Читать книгу Algorithms in Bioinformatics - Paul A. Gagniuc - Страница 40

All eukaryotic cells contain membrane-bound organelles (e.g. the nucleus, mitochondria, chloroplasts, and so on). The complexity of the eukaryotic cell is given by the presence and the interaction of organelles. The origin of organelles has always been a mystery difficult to explain. However, the endosymbiotic theory is the leading evolutionary theory for the origin of eukaryotic cells. The idea of endosymbiosis was first proposed by Konstantin Mereschkowski in 1905 [96, 97]. According to the theory of endosymbiosis, the eukaryotic cell is like a Matryoshka (Russian doll). A symbiotic relationship where one organism lives inside the other is known as endosymbiosis. The term “primary endosymbiosis” refers to the engulfment and retention of a prokaryote organism by another prokaryote or eukaryote organism. The term “secondary endosymbiosis” refers to one eukaryote organism having engulfed and retained another eukaryote organism with an organelle already obtained by primary endosymbiosis. Note that today the endosymbiotic behavior is most beautifully observed in protists (e.g. Paramecium bursaria).