A principle of natural self-organization

The Science of Nature - This paper is the first part of a trilogy, which comprises a detailed study of a special type of functional organization and demonstrates its relevance with respect to the...     

Transfer-RNA: The early adaptor

Evolutionary history of tRNA is studied by comparative sequence analysis of two specified tRNA's at various phylogenetic levels and of tRNA families within four different species. Criteria are developed that allow 1) to distinguish between convergent and divergent evolution, 2) to determine the mechanism of divergence and 3) to estimate the degree of randomization of the variable parts of the sequences. The conclusion of these investigations is that tRNA's represent ancient molecules that existed in the form of a mutant distribution prior to their integration into genomes.     

Transfer-RNA,an early gene?

The theory of self-reproductive molecular systems involves the consequence that translation must have started from a selected distribution of RNA molecules, that comprised GC-rich sequences of a length < 100 nucleotides. This implies a joint function of messenger and adaptor, which both had to be recruited from the same mutant distribution. The reconstruction of tRNA precursors yields such a molecule showing some reverberation of a codon pattern GNC. These findings suggest that tRNA has been the earliest component of the translation machinery.     

Transferability of HIV by arthropods supports the hypothesis about transmission of the virus from apes to man

The primate Pan troglodytes troglodytes, a chimpanzee subspecies, has recently been defined as a natural animal host of the human immunodeficiency virus (HIV). Apes are traditionally hunted in Africa and are offered for sale in open-air meat markets. The bloody carcasses are regularly covered with blood-feeding flies, amongst them possibly the stable fly (Stomoxys calcitrans L.), a cosmopolitically occurring biting fly. This fly is the effective vector for the retrovirus causing equine leukemia. According to laboratory experiments, the infectivity of ingested HIV is not reduced in the regurgitates of this fly. These findings are combined to explain the mechanism for a possible primary transmission of HIV from ape to man.     

The Hypercycle

The Science of Nature - The proposed model for a ‘realistic hypercycle’ is closely associated with the molecular organization of a primitive replication and translation apparatus....