Diversity and selective pressures of anticoagulants in three medicinal leeches (Hirudinida: Hirudinidae, Macrobdellidae).
Diversity and selective pressures of anticoagulants in three medicinal leeches (Hirudinida: Hirudinidae, Macrobdellidae).
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DOI：
10.1002/ece3.480
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发表时间：
2013-04
影响因子：
2.6
通讯作者：
Siddall, Mark E
中科院分区：
文献类型：
--
作者：
Kvist, Sebastian;Min, Gi-Sik;Siddall, Mark E
虽然药用水蛭长期以来一直被用于治疗各种疾病，因为它们具有强大的抗凝因子，但抑制凝血的唾液成分的全部多样性以及作用于它们的进化选择都没有得到彻底的研究。在这里，我们构建了表达序列标签库从两个物种的药用水蛭，水蛭verbana和Aliolimnatis fenestrata的唾液腺，并确定抗凝剂的直系同源物通过BLASTx搜索。数据集，然后增加了一个以前构建的EST库从macrobdelloid水蛭Macrobdella decora。然后将鉴定的直系同源物与来自具有不同食性的各种水蛭（包括非嗜血物种）的充分表征的抗凝剂进行比较和对比。此外，四种不同的统计方法用于预测正和负进化压力的特征，每种方法用于10轮，以评估作用于整个分子和特定位点的选择的水平和类型。总的来说，在A. fenestrata和H. verbana EST文库。选择压力分析预测高水平的纯化选择抗凝剂的多样性，虽然一些孤立的网站显示出积极的选择签名。这项研究代表了第一次尝试在映射的抗凝剂库在几个水蛭家庭的比较方式。
Although medicinal leeches have long been used as treatment for various ailments because of their potent anticoagulation factors, neither the full diversity of salivary components that inhibit coagulation, nor the evolutionary selection acting on them has been thoroughly investigated. Here, we constructed expressed sequence tag libraries from salivary glands of two species of medicinal hirudinoid leeches, Hirudo verbana and Aliolimnatis fenestrata, and identified anticoagulant-orthologs through BLASTx searches. The data set then was augmented by the addition of a previously constructed EST library from the macrobdelloid leech Macrobdella decora. The identified orthologs then were compared and contrasted with well-characterized anticoagulants from a variety of leeches with different feeding habits, including non-sanguivorous species. Moreover, four different statistical methods for predicting signatures of positive and negative evolutionary pressures were used for 10 rounds each to assess the level and type of selection acting on the molecules as a whole and on specific sites. In total, sequences showing putative BLASTx-orthology with five and three anticoagulant-families were recovered in the A. fenestrata and H. verbana EST libraries respectively. Selection pressure analyses predicted high levels of purifying selection across the anticoagulant diversity, although a few isolated sites showed signatures of positive selection. This study represents a first attempt at mapping the anticoagulant repertoires in a comparative fashion across several leech families.