A. A. Minin

Role of vimentin in cell migration

Cell migration plays a crucial role in embryonic development, wound healing, regeneration, inflammation, and immune response, as well as in dissemination of malignant tumors. Vimentin is the marker of migrating cells, but its role in cell migration is still unclear. However, recent studies have revealed novel functions for vimentin related to the migration, such as determination of cellular polarity, regulation of cell contact formation, and arrangement and transport of signal proteins involved in cell motility. The review sums up the latest data on vimentin functions and its involvement in molecular mechanisms underlying cell migration.Early studies demonstrated that vimentin expression during embryonic development is associated with cell migration. However, having obtained vimentin knockout mice without apparent impairments in development and ability to reproduce, doubts have appeared if vimentin is required for cell migration during embryonic development. In the present review, we also discuss involvement of vimentin in migration processes at different stages of development and try to resolve current contradictions concerning the role of vimentin in various events of cell migration.

Spontaneous activation of fish eggs is abolished by protease inhibitors

During spawning, eggs of most fish species entering the aquatic environment remain fertilizable for a relatively short period of time. This is due to the “spontaneous egg activation” giving rise to the fertilization membrane, which prevents the penetration of excessive and foreign sperm into the egg during normal fertilization. This work demonstrates that the fertilization membrane formation and the loss of fertilizability in aqueous solutions of different composition are inhibited by protease inhibitors, in particular, leupeptin and aprotinin. The presence of natural protease inhibitors in the ovarian fluid that prevent spontaneous egg activation is proposed. The decrease in the concentration of these inhibitors as the ovarian fluid is diluted in aquatic medium during spawning can explain egg activation in the absence of sperm.

Fish ovarian fluid contains protease inhibitors

Studies of the conditions under which fish egg is activated spontaneously without the sperm showed that the egg retains the ability for fertilization in the ovarian (coelomic) fluid, which surrounds it in the gonad cavity after ovulation. Earlier, we showed that, in artificial media, the spontaneous activation is suppressed by protease inhibitors. In this study, we investigated the presence of natural protease inhibitors in the ovarian fluid and showed that the ovarian fluid of zebrafish and loach contains protease inhibitors, in particular, type I serpin a, a protein inhibitor of trypsin proteases.

[Homeostatic responses of plants to modern climate change: spatial and phenological aspects].

A series of dates of unfolding of the first leaves and duration of the season of vegetation in the silver birch (Betula pendula Roth. (B. verrucosa Ehrh.)), as well as the duration of flowering of the bird cherry (Padus avium), mountain ash (Sórbus aucupária), and small-leaved lime (Tilia cordata Mill.) for the period 1970–2010 in the central part of European Russia were studied in order to assess the trends. Differences in phenological responses to homogeneous climate changes in the trees of the same species from the northern and southern parts of the range were revealed. If spring events occur 3–7 days earlier in the northern part, no such effect is observed in the south. This fact can be interpreted as a manifestation of the different mechanisms of homeostasis in different populations determined by their biological characteristics (in particular, by the need to pass successfully the periods of organic rest and vegetation).

A Study of Proteins of Annexin Group in Early Fish Development. IV. Identification of Calcium-Binding Proteins in Zebrafish Egg by Mass Spectrometry

Calcium-binding proteins were isolated from zebrafish (Brachydanio rerio) eggs by the method of precipitation with acidic phospholipids in the presence of calcium ions. The revealed proteins separated by SDS-PAGE were identified by mass spectrometric tryptic peptide fingerprinting. The proteins included annexins A2a, A1a, A13.1, and A5. In addition, copine III, a member of the recently described copine family of C2 domain-containing proteins, was identified. Total RNA was analyzed in mature oocytes by RT-PCR and transcripts of two different annexin A13 forms (A13.1 and A13.2) as well as of annexin A3 were detected. Thus, the presence of both proteins and mRNAs of annexins has been shown in the zebrafish egg.

Videomicroscopic Studies of the Movement of Mitochondria

A stable cell line CV-1 was obtained for vital observation of the transport of mitochondria in animals cells, which express a fragment of the resident protein of mitochondria marked by yellow fluorescent protein. The parameters and conditions of movement of the mitochondria in living cells were established using fluorescence videomicroscopy. Under the normal conditions, only a small part of mitochondria (ca. 7%) was transported over significant distances, while others were in the state of relative rest. The effective transport of mitochondria strictly depended on the dynamic properties of microtubules. Incubation of cell in a serum-free medium suppressed active transport of mitochondria, thus suggesting its dependence on certain, not yet determined environmental factors.

Hormonal induction of in vitro maturation and ovulation of loach oocytes and obtaining egg cells capable of fertilization and development

Loach oocytes that have reached a definitive size and are surrounded by follicular envelopes are capable of maturation and ovulating under the effect of 1 μg/mL progesterone in 75% Leibovitz medium with 1 g/L sodium bicarbonate or with pH adjustment to 9.0 by 1 N sodium hydroxide. Inseminated eggs are developed until the stage of prelarvae when adding 20% bovine serum to the incubation medium. Substitution of the bovine serum with 10–20% loach ovarian fluid or 20% carp ovarian fluid provides more complete development of inseminated eggs until the stage of larva that pass to active feeding.

Hormone-induced in vitro maturation and ovulation of Danio rerio oocytes and production of eggs capable of fertilization and futher development

It is common knowledge that zebrafish, Danio rerio, oocytes in their follicular envelope that have reached definitive size undergo in vitro maturation in 90% Leibovitz’s medium, pH 9.0, when treated with 17α, 20β-dihydroxyprogesterone and acquire developmental competence but do not ovulate (Seki et al., 2008). We have demonstrated that zebrafish oocytes that have undergone maturation under the indicated conditions ovulate when treated with prostaglandin F2α (5 μg/mL) and/or 20% carp ovarial fluid and are capable of development towards the actively feeding larvae upon fertilization (the maximum follow-up period).

Ethical Problems of Science in the Legacy of A.A. Neyfakh

There is a widespread opinion that Neyfakh at a certain moment abandoned science and got involved in popular and personal life, political activity, etc. and that science greatly suffered as a result. However, this side of Neyfakh’s life, like his research, proved to be far from fruitless. There are rather many science-popular and publicistic papers and autobiographic notes written by him, in which his views on problems not related to the science directly, the problems that affected and interested him, were reflected. The role of knowledge, science, and scientists in the society, intellect as a foundation of human activity and property of Homo sapiens , and problems of conscious choice—all these problems always attracted Neyfakh and were reflected in his works. It occurs not so often that more or less complete statements of a man on all these problems be preserved, especially if the man is a “physicist”, rather than “lyrist”, scientist and, in addition, a bright original man.