Polymeric genes MEL8, MEL9 and MEL10 — new members of α-galactosidase gene family in Saccharomyces cerevisiae

Summary We used a combination of genetic hybridization analysis and electrokaryotyping with radioactively labelled MEL1 gene probe hybridization to isolate and identify seven polymeric genes for the fermentation of melibiose in strain CBS 5378 of Saccharomyces cerevisiae (syn. norbensis). Four of the MEL genes, i.e. MEL3, MEL4, MEL6 and MEL7, were allelic to those found in S. cerevisiae strain CBS 4411 (syn. S. oleaginosus) whereas three genes, i.e. MEL8, MEL9 and MEL10 occupied new loci. Electrokaryotyping showed that all seven MEL genes in CBS 5378 were located on different chromosomes. The new MEL8, MEL9 and MEL10 genes were found on chromosomes XV, X/XIV and XII, respectively.     

Immunochemical analysis of glial and neuronal fractions of rat brain

A method of obtaining antineuronal and antiglial immune sera is described. The results of a quantitative immunochemical analysis of antigens of neuronal and glial fractions of rat brain are given. Neurons were shown to contain four, and glia three brain-specific proteins; in addition, one or two proteins are common to these cellular fractions.Department of Normal Physiology, Moscow Medical Stomatological Institute. Course of Physiology, Medico-Biological Faculty, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 156–158, February, 1977.     

Mitochondrial DNA and Y-Chromosome Variation in the Caucasus

We have analyzed mtDNA HVI sequences and Y chromosome haplogroups based on 11 binary markers in 371 individuals, from 11 populations in the Caucasus and the neighbouring countries of Turkey and Iran. Y chromosome haplogroup diversity in the Caucasus was almost as high as in Central Asia and the Near East, and significantly higher than in Europe. More than 27% of the variance in Y‐haplogroups can be attributed to differences between populations, whereas mtDNA showed much lower heterogeneity between populations (less then 5%), suggesting a strong influence of patrilocal social structure. Several groups from the highland region of the Caucasus exhibited low diversity and high differentiation for either or both genetic systems, reflecting enhanced genetic drift in these small, isolated populations. Overall, the Caucasus groups showed greater similarity with West Asian than with European groups for both genetic systems, although this similarity was much more pronounced for the Y chromosome than for mtDNA, suggesting that male‐mediated migrations from West Asia have influenced the genetic structure of Caucasus populations.     

Nature of Rec+ revertants isolated from Escherichia coli K-12 cultures with recA- mutations

The nature of Rec⁺ revertants isolated previously from cultures of recombinationally defective strainEscherichia coli K-12 AB 2463 recA13 was studied. With the aid of phage P1 vira the chromosome region of the recA gene in cells of strain JC2915F^- were transduced, after which the recombination capacity of the transductants was determined by crossing with JC158Hfr cells and their resistance to ultraviolet radiation was established. Sensitivity of the transductants to suppressor phages was determined. The Rec⁺ revertants were shown to differ with respect to the recA gene. In some Rec⁺ revertants the Rec⁺ phenotype appeared as the result of a back mutation in this gene from rec^- to rec⁺, whereas in other revertants the Rec⁺ phenotype was due to indirect suppression.Department of Biology and General Genetics, Patrice Lumumba Peoples' Friendship University, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. M. Zhdanov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 12, pp. 1487–1488, December, 1976.     

Physical mapping of the MEL gene family in Saccharomyces cerevisiae

Nine members, MEL2–MEL10, of the MEL gene family coding for -galactosidase were physically mapped to the ends of the chromosomes by chromosome fragmentation. Genetic mapping of the genes supported the location of all the MEL genes in the left arm of their resident chromosomes.     

Ion currents through batrachotoxin-modified sodium channels of node of Ranvier membranes at high positive and negative potentials

Ionic currents through batrachotoxin-modified sodium channels in frog nerve fibres were measured over a wide range of membrane potentials. At potentials above +80 mV currents decay in time and their steady-state level decreased as potentials increased. "Instantaneous" current measurements have shown that this phenomenon was due to the decrease in net channel conductance. Scorpion toxin affected current kinetics only slightly at these potentials, which suggested that these decays were not caused by usual inactivation process. Externally applied procaine induced slow (tens of ms) potential-dependent block of batrachotoxin-modified channels at large positive potentials. At large negative potentials (above -100 mV) "instantaneus" currents decreased due to fast voltage-dependent block of the channels by calcium ions.     

The influence of the relieving-dietetic therapy on the calculi acoustic properties in biliary calculous disease

In 45 patients with biliary calculous disease the relieving-dietetic therapy course was performed. The fragmentation or lysis of echopermeable echononsolid, echononpermeable echononsolid, echopermeable echosolid calculi was established. There was not noted fragmentation of echononpermeable echosolid calculi.     

Characterization of visual manifestations and identification of risk factors for permanent vision loss in patients with giant cell arteritis

Clinical Rheumatology - Permanent vision loss (PVL) is a feared complication and a leading cause of morbidity in giant cell arteritis (GCA). The objective of this study is to describe visual...