Association with Primitive Organisms

We also know that a considerable enrichment of prebiotic moieties may have come from submarine vents and other hydrothermal sources (see, for example, Miller and Bada, 1988 Holm and Andersson, 1998 Stetter, 1998). Let s start with the 1979 discovery of deep-sea vents with black smokers, which are associated with an extraordinary abundance of the most phylogenetically primitive organisms on Earth. This ecosystem is sulphur based, and is distinct from the more familiar, photosynthetically-based ecosystem that dominates Earth s surface. Corliss et al. (1981) were struck by the richness of the vent biota, based on chemosynthesis, and proposed that these were the origin of life. 

PROTIST A unicellular nucleate organism a primitive type or relatively primitive type, of organism always having nucleate cells it may be distinctly animal-like, distinctly plant-like, or they may have characteristics ordinarily associated with both plants and animals any member of the kingdom Protista. 

The pathology of scurvy has been summarized as a generalized structural breakdown of the intercellular matrix associated with undifferentiated cell proliferation, or in evolutionary terms (provided such a disintegrating individual could be kept alive), the gradual reversion from multicellular organization to a primitive unicellular state (50). 

In conclusion, these results indicate that Sulfolobus solfataricus ceU-free system contains a significant ADP-ribosyl transferase activity. It seems of relevant interest that this archaebacterium is the most primitive organism in which ADP-ribosylation has been demonstrated. Furthermore the enzymatic activity appears to be thermophilic, a unique property never observed for the same kind of enzyme isolated from other sources (17). Further studies are in progress on the purification and characterization of the enzyme to investigate its biological role. As mentioned above, several biochemical properties demonstrated that sulfur-dependent archaebacteria are closer related to eukaryotes than to eubacteria (3). These findings support the hypothesis that the ADP-ribosyl transferase activity which we found associated primarily with the nucleoprotein fraction of Sulfolobus solfataricus, could play a role in any cellular event in which the enzyme is known to be involved in eukaryotic cells (17). 

The interaction of polysilicic acids with polysaccharides appears to be an open field for investigation. There may be some common factor, as further evidenced by the finding that in the serum of silicotic patients there is an increase in mucoproteins and protein-bound hexoses, along with higher level of silica (248). Some association of polysaccharides with silica has probably existed since life began because in a primitive organism such as the diatom, when silica is deficient the cells become coated with a polyuronide of glucuronic residues (42), and no doubt the microporous silica skeleton is interpenetrated by this polymer. 

Significance and Mode of Action.— Langdon Brown has suggested that the animal autacoids are the survival of the primitive chemical apparatus which regulated the organism before the evolution of a central nervous system, which, when it arose, became allied to the pre-existing endocrine system in two ways. The sympathetic mechanism became associated with the adrenal, thyroid and pituitary glands the parasympathetic mechanism became associated with the insular tissue of the pancreas and with the choline bases. 

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