[Comparative morpho-functional characteristics of the organs of the reproductive system of small mammals under conditions of anthropogenic transformation of Southern Ural steppe ecosystems].

The morpho-functional characteristics of reproductive organs of small mammals--striped field mouse (Apodemus agrarius Pallas, 1771), house mouse (Mus musculus Linnaeus, 1758), wood mouse (Sylvaemus uralensis Pallas, 1811), common vole (Microtus arvalis Pallas, 1778), bank vole (Clethrionomys glareolus Schreber, 1780), steppe lemming (Lagurus lagurus Pallas, 1773), little suslik (Spermophilus pygmaeus Pallas, 1778), and red-heeked suslik (Spermophilus major Pallas, 1779)--belonging to the populations inhabiting anthropogenically modified steppe landscapes (zones influenced by the ferrous metallurgy plants and gas processing plant, as well as the territory of the large city) were studied using histological, electron microscopic, immunocytochemical and morphometric methods. In animals studied, inhabiting technologically modified ecosystems, in contrast to those from ecologically safe regions, the testis demonstrated the increased destruction of spermatogenic epithelium. In the ovaries, the accelerated exhaustion of follicular reserve was detected. The increased embryonic death rate was also observed. The portion of the animals participating in reproduction was enlarged, the female fecundity was increased, while the age at puberty was decreased. Among the animal species studied, the variable degree of stability against the effect of the negative factors was demonstrated.