When two amoeba cells form from one amoeba, does spindle fibers form? Some sources say that spindle fibers do not form while an amoeba cell is undergoing cell division. If spindle formation does not occur, than how are the chromosomes pulled apart? Which intracellular transport mechanisms are used?
Amoebas undergo binary fission, which is a much more simplistic process than mitosis. In binary fission, the duplicated chromosomes simply separate as the cells is pulled apart. There are no spindle fibers used in this method of cell division.
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Ok - so some of my references were a bit older, and I went through and looked through the literature a bit further - and found this great newer (ish) reference that actually used optical imaging to document the process of cell division: https://link.springer.com/content/pdf/10.1134/S1990519X16010041.pdf Demin, S. Y., Berdieva, M. A., Podlipaeva, Y. I., Yudin, A. L., & Goodkov, A. V. (2016). Optical tomography analysis of Amoeba proteus chromatin organization at various cell cycle stages. Cell and Tissue Biology, 10(1), 84-94.
The process by which they undergo chromosomal separation is a bit different in that there is no clearly identified kinetichore, but it looks as if microtubule spindles are involved. My error! The process of DNA replication and other stages are quite different in this process that in typical mitosis.