Ecological scenario of the plague microbe <i>Yersinia pestis</i> speciation underlying adequate molecular evolutionary model

Abstract

It is known that the psychrophilic pseudotuberculosis microbe serotype 1 (Y. pseudotuberculosis 0:1b) causing Far East scarlet-like fever (FESLF) an intestinal infection found in a wide range of invertebrates and vertebrates inhabiting cold regions in the Northern and Central Asia as well as Far East is direct ancestor of the plague causative agent Yersinia pestis. However, the mechanism of Y. pestis speciation remains poorly elucidated. Numerous Y. pestis phylogenies created by using molecular genetic (MG) technologies are largely contradictory, being not in line with reliable data obtained by natural science approaches (e.g., ecology, epizootology, biogeography, and paleontology), which disagree with current evolutionary doctrine (synthetic theory of evolution). The MG approach provides no definitive answer to the questions of where, when, how, and under what circumstances the species Y. pestis arose. One of the reasons for such situation might be due to inadequacy of using the molecular evolutionary model for Y. pestis phylogenetics. Knowledge of the life cycles for the ancestral pseudotuberculosis and derivative plague microbes as well as related unique environmental features allows to create a reliable ecological model for the plague microbe evolution to be further used for assessing patterns of molecular variability and building proper molecular model that might be accepted for MG-reconstruction of plague microbe history. According to the ecological model, the species Y. pestis was formed in a tritopic manner (almost) simultaneously from FESLF clones (populations) in the three geographical populations of the Mongolian marmot-tarbagan (Marmota sibirica) and the flea Oropsylla silantiewi parasitizing on it. The inducer of speciation was coupled to the last maximum (Sartan) cooling in Central Asia occurred 2215 thousand years ago. Soil cooling and deep freezing resulted in altered behavior of the marmot flea larvae with emergence of facultative hematophagy, which, in turn, led to a unique traumatic (compared to routine alimentary) infection route of sleeping marmots with FESLF and, as a result, a unique way of Y. pestis speciation. The molecular model should predict a Y. pestis peripatric tritope speciation, existing numerous parallelisms in intraspecific variability associated with tritope speciation, and the quantum principle of speciation in the highly variable heterothermic (heteroimmune) stressful marmot-flea (Marmota sibirica Oropsylla silantiewi) host-vector environment involving stress-induced mutagenesis. Such molecular model of evolution may be useful for improving molecular methodology of phylogenetic constructions for a wide range of parasitic microorganisms.

Molecular phylogenies of the plague microbe <i>Yersinia pestis</i>: an environmental assessment

“…The causative agent of plague is the sole flea-borne ‘blood’ microbe of the ‘intestinal’ Enterobacteriaceae family, which suggests a unique way of its evolution and thus the application of an ad hoc evolutionary model for the reconstruction of its history [26] , [27] . Two aforementioned MG discoveries related to the evolution of the plague microbe allowed narration of a plausible ecological scenario of its history.…”

“…Two aforementioned MG discoveries related to the evolution of the plague microbe allowed narration of a plausible ecological scenario of its history. The uniqueness of transformation of the population (clone) of the ancestral causative agent of FESLF into the population of the plague microbe, i.e., the speciation, is in infecting the original host of the plague microbe, the Mongolian marmot, not by the traditional alimentary way on pasture, but by the traumatic way during hibernation [26] , [27] . The speciation process conformed to the quantum principle.…”