[Properties and functions of a new nucleolar protein, Surf-6, in 3T3 mouse cells].

The localization of the specific protein Surf-6 from nucleoli of eukaryotic cells in mitosis and its sensitivity to the treatment of cells with RNase A and DNase I in situ were studied. It was shown that, in interphase nucleoli of 3T3 mouse cells, Surf-6 is probably associated with RNA and practically is not associated with DNA. In mitosis, Surf-6 appears in forming nucleoli after the known RNA-binding proteins fibrillarin and B23/nucleofozmin, which are involved in the early and late stages of the assembly of ribosomal particles, respectively. These observations and the regularities of migration of early and late proteins of ribosome assembly to nucleoli in the telophase of mitosis led us to the presumption that Surf-6 is involved in the terminal stages of the assembly of ribosomal particles in murine cells. An immunoblot analysis of the Surf-6 content in synchronized 3T3 cells showed for the first time that Surf-6 is present at all stages of the cell cycle but its content markedly decreases when cells enter the G0 period. Conversely, the activation of cells for proliferation is accompanied by an increase in the Surf-6 content. These observations allow one to regard Surf-6 as a marker of the cell proliferative state and suggest its implication in the regulation of the cell cycle. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2005, vol. 31, no. 6; see also http://www.maik.ru.

[Localization of chromosomal nucleus organizing regions in one-cell mouse embryos and oocytes by fluorescence in situ hybridization]. / Vyiavlenie iadryshkoobrazuiushchikh raionov khromosom v odnokletochnykh zarodyshakh myshi s pomoshch'iu fluorestsentnoi gibridizatsii in situ.

In mouse zygotes, ribosomal genes (rDNA) are transcriptionally silent and so-called "nucleolar precursor bodies" are present instead of typical nucleoli. However, the functional significance of these structures remains obscure. Specifically, it remains unknown whether structural association between the nucleolar precursor bodies and rDNA are maintained when rDNA synthesis is switched off. Here, we studied for the first time the rDNA topology in one-cell mouse embryos and MII oocytes using fluorescence in situ hybridization and mouse rDNA probes. Our data suggest that in the pronuclei of one-cell embryos, rDNAs form rather compact clusters, whose number does not exceed that of nucleolus organizing chromosomes characteristic for the haploid set of mouse chromosomes. In zygotic pronuclei, not all nucleolar precursor bodies are associated with rDNA and not all rDNA repeats are attached to the nucleolar precursor bodies. Altogether, these data favor the idea that spatial interactions of nucleolus organizing chromosomes and nucleolar precursor bodies are not obligatory. We assume that associations between nucleolar precursor bodies and nucleolus organizing chromosomal regions are mediated by centromeric heterochromatin. The total numbers of silver stained nucleolus organizing chromosomes in CBA and C57BL mice are different. rDNA genes are unequally distributed among nucleolus organizing chromosomes and nucleolus organizing regions of sister chromatids.

[Expression of ouabain-sensitive H+,K+-ATPase catalytic subunit gene in the rat epidermis]. / Ekspressiia gena kataliticheskoi sub''edinitsy uabainchuvstvitel'noi H+,K+-ATP-azy v épidermise kozhi krysy.

A comparative localization of Na+,K(+)-ATPase and ouabain-sensitive H+,K(+)-ATPase in rat skin was performed using in situ RNA hybridization and immunohistochemistry. Na+,K(+)-ATPase was predominantly detected in the basal layer of epithelium, whereas the ouabain-sensitive H+,K(+)-ATPase, in the granular and prickle cell layers. The genes of these ATPases are thus expressed in epithelial cells at different stages of their development. The hypothesis was advanced that the ouabain-sensitive H+,K(+)-ATPase is involved in maintaining the skin pH value. The probes specific to the mRNAs of the full-size alpha-subunit of the ouabain-sensitive H+,K(+)-ATPase and its truncated form were used to establish a similar distribution of both mRNA variants in skin. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2002, vol. 28, no. 4; see also http://www.maik.ru.

[Some behavioral features in Drosophila melanogaster lines carrying a flamenco gene mutation]. / Nekotorye povedencheskie osobennosti v liniiakh Drosophila melanogaster mutantnykh po genu flamenco.

Olfactory sensitivity and locomotor activity was assayed in Drosophila melanogaster strains carrying a mutation of the flamenco gene, which controls transposition of the mobile genetic element 4 (MGE4) retrotransposon the gypsy mobile element. A change in olfactory sensitivity was detected. The reaction to the odor of acetic acid was inverted in flies of the mutator strain (MS), which carried the flam mutation and active MGE4 copies and were characterized by genetic instability. Flies of the genetically unstable strains displayed a lower locomotor activity. The behavioral changes in MS flies can be explained by the pleiotropic effect of the flam mutation or by insertion mutations which arise in behavior genes as a result of genome destabilization by MGE4.

[Study of the olfactory response in the Drosophila homeotic mutant leg-aristae-wing complex gene]. / Issledovanie ol'faktornoi chuvstvitel'nosti u gomeozisnykh mutantov gena leg-aristae-wing complex u drozofily.

Antennae are known to be olfactory organs in Drosophila. The leg-aristae-wing complex (lawc) mutation causes a homeotic transformation of the arista (the fifth element of antenna) into tarsal elements. To test how the homeotic transformation of the arista into the tarsus can affect behavior, we studied the olfactory response in the lawc mutants. The data were carefully processed by statistical methods. In spite of a low penetrance of the trait of arista transformation, the mutant flies were found to be approximately half as perceptible to attractant odors than the wild-type flies.

[Mating success and courtship ritual in strains of Drosophila melanogaster carrying mutation flamenco]. / Uspeshnost' sparivaniia i osobennosti rituala ukhazhivaniia v liniiakh Drosophila melanogaster, mutantnykh po genu flamenco.

Mating success was examined in groups of Drosophila melanogaster carrying mutation flamMS (SS, MSn1-2, and MSn1-3) and in wild-type flies. The proportion of normally copulating males was significantly lower in the mutant strains. The reduction in mating efficiency was caused by changes in male behavior rather than in female attractiveness. Individual analyses showed that male mating behavior in strains carrying flamMS was qualitatively and quantitatively different from that in the wild-type strain Canton S. The proportion of males that performed consecutive courtship stages was significantly lower in the mutant strains. The sequence and duration of some courtship stages (in particular, orientation and wing vibration) in mutant flies was shown to be altered. The significance of the flamenco locus in regulation of processes occurring at the organismal level are discussed.

Ouabain-sensitive H,K-ATPase: tissue-specific expression of the mammalian genes encoding the catalytic alpha subunit.

Human ATP1AL1 and corresponding genes of other mammals encode the catalytic alpha subunit of a non-gastric ouabain-sensitive H,K-ATPases, the ion pump presumably involved in maintenance of potassium homeostasis. The tissue specificity of the expression of these genes in different species has not been analyzed in detail. Here we report comparative RT-PCR screening of mouse, rat, rabbit, human, and dog tissues. Significant expression levels were observed in the skin, kidney and distal colon of all species (with the exception of the human colon). Analysis of rat urogenital organs also revealed strong expression in coagulating and preputial glands. Relatively lower expression levels were detected in many other tissues including brain, placenta and lung. In rabbit brain the expression was found to be specific to choroid plexus and cortex. Prominent similarity of tissue-specific expression patterns indicates that animal and human non-gastric H,K-ATPases are indeed products of homologous genes. This is also consistent with the high sequence similarity of non-gastric H,K-ATPases (including partial sequences of hitherto unknown cDNAs for mouse and dog proteins).

Genetic aspects of animal reasoning.

This paper reviews the investigations of Prof. L. V. Krushinsky and his colleagues into the genetics of complex behaviors in mammals. The ability of animals to extrapolate the direction of a food stimulus movement was investigated in wild and domesticated foxes (including different fur-color mutants), wild brown rats, and laboratory rats and mice. Wild animals (raised in the laboratory) were shown to be superior to their respective domesticated forms on performance of the extrapolation task, especially in their scores for the first presentation, in which no previous experience could be used. Laboratory rats and mice demonstrated a low level of extrapolation performance. This means that only a few laboratory animals were capable of solving the task, i.e., the percentage of correct solutions was equivalent to chance. The brain weight selection program resulted in two mice strains with a 20% (90-mg) difference in brain weight. Ability to solve the extrapolation task was present in low-brain weight mice in generations 7-11 but declined with further selection. Investigation of extrapolation ability in mice with different chromosomal anomalies demonstrated that animals with Robertsonian translocations Rb(8,17) 1lem and Rb(8,17) 6Sic were capable of solving this task in a statistically significant majority of cases, while mice with fusion of other chromosomes, as well as CBA normal karyotype mice, performed no better than expected by chance. Mice with two types of partial trisomies and animals homo- and heterozygous for translocations were also tested.(ABSTRACT TRUNCATED AT 250 WORDS)

A genetic, physiological, and biochemical investigation of audiogenic seizures in rats.

Two kinds of audiogenic seizures are characteristic of the KM rat strain, selected by Krushinsky and Molodkina in Moscow in the 1940s. This strain is now approximately 100% sound sensitive. Diallel crosses have demonstrated the polygenic nature of this behavior, with most alleles for seizures being recessive. Myoclonic seizures which develop after several sound exposures are a special form of kindling, involving the limbic system. Selection for low and high rates of myoclonic seizures was successful. Several unique, physiological features of the audiogenic seizures in this rat strain are described, as well as data on RNA and protein synthesis inhibition effects on seizure formation.

[Effect of individual chromosomes on sex behavior of Drosophila]. / Vliianie otdel'nykh khromosom na polovoe povedenie Drosophila.

Dependence of intensity of Drosophila virilis male sexual behaviour on age-related differences was studied. Most active proved to be those age periods which correlated with the time of S-esterase elevated activity. Courtship displays were compared in strains 101 and 160, interstrain differences correlating with the S-esterase activity level. As S-esterase plays an important role in fertilization, this relationship seems to be non-random. It is quite possible that the level of S-esterase activity regulates male sexual activity in natural populations. Some variations in male courtship display in interspecies hybrids (D. virilis x D. littoralis) were demonstrated which depended on the gene dose of respective species. It may well be that in the bk and dt gene regions those genes are localized which are responsible for courtship behaviour. The analysis of sexual behaviour in interstrain and interspecies hybrids proved to be successful approach to elucidating possible role of separate chromosomes in sexual behaviour determination.

[Autocatalytic nature of "slow virus infections"]. / Ob avtokataliticheskoi prirode "medlennykh virusnykh infektsii".

A concept that considers the causative nature of the so-called "slow virus infections", causing syndromes of spongiform encephalopathies in man and animals as a chain autocatalytic process is put forward. According to this concept, PrP(27-30) protein, isolated recently from the brains of scrapie-infected animals, is a C-terminal domain of the normal protein component of brain tissue which is a latent zimogen. Certain clinical and experimental data are discussed within the framework of this concept. Exogenous proteinases are presumed to be capable of triggering such a chain autocatalytic process in the brains of susceptible animals. Indeed, in one of our experiments, a subtoxic dose of pronase injected into mouse brain induced the development of a syndrome indistinguishable from spongiform encephalopathy in its clinical and pathomorphological manifestations. The probable role of neuron-specific proteins of intermediate filaments in such pathological processes is discussed. It seems possible that spongiform encephalopathies are particular cases of pathological processes that have catalytic nature. Presumably, the Alzheimer disease has such a catalytic causative nature.

[Behavior of mice with robertsonian translocations of chromosomes]. / Povedenie myshei s robertsonovskimi translokatsiiami khromosom.

The behaviour of mice with normal karyotype and those with robertsonian translocations was studied. The ability of the animals to solve an extrapolatory task was analysed. The experimental procedure was initiated with presentation of a food bait which the animal could reach only through a small opening in a screen. As the mouse started drinking, the food cup was moved leftward or rightward disappearing from the animal's view. The problem was to move in the direction of food, in which case the mouse could find it behind one of two feeding holes, to the right or to the left of the starting point. Laboratory mice were not able to solve this problem, whereas mice containing Rb(8, 17)1 IEM in karyotype demonstrated the extrapolatory ability - they solve the task correctly in a significant majority of cases. By means of a series of backcrosses of Rb(8, 17)1 IEM carriers on CBA strain (these mice have no extrapolatory ability) and subsequent inbreeding, a novel inbred strain was obtained, coisogenic to CBA and possessing the robertsonian translocation Rb(8, 17)1 IEM. These mice with the CBA genetic background solve the extrapolatory problem successfully, the level of correct choices being significantly above the 50% chance level. At the same time, their performance was lower than that of outbred mice with Rb(8, 17)1 IEM, the phenomenon possibly being the result of the influence of CBA genetic background. Mice with Rb(8, 17)6 Sic were also shown to possess the extrapolatory ability.(ABSTRACT TRUNCATED AT 250 WORDS)

[Disability dynamics and specialized employment of osteoarthrosis deformans patients]. / Dinamika invalidnosti i trudoustroistvo bol'nykh deformiruiushchim osteoartrozom.

According to the data obtained during expert medical evaluation of the working capacity a considerable proportion among the examined accounts for patients with deforming osteoarthrosis (DOA), both primary and secondary. Despite the disease intensity and gravity of complications because of the development of compensatory processes most patients preserve work fitness for a long enough period of time, provided they are given proper work. To prevent the disease progress and grave disability, it is advisable that physicians engaged in the commissions for expert medical evaluation of the working capacity should prolong the time of temporary disability for more than 4 months, namely for the period of the development of compensation, provided the clinical and work fitness prognosis is favourable. Rehabilitation is also promoted by the use of concrete recommendations as to the specialized employment.

[Cytoarchitectonics of the cerebral cortex in mice selected for high and low brain weight]. / Tsitoarkhitektonika kory golovnogo mozga myshei, selektirovannykh na bol'shoi i malen'kii ves mozga.

The cortex cytoarchitectonics was studied in mice, which had been genetically selected for high (H-line) and low (L-line) brain weight and manifested some differences in their behaviour. Microscopic brain sections were analysed to estimate the areas of the neocortex, archicortex and paleocortex and to investigate quantitatively the microstructure in different zones of the neocortex. In the H-line, absolute value of total cortical area is, on the average, by 18% higher than that in the L-line--mainly owing to the larger area of neocortex, while the mean values of neurone volume fraction and profile field reveal no significant difference between the H- and L-line. Hence, the total number of neurones in the neocortex of mice from H-line should be greater, as compared with the L-line. Besides, within the framework of the same cerebral organization in general, the obtained data are indicative of a somewhat higher spatial differentiation of the neocortex in mice from the H-line.

[Features of higher nervous activity in mice with Robertsonian chromosomal translocations]. / Osobennosti vysshei nervnoi deiatel'nosti myshei s robertsonovskimi translokatsiiami khromosom.

The ability of laboratory mice to learn to solve a simple food searching task, and their ability to extrapolate the direction of stimulus movement, were investigated in animals of CBA inbred strain (64 mice) and in mice with Robertsonian fusion of 8 and 17 chromosomes -- Rb (8, 17) 1 IEM possessing different genetic background (122 mice). As the ability for extrapolation is tested while the animal has no previous experience of such task solving, this form of behaviour seems to be different from conditioning. Mice with Rb (8, 17) 1 IEM but not CBA mice proved to be capable to solve the extrapolatory task at its first presentation. Their learning ability was found to be also superior to that of CBA mice. The present data proved that mice with Rb (8, 17) 1 IEM translocation may serve as a very promising model for investigation of complex behaviour patterns.

[Capacity for learning and extrapolation of mice selected for having different brain weights]. / Sposobnost' k obucheniiu i ékstrapoliatsii u myshei, selektirovannykh na raznyi ves mozga.

Ability for learning a simple food-searching reaction, and for extrapolation of a food stimulus movement has been studied in two lines of laboratory mice selected throughout 15 generations for high (H-line) and low (L-line) brain weight. It has been found that the mice from H-line learn the food-searching reaction more rapidly than those from L-line. In first presentation of the extrapolation task, the percentage of right solvings by mice from H- and L-lines does not differ from the 50%, expected for the random alternative choice. In subsequent presentations, the percentage of right solvings steadily increases in both lines, and taken over all presentations significantly exceeds the 50% random level, while the mean time of performance gradually grows shorter. Thus, no difference is observed between H- and L-lines either in solving the extrapolation task or in learning this practice, in contrast to a noticeable superiority of H-line in learning a simple motor reaction.