Evaluation of the meaning of foraminiferal test morphology based on DNA sequences

为了评估底栖有孔虫测试形态的意义，对几个选定的属进行了分子系统发育分析。选择Glabratella和Bolibella及其相关属进行分析，因为这些属在形态学上已经有了很好的记录。DNA提取和PCR技术大多采用Pawlowski等（1995）。我们分析了路易斯安那州立大学核糖体DNA中约650个核苷酸碱基对。每个PCR步骤都使用有孔虫特异性引物。将扩增的DNA片段克隆到质粒载体上，然后用自动测序仪进行测序。Glabratella当地种群内的遗传变异低于Boliatella和Ammonia。这可能反映了有孔虫属之间生殖方式的差异。从核苷酸测序数据计算的分子同源性比基于形态学数据的同源性具有不同的簇群。用简约法和近邻连接法计算了分子系统树。集群组的分子数据，但是，以及相关的形态集群组的基础上功能形态学。例如，围绕孔区域的径向凹槽，这可能与生殖行为有关，在通过分子聚类分组的类群中是相似的。在Glabratella opercularis中，其中一个种群内的变异大于我们所研究的其他整个物种内的变异。其中，该种群的形态变异是有孔虫种群的典型变异，根据形态特征对种群进行细分是不可能的。这些结果表明，从功能形态学的角度重新评价有孔虫的测试形态，可能会使创建的形态学的基础上，是与分子生物学。

To evaluate the meaning of benthic foraminiferal test morphology, molecular phylogenetic analyzes have carried out for several selected genera. Glabratella and Bolivina and related genera were selected for analysis, because these genera have been well documented morphologically. Both DNA extractions and PCR techniques were mostly adopted from Pawlowski et al. (1995). We analyzed about 650 nucleotic acid base pairs from LSU ribosomal DNA.Specific primers for foraminifera were used for each PCR step. Amplified DNA fragments were cloned at plasmid vectors, then sequenced with an automatic sequencer.DNA sequences of forminifera show several interesting results. Genetic variation within local populations of Glabratella is lower than in Bolivina and Ammonia. This may reflect differences in mode of reproduction among foraminiferal genera. Molecular phylogenies calculated from nucleotide sequencing data had different cluster groups than a phylogeny based on morphological data. Calculations of the molecular phylogenetic trees were made with both parsimony and neighbor joining methods. Cluster groups of molecular data were, however, well related to morphological cluster groups that are based on functional morphology. For instance, radial grooves around the aperture area, which may be related to reproductive behavior, is similar among taxa grouped by molecular clustering. In Glabratella opercularis the variation within one of the populations was greater than that fpund within other entire species that we have studied. Whithin this population morphological variation is typical for foraminiferal populations and it is not possible to subdivide the population based on morphological characters. These results suggest that reevaluation of foraminiferal test morphology from the view point of functional morphology may enable creation of phylogenies based on morphology that are cnoformable with molecular phylogenies.