The mechanisms of the influence of the anterior and posterior hypothalamus on the electrical activity of the large hemispheres of the forebrain and on autonomic reactions in hens

Studies have been made of the effect of stimulation of the anterior and posterior hypothalamus on the electrical activity of the hemispheres, arterial blood pressure, heart and respiration rates. Mainly desynchronizing mechanisms were revealed in the ascending influences from both the anterior and posterior hypothalamus. Concerning the descending influences, it was found that stimulation of the anterior hypothalamus evokes depressor reactions, whereas stimulation of the posterior hypothalamus results in pressor reactions. Peculiarities of evolutionary development of the ascending and descending mechanisms of the posterior and anterior hypothalamus are discussed.     

mtDNA diversity in rhesus monkeys reveals overestimates of divergence time and paraphyly with neighboring species

Reconstructions of the human-African great ape phylogeny by using mitochondrial DNA (mtDNA) have been subject to considerable debate. One confounding factor may be the lack of data on intraspecific variation. To test this hypothesis, we examined the effect of intraspecific mtDNA diversity on the phylogenetic reconstruction of another Plio- Pleistocene radiation of higher primates, the fascicularis group of macaque (Macaca) monkey species. Fifteen endonucleases were used to identify 10 haplotypes of 40-47 restriction sites in M. mulatta, which were compared with similar data for the other members of this species group. Interpopulational, intraspecific mtDNA diversity was large (0.5%- 4.5%), and estimates of divergence time and branching order incorporating this variation were substantially different from those based on single representatives of each species. We conclude that intraspecific mtDNA diversity is substantial in at least some primate species. Consequently, without prior information on the extent of genetic diversity within a particular species, intraspecific variation must be assessed and accounted for when reconstructing primate phylogenies. Further, we question the reliability of hominoid mtDNA phylogenies, based as they are on one or a few representatives of each species, in an already depauperate superfamily of primates.      

Plasmid pCL1 and antimicrobial activity of a strain of Bacillus sp. 62

The 60 kb plasmid pCL1 isolated from Bacillus sp. 62 confers antibacterial activity. Bacteria cured from pCL1 by ethidium bromide treatment loose the sign. Transformation of cured from by pCL1 restores the initial phenotype, while plasmid transfer into B. subtilis 168 does not confer antibacterial activity, which indicates the significance of chromosome locuses in the formation of this sign.     

Intrathalamic afferent connections of the median center of the thalamus

Microiontophoretic local injection of horseradish peroxidase (HP) have been performed into the median center (MC). Many thalamic nuclei are sources of projections into MC, though the role of each nucleus is not equivalent. MC is predominantly connected with nonspecific formations (reticular, parafascicular, central-lateral, paracentral, ventromedial, paraventricular). Among them the reticular nucleus is distinguished, it sends its efferent fibers from the ventral, ventrolateral and lateral areas. In the anterior part of the reticular nucleus there are no HP-labelled cells. In MC little projections from specific nuclei (ventrobasal complex, ventrolateral nucleus, geniculate body) are presented, as well as simple projections from the associative nuclei. The data obtained are in keeping with electron physiological investigations.     

The chromosome number of several species of flowering plants from the flora of the Aragats mountain massif

The chromosome numbers are given for 10 species of the flora from the Aragatz mountainous massif. For 7 species the chromosome numbers are presented for the first time or they differ from those already published by other authors. For the rest 3 species the chromosome numbers are confirmed. Five species of the 10 above-mentioned ones proved to be polyploids of various degree of ploidy, the rest--diploids. For the first time the new pentaploid chromosome race with 2n=30 was found in Scilla sibirica.     

An invisible ubiquitin conformation is required for efficient phosphorylation by PINK1

The Ser/Thr protein kinase PINK1 phosphorylates the well‐folded, globular protein ubiquitin (Ub) at a relatively protected site, Ser65. We previously showed that Ser65 phosphorylation results in a conformational change in which Ub adopts a dynamic equilibrium between the known, common Ub conformation and a distinct, second conformation wherein the last β‐strand is retracted to extend the Ser65 loop and shorten the C‐terminal tail. We show using chemical exchange saturation transfer (CEST) nuclear magnetic resonance experiments that a similar, C‐terminally retracted (Ub‐CR) conformation also exists at low population in wild‐type Ub. Point mutations in the moving β5 and neighbouring β‐strands shift the Ub/Ub‐CR equilibrium. This enabled functional studies of the two states, and we show that while the Ub‐CR conformation is defective for conjugation, it demonstrates improved binding to PINK1 through its extended Ser65 loop, and is a superior PINK1 substrate. Together our data suggest that PINK1 utilises a lowly populated yet more suitable Ub‐CR conformation of Ub for efficient phosphorylation. Our findings could be relevant for many kinases that phosphorylate residues in folded protein domains.