Vol 47, No 3 (2016)

Using ten microsatellite loci, paternity analysis has been conducted for 71 individuals of the Siberian crane (Grus leucogeranus Pallas) obtained under artificial insemination in Oka Crane Breeding Center in 2001–2014. The fathers of 39 chicks were the sires whose sperm was used for insemination directly before fertilized egg laying. Paternity of 23 fertilizations belonged to the sires whose sperm was used in the beginning or middle of insemination cycle. Nine cases of fertilization resulted from natural copulation of artificially inseminated females with their social partners. The terms of sperm storage in the female’s reproductive ducts before fertilization were 0–6 days in the case of paternity of the last sperm donor and 2–15 days in the case of competing sperm by previous donors. Genetic relatedness by microsatellite loci between breeders of the captive Siberian crane population does not prevent fertilization and does not always lead to inbreeding depression.

To date, the molecular mechanisms underlying the osmoregulation of pollen grains (PGs) related to the maintenance of their water status and allowing pollen tubes (PTs) to regulate concentrations in them of osmolytes and transmembrane water transport remain to be not so far characterized. In the present work, the data on the participation of IAA and ABA in the osmoregulation of germinating in vitro petunia male gametophyte were obtained. It has been established that the growth-stimulating effect of these phytohormones is due to their action on intracellular pH (pH_c), the membrane potential of plasmalemma (PM), the activity of PM H⁺-ATPase, K⁺-channels in the same membrane and organization of actin cytoskeleton (AC). Two possible targets of the action of these compounds are revealed. These are represented by (1) PM H⁺-ATPase, electrogenic proton pump responsible for polarization of this membrane, and (2) Ca²⁺-dependent K⁺-channels. The findings of the present work suggest that the hormone-induced pH_c shift is involved in cascade of the events including the functioning of pH-dependent K⁺-channels. It was shown that the hormoneinduced hyperpolarization of the PM is a result of stimulation of electrogenic activity of PM H⁺-ATPase and the hormonal effects are mediated by transient elevation in the level of free Ca²⁺ in the cytosol and generation of reactive oxygen species (ROS). The results on the role of K⁺ ions in the control of water-driving forces for transmembrane water transport allowed us to formulate the hypothesis that IAA and ABA stimulate germination of PGs and growth of PTs by activating K⁺-channels. In addition, the studies performed showed that the AC of male gametophyte is sensitive to the action of exogenous phytohormones, with to more extent to the action of IAA. As judged by the action of latrunculin B (LB) the AC may serve as the determinant of the level of endogenous phytohormones that most likely participate in the regulation of the polar growth of PTs impacting on the pool of F-actin in their apical and subapical zones.

Deschampsia antarctica3 E. Desv. is one of the two flowering plants that, along with Colobanthus quitensis (Kunth) Bartl., was able to settle the ice-free areas of Antarctica. In order to identify the possible adaptations of the D. antarctica reproductive system to adverse environmental conditions, comparative cytoembryological analysis of plants of this species growing on the Antarctic Peninsula with plants of the closely related species D. beringensis Hult. from the Kamchatka Peninsula was conducted. It was found that both species are characterized by sexual mode of reproduction, equal size of pollen grains (25.5 ± 2.2 and 26.2 ± 1.9 μm, respectively), same features of the embryo sac structure, and emryo- and endospermogenesis. Interspecies differences have been found in mature embryo sac size (326.8 ± 12.8 and 161.7 ± 10.4 μm), pollen sterility percentage (86.1 ± 8.9 and 35.3 ± 9.2%), and quantity of pollen in the anthers (140 ± 15.3 and 1578 ± 88.6). Possible causes and significance of these differences are discussed. No unique adaptations of seed reproduction system that are inherent exclusively to D. antarctica were found. The D. antarctica reproduction strategy is based on the combination of autogamy (and its extreme form cleistogamy) with production of excess pollen quantity for its mode of pollination.

Neurochemical differentiation of neurons in transplants developing in rat anterior eye chamber was studied. Pieces of the somatosensory neocortex area, isolated from 17-day fetuses of Wistar rats, were used for the transplantation. The general cytological analysis and immunochemical identification of GABAergic neurons in neocortical transplants and in the appropriate brain area of the recipient rats (control) were carried out after 6 months. Cytoarchitectonics typical for neocortex was not revealed in the transplants. Furthermore, a 1.4-fold decrease in numerical density of the entire neuron population was found compared to the control. The proportion of GABAergic nerve cells in the transplanted tissue was reduced even more dramatically— by 13.1 times. The dimensions of all types of neurons, especially GABAergic cells, were greater in the transplants in oculo compared to neocortex in situ. The increase in size occurred mostly due to the cytoplasm. Thus, the nuclei of GABA-positive neurons in the transplants were larger by 1.2 times compared to the control and their perikarya were larger by 1.5 times. The obtained results showed that the conditions in the anterior eye chamber the most dramatically affect the differentiation of GABAergic neurons, and cell hypertrophy, probably, is the functional compensation of the decrease in their number. Considering the literature data on the increased excitability and synchronized neuronal activity in the intraocular transplants, it can be assumed that these transplants can be used as a model for studying the cellular mechanisms of nervous tissue epileptization under disinhibition conditions.

This work is devoted to studying the morphology and biology of preimaginal stages of development of the parasitic wasp Minotetrastichus frontalis. The morphological characteristics of eggs and larvae, the features of interaction of the parasitic wasp with the host (Phyllonorycter issikii), and other biological characteristics were determined. For the species identification of the studied specimens of insects, we performed molecular genetic analysis using a nuclear 28S RNA gene fragment as a molecular marker. The result showed a strong genetic polymorphism of the populations of the studied species for the selected marker.