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A mutation of wing fragility that was not yet been revealed in adult housefly is described. Criss-cross inheritance of the character of fragility of the wing blade, which indicates localization of gene (fw) for this character in the X chromosome. Phenotypic expression of the mutant allele depends on sex. In male flies, the mutant allele in hemizygous state is expressed at the age of 2-3 weeks and older with penetrance close to 100%. In females, the mutant allele in homozygous state is lethal and in heterozygous state, totally recessive.

Confocal microscopy permits to perform quantitative analysis of the fluorescent signals of the nuclei. We determined the level of DAPI and phosphorylated histone-H3 fluorescence, the volume of DAPI and phosphorylated histone-H3 fluorescence in normal (Hikone AW) and colchicine treated third instar Drosophila melanogaster wing imaginal disc mitotic cells. Our analysis permitted to indentify two unknown levels of chromatin package; one in the prometaphase and another at the end of metaphase. These levels disappeared in colchicine treated mitoses. We conclude that quantitative analysis of confocal images is able to detect the differences in chromatin package laying over the resolution of light microscopy.

Deformed wing virus (DWV) was first detected in the honey bee Apis mellifera by reverse transcriptase-polymerase chain reaction (RT-PCT) in the Moscow Region. Molecular phylogenetic analysis of the detected nucleotide sequence of the virus fragment VP2-VP1 of DWV demonstrated that the Russian virus sequence is united in the common cluster with all earlier revealed nucleotide sequences of DWV in the Genbank worldwide, which confirms the previous conclusions that this virus has recently distributed in the honey bee by Varroa destructor mite. It has been shown that the level of homology for all DWV nucleotide sequences is 98%, except for nucleoside sequence of 7D isolate from Turkey (96% homology), 96% homology with Kakugo virus and 84-86% homology with Varroa destructor virus 1; there is a preponderance of insignificant nucleotide substitutions, mainly transitions, which supports the evolutionary propinquity of 3 viruses.

A comparative analysis of the phenotypic values of the proximal and distal fragments of the radial wing vein was carried out in heterogeneous lines of Drosophila melanogaster and in isogenic lines derived from them with the help of a balancer line. The mean values of the traits in the isogenic lines were shown to significantly differ from the corresponding values in the "parental" heterogeneous lines. Apparently, the change in the trait values was caused by a double recombination exchange between the inverted and the "normal" chromosomes, which suggests partial crossing over suppression in the balancer lines.

Molecular and genetic data were compared for the 2B6-2B7-8 region of the Drosophila melanogaster X chromosome. This region contains the dor (deep orange) and swi (single wing) genes influencing ecdysterone-dependent gene expression. Genes which had not been identified previously by genetic methods were shown to be present in this region. Two novel loci, designated a6 and b6, were characterized in detail. Both genes are expressed throughout Drosophila embryogenesis. The product of b6 has a homology with mammalian pentraxins. This is the first Drosophila gene found to contain the pentraxin motif.

In an isogenic line of Drosophila melanogaster carrying the Mendelian mutation radius incompletus, selection for the total length of two segments of the disrupted longitudinal wing vein was conducted. After gamma-irradiation at a dose of 13 Gy, positive and negative truncation selection became highly effective and was completed in 50 generations. The pattern of mobile genetic element Dm412 was almost completely fixed in the course of selection. In the positive direction of selection, fixations of mobile genetic element (MGE) sites exceeded losses; in the negative direction, this relationship was reversed. The number of MGE sites in the pattern increased from 23 to 33 and to 26 in the positive and negative directions, respectively. The mean heterozygosity of MGE sites decreased respectively ten and six times. The dynamics of some sites (6F, 43B, 66A, 69E, and others) corresponded to that expected with an adaptive response to selection. Two out of these sites (43B and 66A) were previously assigned to hot sites of Dm412 transposition induced by heat shock. Fixation and loss of sites continued on average for tens of generations. Four hypotheses describe the relationship between patterns of polygenes and MGE in the context of explanation of the above facts: (1) genetic drift; (2) the linkage of MGE and polygenes without modification of the latter (hitchhiking); (3) the linkage and modifying effect of MGE on polygenes linked with them; (4) the selection of the "champion" pattern of polygenes and a random or adaptive MGE pattern linked with it. Hypotheses 1 and 2 are unlikely, hypothesis 3 is possible in the case of other selection modes, whereas hypothesis 4 seems to be most plausible.

The relationship between wing length, which is a size-related trait, and larval density was studied in laboratory lines of Drosophila melanogaster. Phenotypic variation of wing length was shown to be associated with larval density.

The achaete-scute complex (AS-C) and the cut locus are involved in formation of the nervous system in Drosophila melanogaster. We found that several alleles of the AS-C modified the phenotypic expression of ct allele inducing the appearance of excisions and hair reduction on the external edge of the wing. The effect is a result of damage in correct expression of the scute locus. The effect of some other mutations on the ct6 expression was also described. The system can be used for analysis of interactions of the AS-C and some other genes in the wing imaginal disc.

A brief account of the modern state of X-ray diffraction studies of muscles is presented. Recently many investigaters payed particular attention to concrete changes taking place in structural-executive (protofibrillar) apparatus of muscles at the change of their state. The drawback of these works is the necessity of interpreting the data on the basis of model ideas having definite variability. Our studies here presented differe by the approach to the problem and to a certain extent by the methods applied. Our main task was to study the dynamics of structural changes in muscles while the latter perform their working function. Special attention was payed to the studies of muscles at different shortening eithor on living or fixed samples. The effect of some conventional fixators on structural parameters evaluated by X-ray analysis was studied for the first time. A means of stroboscopic accumulation of X-ray diffraction patterns for periodic fast processes was developed. One of our main tasks was to find the range of applicability sliding mechanism hypothesis for describing muscle shortening. It was observed that the sliding mechanism held true for the desscription of the structure of muscles shortened in a physiological range. X-ray diffraction patterns were obtained which were different for the shortenings according to the sliding mechanism and those with A-disc shortening and during supercontraction. The limits of the sliding model were evaluated by some of these characteristics for muscle of different composition and properties. The problem of the forces realizing muscle shortening is discussed, some of the author's studies being taken into account. Muscle should be assessed as a complex heteromorph biological object and as a complex liquid crystalline system to create the models of its molecular structure and to elucidate the precise mechanism of its functional activity.