[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.

[Morpho-functional characteristics of reproductive organs of rodents from the area affected by a plant, processing gas with the increased content of sulfur compounds].

The biology of reproduction of 5 rodent species--small gopher (Spermophilus pygmaeus Pallas, 1778), reddish gopher (Spermophilus major Pallas, 1779), sasin lemmer (Lagurus lagurus Pallas,1773), forest mouse (Apodemus sylvaticus Linnaeus) and bank vole(Clethrionomys glareolus Schreber, 1780)--inhabiting the sanitary protective zone of the gas processing plant, was investigated with the use of histological, electron microscopical, immunocytochemical and morphometric methods. Intensification of the reproduction (growth of female fecundity, reduction of the puberty age) in some species (forest mouse) compensated for the negative changes in the reproduction, which resulted from the influence of the industrial factors (premature loss of ovarian follicular reserve, accelerated embryonic death rate, increased destructive changes in the gonads) and provided for the preservation of the population sizes. The intense functioning of reproductive organs in the other species (small and reddish gophers) was insufficient to compensate for the damage inflicted by the man-caused actions.