Search

Atavisms have attracted people's attention for a long time. First, atavisms excited their imagination and created fertile ground for myths and superstitions. With the development of science, atavisms became the subject of investigation, which soon provided evidence to support evolutionary theory. However, at the molecular level, the formation of atavisms remained insufficiently understood. Recent progress in comparative genomics and molecular developmental biology has helped in understanding the processes underlying the formation of one of the human atavisms: the vestigial tail. [ABSTRACT FROM AUTHOR]

The dynamics of global flows of matter in the biosphere has been studied. The general law of redistribution of average elemental compositions in the biosphere between the solid and liquid phases (lithosphere–hydrosphere) is established. In these processes, the main role is played by "living matter." The most active processes of redistribution of mean elemental compositions in the biosphere take place in the places of "life thickening" (biogeochemical barriers) such as ocean–atmosphere, river–sea and hydrosphere–lithosphere. The result of these processes is a general relative increase in the concentrations of trace elements in the environment of living organisms. A new methodological approach is proposed to study the role of the transfer of trace elements in the ocean–atmosphere–continent system as a factor in the formation of the elemental composition of the Earth's soil cover. [ABSTRACT FROM AUTHOR]

Abstract: The emergence of genomics and its use in combination with high-resolution bioimaging for the study of animal development mechanisms provide scientists with information on gene sets and regulation thereof during development. This enabled the identification of the core set of transcription factors involved in the development of invertebrates and vertebrates. This approach was particularly efficient due to the widespread use of transparent embryos of zebrafish and other bony fishes in these studies. These embryos can be used as model systems for the analysis of vertebrate development, even at the level of individual cells, as the various processes of development unfold in vivo. [ABSTRACT FROM AUTHOR]

Neurulation is traditionally defined as the process of closure of the neural tube. New data have shown that the major driving forces of neurulation continue to operate with the closure of the neural tube, at least until the central canal of the neural tube has formed. Owing to this, the paper proposes to distinguish two periods of neurulation. According to these notions, early neurulation corresponds to the period of closure of the neural tube, and late neurulation corresponds to the period of formation of the central canal. Examples of neural tube defects that affect late neurulation are discussed. [ABSTRACT FROM AUTHOR]

Mixed lineage leukemia 5 (MLL5) has been implicated in multiple aspects of cell physiology, such as hematopoiesis, cell cycle control and chromatin regulatory network. In this study, we present evidence that MLL5 is involved in the camptothecin (CPT)-induced p53 activation. CPT promoted the degradation of MLL5 protein in a time- and dose-dependent manner in actively replicating cells. The downregulation of MLL5 led to phosphorylation of p53 at Ser392, which was abrogated by exogenous overexpression of MLL5. In MLL5-knockdown cells, p53 protein was stabilized and bound to DNA with higher affinity, leading to activation of downstream genes. Co-immunoprecipitation showed that MLL5 preferentially interacted with the tetramerized form of p53, and knockdown of MLL5 promoted chromatin accumulation of p53 tetramers, suggesting that the association of MLL5 with p53 may prevent the p53 tetramers from binding to the chromatin target sites. The role of MLL5 in CPT-induced p53 activation was conserved in developing zebrafish, where CPT downregulated zebrafish Mll5 protein, and the microinjection of zebrafish mll5 mRNA substantially blocked the CPT-induced apoptosis. In summary, our study proposed MLL5 as a novel component in the regulation of p53 homeostasis and a new cellular determinant of CPT. [ABSTRACT FROM AUTHOR]

The article presents information on the biological process of transition from the maternal form of gene expression to a zygotic form (MZT) or midblastula transition (MBT), with special reference to the development of the loach Misgurnus fossilis. The book "Objects of Developmental Biology" provides detailed description of the developmental stages of loach, which is widely used as a model for research in developmental biology, biochemistry, and cryobiology.

The database “Objects for Storage and Disposal of Radioactive Wastes from Nuclear Fuel Cycle Enterprises” has been developed. Criteria were chosen for assessment of the hazard of storage and disposal (SD) objects for staff and population, and parameters based on these criteria were suggested: local hazard parameter and geospheric hazard parameter. To calculate the latter parameter, it is recommended to use simple models of radionuclide egress into the geosphere. The database can be used as an effective tool for ranging of SD objects of nuclear fuel cycle (NFC) enterprises in the order of decreasing hazard parameters. The use of a procedure for ranging of SD objects, tested with one of NFC enterprises as example, makes it possible to reveal the most hazardous SD objects at NFC enterprises and to decide on priority in decommissioning. [ABSTRACT FROM AUTHOR]

Studies of Km for glutathione peroxidase (GPx) and activities of superoxide dismutase and GPx were carried out in liver and erythrocytes of rats kept on either the normal semisynthetic diet or a high-fat diet with increased content of Cu, Zn, Mn, and Se. The diet containing microelement additions caused the increase in TBH affinity of liver and erythrocyte GPx, as well as the decrease of liver SOD observed on the 14th day of the treatment of rats with the high-fat diet with additional increase of Cu, Zn, Mn, and Se. [ABSTRACT FROM AUTHOR]

RhoA small GTPase, as a key regulator for actin cytoskeletal rearrangement, plays pivotal roles during morphogenesis, cytokinesis, phagocytosis and cell migration, but little is known about its signaling mechanism that controls cell survival in vivo. Using zebrafish as a model, we show that non-overlapping antisense morpholinos that block either translation or splicing of rhoA lead to extensive apoptosis during embryogenesis, resulting in overall reduction of body size and body length. These defects are associated with reduced activation of growth-promoting Erk and decreased expression of anti-apoptotic bcl-2. Moreover, ectopic expression of rhoA, Mek or BCL-2 mRNA rescues such phenotypes. Consistently, combined suppression of RhoA and Mek/Erk or Bcl-2 pathways by sub-optimal dose of rhoA morpholino and pharmacological inhibitors for either Mek (U0126) or Bcl-2 (HA 14-1) can induce developmental abnormalities and enhanced apoptosis, similar to those caused by effective RhoA knockdown. Furthermore, U0126 abrogates the rescue by RhoA and MEK but not BCL-2. In contrast, HA 14-1 effectively abolishes all functional rescues by RhoA, MEK or BCL-2, supporting that RhoA prevents apoptosis by activation of Mek/Erk pathway and requiring Bcl-2. These findings reveal an important genetic and functional relationship between RhoA with Mek/Erk and Bcl-2 for cell survival control during embryogenesis.Oncogene (2008) 27, 1580–1589; doi:10.1038/sj.onc.1210790; published online 17 September 2007 [ABSTRACT FROM AUTHOR]

The GFP gene controlled by a mini-promoter of the keratin-8 gene was cloned into a modified nonautonomous transposon Tol2 from the medaka genome. Such transposon cannot itself transpose, but external transposase allows it to integrate into the germ cell genome, where it remains after transposase is depleted. This gives rise to a transgenic zebrafish line stably maintained for many generations. This approach was used to obtain several tens of transgenic zebrafish lines, each of which demonstrates stably inherited pattern of GFP expression. This pattern depends on the enhancer activity in the vicinity of the transposon integration site. These lines can be used for the analysis of DNA sequences of enhancers, in vivo studies of complex cell morphogenesis, description of organs whose development has not been described in zebrafish, and analysis of activity of genes controlled by the identified promoters during development. Current data on the transgenic lines were integrated into the dedicated ZETRAP database. At the second stage of this project, the transposon was mobilized by a short-term exposure of two transgenic lines to transposase and left the initial chromosomal location. This allowed us to isolate about 20 transgenic lines with new expression patterns. This approach can be successfully used to study the zebrafish biology and anatomy, activity of the regulatory part of the genome, and development of new promising techniques in developmental biology and, in the foreseeable future, gene therapy. [ABSTRACT FROM AUTHOR]

The article recounts the introduction of embryologist Boris Balinsky, author of the book "An Introduction to Embryology," to embryology. Balinsky, an ex-professor of embryology of the Kiev University, got interested in the science of embryology upon reading Sergei Aksakov's story about collecting butterflies. In 1992, he carried his first research project following the experimental scheme set by embryologist Dmitrii Filatov. During and after the writing of the book, Balinsky was amidst social political changes in Russia. The book was finished and published outside Russia, hence Balinksy and his work, were never highly regarded in his country.

The surface instability of laminated composites of regular structure is analyzed in a three-dimensional linearized formulation. A case is considered where the material is compressed by a surface distributed dead or follower load. Numerical results are presented for a specific problem. [ABSTRACT FROM AUTHOR]

The new method for metering of the static parameters of the axially symmetric electron beams in the devices of the extremely high frequency (EHF) range is proposed in the paper. The method is based on using properties of the transition radiation of the optical range. The transition radiation appears when bombarding a metallic target electrode with electrons. Results of the meterings on distribution of current beam density by way of this method are given. The results are compared with the trajectory analysis when moving the electrons in the field of the investigated electron-optical system. [ABSTRACT FROM AUTHOR]