DIVERSE, ENDEMIC AND POLYPHYLETIC CLONES IN MIXED POPULATIONS OF A FRESH-WATER SNAIL (POTAMOPYRGUS-ANTIPODARUM)
DIVERSE, ENDEMIC AND POLYPHYLETIC CLONES IN MIXED POPULATIONS OF A FRESH-WATER SNAIL (POTAMOPYRGUS-ANTIPODARUM)
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DOI：
10.1046/j.1420-9101.1995.8030385.x
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发表时间：
1995-05-01
影响因子：
2.1
通讯作者：
LIVELY, CM
中科院分区：
文献类型：
--
作者：
DYBDAHL, MF;LIVELY, CM
了解克隆的来源和多样性对于解决围绕有性生殖的明显进化稳定性的复杂问题是必要的。克隆的来源是很重要的，因为目前的理论是建立在“其他一切都一样”的假设基础上的，这种假设是基于克隆突变体来自于本地有性种群并与之竞争的观点。克隆多样性很重要，因为它降低了在软选择（纠结河岸假说）或严格频率依赖选择（红皇后假说）下有性生殖的优势。在本研究中，利用蛋白质电泳技术对四个冰湖中被认为有性和无性生殖共存的淡水蜗牛（Potamopyrgus antipodarum）的克隆来源和多样性进行了分析。结果表明：(1)该种群为有性繁殖的二倍体和无性繁殖的三倍体的混合种群；(2)无性繁殖种群的基因型多样性均很高（但低于有性繁殖种群）；(3)无性繁殖种群是由有性繁殖种群多系进化而来。因此，自更新世以来，孤雌生殖的反复突变在所有四个湖泊中引入了一套不同的和多样化的克隆。这种多样性可能会对依赖于频率依赖性选择的性别生态学理论提出挑战。
Understanding the source and diversity of clones is necessary to resolve the complicated issues surrounding the apparent evolutionary stability of sexual reproduction. The source of clones is important because present theory is based on an ''all else equal'' assumption, which is predicated on the idea that clonal mutants are derived from and compete with local sexual populations. Clonal diversity is important because it reduces the advantage of sexual reproduction under either soft selection (the Tangled Bank Hypothesis) or under strict frequency-dependent selection (the Red Queen Hypothesis). In the present study, protein electrophoresis was used to determine the source and diversity of clones in a freshwater snail (Potamopyrgus antipodarum) in four glacial lakes in which sexual and clonal females were thought to coexist. The results showed (1) that the populations were mixtures of diploid sexual and triploid asexual individuals, (2) that genotypic diversity of clonal populations is very high in all four lakes (but lower than in the sympatric sexual populations), and (3) that the clones are polyphyletically derived from their sympatric sexual populations. Consequently, repeated mutation to parthenogenetic reproduction since the Pleistocene has introduced a different and diverse set of clones in all four lakes. Such diversity may provide a challenge for the ecological theories of sex that rely on frequency-dependent selection.