Khan Muhammad Salabat, Guan De-Long, Kvist Sebastian, Ma Li-Bin, Xie Juan-Ying, Xu Sheng-Quan
College of Life Sciences Shaanxi Normal University Xi'an China.
Department of Ecology and Evolutionary Biology University of Toronto Toronto Ontario Canada.
Ecol Evol. 2019 Mar 18;9(8):4706-4719. doi: 10.1002/ece3.5074. eCollection 2019 Apr.
The medicinal utility of leeches has been demonstrated through decades of use in modern hospital settings, mainly as relievers of venous congestion following flap or digit replantation surgery. In the present study, we sequence and annotate (through BLAST- and Gene Ontology-based approaches) the salivary transcriptome of the nonblood feeding hirudinid and assess the differential gene expression of anticoagulation factors (through both quantitative real-time PCR [qRT-PCR] and in silico-based methods) during feeding and fasting conditions. This was done in order to evince the diversity of putative anticoagulation factors, as well as estimate the levels of upregulation of genes immediately after feeding. In total, we found sequences with demonstrated orthology (via both phylogenetic analyses and BLAST-based approaches) to seven different proteins that have previously been linked to anticoagulatory capabilities-eglin C, bdellin, granulin, guamerin, hyaluronidase, destabilase I, and lipocalin. All of these were recovered from leeches both in the fasting and in the feeding conditions, but all show signs of upregulation in the feeding leeches. Interestingly, our RNA-seq effort, coupled with a hypergeometric test, indicated that the differentially expressed genes were disproportionately involved in three main immunological pathways (endocytosis, peroxisome regulation, and lysosome regulation). The results and implications of the finding of anticoagulants in this nonblood feeding leech and the putative upregulation of anticoagulation factors after feeding are briefly discussed in an evolutionary context.
数十年来，水蛭在现代医院环境中的药用价值已得到证实，主要用于缓解皮瓣或断指再植手术后的静脉淤血。在本研究中，我们对非吸血水蛭的唾液转录组进行了测序和注释（通过基于BLAST和基因本体论的方法），并评估了进食和禁食条件下抗凝因子的差异基因表达（通过定量实时PCR [qRT-PCR]和基于计算机模拟的方法）。这样做是为了揭示假定的抗凝因子的多样性，并估计进食后基因的上调水平。我们总共发现了与七种不同蛋白质具有直系同源性的序列（通过系统发育分析和基于BLAST的方法），这些蛋白质先前已与抗凝能力相关——依格林C、蛭素、颗粒蛋白、瓜美蛋白、透明质酸酶、去稳定酶I和脂蛋白。所有这些在禁食和进食条件下的水蛭中均有发现，但在进食的水蛭中均显示出上调的迹象。有趣的是，我们的RNA测序工作结合超几何检验表明，差异表达基因在三个主要免疫途径（内吞作用、过氧化物酶体调节和溶酶体调节）中不成比例地参与。在进化背景下简要讨论了在这种非吸血水蛭中发现抗凝剂以及进食后抗凝因子假定上调的结果和意义。
