片段複製長久以來被當作基因體成長及演化的重要機制[40,57]，最近確實了全基因體複製的確發生在酵母菌[50]及一些硬骨魚種類當中[53-54]。在這裡，我們提供了證據證明全基因體的倒位複製非常可能發生在至少一半的真細菌當中，更甚至絕大部份的染色體裡。我們研究了現有資料庫提供的染色體的倒位對稱並從中得到了證據。發現了絕大部份的染色體都擁有全域的倒位對稱，但在局部上的倒位對稱卻有幾種不同的樣式。這些樣式為倒位對稱的片段複製發生在基因體中的統一論述提供了線索。

Segmental duplication has long been known to be an important mechanism for genome growth and evolution [40,57], and recently it has been firmly established that whole-genome duplications have at least occurred in yeast [50] and in some species of fishes ray-finned fishes [53-54]. Here we present evidence showing that whole-genome inverse duplication very likely occurred in one half of eubacterial genomes, and possibly in most chromosomes, prokaryotic as well as eukaryotic. We derive our evidence through a comprehensive study of the inverse symmetry in all publicly available complete genomes. We find that a vast majority of chromosomes have close to maximum global inverse symmetry, but the chromosomes exhibit starkly distinct patterns of local inverse symmetry. These patterns provide clues for a consistent narrative of the many ways inverse segmental duplications may have occurred in genomes.

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