Cellular differentiation and endosymbiosis revisited

In an earlier post on this page I discussed evidence that the eukaryotic nucleus is compartmentalized and how this compartmentalization may allow one compartment to become irreversibly differentiated through DNA rearrangements and deletions while leaving the remaining compartments untouched. I would like to take this one step further. These compartments may represent endosymbiotic integration events that generated tissue and cell types within multicellular organisms. The three primary germ layers found in all animals: ectoderm, mesoderm, and endoderm may be products of endosymbiotic events involving the genetic integration of three kinds of primitive eukaryotic cells. During differentiation, two of the compartments remain bound up by heterochromatin while the other one is active in producing its respective tissue type. Spatial considerations and signal transduction pathways determine when and where one particular compartment becomes active. Later in time, additional endosymbionts added to these three compartments would generate subcompartments leading to a further refinement in tissue differentiation until all of the known body cells have been generated. Plugging in huge sections of  genetic material (casettes) into a single attachment site would greatly facilitate evolution, allowing rapid selection of good casettes over bad ones through survival of the fittess.

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About frankabernathy

I am a retired cell biologist and alumnus of Ohio State University. I became interested in chromosomes as far back as the 1960's when I wrote a term paper on the effects of radiomimetic drugs on chromosomes. I was fascinated at how they could break apart and reform new structures so easily. I became further involved in the early 1970's after taking a cytogenetics course at the University of Arkansas. I took that knowledge with me to Ohio State in 1980 where I eventually worked on my research and completed my Ph.D. dissertation, "Studies on Eukaryotic DNA Superstructure". My studies and later research suggested that the DNA within the eukaryotic chromosome is not the simple, linear molecular thread so widely suggested in all the classic textbooks published today. Instead, it may be the culmination of a geologically rapid set of endosymbiotic events where microorganisms plug into each other to create something greater than themselves. Feel free to contact me at fabernathy@sbcglobal.net.
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One Response to Cellular differentiation and endosymbiosis revisited

  1. Shanel Incle says:

    Hello.This post was really interesting, especially since I was browsing for thoughts on this subject last Sunday.

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