The mitochondrial challenge: Disorders and prevention strategies.

This short review provides basic knowledge on mitochondrial inheritance, its disorders, and potential ways to overcome them in human reproductive medicine. The latter are currently mostly associated with the so-called mitochondrial replacement (nuclear transfer) procedures, performed at different stages and with slight technical differences. Being promising but obviously highly invasive, these procedures require detailed investigation of their delayed effects on embryogenesis, pregnancy and future health. A special attention is paid to the newest available data on these issues, as well as to their limitations and possible further research directions.

Increasing complexity: Mechanical guidance and feedback loops as a basis for self-organization in morphogenesis.

The article is devoted to physical views on embryo development as a combination of structurally stable dynamics and symmetry-breaking events in the general process of self-organization. The first corresponds to the deterministic aspect of embryo development. The second type of processes is associated with sudden increase of variability in the periods of symmetry-breaking, which manifests unstable dynamics. The biological basis under these considerations includes chemokinetics (a system of inductors, repressors, and interaction with their next surrounding) and morphomechanics (i.e. mechanotransduction, mechanosensing, and related feedback loops). Although the latter research area is evolving rapidly, up to this time the role of mechanical properties of embryonic tissues and mechano-dependent processes in them are integrated in the general picture of embryo development to a lesser extent than biochemical signaling. For this reason, the present article is mostly devoted to experimental data on morphomechanics in the process of embryo development, also including analysis of its limitations and possible contradictions. The general system of feedback-loops and system dynamics delineated in this review is in large part a repetition of the views of Lev Beloussov, who was one of the founders of the whole areas of morphomechanics and morphodynamics, and to whose memory this article is dedicated.

Revisiting the mitogenetic effect of ultra-weak photon emission.

This paper reviews the 90 years long controversial history of the so-called "mitogenetic radiation," the first case of non-chemical distant interactions, reported by Gurwitsch (1923). It was soon described as ultraweak UV, emitted by a number of biological systems, and stimulating mitosis in "competent" (in this sense) cells. In the following 20 years this phenomenon attracted enormous interest of the scientific community, and gave rise to more than 700 publications around the world. Yet, this wave of research vanished after several ostensibly disproving works in late 1930-s, and was not resumed later, regardless of quite serious grounds for that. The authors discuss separately two aspects of the problem: (1) do living organisms emit ultraweak radiation in the UV range (irrespective of whether it has any biological role), and (2) are there any real effects of this ultraweak photon emission (UPE) upon cell division and/or other biological functions? Analysis of the available data permits to conclude, that UV fraction of UPE should be regarded real, while its biological effects are difficult to reproduce. This causes a paradox. A number of presently known qualities of UPE were initially discovered (predicted?) by the "early workers" on the basis of biological effects. Yet the qualities they discovered were proved later (the UV component of UPE, the sources of UPE among biological systems, etc…), while the biological effect they used for UPE "detection" remains questionable. Importance of this area for basic biology and medicine, and potential usefulness of UPE as a non-invasive research method, invite scientists to attack this problem again, applying powerful research facilities of modern science. Yet, because of complexity and uncertainty of the problem, further progress in this area demands comprehensive examination of both positive and negative works, with particular attention to their methodical details.

CO2 mediated interaction in yeast stimulates budding and growth on minimal media.

Here we show that carbon dioxide (CO2) stimulates budding and shortens the lag-period of Saccharomyces cerevisiae cultures, grown on specific weak media. CO2 can be both exogenous and secreted by another growing yeast culture. We also show that this effect can be observed only in the lag-period, and demonstrate minimal doses and duration of culture exposition to CO2. Opposite to the effects of CO2 sensitivity, previously shown for pathogens, where increased concentration of CO2 suppressed mitosis and stimulated cell differentiation and invasion, here it stimulates budding and culture growth.

Bridging the gap between physics and biology.

The work is devoted to the historical development of physics and biology. Various aspects of their interactions are shown: antagonism, mutual penetration and a lot of bridges, built or being built between them. The gradual "evolution of the world picture" from going away of the "pre-scientific" animated Universe and the appearance of mechanicism and vitalism to the development of systems and field approaches is traced. The last part of the paper is concerned with some present-day works at the joint between physics and biology.