The zebrafish van gogh mutation disrupts tbx1, which is involved in the DiGeorge deletion syndrome in humans

The van gogh (vgo) mutant in zebrafish is characterized by defects in the ear, pharyngeal arches and associated structures such as the thymus. We show that vgo is caused by a mutation in tbx1, a member of the large family of T-box genes. tbx1 has been recently suggested to be a major contributor to the cardiovascular defects in DiGeorge deletion syndrome (DGS) in humans, a syndrome in which several neural crest derivatives are affected in the pharyngeal arches. Using cell transplantation studies, we demonstrate that vgo/tbx1 acts cell autonomously in the pharyngeal mesendoderm and influences the development of neural crest-derived cartilages secondarily. Furthermore, we provide evidence for regulatory interactions between vgo/tbx1 and edn1 and hand2, genes that are implicated in the control of pharyngeal arch development and in the etiology of DGS.     

Effect of weak magnetic fields on the capacity of various proteins and polyamino acids to form complexes with DNA

It was shown that preliminary treatment of the protein component (histone H3, protamine sulfate, polyarginine) of a DNA-protein complex with weak combined (42 microT) and low-frequency (3.5-5.0 Hz) alternating (0.06 microT) magnetic fields adjusted formally to the cyclotron resonance of amino acid ions charged under natural conditions leads to substantial changes in complex formation and formation of complexes of a different type than without treatment.     

Investigation of the possibility of exceeding the Greenwald density limit during ECRH in T-10

In T-10 experiments, attempts were made to significantly exceed the Greenwald limit $\bar n_{Gr} $ during high-power (P _ab=750 kW) electron-cyclotron resonance heating (ECRH) and gas puffing. Formally, the density limit $(\bar n_e )_{\lim } $ exceeding the Greenwald limit $({{(\bar n_e )_{\lim } } \mathord{\left/ {\vphantom {{(\bar n_e )_{\lim } } {\bar n_{Gr} }}} \right. \kern-0em} {\bar n_{Gr} }} = 1.8)$ was achieved for q _L=8.2. However, as q _L decreased, the ratio ${{(\bar n_e )_{\lim } } \mathord{\left/ {\vphantom {{(\bar n_e )_{\lim } } {\bar n_{Gr} }}} \right. \kern-0em} {\bar n_{Gr} }}$ also decreased, approaching unity at q _L≈3. It was suggested that the “current radius” (i.e., the radius of the magnetic surface enclosing the bulk of the plasma current I _p), rather than the limiter radius, was the parameter governing the value of $(\bar n_e )_{\lim } $ . In the ECRH experiments, no substantial degradation of plasma confinement was observed up to $\bar n_e \sim 0.9(\bar n_e )_{\lim } $ regardless of the ratio ${{(\bar n_e )_{\lim } } \mathord{\left/ {\vphantom {{(\bar n_e )_{\lim } } {\bar n_{Gr} }}} \right. \kern-0em} {\bar n_{Gr} }}$ . In different scenarios of the density growth up to $(\bar n_e )_{\lim } $ , two types of disruptions related to the density limit were observed.     

Study of the integral toxicity of aqueous media, polluted by petroleum and petroleum products using bacterial tests

A biotest kit was used to assess the integral toxicity level of aquatic medium contamination with petroleum and petroleum-based products. The integral toxicity dynamics was also monitored during biodegradation of petroleum and petroleum-based products by an association of petroleum-degrading strains including Acinetobacter sp., Mycobacterium flavescens, and Rhodococcus sp. The following bacterial tests were used: the bioluminescence (BL) test based on Photobacterium leiognathi; electro-orientation (EO), optoosmotic (OO), and growth test; as well as the reducing activity (RA) test based on the Agrobacterium radiobacter culture. No significant increase in the integral toxicity level of aquatic medium was observed when diesel fuel and kerosene contamination had been subjected to biodegradation. Although express biotests (EO, OO, RA, and BL) detected a pronounced increase in the integral toxicity of aquatic medium, long-term growth biotest revealed no statistically significant increase in the toxicity level.     

Allozyme Variation Patterns and Multiple Hybridization Origins: Clonal Variation Among Four Sibling Parthenogenetic Caucasian Rock Lizards

Allozyme electrophoresis of four sibling parthenogenetic Caucasian rock lizards Darevskia unisexualis, D.uzzelli, D.sapphirina, and D.bendimahiensis found seven clones and five variable loci. The data supported the hypothesis that D.raddei and D.valentini are the parental species of all four parthenogens. Variation patterns in Darevskia were summarized. Species that originated from a single F₁ typically consisted of one widespread clone with a few rare clones. Species with multiple origins displayed variation only slightly higher than species with a single origin. This is contrary to other genera of parthenogenetic lizards, in which cases massive clonal variations were observed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Transabiotic factors in an aqueous environment (a review)

Excretion of metabolites is a characteristic feature of any alive organism. A big group of these products--second metabolites--because of their variability, quantity and physico-biological activity have a special importance in aquatic environment. Exometabolites of some organisms become an important part of environment for the others. The authors discussed the origin and evolution of exometabolites from simple waste products to biologically active substances. Quantitative and qualitative aspects of metabolic excretion by organisms in water conditions are analysed. The data on composition, origin and biological function of some second metabolites of different groups of aquatic organisms are presented. The authors propose a classification of second metabolites according to their functional significance. The role of metabolites and decay products in the development of chemical information streams in hydrobiocoenosis is analysed. Metabolites (soluble organic substances) form a field of chemical information for biotic community. The most important functions of this field are communication and conditioning. The authors emphasize the importance of investigations of chemical bioinformation field in aquatic ecosystems.