Warburton Elizabeth M, Khokhlova Irina S, Kiefer Daniel, Krasnov Boris R
Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben-Gurion 8499000, Israel
Wyler Department of Dryland Agriculture, French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben-Gurion 8499000, Israel.
J Exp Biol. 2017 Apr 1;220(Pt 7):1307-1312. doi: 10.1242/jeb.148338. Epub 2017 Jan 30.
Morphological asymmetry is widely used to measure developmental instability and higher levels of asymmetry often correlate with decreased mating success, increased inbreeding, increased stress and decreased habitat quality. We studied asymmetry and relationships between asymmetry and host identity in two flea species, host generalist and host specialist , and asked: (1) what the level of asymmetry was in their femurs and tibiae; (2) which type of asymmetry predominates; and (3) whether fleas that fed on host species distantly related to their principal host species produced offspring that exhibited greater asymmetry compared with offspring of fleas that fed on their principal host species. We found fluctuating asymmetry in femurs and tibiae of and in the tibiae of as well as significantly left-handed directional asymmetry in the femurs of Host species identity significantly impacted asymmetry in leg segments of but not in those of Offspring asymmetry increased when mother fleas fed on a host that was distantly related to the principal host. Fleas parasitizing multiple host species might compensate for developmental instability when utilizing a novel host species; therefore, host-switching events in host-specific parasites could be constrained by the relatedness between a novel and a principal host species.
形态不对称性被广泛用于衡量发育不稳定性，较高水平的不对称性通常与交配成功率降低、近亲繁殖增加、压力增大以及栖息地质量下降相关。我们研究了两种跳蚤（广宿主跳蚤和专宿主跳蚤）的不对称性以及不对称性与宿主身份之间的关系，并提出以下问题：（1）它们股骨和胫骨的不对称水平如何；（2）哪种类型的不对称占主导；（3）以与其主要宿主物种亲缘关系较远的宿主物种为食的跳蚤所产生的后代，与以主要宿主物种为食的跳蚤的后代相比，是否表现出更大的不对称性。我们发现，[具体跳蚤物种1]的股骨和胫骨以及[具体跳蚤物种2]的胫骨存在波动不对称性，同时[具体跳蚤物种3]的股骨存在显著的左旋方向不对称性。宿主物种身份对[具体跳蚤物种1]腿部节段的不对称性有显著影响，但对[具体跳蚤物种2]没有影响。当母蚤以与主要宿主亲缘关系较远的宿主为食时，后代的不对称性会增加。寄生于多种宿主物种的跳蚤在利用新宿主物种时可能会补偿发育不稳定性；因此，宿主特异性寄生虫中的宿主转换事件可能会受到新宿主与主要宿主物种之间亲缘关系的限制。
