Stem cells ancient

Stem cells, haploid germ cells, somatic cells, transformed cells. The ancient unicellular life forms survived under the most adverse conditions in a chemically hostile, overheated (boiling water pouring lava volcanic fumes), chemically imbalanced as to excessive acidity or alkalinity, and heavily radioactive environment. The y-rays-irradiated but radiation-resistant Deinococcus radiodurans (Figure 4) suffers genomic damage it is its chaperone proteins in its proteome that perform the rescue of the genome (Mediterranean Instimte for Life Sciences, Split, Croatia). 

In multicellular hosts, the stem cell compartments preserved most of the faculties of the ancient RNA/DNA complex. The healthy stem cells RNA/DNA complex serves its multicellular host in its ontogenesis (in fertized egg cells, in the larvae, pupae and nymphs, or in the embryo). The pluripotent and asymmetrically dividing... 

The differentiated somatic cell of the integument (a keratinocyte) obeys proper biochemical orders (in the form of proto-oncoproteins with or without chemo-, cyto-, and lymphokines) to reverse its trajectory and become a stem cell, and then to re-differentiate into a nerve cell (Shinya Yamanaka s Nobel Prize, 2012). Improperly stimulated, it may become a basal cell carcinoma, or a squamous cell carcinoma. The ancient RNA/DNA complex will de-di ferentiate the mature somatic cell to its ancestral stage of existence. A fatal event mistakenly installed A process of re-juvenation inherently installed Is this a blind duty of the genomic retrotransposons for the maintenance of the living matter in whatever formation or shape (see in the text) ... 

The p53 protein induces miR-145. The ancient physiological posttranscriptional control of gene expression served the unicellular, and the non-vertebrate multicellular, hosts in environmental distress for survival. Stem cells of multicellular... 

Comment. There appear evidences that in the so called malignant transformation of somatic or stem cells in multicellular hosts, reversion takes place to an ancient life style of the cell. Trypanosoma can conceal its smface antigens, as transformed cells in a multicellular host also refrain from antigenic expression by withholding their histocompatibility complexes. In a nutrient rich environment. Trypanosoma cells replicate and maintain their telomere lengths after each cell divisions (especially when replicating in liquid media). 

Ancient stem cells at work. Signaling was fiiUy operational over 550 million years ago in the phylum Cnidaria. Extant representative descendants are the eumetazoan Hydra polyps, the colonial marine hydroids, Hydractinia, and the starlet sea anemone, Nematostella vectensis (Anthozoa, within Cnidaria) (Figure 37). 

Figure 37 The Ancient Stem Cells Regenerate the Mutilated Cnidaria Hydra. Reference Appendix 2, Explanations to the Figures...

Comment. The trajectory of the proto-oncogenes of the multicellular hosts covered the distance close to a miUiard (billion) years. In the stem cells of the multicellular hosts, these genes still may display their ancient features in dictating early cell divisions and instant telomere repairs, thus exempting their vehicles (the cells) from senescence and natural death. 

Comment. In the primordial cells, and in the early multicellular eukaryotes, the RNA/DNA complex raled the intron-rich primordial cells (LECA/LUCA of Csuros et al). In multicellular eukaryotes, the single stem cells retain the ancient mler, the RNA/DNA complex. So are the zygote-derived early embryonic cells. The dominant somatic cell mass in the advanced multicellular hosts is under the strict rule of a DNA/RNA complex. Once transformed, in these cells the RNA/DNA complex regains its primordial vitality manifested by the expression of introns and their derivative multiple RNAs. The presumably intron-rich transformed cell re-gained the immortality, independence and persistence endowed to the original unicellular eukaryotes, which survived the most severe conflicts in the environment of the... 

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