Hoef-Emden Kerstin, Shrestha Roshan Prakash, Lapidot Miri, Weinstein Yacob, Melkonian Michael, Arad Shoshana Malis
Universität zu Köln, Botanisches Institut, Lehrstuhl I, Gyrhofstr. 15, Köln, 50931, Germany.
J Mol Evol. 2005 Sep;61(3):360-71. doi: 10.1007/s00239-004-0366-3. Epub 2005 Jul 21.
The molecular phylogeny of red algal actin genes, with emphasis on the paraphyletic "Bangiophyceae," was examined and compared to the rhodophyte SSU rDNA phylogeny. Nineteen new genomic actin sequences and seven SSU rDNA sequences were obtained and subjected to diverse phylogenetic analyses (maximum likelihood, distance/neighbor-joining, maximum parsimony, Bayesian analyses, and, with respect to protein sequences, also quartet puzzling). The actin trees confirmed most of the major clades found in the SSU rDNA phylogenies, although with a lower resolution. An actin gene duplication in the florideophycean lineage is reported, presumably related to an increased complexity of sexual reproduction. In addition, the distribution and characteristics of spliceosomal introns found in some of the actin sequences were examined. Introns were found in almost all florideophycean actin genes, whereas only two bangiophyte sequences contained introns. One intron in the florideophycean actin genes was also found in metazoan, and, shifted by one or two nucleotides, in a glaucocystophyte, a cryptophyte, and two fungal actin genes, and thus may be an ancient intron.
研究了红藻肌动蛋白基因的分子系统发育，重点关注并系的“红毛菜纲”，并与红藻小亚基核糖体DNA（SSU rDNA）系统发育进行了比较。获得了19个新的基因组肌动蛋白序列和7个SSU rDNA序列，并进行了多种系统发育分析（最大似然法、距离/邻接法、最大简约法、贝叶斯分析，对于蛋白质序列还进行了四重奏迷惑法）。肌动蛋白树证实了在SSU rDNA系统发育中发现的大多数主要分支，尽管分辨率较低。报道了在红藻纲谱系中的一次肌动蛋白基因复制，推测与有性生殖复杂性的增加有关。此外，还研究了在一些肌动蛋白序列中发现的剪接体内含子的分布和特征。几乎在所有红藻纲肌动蛋白基因中都发现了内含子，而只有两个红毛菜纲序列含有内含子。红藻纲肌动蛋白基因中的一个内含子在后生动物中也有发现，并且在蓝隐藻、隐藻和两个真菌肌动蛋白基因中，其位置偏移了一两个核苷酸，因此可能是一个古老的内含子。
