Habura Andrea, Goldstein Susan T, Parfrey Laura W, Bowser Samuel S
Division of Molecular Medicine, Wadsworth Center, PO Box 509, Albany, New York 12201, USA.
J Eukaryot Microbiol. 2006 May-Jun;53(3):204-10. doi: 10.1111/j.1550-7408.2006.00096.x.
The classification of the Foraminifera, a widely distributed group of largely marine protists, has traditionally been based on morphological characters. The most important of these are the composition and structure of the shell or "test." Here, we use both phylogenetic analysis of the genes for small subunit rRNA and beta-tubulin and ultrastructural analysis to document a reversion in wall type from more derived calcareous tests to an agglutinated test. These data indicate that the genus Miliammina, and possibly other members of the Rzehakinidae, should be placed in the Order Miliolida as opposed to their current assignment in Order Textulariida. We also address the effects this reversion may have had on the ability of rzehakinacids to effectively colonize marginal marine environments. Finally, the hypothesis that some multilocular agglutinated foraminiferans descended from calcareous lineages has implications for interpretation of the foraminiferal fossil record.
有孔虫是广泛分布的主要为海洋原生生物的一个类群，其分类传统上基于形态特征。其中最重要的是外壳或“壳体”的组成和结构。在此，我们利用小亚基核糖体RNA和β-微管蛋白基因的系统发育分析以及超微结构分析，来记录壁类型从更为衍生的钙质壳体向胶结壳体的逆转。这些数据表明，麦粒虫属以及可能的泽哈金科的其他成员，应归入粟米虫目，而不是它们目前所属的编织虫目。我们还探讨了这种逆转可能对泽哈金酸有效地定殖于边缘海洋环境的能力产生的影响。最后，一些多房室胶结有孔虫起源于钙质谱系的假说对有孔虫化石记录的解释具有启示意义。
