Editing Inverted repeat (section)

===Regions where presence is obligatory===
Terminal inverted repeats have been observed in the DNA of various eukaryotic transposons, even though their source remains unknown.<ref name=Zhang>{{cite journal|last=Zhang|first=HH|author2=Xu, HE |author3=Shen, YH |author4=Han, MJ |author5= Zhang, Z |title=The Origin and Evolution of Six Miniature Inverted-Repeat Transposable Elements in Bombyx mori and Rhodnius prolixus|journal=Genome Biology and Evolution|date=January 2013|volume=5|issue=11|pages=2020–31|pmid=24115603|doi=10.1093/gbe/evt153 |pmc=3845634}}</ref> Inverted repeats are principally found at the origins of replication of cell organism and organelles that range from phage plasmids, mitochondria, and eukaryotic viruses to mammalian cells.<ref name=Pearson>{{cite journal|last=Pearson|first=CE|author2=Zorbas, H |author3=Price, GB |author4= Zannis-Hadjopoulos, M |s2cid=22204780|title=Inverted repeats, stem-loops, and cruciforms: significance for initiation of DNA replication|journal=Journal of Cellular Biochemistry|date=October 1996|volume=63|issue=1|pages=1–22|pmid=8891900|doi=10.1002/(SICI)1097-4644(199610)63:1<1::AID-JCB1>3.0.CO;2-3}}</ref> The replication origins of the phage G4 and other related phages comprise a segment of nearly 139 nucleotide bases that include three inverted repeats that are essential for replication priming.<ref name=Pearson />