Identification and Characterization <Emphasis Type="Italic">in silico</Emphasis> of Meiotic DNA

A method of in silico search for specific repetitive DNA sequences related to the synaptonemal complex (meiDNA) in mammalian genomes was developed. A study of the distribution of these repeats over chromosomes revealed their scarcity on the Y chromosome and a decrease in recombination frequency in regions enriched in meiDNA. The results are discussed in context of the model of the looplike meiotic chromosome organization during the formation of the synaptonemal complex.__________Translated from Genetika, Vol. 41, No. 5, 2005, pp. 697–701.Original Russian Text Copyright © 2005 by Grishaeva, Dadashev, Bogdanov.     

Determination of Fitness Components of Flies Bearing the Recessive Lethal l(2)M167DTS Mutation with Dominant Heat Sensitivity in Artificial Drosophila melanogaster Populations

Elimination of the heat-sensitive l(2)M167 ^DTS mutation from artificial Drosophila melanogaster populations at constant temperature 25°C and various frequencies of the mutation in the parental generation was studied. Components of fitness of the l(2)M167 ^DTS mutation were estimated in the artificial populations by means of the recurrent model of the dependence of the frequency of this mutation in a given generation on its frequency in the previous generation. The model was solved by a numerical method with limitations on the values of some fitness components obtained in test experiments. According to the limitations and frequencies of the l(2)M167 ^DTS mutation, the leading role and limits of the variation in egg-to-adult viability and female fertility were determined. The previously suggested effect of the positive selection for viability of individuals heterozygous for l(2)M167 ^DTS was confirmed.__________Translated from Genetika, Vol. 41, No. 6, 2005, pp. 767–777.Original Russian Text Copyright © 2005 by Kulikov, Kuznetsov, Marec, Mitrofanov.     

Innovation and technological knowledge in the Upper Paleolithic of Northern Eurasia

The technology of modern humans is unique in the animal kingdom with respect to its complexity and capacity for innovation. Evidence of technological complexity and creativity in the archeological record is broadly coincident with and presumably related to traces of creativity in art, music, ritual, and other forms of symbolism. The pattern of modern human technology is part of a larger package of behavior (sometimes referred to as “behavioral modernity”) that emerges with the appearance of industries in Eurasia classified as Upper Paleolithic, but has deeper roots in the African Middle Stone Age. 1 - 5 .     

Structure of Mitochondria and Activity of Their Respiratory Chain in Successive Generations of Yeast Cells Exposed to He-Ne Laser Light

The data on the aftereffect of He-Ne laser light (λ = 632.8 nm) on mitochondria of yeasts in late log phase were reviewed. The quantitative analysis of the ultrathin cell sections demonstrated a nonuniform thickness of the giant branched mitochondria typical for budding yeasts. Exposure to a dose of 460 J/m² (accelerating cell proliferation and activating respiratory chain enzymes, cytochrome c oxidase and NADH dehydrogenase), changed the macrostructure of the giant mitochondria—much of the narrow regions of the mitochondrial tube with profiles ≤0.06 μm² were expanded (while no signs of organelle damage were observed). Such mitochondria are characterized by increased relative surface area of the cristae, which can be due to the activation of their respiration and ATP synthesis. The number of associations between mitochondria and endoplasmic reticulum increased in irradiated cells in early log phase, which reflects the increased capacity of mitochondria to uptake Ca²⁺. Altered giant mitochondria configuration can increase the efficiency of both energy transfer and Ca²⁺ propagation through the cytoplasm. __________ Translated from Izvestiya Akademii Nauk, Seriya Biologicheskaya, No. 6, 2005, pp. 672–683. Original Russian Text Copyright ? 2005 by Manteifel, Karu.     

Changes in the properties of oily gray forest soil during biological reclamation

Biological reclamation of gray forest soil severely contaminated by separator oil using Bacispecin was demonstrated. Agrophysical, agrochemical, physicochemical, and biological properties of the soil were restored in the plow layer during the reclamation.Translated from Izvestiya Akademii Nauk, Seriya Biologicheskaya, No. 1, 2005, pp. 109–115.Original Russian Text Copyright © 2005 by Suleimanov, Gabbasova, Sitdikov.     

Inducible nitric oxide synthase expression is inhibited by myeloperoxidase.

Nitric oxide (NO) plays key roles in vasodilation and host defense, yet the overproduction of NO by inducible nitric oxide synthase (iNOS) at inflammatory sites can also be pathogenic. Here, we investigate the role of MPO in modulating the induction of iNOS by IFNgamma/LPS (IL). In monocyte-macrophages (Mvarphi) treated with IL, MPO gene expression was found to be downregulated as iNOS was upregulated. In Mvarphi from MPO-knockout (KO) mice, the induction of iNOS by IL was earlier and higher than in MPO-positive cells, suggesting MPO is inhibitory. Consistent with that interpretation, the addition of purified MPO enzyme to cultured macrophages inhibited iNOS induction by IL. In addition, an inhibitor of MPO enzyme, 4-aminobenzohydrazide, enhanced iNOS induction in MPO-positive cells, but not in MPO-KO cells. Similarly, taurine, a scavenger of MPO-generated HOCl, enhanced iNOS induction in MPO-positive cells, but not in MPO-KO cells. MPO affects an early event, suppressing iNOS induction when added within 2h of IL, but not when added several hours after IL. The suppression by MPO was alleviated by NO donor, sodium nitroprusside, suggesting the suppression results from scavenging of NO by MPO. This interpretation is consistent with earlier reports that MPO consumes NO, and that low levels of NO donor augment induction of iNOS by IFNgamma/LPS. The implication of these findings is that MPO acts as gatekeeper, suppressing the deleterious induction of iNOS at inflammatory sites by illegitimate signals. The combined signaling of IFNgamma/LPS overrides the gatekeeper function by suppressing MPO gene expression.     

The role of prostaglandins in triggering the liver regeneration cascade.

Following injury or surgical resection, the liver has the remarkable ability to regenerate. Despite over 100 years of research, the trigger of the liver regeneration cascade has only recently been identified. Shear stress-induced nitric oxide (NO), released secondary to a hemodynamic event following partial hepatectomy (PHX), has been implicated as the trigger of the liver regeneration cascade. However, it is also known that prostaglandins (PGs) are released following PHX, and in response to shear stress. Therefore, it is hypothesized that PGs, released secondary to an increase in the blood flow-to-liver mass ratio following PHX, trigger the liver regeneration cascade, and that NO and PGs interact during the triggering event. An index of initiation of the liver regeneration cascade, c-fos mRNA expression 15 min after PHX, has been employed. As expected, c-fos mRNA expression increased 15 min after PHX and this increase was inhibited by the NO synthase antagonist, l-NAME. This inhibition was reversed by the NO donors, SIN-1 and SNAP, and by the PGs, PGE2 and PGI2. Also, the increase in c-fos mRNA expression was inhibited by indomethacin, a cyclooxygenase antagonist. This inhibition was also reversed by the NO donors, SIN-1 and SNAP, and by the PGs, PGE2 and PGI2. These results suggest that there is interaction between NO and PGs in triggering the liver regeneration cascade, and that in a situation where either NO or COX is inhibited, provision of excess exogenous NO or PGs can reverse the inhibition. This suggests that exogenous NO and/or PGs may play a role in potentiation of the liver regeneration cascade.