Reyes-Prieto Adrian, Bhattacharya Debashish
Mol Biol Evol. 2007 Nov;24(11):2358-61. doi: 10.1093/molbev/msm186. Epub 2007 Sep 6.
The phylogenetic position of the glaucophyte algae within the eukaryotic supergroup Plantae remains to be unambiguously established. Here, we assembled a multigene data set of conserved nuclear-encoded plastid-targeted proteins of cyanobacterial origin (i.e., through primary endosymbiotic gene transfer) from glaucophyte, red, and green (including land plants) algae to infer the branching order within this supergroup. We find strong support for the early divergence of glaucophytes within the Plantae, corroborating 2 important putatively ancestral characters shared by glaucophyte plastids and the cyanobacterial endosymbiont that gave rise to this organelle: the presence of a peptidoglycan deposition between the 2 organelle membranes and carboxysomes. Both these traits were apparently lost in the common ancestor of red and green algae after the divergence of glaucophytes.
蓝藻植物在真核生物超群植物界中的系统发育位置仍有待明确确定。在这里，我们从蓝藻植物、红藻和绿藻（包括陆地植物）中组装了一个多基因数据集，该数据集包含由蓝细菌起源的保守核编码质体靶向蛋白（即通过初级内共生基因转移），以推断这个超群内的分支顺序。我们发现有力证据支持蓝藻植物在植物界中早期分化，这证实了蓝藻植物质体与产生该细胞器的蓝细菌内共生体共有的两个重要的假定祖先特征：两层细胞器膜之间存在肽聚糖沉积以及存在羧酶体。在蓝藻植物分化后，这两个特征在红藻和绿藻的共同祖先中显然消失了。
