Generation of LEPR Knockout Rabbits with CRISPR/CAS9 System.

The LEPR gene encodes a leptin hormone receptor, and its mutations are associated with morbid obesity, dysregulation of lipid metabolism, and fertility defects in humans. Spontaneous Lepr mutations have been described in rodents, and Lepr knockout animals have been generated, in particular, using the CRISPR/Cas9 system. Lipid metabolism in rodents significantly differs from that in humans or rabbits, and rabbits are therefore considered as the most relevant model of morbid obesity and lipid metabolism dysregulation in humans.

Melanophilin Polymorphism in Ferrets of Different Color.

In mammals, the main contribution to the variability of pigmentation is made by two groups of genes directly related to the metabolic pathways of pigment synthesis and controlling the transport of melanosomes in melanocytes to keratinocytes. In order to identify the genetic basis of pigmentation variants, the nucleotide sequences of the melanophilin gene were compared in two groups of ferrets-silver-colored and wild-type animals-using sequencing of 16 exons. In carriers of silver color, a single nucleotide deletion was detected in the 9th exon, leading to a shift in the reading frame and the formation of a stop codon downstream.

Leukocytosis and Expression of Bovine Leukemia Virus microRNAs in Cattle.

Bovine Leukemia Virus (BLV) is an established model for studying retroviral infections, in particular the infection by the human T-cell leukemia type 1 (HTLV-1) virus. Here, we quantified gene expression of several BLV-related genes: effector protein of and NK-killer cells NK-lysin (), reverse BLV transcriptase receptor (, and also key enzymes of the microRNA maturation, Dicer () and Argonaut (). The differences in the expression of the above genes were compared between five groups: (1) BLV infected cows with high and (2) low lymphocyte count, (3) with and (4) without BLV microRNA expressions, and (5) cows without BLV infections (control group).

Intestinal amino acid and peptide transporters in broiler are modulated by dietary amino acids and protein.

This study evaluated the effect of three levels of digestible amino acids (DAA; 100, 107 and 114% of Cobb recommendations) on mRNA abundance of peptide (PepT1) and amino acid (AA) transporters in 480-day-old broilers during prestarter period. Jejunal mRNA levels of the PepT1 and bAT increased as DAA level increased from 100 to 114%. The expression of CAT1 mRNA in the jejunum was higher in birds fed 100% DAA diet.

Helitrons and Retrotransposons Are Co-localized in Genomes.

Background: DNA transposons helitrons are mobile genetic elements responsible for major movements of the genetic material within and across different genomes. This ability makes helitrons suitable candidate elements for the development of new approaches of multilocus genotyping of live-stock animals, along with the well-known microsatellite loci.

Objective: We aimed to estimate the informativeness of helitron and microsatellite markers in assessing the consolidation and the "gene pool" standards of two commercial dairy cattle breeds (Ayrshire breed and holsteinized Black-and-White cattle) and one local breed of Kalmyk cattle, and to reveal any inter-breed difference in the organization of genomic regions flanked by helitrons in the studied cattle breeds.

Sources of contradictions in the evaluation of population genetic consequences after the chernobyl disaster.

The review covers the analysis of our own and published data pertaining to population and genetic consequences in various mammalian species under conditions of high levels of ionizing radiation as a result of the Chernobyl accident. The findings indicate that these conditions have promoted the reproduction of heterozygotes in polyloci spectra of molecular genetic markers and animals with a relatively increased stability of the chromosomal apparatus. The prospects of using the reproductive "success" of the carriers of these characteristics as an integral indicator of the selective influence of environmental stress factors are discussed.

Karyotype alterations in human lung adenocarcinoma cells after long-term action of interferon-alpha.

Aim: To estimate the effect of long-term IFN treatment of human non-small-cell lung cancer cell line A-549 on their karyotype characteristics and on the clonal structure of cell population.

Methods: Cytogenetic research was performed by standard methods using routine and differential staining. Cytogenetic characteristics were estimated per 1000 cells (ppm, (per thousand)).

Spontaneous premature condensation of chromosomes in normal and transformed mammal cells.

Aim: To study the relation between premature chromosome condensation and the ability of the cells to undergo malignant transformation.

Methods: Standard cytogenetic analysis of bone marrow cells and cultured normal and tumor cells has been used.

Results: Comparative analysis of the frequency of occurrence of the cells with premature chromosome condensation (PCC) (cell "arrest" at G2/M phase) in relation to dividing cells in the cultures of human immortalized cells of hematopoietic origin, human lung carcinoma A-549 cells, and in populations of bone marrow cells of BALB/c and C57BL/6 mice differing in predisposition for myeloma development has been performed.

[Spontaneous mutagenesis in bone marrow cells in the CBA and CBA/H-T6 mouse strains].

Comparative analysis of cytogenetic characteristics in bone marrow cells of the mouse lines CBA and CBA/H-T6 has been carried out. It was shown that translocation T6 effects the apparatus of cell division and can cause additional cytogenetic abnormalities.

[The possible ways of the diploidization of the polyploid germinative stem cells in the mouse BALB/c line].

Quantitative and qualitative chromosome rearrangements in the cell line G1 established from a genital ridge of the 12,5 dpc BALB/c mouse embryo were analysed. Cytogenetic analysis was performed on the 75th passage of in vitro cultivation. It has been shown that by this passage the cell population was heterogenous.

[Chronic low doze ionizing irradiation and polyfactors of adaptation].

The analysis of cytogenetic anomaly dynamics in conditions of chronic low doze effect of ionizing irradiation in generations of genetically homogeneous laboratory line of mice CC57W/Mv and genetically heterogeneous populations of vole's species, trapped in alienation zone of Chernobyl's NPP in places with different levels of radio nuclide contamination in 1994-2001 was carried out. The data about the physiological adaptation to ionizing irradiation effects under age of linear mice and non-linearity of frequency changes of separate cytogenetic anomalies in generations as laboratory line of mice, and genetically heterogeneous populations of vole's species were obtained. Was supposed, that the number of non-linear effects of the ionizing irradiation in low doze range could be stipulated by comparability between the intensity of it's damage effects and the activation by it the polyfactor systems of anti oxidant ones, reparation events, and also elimination of defective cells.

["Chain" karyotypic evolution of embryonic stem cell line R1 in vitro].

Cytogenetic anomaly frequencies were analysed in three sublines of ES R1 line in its five clonal sublines, obtained from two cell colonies after transformation of ES R1 cells by plasmid with gene lif. Cell transformation did not increase cytogenic anomalies, however, the initial sublines of ES R1 line, as well as its transformed clonal descendants bore a redundant quantity of the chromosome 8 material within the structure of various Robertsonian translocations even in cells with diploid chromosome quantity (2n = 40). In the initial sublines ES R1 and its clonal descendants a common Rb (8; 15) was revealed.

[Species specificity of karyotype instability under conditions of radionuclide contamination (the Chernobyl Nuclear Power Plant) in the voles, Micrototus oeconomus, Micrototus arvalis, and Clethrionomys glareolus].

The comparative analysis of frequencies of different type cytogenetic anomalies in voles Microtus oeconomus, Microtus arvalis, Clethrionomys glareolus trapped in territories with different levels of radionuclide contamination inside the 30-km zone of estrangement around the Chernobyl NPP was carried out. Animals with constitutive chromosome abnormalities were not revealed. The frequency of lympocytes with micronuclei was the most universal and sensitive character to chronic low-dose radiation in investigated species.

[The interrelations between karyotypic stability and interchromosomal associations in mammalian cells].

The interchromosome associations between heterologous chromosomes (for the type of Robertsonian translocations); frequencies of the association between individual chromosomes (identified by G-bands) and mouse line pecularities, the directions of cytodifferentiation, the stages of cell neoplastic transformation in cell populations of various origin have been estimated. The presence of interrelations between individual chromosome associations and genetic and cytological cell characteristics with the use of different mathematical methods of analysis has been revealed.

[The heterogeneity of the cytogenetic variability in the bone marrow cells of laboratory and wild rodents in the exclusion zone of the Chernobyl Atomic Electric Power Station].

Analysis of the characters of cytogenetic variabilities and correlative interrelations between them revealed the group specificities of karyotype instability in bone marrow cells of some lines of laboratory and of wild mice under the conditions of increased radionuclide pollution in the Chernobyl zone. The complex correlative interrelations between the frequencies of cytogenetic anomalies and the character of cell division (the number of metaphases, binucleated leukocytes per 1000 cells) were observed. The obtained data indicate the stimulatory influence of chronic low doses of ionizing radiation on the manifestation of spontaneous mutagenesis, which has own genotype specific characteristics.

[The variability of different cytogenetic characteristics in groups of Black Pied cattle].

The comparative analysis of frequency of occurrence of different indications of cytogenetic variabilities in blood cells of cattle groups (relative healthy, infected by bovine leukosis virus and exposed to ionizing radiation in the Chernobyl zone) was carried out. Both genotoxic influences induced increases in frequencies of cytogenetic defects, but only ionizing radiation induced the increase of chromosome aberration frequency. The heterogeneity of all cattle groups for investigated cytogenetic characters was revealed.

[The independent variability of different karyotypic characteristics during the spontaneous neoplastic evolution of mouse embryo fibroblasts].

The dynamics of some karyotype characteristics throughout the spontaneous neoplastic evolution of embryonal fibroblasts of different mouse strains was studied using a differential staining of chromosomes. The independent variability of chromosome modal numbers, the number of polyploid cells in the cell line, the number of chromosomal rearrangements within one cell, the activity of formation of different types of chromosomal rearrangements and the activity of interactions of the homologous chromosomes in 15 studied cell lines were revealed. Possible levels of variability regulations of different karyotype characteristics are discussed.

[Hematologic chimerism in cattle twins].

A cytogenetic examination of a cow and its offsprings, obtained by pair transplantations of the embryos was carried out. The fragile X and the heteromorphism of the chromosomes XX of this cow and some of its offsprings were revealed. The variability of the hematological chimerism of the pair transplanted embryos was observed.

[The spontaneous aneuploidy of the embryonic fibroblasts in C3H/He and CBA/Ca mouse strains occurring during their neoplastic evolution].

Karyological analysis of 6 cell lines with distinct tumorigenic properties of mouse strains C3H/He and CBA/Ca has been carried out using differential chromosome staining. All the cell lines are characterized by a decreased number of copies of normal chromosome 7, the increased number of normal copies of chromosome 10 being specific of the cell lines with intermediate tumorigenicity. Cell lines with maximum tumorigenicity differed from all other lines by the increased number of copies of chromosome 5 and by the decreased number of copies of chromosome 6.

[The karyotypic variability of mouse embryonic fibroblasts of 2 genotypes during spontaneous neoplastic transformation].

Karyological analysis of 6 lines with distinct tumorigenic properties of mouse strains C3H/He and C57BL/6 has been carried out using a differential staining of chromosomes. The number of normal copies of chromosomes varied in all the investigated cell lines. The more and the less stable chromosomes different from line to line.

[Approaches to the analysis of reciprocal chromosome distribution in the bone marrow cells of mice].

A study was made of G-banding chromosome preparations made of bone marrow cells of BALB/c mouse females, injected intraperitoneally with a single dose of the antibiotic adriamycin 23 hours before sacrifice. Frequencies of different chromosome fusions in pericentromeric regions were analysed. All chromosomes were found to be involved in the interchromosomal associations, different chromosomes participating in such fusions with different frequency.

[Karyotypic characteristics of a number of clonal lines of an interspecific mouse-mink hybridoma].

Using G-banding method, a study was made of the karyotypes of mouse myeloma cell line P3-X63-Ag8.653 and some cell hybrid lines originated from a fusion of mink immunized spleen cells and this myeloma. Normal chromosomes 6, 12 and X were not detected in either examined cell of the parental myeloma.

[Mechanism of a decrease of inducibility of tyrosine aminotransferase by carcinogenic aminoazo dyes. Absence of direct influence of o-aminoazotoluene on the enzyme molecules].

The effect of o-aminoazotoluene (OAT) on the activity of tyrosine aminotransferase (TAT) from mouse liver cytosol under its incubation in the presence of the systems providing for the metabolic activation of the cancerogen (liver microsomes and NADPH2) and dephosphorylation of TAT molecules (light mitochondria and ATP) was studied. It was shown that OAT has neither direct nor indirect (via the phsophorylation--dephosphorylation systems) effect on the activity of TAT. It was concluded that the decrease of TAT induction by hydrocortisone in vivo resulting from injection of OAT to the mice is not due to the direct influence of the cancerogen on the enzyme molecules.

[Mechanisms of the immunodepression caused by ortho-aminoazotoluene and its noncarcinogenic analog in mice].

Single injections of ortho-aminoazotoluene (OAT) or aminoazobenzene (AB) decrease the immune response of DD mice to the strain-nonspecific Krebs-2 tumor. The immunosuppressive action of AB is due to its toxicity for lymphoid cells, whereas the OAT effect is mediated by adrenal glands. After OAT injection,II-oxycorticosteroids level is elevated although their production by adrenal glands is not increased.