Alternative types of small mammal ontogeny: Contribution to the radiobiology and radioecology.

Abstract

96 Cyclomorphic mammals (including most small rodents) are characterized by cyclic changes in most biological parameters over a period of about one year, mass reproduction, and generation overlap with two alternative developmental pathways. They provide a basis for structural and functional rearrangements that facilitate survival through changing environmental conditions. It has been proved that every animal is polyvalent; i.e., it inherits two alternative programs of ontogenetic development in a single genotype, but only one of them is implemented under the influence of environmental factors [1]. The existence of two types of ontogeny is especially characteristic of rodent populations in temperate regions of the northern hemisphere with a strongly continental climate. This study considers the role of alternative ontoge� netic pathways when estimating radiation effects. It has been shown that acute and chronic radiation expo� sure is determined by the functional structuring of small rodent populations. Reactions of the population to acute and chronic radiation have been described. It was concluded that the ontogenetic type of animals should be taken into account in a wide range of stud� ies, when analyzing any biological parameters in the regions under techogenic pollution. The purpose of this study was to investigate radioresistance and effects produced by acute radia� tion (laboratory experiment), as well as strontium�90 accumulation in murine rodents representing alterna� tive types of ontogeny in the zone under technogenic