Episodes of Rapid Recovery of the Functional Activity of the ras85D Gene in the Evolutionary History of Phylogenetically Distant Drosophila Species.

As assemblies of genomes of new species with varying degrees of relationship appear, it becomes obvious that structural rearrangements of the genome, such as inversions, translocations, and transposon movements, are an essential and often the main source of evolutionary variation. In this regard, the following questions arise. How conserved are the regulatory regions of genes? Do they have a common evolutionary origin? And how and at what rate is the functional activity of genes restored during structural changes in the promoter region? In this article, we analyze the evolutionary history of the formation of the regulatory region of the ras85D gene in different lineages of the genus Drosophila, as well as the participation of mobile elements in structural rearrangements and in the replacement of specific areas of the promoter region with those of independent evolutionary origin. In the process, we substantiate hypotheses about the selection of promoter elements from a number of frequently repeated motifs with different degrees of degeneracy in the ancestral sequence, as well as about the restoration of the minimum required set of regulatory sequences using a conversion mechanism or similar.

Heat shock protein 70 from a thermotolerant Diptera species provides higher thermoresistance to Drosophila larvae than correspondent endogenous gene.

Heat shock proteins (Hsp70s) from two Diptera species that drastically differ in their heat shock response and longevity were investigated. Drosophila melanogaster is characterized by the absence of Hsp70 and other hsps under normal conditions and the dramatic induction of hsp synthesis after temperature elevation. The other Diptera species examined belongs to the Stratiomyidae family (Stratiomys singularior) and exhibits high levels of inducible Hsp70 under normal conditions coupled with a thermotolerant phenotype and much longer lifespan. To evaluate the impact of hsp70 genes on thermotolerance and longevity, we made use of a D. melanogaster strain that lacks all hsp70 genes. We introduced single copies of either S. singularior or D. melanogaster hsp70 into this strain and monitored the obtained transgenic flies in terms of thermotolerance and longevity. We developed transgenic strains containing the S. singularior hsp70 gene under control of a D. melanogaster hsp70 promoter. Although these adult flies did synthesize the corresponding mRNA after heat shock, they were not superior to the flies containing a single copy of D. melanogaster hsp70 in thermotolerance and longevity. By contrast, Stratiomyidae Hsp70 provided significantly higher thermotolerance at the larval stage in comparison with endogenous Hsp70.

Factors Associated with Unwanted Pregnancy among Adolescents in Russia.

STUDY OBJECTIVE: To identify social and behavioral factors associated with unintended pregnancy among adolescents in Russia. DESIGN: Cross-sectional. SETTING AND PARTICIPANTS: The investigation group consisted of 145 adolescents aged 15-19 years admitted to a youth-friendly clinic for induced abortion. The control group consisted of 77 sexually active never pregnant adolescent girls of similar age admitted for other reasons. INTERVENTIONS: Both groups completed a self-administered questionnaire about their occupation, educational level of their mother, family structure and socioeconomic status, relationship with their mother, sexual behavior, and substance use. MAIN OUTCOME MEASURES: Factors associated with unintended pregnancy. RESULTS: In the bivariate analysis pregnant adolescents tended to have a lower educational level, to live in a nonintact family, to prefer stronger alcohol drinks, and to have a younger age at sexual debut and more frequent sexual intercourse. In the log-linear model six factors appeared to be directly linked to pregnancy: mother's lower education, alcohol consumption, nonintact family structure, low academic grades, higher frequency of sexual intercourse, and lower age at sexual debut. CONCLUSION: Although the issue of unwanted pregnancy and possible ways to prevent it should be kept in mind in the psychosocial assessment of any adolescent, the results of our study suggest that some adolescents are at increased risk of unwanted pregnancy. This group includes adolescent girls with low educational attainment, living in a disrupted family, and reporting other risk behaviors. These adolescents might specially benefit from specific preventive programs to reduce the number of adverse outcomes.

[Comparative Analysis of Polymorphisms of the Serotonin Receptor Genes HTR1A, HTR2A, and HTR1B in Hadza and Datoga Males].

The distribution of the allele and genotype frequencies of polymorphic loci of serotonin receptor genes (HTR1A, rs6295; HTR2A, rs6311; HTR1B, rs6296) in Hadza (n = 197) and Datoga males (n = 230) living in Tanzania was determined. It was shown that the populations significantly differ by the frequencies of alleles and genotypes of the rs6295 locus of the HTR1A gene. The G-allele (0.779) and the genotype G/G (0.590), which are markers of increased risk of suicidal and impulsive behavior, respectively, are revealed in Hadza with high frequency. It was found that the frequency of homozygous G/G of the rs6296 locus of the HTR1B gene, which is a marker of increased risk of outward directed aggression, is higher in Datoga (0.563) than in Hadza (0.457). The allele and genotype frequencies of the rs6311 locus of the HTR2A gene do not differ among the Hadza and Datoga males. The data on the distribution of allele and genotype frequencies of the HTR1A, HTR2A, and HTR1B genes can be used to determine the associations of the identified markers with various forms of human aggressive behavior.

[The 3'-UTR polymorphism of dopamine transporter gene in hadza and datoga males].

The study of VNTR-polymorphism and the molecular struc ture of 3'-UTR of the dopamine transporter gene (DAT1/SLC6A3) was performed in hadza and datoga males. It was shown that hadza and datoga differed in allele and genotype frequencies. Allele with 9 repeats in 3'-UTR is more common in hadza as well as homozygous genotype DAT19/9. Allele with 10 repeats is more common in datoga as well as homozygous genotype DAT1 10/10. The molecular structure of the DAT alleles with 3, 8 and 12 repeats was determined for the first time. In addition it was found that DAT1 allele with 11 repeats in datoga significantly differed from previously described ones in other populations in repeats type and arrangement. We suggest that variations of the repeats num ber and type in the 3'-UTR of allelic variants may affect the dopamine transporter gene function.

[Polymorphism of 5-HTTLPR and Stin2 loci of the serotonin transporter gene in males of African ethnic populations Hadza and Datoga].

A molecular-genetic study of 5-HTTLPR and the Stin2 loci of the serotonin transporter gene (5-HTTL) in males of the African ethnic populations Hadza and Datoga, which differ in the level of culturally acceptable aggression, was carried out. The distribution of allele and genotype frequencies of these two loci was established. It was shown that the frequency distribution of genotypes and alleles among Hadza and Datoga in the examined samples is practically identical by the VNTR-polymorphism of both loci. However, the Hadza populations, as compared to Datoga, showed a significant (p = 0.006) increase in the frequency of the transcriptionally less active allele L(G) of the 5-HTTLPR locus. For the first time, the structure of the allelic variant of locus Stin2 with eight repetitions (Stin2.8) is described and established for African populations. The test for independence of the frequency distribution of the alleles of the studied loci showed highly significant linkage disequilibrium among Hadza (p << 0.001) and Datoga (p = 0.021). In analysis of the genotype combinations of two loci, it was revealed that thestudied populations differed significantly by the L(A)L(G) 10/12 genotype (p << 0.001). When combining the genotypes, no significant differences between the populations based on their expression activity were identified. We assume that the identified combined genotypes reflect the effects of similar behavioral traits for both populations.

[Databases as instruments for analysis of large-scale data sets on interactions between molecular biological objects].

We have surveyed the most well-known and accessible informational resources, consolidating data on interactions of molecular biological objects. Three main criteria are discussed: quality (coverage and reliability) of the information present, ability to analyze experimental data, and ease of results visualization. Several algorithms of data analysis, base on various types of resources, and statistics for its evaluation are named.

[Interspecies variability of number of bristles on dorsal surface of aedeagus in D. virilis species group and its genetic mapping with interspecies hybrids of D. virilis and D. lummei].

The results of morphologic and hybrid analyses of the feature of the male reproductive system of sibling species in the virilis group were presented. Bristles appeared on the surfaces of male genitals (aedeagus). The occurrence of a specific expression of the examined feature in the phyllades of D. virilis group, the correspondence of both the number and distribution pattern of the bristles on surfaces ofthe aedeagus and developmental temperature in D. virilis and D. lummei, as well as the link between feature and sexual behavior, have been shown. Dominance of D. lummei phenotype in the interspecies D. virilis x D. lummei was found. The interspecies hybrids D. virilis and D. lummei were used for a genetic analysis of the variability of the examined feature. The significant influence of chromosomes 2 and 6 on the number of bristles on the aedeagus in hybrid males was shown. Furthermore, the correspondence between the effects of the autosomes 2 and 6 on the variability of the examined feature and the genetic status of the other chromosomes (the effect of interaction between genetic factors, chromosomes here) was revealed. The adaptive value of the examined feature related to the involvement in the formation of isolating barriers at the copulation stage is under discussion.

[Molecular genetic polymorphism of androgen receptor gene (AR) in African populations of Hadza and Datoga].

The molecular genetic analysis of the polymorphic variants of the CAG repeat-containing locus of the andro- gen receptor (AR) gene was performed in the populations of Hadza and Datoga. Allele frequency distribution patterns were established. Alleles containing 20-25 repeats were the most abundant in both populations were the. The populations studied were compared with Asians (Han), white Americans, and Africans (Ariaal). Sta- tistically significant difference between populations of Hadza and Datoga in the distribution of the AR allelic variants was demonstrated.

[Dominance status of shape of male genitalia in interspecific crosses of some Drosophila virilis group species].

The heritability of the shape of the main species-specific morphological trait for the Drosophila virilis group--the male mating organ has been analyzed using the hybrid males D. virilis x D. lummei and D. virilis x D. novamexicana. The results suggest an increase in the share of the characters with a recessive status in the evolutionarily younger species and demonstrate the role of sex chromosomes in the implementation of a dominant or recessive status of the trait. The roles of additive and epistatic components of the total variation in the evolution of dominance status, shown in several known theoretical models and confirmed by our data, are considered. The published data on sterility of hybrid males in interspecific crosses are discussed from the standpoint of the evolution of dominance.

[Polymorphism of the dopamine D4 receptor (DRD4) and serotonin transporter (5-HTTL) gene promoter regions in African tribes of Hadza and Datoga].

Molecular genetic analysis of the allelic variants of the DRD4 and 5-HTTL gene promoter regions was performed in African tribes of Hadza and Datoga, characterized by different levels of socially acceptable aggression. It was demonstrated that Hadza and Datoga people differed in the structural organization of one of the 5-HTTL alleles (extra long allele xL). Analysis of the allele length polymorphism of both genes showed that in the Hadza and Datoga samples examined, variation parameters, as well as the genotype and allele frequency distribution pattern were almost the same. At the same time, analysis of the SNP polymorphism at the A/G substitutions of the 5-HTTL locus revealed a substantial decrease of the active allele L(A) frequency in the population of Hadza compared to the population of Datoga (chi2 = 3.77; d.f = 1; P = 0.052).

[Nonuniformity in the evolutionary rate in the virilis: II. group of Drosophilas: application of the method of Tajima's test].

The steadiness of the molecular clock was estimated in 11 Drosophila species of the virilis group by sequences of five genes by applying Tajima's Simple Method. The main characteristic of this method is the independence of its phylogenetic constructions. The obtained results have completely confirmed the conclusions drawn relying on the application of the two-cluster test and the Takezaki branch-length test. In addition, the deviation of the molecular clock has found confirmation in D. virilis evolutionary lineages.

[Irregular evolutionary rate of the fruit fly from the Virilis group: I. Use of phylogeny-mediated Takezaki tests].

The aim of this study is to test the hypothesis about an inconsistency in time estimation of the divergence and topology of species Drosophila kanekoi, D. ezoana, and D. littoralis which is caused by the irregular accumulation rate of replacements in different DNA sequences used for analysis and in evolutionary lineages. The phylogenetic relationships based on sequences of five genes among 11 fruit fly species of virilis group are revised, and estimation of molecular clock regularity in several phylogenetic lineages of this group is given. It was shown that Drosophila kanekoi, D. ezoana, and D. littoralis assembled in a single cluster, which was most related to the subfilade montana. The irregularity of molecular clocks was shown for the high conservative sequences of mt 12S-16S.

[The relationships among the species of the Drosophila virilis group inferred from the gene Ras1 sequences].

Comparative analysis of a group of closely related Drosophila species (D. virilis, D. lummei, D. novamexicana, D. americana texana, D. flavomontana, D. montana, D. borealis, D. lacicola, D. littoralis, D. kanekoi, and D. ezoana) was conducted based on an incomplete sequence of gene Ras1. The pattern of the relationships among the species corresponded to that expected from analysis of morphological and cytogenetic characters. Statistical data favoring neutrality of the substitutions examined in the Ras1 gene are presented. This character of the gene Ras1 evolution confers more reliability to reconstruction of phylogenetic relationships among closely related species. The resultant tree for main phylads of the group is as follows: (D. virilis, D. lummei, D. montana, D. ezoana).

[The endosymbiotic bacterium Wolbachia enhances the nonspecific resistance to insect pathogens and alters behavior of Drosophila melanogaster].

To determine biologically important effects of the cytoplasmic endosymbiont Wolbachia, two substrains of the same Drosophila melanogaster strain have been studied, one of them infected with Wolbachia and the other treated with tetracycline to eliminate the bacterium. Female D. melanogaster infected with Wolbachia are more resistant to the fungus Bauveria bassiana (an insect pathogen) than uninfected females; infected females also exhibited changes in oviposition substrate preference. Males infected with the bacterium are more competitive than uninfected males. The possible role of Wolbachia in the formation of alternative ecological strategies of D. melanogaster is discussed.

[A RAPD fingerprinting of sibling species of the Drosophila virilis group].

A comparative analysis of the sibling species of Drosophila virilis was performed by RAPD-PCR technique using a set of random primers. The degree of relatedness was studied by cluster analysis (UPGMA) and multi-dimensional scaling. The resulting pattern of species relationships contradicts the classical taxonomy. The main result of the cluster analysis is that D. virilis does not cluster with the remaining three species of its phylad, while according to multidimensional scaling, D. virilis is equidistant from all the species of its group, from both the species of its phylad and the species of the montana phylad. The montana phylad is extremely heterogeneous; moreover, the species D. littoralis, D. ezoana, and D. kanekoi appear to be closer to the virilis phylad than to the other species of the montana phylad, wherein these species are traditionally included. The phylogenetic relationships between the studied species discovered using RAPD fingerprinting comply with the results obtained using protein markers and quantitative traits.

[Hypothesis of "immunological testing" of partners--systems of "friend and foe" recognition in historical prospect].

The hypothesis of "autoimmune testing" of mating partners assumes formation of individual system of perception on the basis of an immunologic principle, i.e. by lifetime selection of "direct" or "reverse casts" of own key antigens or signal molecules. Such system provides the coordinated change of signaling systems and system of their perception at formation of new adaptations that leads to automatic formation of reproductive isolation within the limited number of generations. Presence of the "friend-foe" recognition systems practically in all living organisms assumes formation of potential mating partners "autoimmune testing" mechanisms at the earliest evolution stages. In this article we analyze possible mechanisms of a "friend and foe" discrimination with MHC-proteins and their homologues in historical prospect--from bacteria to the lower Chordates.

[Identification of individual genotype parameters, informative for medical care in piloted space missions: modern and future capabilities].

The factors of space flight provoke some negative shifts in crew health. Improvement of the methods of diagnostics, evaluation of predisposition to diseases and correction of functional deviations is within the scope of the crew medical operations personnel. It is also a new focus of biomedical research referred to as "personalized medicine" the corner stone of which is genetic analysis. Investigations in this area are prediscovery by character; population genetics seems to be the most adequate approach. The authors give examples of candidate genes the genotypes of which could be of significance to medical operations and discuss the genetic safety of space flight. Aside from the applied aspects, the genetic investigations of space crews are of their own concernment in understanding the genetic basis of differences in biological resistance to unhealthy environment.

[The hypothesis of immune testing of partners--coordinated adaptations and changes in mating preferences].

Reproductive isolation plays the key role in speciation. According to the prevailing ideas, the main speciation mechanism is gradual accumulation of genetic differences in isolated populations (allopatric phase of speciation) based on mutations, selection, and genetic drift. In this case, reproductive isolation emerges as an occasional byproduct of adaptation to different conditions (ecological speciation) or accumulation of random changes in the gene pool resulting from long-term isolation. Pure sympatric speciation assumes isolation as a direct product of selection (divergent or disruptive selection) that favors individuals selectively mating with their likes. A third possibility is substantiated below. We believe that isolation can be a regular and determined product rather than occasional byproduct of divergence. It can rely on the friend/foe discrimination mechanisms, some of which can be "immune-based" and compare the partner's and own properties (signaling molecules, pheromones, and other antigens in a broad sense). Antigens of the major histocompatibility complex (MHC) can play a substantial role in such testing of potential mates.

[Fertility of Drosophila melanogaster females affected by mutation l(2)M167DTS].

We studied the fertility of D. melanogaster females heterozygous for the dominant temperature sensitive mutation l(2)M167DTS, which exerts a recessive lethal effect at 25 degrees C, under the conditions of stable temperature regimes 25, 28, and 29 degrees C and changing regimes 25-->29 degrees C and 29-->25 degrees C. It was shown that inhibition of total activity of oogenesis due to a decreased number of functioning ovarioles is one of the mechanisms underlying the decreased fertility of l(2)M167DTS /+ females. Analysis of individual fertility of each female confirmed also the role of sterility as a component of fertility of the females. Sterilization was realized due both to full depletion of functioning ovarioles and disturbed mechanism of laying the mature eggs onto a substrate as a result of violation of the feedback blocking normal ovulation, which led to the breakdown of ovarioles and filling of the abdominal cavity with mature oocytes. A significant polymorphism of heterozygous females by their fertility was observed. The intensity of sterilization and mortality of l(2)M167DTS/+ females sharply increased at an elevated temperature (29 degrees C), especially at the pupal stage.