[SPECTRUM OF SPONTANEOUS PATHOLOGICAL CHANGES IN MOLE-VOLES AND THE EFFECT OF MITOCHONDRIA-TARGETED ANTIOXIDANT SkQ1 ON IT].

The mole vole (Ellobius talpinus (Pallas), Rodentia) is the object of interest for cytogenetics, ecology and gerontology research, peculiarly because of partial similarity of this animal to the unique long-living rodent, mole rat. In this work, the mole vole has been found to have very specific spectrum of tumors and non-tumor pathologies which vastly differs from pathological lesions spectrum in mole rat, laboratory mouse, rat and hamster. Mole voles had relatively small tumor incidence (9% totally in the observed population and 16% in animals dead after the achievement of the first tumor development age) and long minimal span of tumor latency (549 days) that is why this species could be categorized as cancer-resistant in compare to laboratory rodents (mice, rats, hamsters). The most common tumors in mole voles were hepatocellular neoplasms. Main non-tumor lesions were pneumonias and other septic and purulent diseases. Non-incapsulated, Gram-positive streptococci have been elucidated to be sole etiological agents in lesioned tissues. It is very important that septic and purulent diseases in mole voles commonly induced the neoplasia-like lesions (leukemoid reaction and "inflammatory pseudotumors"). Sex differences in pathological spectrum and incidences were not found. At last, it has been established that mitochondria-targeted antioxidant SkQ1 (which prolonged mole vole life span) did not significantly influence on spectrum and incidences of pathologies in mole voles.

[The activation of specific immunity in male mice stimulates fertility of their breeding partners: the phenomenon of lot's daughters].

In previous experimental studies on laboratory mice, it was shown that activation of specific immunity by injection with sheep red blood cells (SRBC) lessens males' sexual olfactory attractiveness for intact females. However, reduced attractiveness can decrease males' reproductive efficiency only under the conditions of free mating, which is not obligatory for natural populations. The goal of this work was to study the influence of immunoenhancement on sexual behavior and reproductive output of outbred ICR male mice. Males, either injected with saline (control group) or SRBC-treated, were kept with intact females during 5 days after injection. While the number of fertile copulations was practically equal in both groups, the potential (ovulated ova) and actual (number of embryos) fecundity was significantly higher in females having been paired off with SRBC-treated males. Main reproductive effects were registered at 3-5th day after injection, when specific antibody-forming process starts and males' scent becomes less attractive for females. On the base of previous and present data, the hypothesis is proposed that if the quality of a non-alternative mating partner is compromised by activation of specific immunity, a female tries to maximize its reproductive output (due to low chance of repeated copulation). This responsibility for the next generation is reminiscent of the Bible story about Lot and his daughters, and may help to sustain the species existence under conditions of parasitic press.

[The sexual behavior, chemosignals and reproductive success in the male mice during activation of nonspecific immune response].

Hypothesis of reproductive compensation (Gowaty et al., 2007) suggests that constraining of free mating preference leads to reduction of the viability of progenies, which could be, partially, compensated by higher fecundity of the constrained parents. We consider infection as one of natural causes constraining female mating choice, because infection or immune response to infection can modulate male sexual demonstrations. Here we studied influence of LPS (bacterial endotoxin, activating non-specific immune response) on chemical attractiveness, sexual behavior and reproductive success in the outbreed male mice mated with the non-treated females. Single or repeated LPS administrations lead to increase of scent attractiveness of the male urine and soiled bedding for the non-estrus females. Injection of LPS (dose 50 mkg/kg) did not suppress the male sexual behavior. Time from pairing to successful mating correlates positively with the body mass of 16 day embryo. Embryos development, assessed by their body mass, was reduced in the females mated with the LPS-treated males. Higher level of plasma progesterone found in the females mated with the LPS-treated males, and shift of successful mating to the later time did not compensate reduction of embryo mass. At the same time the females mated with the LPS-treated males showed lower embryo lost in comparison with the females mated with the control males.

[Scent-marking costs and reproductive success in male mice of outbred strain ICR].

Since non-territorial mice have as good chances for reproduction as territorial mice, we suppose that low territorial compatibility is compensated by higher breeding activity. Based on the scent war hypothesis, proteinuria was used as the criterion of territorial compatibility for male mice. Correlation between proteinuria, assessed as the protein/creatinine ratio, and reproductive output was studied in 22 male mice. Each male was caged with two females for five days. HPLC of urinary samples showed that more than 70 per cent of the proteins lay within the range 15-20 kDa. This result is typical for the major urinary proteins (MURs) which play the key role in chemical signalling im mice. Individual variation of the protein/creatinine ratio had good repeatability in the resampled urinary samples. Male proteinuria correlated negatively with early behavioural response to females, with mating success during the first two days, and with prenatal development of the progeny. Thus, the tradeoff between scent-marking efficiency determined by MUPs and breeding efficiency equalized the reproductive success of male mice with different ability of territorial competition.