Le transfert autonome des facteurs mitochondriaux (la cytoduction) lors du croisement des cellules de levure Saccharomyces cerevisiae

When crossing the genetically marked yeast strains obtained from the Gif collection we observed the appearance of haploid nucleo-cytoplasmic hybrids carrying the 3 nuclear markers of the ρ⁻ parent and the mitochondrial markers (rho⁺ E^R C^R) of the other parent. The frequency of such cytoduction was about 1 per cent. The mitochondrial markers E^R and C^R were transmited to cytoductants together and did not segregate. The possible mechanisms of the cytoduction and its significance are discussed.     

Continuous monitoring of human erythrocyte breakdown in the circulating blood by means of multiple light scattering

The method of hemolysis control in human circulating blood is described. The method was used for studying erythrocyte destruction resulting from osmotic swelling and shear stress in the blood flow and may be applied in the artificial blood circulation system.     

The autonomic transfer of mitochondrial factors (cytoduction) during crossing of Saccharomyces cerevisiae cells]

When crossing the genetically marked yeast strains obtained from the Gif collection we observed the appearance of haploid nucleo-cytoplasmic hybrids carrying the 3 nuclear markers of the rho- parent and the mitochondrial markers (rho+ ER CR) of the other parent. The frequency of such cytoduction was about 1 per cent. The mitochondrial markers ER and CR were transmited to cytoductants together and did not segregate. The possible mechanisms of the cytoduction and its significance are discussed.     

Effect of tissue-specific proliferation inhibitors on the level of mitotic activity and cell adhesion in disordered innervation

In the work there was studied the influence of hepatic chalones on the level of mitotic activity and on the degree of adhesion of hepatocytes after the violation of parasympathetic and sympathetic innervation under the physiological conditions of liver function and in regenerating organ. Some definite regularities were revealed in the change of the power of linkage among the cells of liver parenchyma after the disturbance of its innervation and chalones affected. Significant differences in the effect of the influence of tissue inhibitors of proliferation on the process of regeneration in liver, which has intact or disturbed innervation were discovered. Particularly one can underline the effect of the loss of hepatocytes sensitivity to chalones in vagotomized liver.     

Concerning the enigmatic cytochrome b-559 of oxygenic photosynthesis

Photosynthesis Research - Although there is an extensive literature on the properties and possible electron transfer pathways of cytochrome b-559, which is a prominent subunit of the multi-subunit...     

DNA barcoding reveals twelve lineages with properties of phylogenetic and biological species within Melitaea didyma sensu lato (Lepidoptera,Nymphalidae)

The complex of butterfly taxa close to Melitaea didyma includes the traditionally recognized species Melitaea didyma, Melitaea didymoides and Melitaea sutschana, the taxa that were recognized as species only relatively recently (Melitaea latonigena, Melitaea interrupta, Melitaea chitralensis and Melitaea mixta) as well as numerous described subspecies and forms with unclear taxonomic status. Here analysis of mitochondrial DNA barcodes is used to demonstrate that this complex is monophyletic group consisting of at least 12 major haplogroups strongly differentiated with respect to the gene COI. Six of these haplogroups are shown to correspond to six of the above-mentioned species (Melitaea didymoides, Melitaea sutschana, Melitaea latonigena, Melitaea interrupta, Melitaea chitralensis and Melitaea mixta). It is hypothesized that each of the remaining six haplogroups also represents a distinct species (Melitaea mauretanica, Melitaea occidentalis, Melitaea didyma, Melitaea neera, Melitaea liliputana and Melitaea turkestanica), since merging these haplogroups would result in a polyphyletic assemblage and the genetic distances between them are comparable with those found between the other six previously recognized species.     

Prediction of the three-dimensional structure of aflatoxin of Aspergillus flavus by homology modelling

Aflatoxins are polyketide-derived secondary metabolites produced by Aspergillus spp. The toxic effects of aflatoxins have adverse consequences for human health and agricultural economics. The aflR gene, a regulatory gene for aflatoxin biosynthesis, encodes a protein containing a zinc-finger DNA-binding motif. AFLR-Protein three-dimensional model was generated using Robetta server. The modeled AFLR-Protein was further optimization and validation using Rampage. In the simulations, we monitored the backbone atoms and the C-α-helix of the modeled protein. The low RMSD and the simulation time indicate that, as expected, the 3D structural model of AFLR-protein represents a stable folding conformation. This study paves the way for generating computer molecular models for proteins whose crystal structures are not available and which would aid in detailed molecular mechanism of inhibition of aflatoxin.     

Molecular phylogeny of Cryptocercus wood-roaches based on mitochondrial COII and 16S sequences, and chromosome numbers in Palearctic representatives

Woodroaches of the genus Cryptocercus are subsocial and xylophagous cockroaches, distributed in North America and Asia. Studies on male chromosome number in Nearctic species have shown that diploid numbers vary from 2n=37 to 2n=47; numbers from Palearctic species were heretofore unknown. Two hypotheses have been proposed to explain the varying number of chromosomes among Nearctic species: the serial reduction hypothesis, and the parallel scenario. We performed phylogenetic analyses of the COII gene in these species and found evidence for the topology (47(45(43(39,37), which is congruent with the serial reduction hypothesis. We also determined chromosome numbers for the first time in Palearctic species, and found Cryptocercus primarius and Cryptocercus relictus to have relatively low chromosome numbers (2n=17-21) compared to their Nearctic relatives. Finally, our study determined the phylogenetic position of Cryptocercus primarius among other Asian taxa.