Niloufar Boustanabadimaralan Düz, Pervin R Dinçer
Nucleus (plural nuclei) is the Latin term for the central organelle of eukaryotic cells. While the building blocks of eukaryotic cells (humans, plants and amoebas) feature command centers containing DNA, prokaryotes (Eubacteria and Arch aeb acteria) do not. This membrane-bound nucleus has played an indispensable role in the diversification of today's multicellular life, and the uncertainty surrounding its evolution has long been a puzzle for scientists studying the evolution of modern organisms. Emergence of the nucleus and our own origin are quite interlinked. Over the years, the subject of the origin of the eukaryotic nucleus has been discussed in depth by microbiologists, evolutionary biologists, cell biologists, etc., and even though the subject has brought many biologists together, their studies continue to produce different perspectives of the birth of the nucleus. We discuss here primarily theories arguing for the prokaryotic or viral origin of the nucleus, but also investigate reductive or gemmate theory which suggests that the origin of the nucleus dates back to the Last Universal Common Ancestor (LUCA), and that prokaryotes are a product of reductive evolution. Finally, we take a brief glance at the domain cell theory of life supporting the LUCA as the origin of the nucleus. In concordance with the domain cell theory, we also concluded that the origin of the nucleus rooted from the last universal common ancestor and all three domains of life evolved separately.