CNS Maturation Process in Children and Adolescents in the Northern Region of the Russian Federation and Its Reflection in the Dynamics of Integral EEG Parameters

Neuroscience and Behavioral Physiology - We present here results from analysis of the formation of brain bioelectrical activity in children and adolescents living in the northern region of Russia...     

Chromosome painting in Tragulidae facilitates the reconstruction of Ruminantia ancestral karyotype

Although Tragulidae, as the basal family in Ruminantia phylogenetic tree, is the key taxon for understanding the early chromosome evolution of extant ruminants, comparative molecular cytogenetic data on the tragulids are scarce. Here, we present the first genome-wide comparative map of the Java mouse deer (Tragulus javanicus, Tragulidae) revealed by chromosome painting with human and dromedary probes. Together with the published comparative maps of major representative cetartiodactyl species established with the same set of probes, our results allowed us to reconstruct a 2n = 48 Ruminantia ancestral karyotype, which is similar to the cetartiodactyl ancestral karyotype. The karyotype evolution of T. javanicus has involved multiple rearrangements, most of which appear to be apomorphic and have not found in karyotype evolution of pecoran species (i.e., Ruminantia excluding Tragulidae). The rate of chromosome evolution of the mouse deer was rather low—0.4 R/Ma, while the estimated tempo of chromosome changes on the lineages leading from Cetartiodactyla ancestor to Ruminantia and from Ruminantia to Pecora were roughly the same (about 1.2 R/Ma).     

The origin of the genetic code and of the earliest oligopeptides

Reconstruction of the earliest proteins in the ancient binary alphabet [glycine family G, alanine family A] leads to repeats of G alternating with repeats of A. In addition, omnipresent motifs can be assembled in two of the earliest genes involved in energy supply, crucial for Life, i.e. ATP/GTP binding and ATPase activity. They are an almost perfect match to the alternating G and A and are complementary to each other.     

Karyotype evolution and phylogenetic relationships of hamsters (Cricetidae, Muroidea, Rodentia) inferred from chromosomal painting and banding comparison

The evolutionary success of rodents of the superfamily Muroidea makes this taxon the most interesting for evolution studies, including study at the chromosomal level. Chromosome-specific painting probes from the Chinese hamster and the Syrian (golden) hamster were used to delimit homologous chromosomal segments among 15 hamster species from eight genera: Allocricetulus, Calomyscus, Cricetulus, Cricetus, Mesocricetus, Peromyscus, Phodopus and Tscherskia (Cricetidae, Muroidea, Rodentia). Based on results of chromosome painting and G-banding, comparative maps between 20 rodent species have been established. The integrated maps demonstrate a high level of karyotype conservation among species in the Cricetus group (Cricetus, Cricetulus, Allocricetulus) with Tscherskia as its sister group. Species within the genera Mesocricetus and Phodopus also show a high degree of chromosomal conservation. Our results substantiate many of the conclusions suggested by other data and strengthen the topology of the Muroidea phylogenetic tree through the inclusion of genome-wide chromosome rearrangements. The derivation of the muroids karyotypes from the putative ancestral state involved centric fusions, fissions, addition of heterochromatic arms and a great number of inversions. Our results provide further insights into the karyotype relationships of all species investigated.     

In vivo testing of Enterogenin for a mutagenic activity of bone marrow hemopoietic tissue of mice.

The purpose of the present study was to test Enterogenin for genotoxicity. The micronuclearic test of Schmid W. was used. Enterogenin was introduced intraperitoneally, once and/or twice in two doses on male and female mice of the BDF 1 hybrid line. The positive controls were injected with clastogenic agent. Bone marrow smear preparations were made, determining the ratio between the normochromic erythrocytes (NCE) and polychromic erythrocytes (PCE), and the number of micronuclearic erythrocytes (MNE). Enterogenin has no genotoxic effect on the hemopoietic tissue of bone marrow of mice the ratio NCE/PCE being within the reference values. The preparation showed no clastogenic effect (p > 0.05), compared to the controls, as the number of PCE with micronuclei did not change 24, 48 and 72 hours after treatment with the two studied doses.