Volume 50, Nº 5 (2019)

The article presents a brief review of the latest experimental data on sexual reproduction in the colonial volvocine algae, which represent a promising model for research on developmental biology. The main focus is on the MID gene, which determines sex and controls the “minus”/male differentiation in iso-gamous, anisogamous, and oogamous volvocine species. The experiments on sex transformation in a model species Volvox carteri f. nagariensis are critically analyzed. Studies of the gene FUS1, which controls gamete recognition and fertilization in the isogamous and anisogamous volvocine algae, are also considered.

The change in the rate and mass-specific rate of oxygen consumption was studied during individual ontogenesis of nine Planorbarius corneus individuals starting from 3 weeks after hatching until the death of animals. It is shown that, at the initial stages of development, the mass-specific rate of oxygen consumption increases, reaching a maximum at 3–7 weeks after hatching. The rate of oxygen consumption then permanently increases, and the mass-specific rate of oxygen consumption permanently decreases. The dependences of mass-specific rate of oxygen consumption (q) on the age (t) for individual P. corneus can be described by the equation q_st/(1 – exp(–k (t + t₀))). The values ​​of the coefficients of this equation for different specimens do not differ significantly and are, on average, k = 0.134 ± 0.016 weeks^–1; q_st = 0.117 ± 0.006 mL O₂/(h g). The dependence of the rate of oxygen consumption (Q, mL O₂/h) on body weight (M, g) in individual development is well described by allometric equations, the power coefficients of which vary from 0.647 to 0.944 and significantly differ from each other (p < 0.001). Nevertheless, the data for all mollusks can be described by the united equation Q = 0.061 M^0.795. The power coefficient of this equation does not significantly differ from the Hemmingsen constant 0.75.

Auxin is an important inductor of organogenesis. During leaf development, local sites with high auxin concentration initiate the formation of leaf primordia and venation, control the growth of lamina and lamina margin development. The proliferative activity of the leaf cells of the Arabidopsis thalianataeniata (tae) mutant and the role of auxin in the development of the ectopic secondary margins and lobes on the leaf of the mutant were analyzed in the study. It has been established that, in addition to the ability for ectopic proliferation of leaf cells, the tae mutant demonstrates a complex of traits characteristic of plants with impaired auxin transport. It was shown that a mutation in the PID gene, which disrupts the polar auxin transport, causes the suppression of ectopic outgrowths on the leaf of the tae mutant. These data indicate the important role of auxin transport in maintaining the leaf cell pluripotency and the development of lobes on the leaf of the tae mutant.

Analysis of root growth rate’s dependence on the holoploid DNA content was carried out on different plant species. Such dependence was found weakly negative in the primary roots of the dicot seedlings and in the lilioid adventitious root. The dependence was absent in the primary roots of the monocot seedlings. The relative elongation rate for the cortex cells of the dicot seedlings' primary roots also decreased with the increase in the holoploid DNA content. The data represent another example of a physiological process that is not directly related to DNA replication but whose rate depends on the genome size.

The aim of this work is to investigate the dynamics for the ovarian tissue engraftment of inbred August rats transplanted to outbred Wistar rats and vice versa on the background of the induction of donor-specific tolerance and to identify the features of proteasome pools in the surviving grafts and tissue replacing the rejected grafts in animals of both groups. By day 14 after transplantation, a slight difference in graft engraftment was revealed in studied recipients: 87% in Wistar rats and 80% in August rats. At the same time, ovarian tissue allografts with well-preserved structure and significant vascularization represented 76% in Wistar rats and only 29% in August rats on day 37. The difference revealed in the remote period is apparently connected with the special condition of the central nervous system of August rats caused by the increased content of monoamines and heat-shock protein 70. The total proteasome level on day 37 was the same both in intact donor tissue and in the surviving grafts, as well as in the tissue replacing the rejected grafts, and did not depend on the donor–recipient differences. However, the increased expression of immune proteasomes was found in the surviving tissue and tissue replacing the rejected grafts compared to intact donor tissue. The surviving grafts were enriched with proteasomes with immune subunit LMP2, and the tissue replacing the rejected grafts was enriched with proteasomes with immune subunit LMP7 equally in August and Wistar rats. In addition, the surviving grafts in both groups of animals were characterized by equally high expression of proteasome activator РА28αβ compared to the replacement and intact donor tissues. Thus, transplant proteasomes containing immune subunits LMP2, and probably associated with the activator RA28αβ, serve as one of the key factors for engraftment regardless of the genetically determined differences of the recipients.

In the search for stable factors regulating direct cell–cell interactions and effects on the properties of cells in aging organisms, the regulatory peptides Semax and HLDF-6 were studied. The circahoralian rhythm of protein synthesis in cells in vitro served as a marker of cell–cell interactions. The peptides normalized the cell–cell interactions, which are greatly weakened during aging. It is shown that the peptides organize the protein-synthesis rhythm in primary rat hepatocyte cultures. The effect of the HLDF-6 peptide was realized via metabotropic glutamate receptors; the blockade of these receptors by the antagonist MCPG abolished the effect of the peptide. The protein kinase inhibitor H7 prevented the effect of the peptides on the protein-synthesis kinetics. Just as for other signaling factors, the activation of protein kinases in the case of the peptides regulates the key process of direct cell–cell interactions. The effect of a single signal of each of the peptides was retained for at least 1 day. Our data allow the peptides to be recommended for improving elderly people’s condition and block the factors that disorganize the protein-synthesis kinetics.

Highly-efficient antiretroviral therapy allows controlling human immunodeficiency virus (HIV) and preventing the development of immunodeficiency. However, the patients who receive therapy may develop different complications, including B-cell lymphomas. One of oncogenesis’ mechanisms in HIV-infected patients is associated with the activity of the viral Tat protein, which is able to penetrate into B-cells. In order to study the effect of the Tat protein on B-cells, a report is given on the production and characterization of the cell lines based on the cultured RPMI 8866 B-cell line demonstrating constant and inducible expression of the Tat protein.

Embryonic development observations of the masked greenling H. octogrammus and the whitespotted greenling H. stelleri inhabiting the Tauiskaya Bay of the northern part of the Sea of Okhotsk have been performed under laboratory conditions. Both fish species developed a periblastic sinus during the fifth stage of embryogenesis; this has been observed for the first time for the representatives of Hexagrammidae family.