Microbial biosensors for detection of biological oxygen demand (a Review)

The review briefs recent advances in application of biosensors for determining biological oxygen demand (BOD) in water. Special attention is focused on the principles of operation of microbial BOD sensors; the information about biorecognition elements in such systems and the methods used for immobilization of biological components in film biosensors is summarized. Characteristics of some BOD sensor models are considered in detail.     

Action of beta radiation on the black bean aphid Aphis fabae Scop. (Aphididae, Homoptera)

A study was made of the effect of direct single exposure to beta-radiation of 0.5, 5, 10, 20, 30, and 50 Gy on development and reproduction of Aphis fabae Scop. (Aphididae, Homoptera). The numbers of bean aphid are prognosticated with regard to the radiation dose applied.     

Trafficking and localization studies of recombinant alpha1, 3- fucosyltransferase VI stably expressed in CHO cells

Peripheral alpha1,3-fucosylation of glycans occurs by the action of either one of five different alpha1,3-fucosyltransferases (Fuc-Ts) cloned to date. Fuc-TVI is one of the alpha1,3-fucosyltransferases which is capable to synthesize selectin ligands. The major alpha1, 3- fucosyltransferase activity in human plasma is encoded by the gene for fucosyltransferase VI, which presumably originates from liver cells. While the sequence, chromosomal localization, and kinetic properties of Fuc-TVI are known, immunocytochemical localization and trafficking studies have been impossible because of the lack of specific antibodies. Here we report on the development and characterization of a peptide-specific polyclonal antiserum monospecific to Fuc-TVI and an antiserum to purified soluble recombinant Fuc-TVI crossreactive with Fuc-TIII and Fuc-TV. Both antisera were applied for immunodetection in stably transfected CHO cells expressing the full-length form of this enzyme (CHO clone 61/11). Fuc-TVI was found to be a resident protein of the Golgi apparatus. In addition, more than 30% of cell-associated and released enzyme activity was found in the medium. Maturation and release of Fuc-TVI was analyzed in metabolically labeled CHO 61/11 cells followed by immunoprecipitation. Fuc-TVI occurred in two forms of 47 kDa and 43 kDa bands, while the secreted form was detected as a 43 kDa. These two different intracellular forms arose by posttranslational modification, as shown by pulse-chase experiments. Fuc-TVI was released to the supernatant by proteolytic cleavage as a partially endo-H resistant glycoform.      

Comparative morphology and phylogeny of the family Thompsoniidae (Cirripedia, Rhizocephala, Akentrogonida), with descriptions of three new genera and seven new species

Akentrogonid rhizocephalans morphologically resembling the genus Thompsonia are revised as a result of examination of new material. The species concerned are all obligatorily colonial and have ovoid or cylindrically shaped externae with a terminal stalk and a much reduced anatomy. A numerical cladistic analysis of all Rhizocephala Akentrogonida using the Hennig 86 program leads to a redefinition of the Thompsoniidae HOeg and Rybakov, 1992. Autapomorphies for the Thompsoniidae are primarily the morphology of the attachment to the host and the total absence of a mesentery. The cladistic analysis refutes that the Thompsoniidae should have a plesiomorphic morphology and branch off very low on the rhizocephalan phylogeny. The family now comprises four genera: Pottsia gen. n. (monotypic), Diplothylacus gen. n. with two species, Thompsonia Kossmann with five species. A revived and redefined Thylacoplethus Coutière includes eight species. The genera are distinguished by the location of the spermatogenic tissue, the site where the eggs are fertilized, the presence or absence of a mantle pore and the way it is formed, the number or absence of oviducts, and the number of cuticular annuli on the stalk. All 16 species, of which six are new to science, are described when necessary, and, if possible, illustrated. A phylogeny for the redefined family is proposed. Thylacoplethus is morphologically closest to the hypothetically ancestral thompsoniid and is likely paraphyletic. The new genus Polysaccus with two species, one of them new to science, and the monotypic genus Pirusaccus Lützen resemble thompsoniids in externa morphology and in being obligatorily colonial.     

Aggressive behavior as a mechanism of spatial differentiation of juvenile salmonid fishes (based on Black Sea brown trout Salmo trutta labrax (salmonidae))

Aggressive behavior of hatchery-reared juvenile Black Sea brown trout Salmo trutta labrax at the age of 5.5–6.0 months is investigated. Shortage of suitable territory leads to the separation of the fish into two spatial groups: demersal and pelagic. During the process of spatial differentiation of the fish, the individuals that have not selected permanent habitats (demersal or pelagic) are characterized by the highest aggression level. The duration of the formation of stable spatial differentiation of the fish depends on the stocking density. At a low stocking density (10–45 fish/m²), spatial differentiation is established by the beginning of the second day after the transfer of the fish to new conditions; at a high stocking density (182 fish/m²), it is established approximately by the seventh day. Following the establishment of the (secondary) spatial groups, aggressive acts are registered mainly between the individuals from the same spatial group. A role of aggressive behavior in intrapopulation differentiation of brown trout is discussed.     

A multienzyme bioreactor based on a chitinase complex

A heterogeneous biocatalyst containing a complex of chitinolytic enzymes isolated from the culture medium of bacteria Clostridium paraputrificum on the surface of macroporous monolithic minidisc was obtained. The complex of chitinolytic enzymes was immobilized on the polymer matrix using a multistep method involving the introduction of an intermediate macromolecular spacer. The endochitinase and N-acetylglucosaminidase activity of the heterogeneous biocatalyst was studied.     

Selective effect of the duration of the critical temperature period on some allozyme loci of Atlantic salmon Salmo salar L. (Salmonidae)

Genetic structure of juvenile fish from the populations of the Atlantic salmon Salmo salar inhabiting the rivers of Murmansk oblast, Arkhangelsk oblast, and Karelia, as well as of juveniles from hatcheries was examined at five allozymic loci: aspartate aminotransferase (AAT-4*), isocitrate dehydrogenase (IDHP-3*), iditol dehydrogenase (IDDH-2*), esterase D (ESTD*), and malic enzyme (MEP-2*). High genetic differentiation of both natural and "hatchery" juvenile fish was revealed. It was demonstrated that the gene pool of juveniles at three of the five loci tested was to a considerable degree formed by natural selection. In this case, the role of limiting factor was played by the duration of critical temperature regime in the rivers. The differentiation factors for juveniles from nature were not established, however, their clusterization pattern pointed to a possible role of natural selection in this process.     

High frequency induction of mitotic recombination by ionizing radiation in Mlh1 null mouse cells

Mitotic recombination in somatic cells involves crossover events between homologous autosomal chromosomes. This process can convert a cell with a heterozygous deficiency to one with a homozygous deficiency if a mutant allele is present on one of the two homologous autosomes. Thus mitotic recombination often represents the second mutational step in tumor suppressor gene inactivation. In this study we examined the frequency and spectrum of ionizing radiation (IR)-induced autosomal mutations affecting Aprt expression in a mouse kidney cell line null for the Mlh1 mismatch repair (MMR) gene. The mutant frequency results demonstrated high frequency induction of mutations by IR exposure and the spectral analysis revealed that most of this response was due to the induction of mitotic recombinational events. High frequency induction of mitotic recombination was not observed in a DNA repair-proficient cell line or in a cell line with an MMR-independent mutator phenotype. These results demonstrate that IR exposure can initiate a process leading to mitotic recombinational events and that MMR function suppresses these events from occurring.     

Stromules-like protrusions of the membrane environment of plastids in the root cells

The results of visualization of the stromules-like protrusions of the membrane environment of plastids in the root cells with the help of an electronic microscope are submitted. The cases of occurrence of long narrow protrusion of the external membrane with more short protrusion of the internal membrane of plastid environment inside it are discussed. The possible role of cytoskeleton and plastoskeleton in formation, accordingly, of "external" and "internal" protrusions is considered. The conclusion that the structure and functions of stromules in plant cells should be considered in unity with the structure and functions of the endoplasmic reticulum internal space is made.