PRODUCTIVE AND BIOLOGICAL CHARACTERISTICS OF RUSSIAN MEAT MERINOS SHEEP WITH DIFFERENT LINEAR SELECTION

Line breeding is a difficult but effective zootechnical process in purebred sheep husbandry. Linear sheep consistently transmit their characteristics to offspring in order to increase and identify the most promising genotypes, characterized by high productivity and breeding efficiency, by detecting interline selection. The main purpose of the work was to identify the most suitable options for intra- and interline selection of the Russian meat merino breed. The article studies the early development of animals’ growth and physique, the high rates of animals, live weight in different age periods, slaughter and meat qualities. We established that young animals obtained by mating between the animal lines VK-40 and ME-50 were characterized by more proportional body shapes, better slaughter and meat qualities. The increase in live weight of lambs obtained by mating queens of the VK-40 line and rams of the ME-50 line (group III) was more intense than their peers from the intraline selection of the VK-40 line (I group) and of queens of the line AC- 30 with ME-50 rams (group II). The heaviest carcasses were in lambs obtained from the mating of queens of the VK-40 line and rams of the ME-50 line (13.26 kg), the weight of the carcass was greater, compared with the same indicator of the peers of groups I and II, respectively, by 7.7% and 4.0%, by internal fat mass – by 21.8% and 9.8%, by slaughter weight – by 8.3% and 4.3%

WOOL PRODUCTIVITY AND QUALITY OF RUSSIAN MEAT MERINO SHEEP FROM INTRA- AND INTERLINE SELECTION

Line breeding is often used in purebred animal husbandry, although the combination of lines may affect undesirable result. Therefore, it is very important for animal breeders to know which lines of animals can be combined to produce highly productive offspring with high meat and wool properties. This article studies the influence of interline selection of Russian meat merino breed on wool productivity, quality and skin histostructure. We found that the highest clipping was in the animals of group III obtained from ME-50 line rams and AS-30 line ewes. Ewes exceeded their peers of group II from the intraline AC-30 selection and peers of group IV from AS-30 line rams and ME-50 line queens. At the same time, ewes of group III insignificantly exceeded peers of group I from intraline selection of ME-50 line animals by 2.0% (P>0.05). Animals of group III had rather high fleece indices in terms of the wool condition due to the influence of ME-50 rams. Moreover, they had the highest ratio of “fat:sweat” (0.84), which confirms the high technological wool properties of this genotype. The quality of sheepskins depends on the nature of the connection of collagen fibers in the reticular layer. In terms of the thickness of the skin reticular layer young ewes of the group III exceeded their peers in groups I, II and IV by 5.3% (P> 0.05), 21.9% ( P<0.01) and 12.0% (P<0.05) respectively

Epigenetic Silencing of ALDH1L1, a Metabolic Regulator of Cellular Proliferation, in Cancers

FDH (10-formyltetrahydrofolate dehydrogenase, the product of the ALDH1L1 gene), a major folate-metabolizing enzyme in the cytosol, is involved in the regulation of cellular proliferation. We have previously demonstrated that FDH is strongly and ubiquitously down-regulated in malignant human tumors and cancer cell lines. Here, we report that promoter methylation is a major mechanism controlling FDH levels in human cancers. A computational analysis has identified an extensive CpG island in the ALDH1L1 promoter region. It contains 96 CpG pairs and covers the region between −525 and +918 bp of the ALDH1L1 gene including the promoter, the entire exon 1, and a part of intron 1 immediately downstream of the exon. Bisulfite sequencing analysis revealed extensive methylation of the island (76%-95% of CpGs) in cancer cell lines. In agreement with these findings, treatment of FDH-deficient A549 cells with the methyltransferase inhibitor 5-aza-2′-deoxycytidine restored FDH expression. Analysis of the samples from patients with lung adenocarcinomas demonstrated methylation of the ALDH1L1 CpG island in tumor samples and a total lack of methylation in respective normal tissues. The same phenomenon was observed in liver tissues: the CpG island was methylation free in DNA extracted from normal hepatocytes but was extensively methylated in a hepatocellular carcinoma. Levels of ALDH1L1 mRNA and protein correlated with the methylation status of the island, with tumor samples demonstrating down-regulation of expression or even complete silencing of the gene. Our studies have also revealed that exon 1 significantly increases transcriptional activity of ALDH1L1 promoter in a luciferase reporter assay. Interestingly, the exon is extensively methylated in samples with a strongly down-regulated or silenced ALDH1L1 gene

Activation of p21-Dependent G1/G2 Arrest in the Absence of DNA Damage as an Antiapoptotic Response to Metabolic Stress

The folate enzyme, FDH (10-formyltetrahydrofolate dehydrogenase, ALDH1L1), a metabolic regulator of proliferation, activates p53-dependent G1 arrest and apoptosis in A549 cells. In the present study, we have demonstrated that FDH-induced apoptosis is abrogated upon siRNA knockdown of the p53 downstream target PUMA. Conversely, siRNA knockdown of p21 eliminated FDH-dependent G1 arrest and resulted in an early apoptosis onset. The acceleration of FDH-dependent apoptosis was even more profound in another cell line, HCT116, in which the p21 gene was silenced through homologous recombination (p21−/− cells). In contrast to A549 cells, FDH caused G2 instead of G1 arrest in HCT116 p21+/+ cells; such an arrest was not seen in p21-deficient (HCT116 p21−/−) cells. In agreement with the cell cycle regulatory function of p21, its strong accumulation in nuclei was seen upon FDH expression. Interestingly, our study did not reveal DNA damage upon FDH elevation in either cell line, as judged by comet assay and the evaluation of histone H2AX phosphorylation. In both A549 and HCT116 cell lines, FDH induced a strong decrease in the intracellular ATP pool (2-fold and 30-fold, respectively), an indication of a decrease in de novo purine biosynthesis as we previously reported. The underlying mechanism for the drop in ATP was the strong decrease in intracellular 10-formyltetrahydrofolate, a substrate in two reactions of the de novo purine pathway. Overall, we have demonstrated that p21 can activate G1 or G2 arrest in the absence of DNA damage as a response to metabolite deprivation. In the case of FDH-related metabolic alterations, this response delays apoptosis but is not sufficient to prevent cell death

Avalanche delay and dynamic triggering in gaas-based s-diodes doped with deep level impurity

The article is concerned with a detailed switching delay effect exhibited by avalanche S-diodes-superfast GaAs closing switches doped with deep Fe centers. The current and voltage time dependences are simulated in a simplified generator. The dynamic electric field and charge profiles in the structures are calculated. This article describes an impact that Fe capture cross sections of free charge carriers have on delayed switching. The simulation results show that delayed switching is associated with deep center recharging in a double injection mode due to three different processes. There are two different delay mechanisms to be herewith distinguished. A delay effect is experimentally viewed to control the dynamic switching voltage (and the avalanche breakdown voltage) using constant voltage adjustment capability enabled by a triggering circuit supply. The authors demonstrate the way it is possible to adjust the amplitude of current nanosecond pulses in the range of 20-45 A through a lidar transmitter circuit with a semiconductor laser and nonoptimized S-diode. The findings are consistent with the results of numerical simulation

Suppression of dynamic current leakage in avalanche S-diode switching circuits

Abstract This work investigates the dynamic current leakage of $S$-diode, which is a GaAs-based avalanche switch doped with deep Fe acceptor traps. The dynamic leakage has negative effect on superfast switching parameters of this unique device, and here we suggest an original way of reducing the leakage by means of circuit design. It is shown that an additional bias for avalanche S-diode in the current pulse generation circuit forms a negatively charged layer of iron traps near the electron-injecting junction. As a result, the concentration of nonequilibrium electrons goes down, which leads to a decrease in leakage current by ∼3–4 times, and a rise in S-diode switching voltage. The results were obtained in the experimental study and are approved by calculation

Avalanche delay and dynamic triggering in GaAs-based S-diodes doped with deep level impurity

Abstract The article is concerned with a detailed switching delay effect exhibited by avalanche S-diodes-superfast GaAs closing switches doped with deep Fe centers. The current and voltage time dependences are simulated in a simplified generator. The dynamic electric field and charge profiles in the structures are calculated. This article describes an impact that Fe capture cross sections of free charge carriers have on delayed switching. The simulation results show that delayed switching is associated with deep center recharging in a double injection mode due to three different processes. There are two different delay mechanisms to be herewith distinguished. A delay effect is experimentally viewed to control the dynamic switching voltage (and the avalanche breakdown voltage) using constant voltage adjustment capability enabled by a triggering circuit supply. The authors demonstrate the way it is possible to adjust the amplitude of current nanosecond pulses in the range of 20—45 A through a lidar transmitter circuit with a semiconductor laser and nonoptimized S-diode. The findings are consistent with the results of numerical simulation

Disposition of GNMT in cellular metabolism.

<p>GNMT converts SAM to SAH, methylating glycine to sarcosine. This reaction regulates SAM/SAH ratio and shuttles methyl groups, from activated methyl cycle back to the folate pool. Inhibitory effect of 5-CH3-THF (5-MTHF) on GNMT catalysis is indicated. Hcy, homocysteine; Sarc, sarcosine; THF, tetrahydrofolate.</p