. torrenticola. The chemical structures of BDs isolated fromB. j. formosuswere studied several decades ago, but there is no further information on the toxic components of Japanese toads and their metabolism. In this study, we analyzed BDs of toads from throughout Japan and compared the BD profiles by liquid chromatography/mass spectrometry (LC/MS) and hierarchical cluster analysis (HCA). We observed BDs in three taxa of Japanese toads, and identified five of the most common BDs by nuclear magnetic resonance (NMR) analyses. Of the five BDs, only bufalin was detected in all individuals. HCA of individual BD profiles divided the three taxa into five primary clusters and several subclusters. This result indicates that BD profiles differ both among and within the taxa. The clustering pattern of BDs is generally concordant with a phylogenetic tree reconstructed from the mitochondrial cytochromebgene of Japanese toads. Our results suggest that the BDs of Japanese toads have diversified not in response to specific selective pressures, but simply due to population structuring over evolutionary time.