[Comparative analysis of the life span in HA and BA Drosophila melanogaster].

We studied lifespan (LS) of Drosophila melanogaster strains HA and BA. The first one was generated by long-term selection for low male sexual activity and features decreased LS as well as the changes in a relatively constant index--coefficient of LS variation. The BA strain was derived from the HA strain by reverse selection and has the mean LS and coefficient of LS variation similar to those of the normal strain D-32.

[Molecular genetic analysis of hobo mobile genetic element polymorphism in the genome of Drosophila melanogaster line subjected to long-term selection].

The distribution of mobile genetic element hobo was examined in Drosophila melanogaster lines HA (high male mating activity) and LA (low male mating activity) before and after their isogenization using Southern blot hybridization. The probe containing a full-size hobo copy was shown to produce polymorphic multilocus hybridization with chromosomal DNA. The polymorphism was line-specific.

Prolonged negative selection of Drosophila melanogaster for a character of adaptive significance disturbs stress reactivity.

The metabolism of juvenile hormone by JH-esterase and JH-epoxide hydrolase, and octopamine by tyrosine decarboxylase were studied under normal and stress conditions in flies of two related lines of D. melanogaster. One was selected for high (HA line) and another for low (LA line) male sexual activity for more than 700 generations.

[Alkaline phosphatase in Drosophila melanogaster strains differing in male mating activity and their F1 hybrids].

The activity of alkaline phosphatase (AP) was studied in adults of highly active (HA) and low active (LA) Drosophila melanogaster strains and their F1 hybrids, both under normal conditions and after a heat shock (38 degrees C). Under normal conditions, the HA strain expressed a higher AP activity compared to that in the wild-type strain Canton-S and dominated in respect to this character. The AP activity showed a sexual dimorphism, as it was higher in females of both strains.

[Selection for sex behavior changes the metabolism of juvenile hormone in Drosophila melanogaster].

The metabolism of juvenile hormone (JH) was studied in two lines of Drosophila melanogaster selected for differences in mating behavior. The lines were tested under normal conditions and after short-term heat shock. Females of the HA line (selected for high male mating activity) were shown to exhibit a high level of JH hydrolyzing activity under normal conditions.

[Genetic effects of destabilizing selection for adaptively important traits in Drosophila melanogaster lines].

Related lines of Drosophila melanogaster selected for reproductive activity for more than 750 generations were studied. Results of the long-term selection experiment support D.K.

[Directed transpositions in the genome of the mobile hobo element in a long-term selected strain of Drosophila melanogaster].

The object of our investigation was an inbred LA strain of Drosophila melanogaster. This strain was selected during more than 700 generations for low male mating activity and was characterized by complex abnormalities and the remarkably high level of spontaneous mutability. The last property is determined by hobo system of hybrid dysgenesis.

[Directed character of genetic variation during long-term selection of Drosophila melanogaster strains for adaptively important characters].

Related fly strains that were selected for differences in reproductive function for about 700 generations were studied. The low-active (LA) strain differs from other related and highly active strains of interest at a set of characters. Qualitative differences in the spectrum of viability mutations are retained in strains selected in opposite directions.

[Esterase-6 activity in Drosophila melanogaster strains with varying male mating activity].

Analysis of the stocks of Drosophila melanogaster and of interstock hybrids with different male reproductive activity revealed positive connection between this index and the activity of esterase-6 in the reproductive system: ejaculatory duct, paragonies and ejaculatory bulb. X-chromosomes and chromosome 3 participate in genetic control of interstock differences of both sexual and esterase-6 activity.

[Genotypic differences in the level of N-acetyltransferase activity in mice of inbred lines and their hybrids].

There are "slow" and "rapid" acetylator phenotypes in mice according to N-acetyltransferase activity (E.C. 2.

The sources of genetic variability in highly inbred long-term selected strains of Drosophila melanogaster.

A highly inbred, long-term selected for low fitness strain LA of Drosophila melanogaster possesses a significant mutational load and unusually high rates of spontaneous mutability as revealed by CyL/Pm method. Our results indicate that during cross of CyL/Pm to LA strains, destabilization of copia-like and mobile elements and induction of H-E hybrid dysgenesis take place. The role of these processes in causing considerable genetic variability of LA strain is discussed.

Concerted transpositions of mobile genetic elements coupled with fitness changes in Drosophila melanogaster.

In an inbred low-activity (LA) strain of Drosophila melanogaster with a low level of fitness and a complex of inadaptive characters, in situ hybridization reveals an invariant pattern of distribution of three copia-like elements (mdg-1, mdg-3, and copia). Rare, spontaneous, multiple transpositions of mobile elements in the LA strain were shown to be coupled with a drastic increase of fitness. A changed pattern of various types of mobile elements was also observed on selecting the LA strain for higher fitness.

Transpositions of mobile dispersed genes in Drosophila melanogaster and fitness of stocks.

In situ hybridization with polytene chromosomes was used to demonstrate the transposition of mobile dispersed genes (mdg)-1 and 3 following the selection of flies from low reproductive activity and viability (LA stock) for high reproductive activity, viability and fitness (LA+ and HA stocks). The inbred LA stock is continuously selected for low reproductive activity and viability and maintains at least for twenty-five generations a characteristic pattern of mdg-1 distribution in 14-15 sites. Inbred LA+ and HA stocks exhibit a changed pattern of mdg-1 locations and the number of sites reaches 21-25.

[Genetic analysis of laterality in house mice (Mus musculus L.)].

An attempt was made to obtain with the help of selection-genetic method, mice lines with genetically determined differences in lateralization of the fore-legs (right-, left-handedness). In 5 generations of selection, 302 animals-offsprings were studied, obtained through crossing of the lines CBA X C57BL/6. Two parameters of asymmetry were investigated: direction and degree.

[High frequency of spontaneous occurrence of mutations affecting viability in chromosome 2 of Drosophila melanogaster line "HA"].

The frequency of spontaneous mutations affecting viability was estimated in the chromosome II in LA strain of Drosophila melanogaster. The strain has been selected for low sexual activity for more than 180 generations and maintained by close inbreeding. Spontaneous mutation rate in LA strain has appeared to be extremely high--the frequency of lethal and semilethal mutations in the chromosome II in by an order higher than usual mutation frequencies.