Russian Journal of Genetics

It is shown that the size, localization, and structure of telomeres in the Iberian shrew (Sorex granarius) are not characteristic of mammals. In this species, long telomeres of an average size of 213 kb are localized on the short arms of all 32 acrocentrics; ribosomal blocks and active nucleolus-organizing regions (NORs) were also discovered there. At the remaining chromosome ends the average size of telomeres is 3.8 kb. However, in a closely related species, Sorex araneus, all telomeres have size similar to that of human telomeres, i.e., 6.8–15.2 kb. Despite the fact that some long telomeres contain ribosomal repeats in addition to telomeric ones, the long telomeres have preserved asymmetry of G- and C-rich strands as in functional telomeres. It is probable that long telomeres were formed in meiosis at the stage of chromosome bouquet as a result of global reorganization of the chromosome ends. The provoking factors for such reorganization might be the fission of several metacentrics and the necessity of telomerization of the resulting acrocentrics.

mutation Y168H of the human phenylalanine hydroxylase (PAH) gene determining phenylketonuria was described only twice: in a patient from Catalonia (Spain) and by us in a patient from Western Siberia (Russia). The association of Y168H in these families with allelic variants of STR and VNTR repeats and a number of neutral point polymorphisms of the PHA gene (IVS3nt-22C > T, Q232Q, V245V, L385L) was studied in this work. The Y186H mutation in these families was found to be associated with different haplotypes. Strong linkage of the selected markers and the mutation region excludes recombination as a possible cause of association of Y168H with different haplotypes. It was concluded that Y168H occurred independently in different populations.

Human sex chromosome-specific probes were hybridized to metaphase spreads of three fish species, Monopterus albus Zuiew, Danio rerioandMastacembelus aculeatusBasilewsky, to reveal evolutionary conservation of sex chromosomal segments between distantly related species of vertebrates. The human X chromosomal paint disclosed 4, 8, and 6 conserved syntenic segments in the karyotypes of the three fish species respectively, which were scattered in several pairs of homologous chromosomes. But no conserved segment was identified in our experiments when the human Y chromosomal probes were used. The evolution of the X chromosome of vertebrates is discussed.

Replicated breeding during five generations from an outbred population of Wistar rats performed, in contrast to the previous breeding, differentially for predisposition to catalepsy and “nervousness” confirmed earlier data that catalepsy and “nervousness” are two phenotypic expressions of the same bipolar catatonic genotype.

An algorithm for drawing large, complex pedigrees containing inbred loops and multiple-mate families is presented. The algorithm is based on a step-by-step approach to imaging, when the researcher determines the direction of further extension of the scheme. The algorithm is implemented as the PedigreeQuery software package written in Java. The software has a convenient graphical interface. The software package permits constructing not only whole pedigrees, but also their fragments that are particularly interesting for research. It also allows for adding new information on the phenotypes and genotypes of pedigree members. PedigreeQuery is distributed free of charge; it is available at http://mga.bionet.msc.ru/PedigreeQuery/PedigreeQuery.html and ftp://mga.bionet.nsc.ru/PedigreeQuery/.

Genetic analysis of the inheritance of mutation ps in sugar beet was conducted. This mutation causes the meiotic abnormalities leading to the development of diploid pollen grains and influences several other morphological traits, namely, annual or biennial habit, stem color, and aggregation of pollen grains into tetrads, which are controlled by the genes B, Stc, and ap, respectively. The literature data on the linkage of genes B and Stc were confirmed; the obtained recombination coefficient between these genes amounts to 15.0 ± 3.6%. It was demonstrated that gene ap was inherited independently of genes B and Stc. Statistical analysis of the data shows that the mutation ps is recessive and is inherited independently of the mutation ap but in a linked manner with the traits development habit and stem color. The conclusion is made that a gene with a strong phenotypic effect that determines the development of the phenotype characteristic of mutation ps is located in the first linkage group near genes B and Stc.

Shell morphological characters and allozyme electrophoresis were used to study the relationships among six geographical populations of land snails collected from Peninsular Malaysia. Allozyme electrophoresis was used to study the genetic variations to complement the morphological features studied that included shell lengths, numbers of whorls and shell colour. Ten loci coding for six enzymes (MDH, LAP, ALP, PGM, G6P DH, and EST) could be reliably scored in samples from the six populations studied. The dendrogram showed two major clusters with one cluster comprising Subulinidae populations from Perak, Selangor, Johor, Terengganu, and Pahang while the other cluster included only the Streptaxidae Huttonella bicolor (red) population. The Subulinidae populations were grouped into two subclusters: one subcluster included the Subulina sp. populations from Perak, Selangor, and Johor, while the other subcluster included the Opeas sp. populations from Terengganu and Pahang. Morphological features can identify the different families ant therefore they can complement the allozyme genetic studies on the land snail populations. Like other reports in the literature, our results also underline the importance of a genetic approach in conjunction with a morphological approach, for discriminating land snail species. The present results suggest that small land snails, which were similar in colour but different in sizes, were not of the same family/genus.