Burden of hereditary diseases in residents of the Mari El Republic]

A summary of the medical genetic studies of the Marii El population is presented. A total of 276,900 people, 110,894 and 166,006 urban and rural inhabitants, respectively, were examined. Regarding the ethnic composition, the studied population was mostly Mari (61.96%) and Russian (32.04%). Medical genetic examination revealed 480 subjects from 260 families with autosomal dominant (AD) diseases, 234 subjects from 184 families with autosomal recessive (AR) diseases, and 49 subjects from 41 families with x-linked diseases. Segregation analysis revealed a good agreement between the expected and observed segregation frequencies for families with AR and AD diseases and allowed the frequency of hereditary diseases in the urban and rural, as well as the Russian and Mari, populations, to be estimated. The total frequency of AD diseases in Maris was approximately twice as high as in Russians (1.99 and 0.97%, respectively); substantial differences between district populations were found. The total frequency of AR diseases was also two times higher in Maris than in Russians (1.00 and 0.54%, respectively). The frequencies of AR and AD diseases in different districts were correlated with the levels of random and local inbreeding, population size, and the index of maximum selection.     

Nisin formation by immobilized cells of the lactic acid bacterium, Streptococcus lactis]

The problem of microbial cell immobilization at present attracts the ever increasing attention of the scientists, since such organisms may be the source of various enzymes. Production of nizin by the immobilized cells of Str. lactis was studied. It was found that the cells of Str. lactis incorporated into polyacrylamide gel produced nizit on definite media. Still, the amount of the antibiotic was 2-3 times lower than in case of using free cells. The effect of a number of factors on the process of immobilization was studied and the influence of some factors, such as temperature, pH, aeration on nizin synthesis by the immobilized cells of the streptococcus was elucidated. Optimal conditions for nizin biosynthesis by the immobilized cells of Str. lactis were developed.     

Chemical nature of the autoregulating factor d1 in Pseudomonas carboxydoflava

A chromatographically individual fraction with the biological activity of factor d1 was isolated from Pseudomonas carboxydoflava by the techniques of column and thin-layer chromatography. Alkyl hydroxybenzoles were shown to be the active principle of factor d1 inducing the transition of P. carboxydoflava vegetative cells into the hypometabolic or anabiotic state. As was found from the data of PMR, UV and IR spectroscopy and gas chromatography in combination with mass spectrometry, the active principle of factor d1 included alkylresorcins: 5-n-nonadecylresorcin and 5-n-heneicosylresorcin at a ratio of 1:3.     

Various properties of immobilized aldolase

The pH dependence of direct and reverse aldolase reaction rate was studied in the presence of Sephadex-immobilized fructoso-1,6-diphosphate aldolase. The immobilized enzyme retains its activity in the presence of sulfhydryl inhibitors: iodacetate and n-chloromercury benzoate.     

The Drosophila melanogaster homologue of the hsp60 gene is encoded by the essential locus l(1)10Ac and is differentially expressed during fly development

 The hsp60 (heat-shock protein 60) gene family of molecular chaperones has been a subject of study in numerous systems due to its important role in the correct folding of non-native proteins in development as well as after heat-shock treatment. Here we present the characterization of the first Drosophila hsp60 homologue. Drosophila HSP60 is most closely related (72% identity across the entire protein sequence) to the mouse mitochondrial HSP60. Western blot experiments indicate that Drosophila HSP60 is enriched in the mitochondrial fraction. The distribution of HSP60 protein is dynamic during fly embryogenesis, suggesting that various cell types might have different HSP60 requirements. The molecular analysis of a P-element-induced mutation that affects the l(1)10Ac locus shows that the transposon is inserted in a 3-kb intron present in the hsp60 gene. By genetic rescue experiments we prove that Drosophila HSP60 is encoded by the essential locus l(1)10Ac opening the possibility for detailed genetic analysis of HSP60 functions in the fly. Received: 24 March 1997 / Accepted: 16 June 1997     

The differentiation of the nerve and glial cells of neocortical transplants placed into the brain of adult rats

Embryonal neural tissue of 17-day-old rat embryos was transplanted into the brain of adult Wistar rats to test the differentiation of transplants with reference to the normal cerebral cortex development. The control and the experimental rats were decapitated 2, 5, 7, 10, 15, 20, 25, and 35 days after the transplantation. Differentiation of neural tissue was studied using monoclonal antibodies against neurofilaments as well as by counting the proportion of differentiated neurons. The glial differentiation was studied by immunohistochemical method using monoclonal antibodies against acid glial fibrillar protein and vimentin. The differentiation of neural cells of transplants proved to be synchronous with the normal ones while the differentiation of glial cells accelerates.