[Biological activity of fungi from the phyllosphere of weeds and wild herbaceous plants].

Antimicrobial, phytotoxic, and insecticidal activity of 30 fungal isolates obtained from leaves of weeds and wild herbaceous plants was assessed. Antibacterial, antifungal, phytotoxic, and insecticidal activity was found in over 50, 40, 47, and 40% of the isolates, respectively. These findings may be important for toxicological assessment of potential mycoherbicides, as well as provide a basis for investigation of the patterns of development of phyllosphere communities affected by fungal metabolites.

[The role of inversions in adaptation and speciation]. / Rol' inversii v adaptatsii i vidoobrazovanii.

Studies concerning the effect of population-specific inversions on mating behavior of Drosophila lummei Hackman showed that competitiveness of males carrying the inversion for mating with females without the inversion significantly decreases, independently from the location of inversions in chromosomes and the origin of studied strains. Crossing of the competing males with the female carrying the population-specific inversion showed that the competitiveness of males with the inversion in their genome increases in a series of crosses but, nevertheless, remains lower than that of males without the inversion. Hence, it can be suggested that population-specific inversions can be involved in prezygotic isolation of specific forms during the species divergence.

[Variability of inversion polymorphism in populations of Drosophila lummei, Hackman]. / Variabel'nost' inversionnogo polimorfizma v populiatsiiakh Drosophila lummei, Hackman.,

Comparison of inversion polymorphism in Drosophila lummei populations from Finland (Kemi) and Russia (Rybnyi) revealed additional species-specific paracentric inversions in chromosomes 2-4. The newly found inversions, 2V, 3M, 4U, and V, were reported only for the Russian population. The 2U inversion had been earlier detected in D. lummei and in the second chromosome of a D. ezoana population from Kamchatka. Species-specific 5T inversion from the Finland population was not found in the Russian population. 4R, S, and 5S inversions were common for both populations but had different sample frequencies. 4R and 5S inversions were more frequent in the Finland, and 4S in the Russian population which may indicate their different adaptive values in these areas. All inversions except 3M were localized in subterminal chromosome regions. 3M inversion was localized in the submedian region.

[Inversion polymorphism in populations of Drosophila lummei, Hackman]. / Inversionnyi polimorfizm v populiatsiiakh Drosophila lummei, Hackman.

Four population inversions have been revealed in the chromosomes set of Drosophila lummei, Hackman, two of them being found for the first time. The new inversions (5S and 5R) are only typical of individuals from the Finnish population. The lines analysed are heterogeneous for inversions 4R and 4S. Individuals with the inversion 4R outnumber those with the 4S. In the USSR we found no predominance of these inversions in the D. lummei populations. The breaking points of the new inversions (5S and 5R) were located, and the boundaries of earlier described inversions in chromosome 4 were specified.

[Puffing in the regions of the esterase and ecdysterone genes in Drosophila lummei strains differing in beta-esterase expression]. / Pufing v raionakh ésteraznykh i ékdisteronovykh genov v liniiakh Drosophila lummei, razlichaiushchikhsia po ékspresii beta-ésterazy.

Correlation between the activity of esterase and ecdysterone puffs was observed by comparison of puff expression in the areas of alpha- and beta-esterase genes localization and exogenous ecdysterone-sensitive areas (2-G-1-2-G-5). 2-G-5 puff expression and beta-esterase activation correlated with decrease of ecdysterone puffs activity. Constant puffing in 2-G-1 and 2-G-4 matched with constant activity of alpha-specific isoenzymes. The F1 larvae from cross between lines with normal and null-allele beta Est2 gene carried heteromorph puff and its expression depended upon cross direction.

[Incorporation of 5-bromodeoxyuridine-6-3H in salivary gland cells of Drosophila virilis Sturt. during prolonged labeling]. / Vkliuchenie 5-bromdezoksiuridina-6-3H v kletki sliunnykh zhelez Drosophila virilis Sturt. pri prolongirovannom mechenii.

When rearing the D. virilis larvae on the nutrient medium with 5-bromodeoxyuridine-6-3H (3H-BDU) at different developmental stages, it was found that the intensity of isotope incorporation in the chromosomes and cytoplasm of the salivary gland cells depended on the duration of effect and concentration. The distribution of label along the chromosomes does not occur at random. The spectrum of isotope incorporation is specific for each chromosome. All regions which changed their puffing pattern as a result of rearing the larvae on the medium with 3H-BDU incorporated the isotope and the frequency of incorporation in the most of them differed reliably from the random one. The intensity of incorporation increased with the duration of labelling and the isotope concentration.

[Age specificity of the effect of 5-bromdeoxyuridine on the differentiation and puff spectrum of the salivary gland chromosomes of Drosophila virilis Sturt. I. Relationship between the viability of individuals and induction of new puffs and the period of action of 5-bromdeoxyuridine]. / Vozrastnaia spetsifichnost' deistviia 5-bromdezoksiuridina na differentsirovku i spektr pufov khromosom sliunnykh zhelez u Drosophila virilis Sturt. Soobshchenie I. Zavisimost' vyzhivaemosti osobei induktsii novykh pufov ot perioda deistviia 5-bromdezoksiuridina.

5-Bromodeoxyuridine (BUdR) influences the differentiation of the imaginal discs, larval viability and the chromosome puffing throughout the larval development. The differentiation of imaginal discs is more sensitive during the early 3rd instar. "cryptocephal" phenocopy appeared if the larvae were reared in the BUdR medium till the late 2nd instar. 2nd and 3rd instars are critical for the larval viability. During the period of the middle 3rd instar BUdR induced the complete spectrum of the newly forming specific puffs.

[Age specificity of the effect of 5-bromdeoxyuridine on the differentiation and spectra of chromosomal puffs in the salivary glands of Drosophila virilis Sturt. II. Alteration of the puff spectrum in salivary gland chromosomes]. / Vozrastnaia spetsifichnost' deistviia 5-bromdezoksiuridina na differentsirovku i spektr pufov khromosom sliunnykh zhelez u Drosophila virilis Sturt. Soobshchenie II. Izmenenie spektra pufov v khromosomakh sliunnykh zbelez.

The expressivity and temporal patterns of function of the various puff groups are changed, when larvae of Drosophila virilis are kept on BUdR containing medium during different periods of their larval development, as compared with the control animals kept on BUdR-free media. The magnitude of the effect depends on the stage at which the treatment is conducted; the larvae of the 3rd instar are more sensitive to BUdR. The effect of BUdR becomes considerably lower by the end of the 3rd instar period.

[Puff expression in relation to genotype]. / Vyrazhennost' pufov v zavisimosti ot genotipa

The studies of genotype influence on puff size in salivary gland chromosomes of Drosophila virilis (stocks 9, 101, 142, 151) and D. texana (the stock 123) reveal significant differences between the species concerning the structure of puff in the 3-C-6 region at the stage of puparium formation. In reciprocal F1 hybrids the size of the puff was intermediate in comparison with parental forms having a slight maternal effect. The differences in puff size in the 5th chromosome between interspecific hybrids and the special stock of D. virilis carrying a region of D. texana 5th chromosome in heterozygous condition (inserted into D. virilis 5the chromosome by double crossing-over) were observed. The transfer of the region of the third chromosome to near centrimetric heterochromatic of the 5th chromosome by translocation resulted in the increase in the 3-B-2 puff size. However, the transposition of the 3-B1 region in the proximal direction with respect to chromocenter did not affect the puff size.

[Association of telomeric regions of salivary gland chromosomes in Drosophila species of the virilis group]. / Assotsiatsii telomernykh raionov khromosom sliunnykh zhelez u vidov Drosophila gruppy virilis

The frequency of participating salivary gland chromosomes in telomeric associations and specific combinations of associated chromosomes were studied in the following species belonging to "virilis" group of Drosophila: D. virilis, D. texana, D. littoralis Sokolov and D. imeretensis Sokolov. In all species studied predominantly telomeres of two chromosomes form an association. In females of the species mentioned the X-chromosome takes part in association twice as frequent as in males. The total length of the chromosome and the presence of subterminal inversions may sometimes influence the frequency of participating the chromosome in associations. However, the data obtained enable to postulate that internal homology of telomeric regions plays the main role in the process. The equal frequency of participating in telomeric associations for definite chromosomes in species studied may resemble the phylogenetic relation of the species.

[Autonomy of association frequencies of telomeric regions in salivary gland chromosomes during interspecific hybridization]. / Avtonomnost' chastot assotsiatsii telomernykh raionov khromosom sliunnykh zhelez pri mezhvidovoi gibridizatsii

The study of association frequency and combination of salivary gland chromosomes participating in telomeric associations in interspecific hybrids between related species of "virilis" group of Drosophila (D. virilis, D. texana and D. imeretensis Sokolov) enables to conclude that each homologous chromosome behaves as an individual unit in the process. Besides, it is shown that the frequency of association of an autonomous property of telomere, i. e. it is not changed in interspecific hybrids in comparison with parental species.

[A change in the puff spectrum during development of Drosophila virilis]. / Izmenenie spektra pufov v protsesse razvitiia u Drosophila virilis

The puff spectrum has been studied in the salivary gland chromosomes of D. virilis from 48 hrs of the 3rd larval until the gland lysis. 142 puffs were observed in the D. virilis genome. Among them, 43% were observed at all developmental stages and other puffs were unstable: 47.1% appear at a certain stage and degrade or remain until the gland lysis; 9.9% are characterized by the "pulse" activity, i.e. they appear at a certain stage, degrade and reappear. The number of newly appeared puffs exceeds that of fully degraded ones, i.e. the number of puffs during the gland development until its lysis increases constantly. At the stage of puparium formation, sexual differences in the puff length were found: puffs were longer in males than in females.