Radiation in sexual and parthenogenetic oribatid mites (Oribatida, Acari) as indicated by genetic divergence of closely related species
Radiation in sexual and parthenogenetic oribatid mites (Oribatida, Acari) as indicated by genetic divergence of closely related species
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DOI：
10.1023/a:1025833814356
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发表时间：
2003-01-01
影响因子：
2.2
通讯作者：
Thomas, RH
中科院分区：
文献类型：
--
作者：
Maraun, M;Heethoff, M;Thomas, RH
对4对近缘有性种（Eupelops hirtus和E. torulosus、距状小甲藻（Oribatella calcarata）和O. quadricornuta; Chamobates voigtsi和Ch. borealis; Liacarus coracinus和L. subhermaneus）和4对近缘孤雌生殖种（Nanhermannia nana和Na. coronata、Nothrus silvestris和No. palustris、Tectocepheus sarekensis和T. minor; Camisia spinifer和Ca. segnis）进行测序，以调查（1）D3区域是否可用作物种标记;（2）密切相关的物种对之间是否存在遗传变异，以及其大小是否与生殖模式相关。此外，我们调查了世界范围内的甲螨物种Platynothrus peltifer的D3区的遗传变异。在所研究的任何物种中，D3区域都没有种内遗传变异;甚至在两个密切相关的孤雌生殖物种（Na.娜娜和娜。coronata）和两个近缘的有性种（E. hirtus和E. torulosus）。其他种对的遗传差异表明孤雌生殖和有性生殖谱系都有不同的年龄。然而，平均而言，密切相关的单性生殖物种之间的差异大于密切相关的有性物种之间的差异，这表明单性生殖谱系在历史上存在，并且可能比有性物种辐射慢。这项研究的结果支持的假设，一些孤雌生殖甲螨类群（Tectocepheus，Nothrus）是“古老的无性生殖”。孤雌生殖物种的D3区域中没有种内或个体内变异与28 S rRNA基因中存在协同进化是一致的。从这一点，我们推断存在的减数分裂过程中，这是一致的automixy已知从其他几个孤雌生殖甲螨物种。
The D3 domain and its flanking regions of 28S rRNA of four pairs of closely related sexual species (Eupelops hirtus and E. torulosus; Oribatella calcarata and O. quadricornuta; Chamobates voigtsi and Ch. borealis; Liacarus coracinus and L. subterraneus) and four pairs of closely related parthenogenetic species ( Nanhermannia nana and Na. coronata; Nothrus silvestris and No. palustris; Tectocepheus sarekensis and T. minor; Camisia spinifer and Ca. segnis) of oribatid mites were sequenced to investigate ( 1) if the D3 region can be used as a species marker and ( 2) if there is genetic variation among closely related species pairs and if its magnitude is related to reproductive mode. Furthermore, we investigated the world-wide genetic variation of the D3 region from the oribatid mite species Platynothrus peltifer. There was no intraspecific genetic variation in the D3 region in any of the species studied; it was even identical in two closely related parthenogenetic species ( Na. nana and Na. coronata) and two closely related sexual species ( E. hirtus and E. torulosus). The genetic differences of the other species pairs indicated that both parthenogenetic and sexual lineages have various ages. On average, however, the differences between the closely related parthenogenetic species were larger than those between closely related sexual species, indicating that parthenogenetic lineages exist historically and may radiate slower than sexual species. The findings of this study support the hypothesis that some of the parthenogenetic oribatid mite taxa ( Tectocepheus, Nothrus) are 'ancient asexuals'. The absence of intraspecific or intra-individual variation in the D3 region of parthenogenetic species is consistent with the presence of concerted evolution in the 28S rRNA gene. From this we infer the existence of a meiotic process, which is consistent with the automixy known from several other parthenogenetic oribatid species.