Heterochromatin protein 1 is involved in control of telomere elongation in Drosophila melanogaster

Telomeres of Drosophila melanogaster contain arrays of the retrotransposon-like elements HeT-A and TART. Their transposition to broken chromosome ends has been implicated in chromosome healing and telomere elongation. We have developed a genetic system which enables the determination of the frequency of telomere elongation events and their mechanism. The frequency differs among lines with different genotypes, suggesting that several genes are in control. Here we show that the Su(var)2-5 gene encoding heterochromatin protein 1 (HP1) is involved in regulation of telomere length. Different Su(var)2-5 mutations in the heterozygous state increase the frequency of HeT-A and TART attachment to the broken chromosome end by more than a hundred times. The attachment occurs through either HeT-A/TART transposition or recombination with other telomeres. Terminal DNA elongation by gene conversion is greatly enhanced by Su(var)2-5 mutations only if the template for DNA synthesis is on the same chromosome but not on the homologous chromosome. The Drosophila lines bearing the Su(var)2-5 mutations maintain extremely long telomeres consisting of HeT-A and TART for many generations. Thus, HP1 plays an important role in the control of telomere elongation in D. melanogaster.     

Relationship between type and age of the inoculum cultures and betalains biosynthesis by Beta vulgaris hairy root culture

From a study of the relationship between the type and age of the inocula, and the growth and biosynthesis of betalains in a Beta vulgaris hairy root culture, the best results were achieved with a 14 d inoculum grown in submerged culture giving 42 mg betalains (16 mg betacyanins and 26 betaxanthins) and 1.5 g dry biomass in 40 ml medium.     

tag7 Gene and gene therapy of cancer

Modern gene therapeutic approaches towards the treatment of malignant neoplasms are discussed. Specifically, results of the first experiments on the development of vaccines on the basis of tumor cells modified with various cytokines and activation molecules are described. We compare effectiveness of different cytokines used for modification of tumor cells are made and consider possible mechanisms of vaccine action. The reasons for impossibility of the development of effective endogenous antitumor immunity are examined. The results of comparative analysis of the Tag7 protein antitumor activity are presented. This evidence clearly shows that Tag7 is a promising agent for anticancer therapy.     

First record of shape Saturnius papernai Overstreet, 1977 in the Black Sea,with a review of the genus shape Saturnius Manter, 1969 (Digenea,Bunocotylidae)

Saturnius papernai Overstreet, 1977 is recorded from the stomach of Mugil cephalus L. (Osteichthyes, Mugilidae) in the Black Sea (a new geographical record) off the southern part of the Bulgarian coast. The species is redescribed and figured on the basis of the Black Sea specimens. Some amendments to the generic diagnosis are proposed concerning the presence of a uterine seminal receptacle and a posterior (third) circular flange. It is proposed that the occurrence of S. papernai is a feature of one of the three shoals of M. cephalus in the Black Sea, i.e. the Balkan shoal. In a zoogeographical analysis, S. papernai is regarded as a Mediterranean immigrant, probably a characteristic element of only the South-Western Faunistic Region of the Black Sea. A review of the genus Saturnius Manter, 1969 is presented.