TreeBASE Search-Trees for study 1035

@ARTICLE{TreeBASE2Ref14696, author = {Anke Behnke and Victor A. Chepurnov and Thomas Friedl and David G. Mann}, title = {Reproductive compatibility and rDNA sequence analyses in the Sellaphora pupula species complex (Bacillariophyta).}, year = {2003}, keywords = {}, doi = {}, url = {}, pmid = {}, journal = {Journal of Phycology}, volume = {}, number = {}, pages = {}, abstract = {In the Sellaphora pupula complex, a model system for investigations of the species concept and speciation in diatoms, it was tested in this study whether ITS rDNA sequence differences are correlated with sexual compatibility. Also the phylogenetic stucture among the demes and the phylogenetic position of the genus within the raphid diatoms was investigated. The division of clones of S. pupula and S. laevissima into groups, based on sequence similarities and phylogenetic analyses, reflected a grouping as based on sexual compatibility: a high ITS sequence divergence was found among clones whose gametangia do not interact, making full alignment difficult or impossible, while there was little sequence divergence among interfertile clones. This is clearly consistent with the idea that 'Z clades' exhibit less intraclade than interclade variation in ITS and, as comparisons of secondary structure models for the RECT and PSEUDOCAP clones showed, that there is an equivalence of 'CBC and Z-clades' in the rectangular and pseudocapitate demes of S. pupula, as earlier hypothesized for chlorophytes. Intraclonal, presumably intraindividual, variation in ITS was found in S. pupula with a degree of variation less than that found within a single Z clade and it was too minor to affect the interclonal relationships in the ITS phylogeny. Sellaphora, which appears monophyletic in 18S phylogenies and with Pinnularia and Navicula pelliculosa as its closest allies, may also include some species currently classified in Eolimna. The S. pupula-S. laevissima group began to diversify in or before the Miocene.} }