Abstract:
The genomes of peridinin-containing dinoflagellate chloroplasts have a very unusual organisation. These genomes are highly fragmented and greatly reduced, with most of the usual complement of chloroplast genes relocated to the nucleus. Dinoflagellate chloroplasts highlight evolutionary changes that are found to varying extents in a number of other organelle genomes. These include the chloroplast genome of the green alga Boodlea and other Cladophorales, and the mitochondrial genomes of blood-sucking and chewing lice, the parasitic plant Rhopalocnemis phalloides, the red alga Rhodosorus marinus and other members of the Stylonematophyceae, diplonemid flagellates, and some Cnidaria. Consideration of the coding content of the remnant chloroplast genomes indicates that organelles may preferentially retain genes for proteins important in initiating assembly of complexes, and the same is largely true for mitochondria. We propose a new principle, of CO-location for COntrol of Assembly (COCOA), indicating the importance of retaining these genes in the organelle. This adds to, but does not invalidate, the existing hypotheses of the multisubunit completion principle, CO-location for Redox Regulation (CORR) and Control by Epistasy of Synthesis (CES).
摘要:
含peridinin的鞭毛蛋白叶绿体的基因组具有非常不寻常的组织。这些基因组是高度分散的,并且大大减少,与大多数常见的叶绿体基因互补迁移到细胞核。鞭毛状叶绿体突出了在许多其他细胞器基因组中发现的不同程度的进化变化。其中包括绿藻Boodlea和其他紫菜的叶绿体基因组,以及吸血和咀嚼虱子的线粒体基因组,一种寄生植物,红藻和Stylonematphyceae的其他成员,双粒鞭毛虫,还有一些Cnidaria.对剩余叶绿体基因组的编码含量的考虑表明,细胞器可能优先保留在启动复合物组装中重要的蛋白质的基因,线粒体也是如此。我们提出了一个新的原则,组装控制(COCOA)的共同位置,表明在细胞器中保留这些基因的重要性。这增加了,但不会无效,多亚单位完成原则的现有假设,用于氧化还原调节(CORR)的共定位和通过合成上位药(CES)进行控制。