The molecular structure of the DNA fragments eliminated during chromatin diminution in Cyclops kolensis

Presumptive somatic cells of the copepod Cyclops kolensis specifically eliminate a large fraction of their genome by the process of chromatin diminution. The eliminated DNA (eDNA) remains only in the germline cells. Very little is known about the nature of the sequences eliminated from somatic cells. We cloned a fraction of the eDNA and sequenced 90 clones that total 32 kb. The following organizational patterns were demonstrated for the eDNA sequences. All do not contain open reading frames. Each fragment contains 1-3 families of short repeats (10-30 bp) highly homologous within families (87%-100%). Most repeats are separated by spacers up to 50 bp long. Homologous regions were found between fragments, motifs from 15-300 bp in length. Among fragments there occur groups in which the same motifs are ordered in the same fashion. However, spacers between the motifs differ in length and nucleotide composition. Ubiquitous motifs (those occurring in all fragments) were identified. Analysis of motifs revealed submotifs, each occurring within several motifs. Thus, motifs may be regarded as mosaic structures composed of submotifs (short repeats). Taken together, the results provide evidence of a high organizational ordering of the DNA sequences restricted to the germline. With this in mind, it appears incorrect to refer to this part of the genome as junk. Moreover, eDNA is redundant for only the somatic cells-its function is to be sought in germline cells.     

Restriction Fragments Length Polymorphism in the NAT1 Gene of Europeans in West Siberia

Restriction fragment length polymorphism in the NAT1 gene was assayed to reveal 7 mutations (97C>T; 190C>T; 350,351G>C; 402T>C; 752A>T; D(1105); D(1025)) in 74 Europeans from West Siberia. New methods for detecting mutations 350,351G>C, 402T>C, 752A>T, D(1105), and D(1025) were proposed.     

Permeability of the blood-brain barrier in newborn rats with induced hyperthermic convulsions

The permeability of the blood-brain barrier in the brain-blood direction is examined in newborn rats with hyperthermic convulsions induced by exposure to infrared radiation. Impaired permeability of this barrier due to convulsions is characterized by increased serum concentration of glial fibrillary acidic protein. Dexason lowers the protein level, which confirms its stabilizing effect on the blood-brain barrier structure. The advantage of early dexason administration is shown. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 123, No. 2, pp. 146–149, February, 1997     

Conditional expression of a Gi-coupled receptor causes ventricular conduction delay and a lethal cardiomyopathy

Cardiomyopathy is a major cause of morbidity and mortality. Ventricular conduction delay, as shown by prolonged deflections in the electrocardiogram caused by delayed ventricular contraction (wide QRS complex), is a common feature of cardiomyopathy and is associated with a poor prognosis. Although the G(i)-signaling pathway is up-regulated in certain cardiomyopathies, previous studies suggested this up-regulation was compensatory rather than a potential cause of the disease. Using the tetracycline transactivator system and a modified G(i)-coupled receptor (Ro1), we provide evidence that increased G(i) signaling in mice can result in a lethal cardiomyopathy associated with a wide QRS complex arrhythmia. Induced expression of Ro1 in adult mice resulted in a >90% mortality rate at 16 wk, whereas suppression of Ro1 expression after 8 wk protected mice from further mortality and allowed partial improvement in systolic function. Results of DNA-array analysis of over 6,000 genes from hearts expressing Ro1 are consistent with hyperactive G(i) signaling. DNA-array analysis also identified known markers of cardiomyopathy and hundreds of previously unknown potential diagnostic markers and therapeutic targets for this syndrome. Our system allows cardiomyopathy to be induced and reversed in adult mice, providing an unprecedented opportunity to dissect the role of G(i) signaling in causing cardiac pathology.     

Synthesis and antifungal activity of some carbamate-containing azaheterocycles

A series of carbamate-containing derivatives of 1,2-and 1,4-oxazine, isoxazoline, isoxazole, benzimidazole-3-oxide, and indole were obtained by [3 + 2]-cycloaddition and ring-closure reactions. The antifungal activity of the synthesized compounds was studied in vitro against Microsporum canis, Trichophyton rubrum, and Candida albicans. Among the tested compounds, the maximum antifungal activity was observed for tautomeric 5(6)-alkoxycarboxamido derivatives of 2-aryl-1-hydroxybenzimidazole-3-oxide sodium salts and 1,2-oxazines.