Talbot Benoit, Balvín Ondřej, Vonhof Maarten J, Broders Hugh G, Fenton Brock, Keyghobadi Nusha
Department of Biology, University of Western Ontario, 1151 Richmond Street, London, Ontario, CanadaN6A 3K7.
Department of Ecology, Czech University of Life Sciences Prague, Kamýcká 129, 165 00 Praha 6 - Suchdol, Czech Republic.
R Soc Open Sci. 2017 Jun 21;4(6):170446. doi: 10.1098/rsos.170446. eCollection 2017 Jun.
Reciprocal selective pressures can drive coevolutionary changes in parasites and hosts, and result in parasites that are highly specialized to their hosts. Selection and host co-adaptation are better understood in endoparasites than in ectoparasites, whose life cycles may be more loosely linked to that of their hosts. Blood-feeding ectoparasites use salivary proteins to prevent haemostasis in the host, and maximize energy intake. Here we looked for signals of selection in salivary protein genes of ectoparasite species from a single genus () that associate with a range of hosts including mammals (bats and humans) and birds (swallows). We analysed two genes that code for salivary proteins that inhibit platelet aggregation and vasoconstriction and may directly affect the efficiency of blood feeding in these species. Significant positive selection was detected at five codons in one gene in all bat-associated species groups. Our results suggest association with bats, versus humans or swallows, has posed a selective pressure on the salivary apyrase gene in species of .
相互的选择压力可推动寄生虫和宿主的协同进化变化，并导致寄生虫对其宿主具有高度特异性。与外寄生虫相比，内寄生虫的选择和宿主共同适应更容易理解，外寄生虫的生命周期可能与其宿主的生命周期联系更为松散。吸血外寄生虫利用唾液蛋白来阻止宿主止血，并使能量摄入最大化。在这里，我们在来自单一属（）的外寄生虫物种的唾液蛋白基因中寻找选择信号，这些外寄生虫与一系列宿主相关，包括哺乳动物（蝙蝠和人类）和鸟类（燕子）。我们分析了两个编码唾液蛋白的基因，这些蛋白抑制血小板聚集和血管收缩，并可能直接影响这些物种的吸血效率。在所有与蝙蝠相关的物种组中，一个基因的五个密码子处检测到显著的正选择。我们的结果表明，与人类或燕子相比，与蝙蝠的关联对 物种的唾液腺苷三磷酸双磷酸酶基因施加了选择压力。
