Soler Juan José, Martinez Juan Gabriel, Soler Manuel, Møller Anders Pape
Departamento de Biología Animal y Ecología, Facultad de Ciencias, Universidad de Granada, E-18071, Granada, Spain.
Laboratoire d'Ecologie, CNRS URA 258, Université Pierre et Marie Curie, 7 quai St. Bernard Case 237, F-75252, Paris Cedex 05, France.
Evolution. 1999 Jun;53(3):947-956. doi: 10.1111/j.1558-5646.1999.tb05388.x.
Host responses toward brood parasitism have been shown to differ among populations depending on the duration of sympatry between host and parasite, although populations not currently parasitized show rejection behavior against parasitic eggs. The persistence of rejection behavior in unparasitized host populations and rapid increases of rejection rate in parasitized ones have sometimes been explained as the result of gene flow of rejecter genes from sympatry to allopatry (rejecter-gene flow hypothesis). We present data on the rejection behavior of magpies (Pica pica) the main European host of the great spotted cuckoo (Clamator glandarius), in 15 populations (nine sympatric six allopatric) across their distribution range in Europe. Rejection rates of mimetic and nonmimetic model eggs were significantly higher in sympatric than in allopatric magpie populations, although differences in rejection rate of both mimetic and nonmimetic model eggs between magpie populations were significantly correlated even after controlling tor phylogenetic effects, with differences between sympatric and allopatric magpie populations being larger for mimetic than for nonmimetic model eggs. Differences in rejection of mimetic model eggs were related to both genetic and geographic distances between populations, but differences in rejection rate of nonmimetic model eggs were unrelated to these distances. However, when comparing only sympatric populations, differences in rejection rate of both mimetic and nonmimetic model eggs were related to geographic distances. A multiple autocorrelation analysis revealed that differences among populations in rejection rates of mimetic model eggs had a strong geographic component whereas the main component of rejection rate of nonmimetic model eggs was genetic rather than geographic. These results support the rejecter-gene flow hypothesis. We discuss differences in rejection rates of mimetic and nonmimetic model eggs that suggest the egg-recognition ability of the host is genetically based, but is affected by a learning process for fine tuning of recognition.
研究表明，宿主对巢寄生的反应在不同种群间存在差异，这取决于宿主与寄生虫的同域共存时间，尽管目前未被寄生的种群对寄生卵表现出排斥行为。未被寄生的宿主种群中排斥行为的持续存在以及被寄生种群中排斥率的快速上升，有时被解释为排斥基因从同域种群流向异域种群的基因流动结果（排斥基因流动假说）。我们提供了关于喜鹊（Pica pica）排斥行为的数据，喜鹊是欧洲大斑杜鹃（Clamator glandarius）的主要宿主，涉及欧洲分布范围内的15个种群（9个同域种群和6个异域种群）。同域喜鹊种群对模拟和非模拟模型卵的排斥率显著高于异域种群，尽管在控制系统发育效应后，喜鹊种群间模拟和非模拟模型卵的排斥率差异仍显著相关，且同域和异域喜鹊种群间模拟模型卵的差异大于非模拟模型卵。模拟模型卵排斥率的差异与种群间的遗传距离和地理距离都有关，但非模拟模型卵排斥率的差异与这些距离无关。然而，仅比较同域种群时，模拟和非模拟模型卵的排斥率差异都与地理距离有关。多重自相关分析表明，模拟模型卵排斥率的种群间差异具有很强的地理成分，而非模拟模型卵排斥率的主要成分是遗传而非地理成分。这些结果支持了排斥基因流动假说。我们讨论了模拟和非模拟模型卵排斥率的差异，这表明宿主的卵识别能力是基于遗传的，但受到一个用于精细调整识别的学习过程的影响。
