[Study of genetic variation in Yakutian cattle (Bos taurus L.) using the prolactin bPRL, growth hormone bGH, and transcription factor bPit-1 genes].

The genetic structure of the Yakutian cattle breed was studied using the following genes: bPRL (RsaI site in exon 3), bGH (AluI site in exon 5), and bPit-1 (HinfI site in exon 6). The values of observed heterozygosity were 0.36 for bPRL, 0.29 for bGH, and 0.16 for bPit-1. These values are within the range of values for this parameter established for a number of Bos taurus breeds. The results obtained show that genetic variation is preserved in this aboriginal Russian breed, despite a catastrophic reduction of the number of animals.

[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).

[Nuclear rDNA variability in laboratory strains of the German cockroach Blattella germanica L. (Blattellidae)].

The polymorphism of nuclear ribosomal DNA has been studied in male German cockroaches. The RFLP analysis has been used to identify seven types of HindIII fragments, the variation of which may serve as the basis for the differentiation of laboratory strains with respect to some population indices, including the average number of fragments per animal (N), the proportion of polymorphic loci (P), and the average pairwise similarity (APS). The interpopulation variation (FST) calculated for nine haplotypes is 53.85%.

[Genetic variation of nuclear ribosomal DNA of the insect order of cockroaches (Blattaria): phylogenetic analysis of restriction fragment length polymorphism]. / Geneticheskaia izmenchivost' iadernoi ribosomnoi DNK nasekomykh otriada tarakany (Blattaria): filogeneticheskii analiz polimorfizma dlin restriktsionnykh fragmentov.

Species-specific characteristics of nuclear ribosomal DNA (rDNA) have been determined for the first time for six insect species of order Blattaria (Insecta, Dictyoptera) with the use of restriction analysis and Southern blotting. Probes containing highly conserved fragments of 18 S- and 28 S-like genes of the ribosomal RNA (rRNA) of Tetrahymena pyriformis were tested in this study. The genetic similarity tree constructed for the species studied agrees with evidence from classical taxonomy based on morphological, ecological, anatomical, and physiological characters.

[Intraspecies polymorphism for the structural organization of ribosomal gene cluster in Blattella germanica]. / Vnutrividovoi polimorfizm strukturnoi organizatsii klastera ribosomnykh genov Blattella germanica.

Intraspecific HindIII restriction fragment length polymorphism (RFLP) for the structural organization of the ribosomal gene cluster was described in Blattella germanica. In this species, homologous chromosomes were shown to contain ribosomal DNA (rDNA) repeats that differ in structure. The pattern of inheritance was determined for various structural variants of rDNA.

[Analysis of differences in the structure of ribosomal DNA from two sibling species: Drosophila melanogaster and Drosophila simulans]. / Analiz razlichii struktury ribosomnoi DNK dvukh vidov-bliznetsov: Drosophila melanogaster i Drosophila simulans.

Southern-blot hybridization studies have revealed structural differences within the ribosomal DNA clusters of two sibling species, Drosophila melanogaster and Drosophila simulans. The approach used was shown to be suitable for taxonomic identification of the species examined.

[The HindIII polymorphism of the ribosomal DNA in the German cockroach (Blattella germanica L.)]. / HindIII polimorfizm ribosomal'noi DNK ryzhego tarakana (Blattella germanica L.).

Structural polymorphism of rDNA from Blattella germanica was analyzed in six colonies of Moscow city different regions. Two electrophoretic variants of HindIII fragments of rDNA were detected by using 28S-like rDNA probe.

[Analysis of the variable structure of a cluster of ribosomal genes in the Insecta class]. / Analiz variabel'nosti struktury klastera ribosomal'nykh genov v predelakh klassa Insecta.

General estimation of ribosomal DNA variation within the Insecta class is presented. It is shown that, using blot-hybridization, one can detect differences in the structure of the ribosomal gene cluster not only between genera within an order, but also between species within a genera, including sibling species. Structure of the ribosomal gene cluster of the Coccinelidae family (ladybirds) is analyzed. It is shown that cloned highly conservative regions of ribosomal DNA of Tetrahymena pyriformis can be used as probes for analyzing ribosomal genes in insects.