The Investigations of Nitric Oxide Influence on Lifespan of Fruit Fly D. melanogaster Transgenic Strain dNOS4

Introduction. Aging and longevity control are among the greatest problems in biology and medicine. The fruit fly Drosophila melanogaster is a nice model organism for longevity investigations because of its biological features. Many D. melanogaster genes have their orthologs, similar in other eukaryotes, including human. The role of nitric oxide (NO) in the D. melanogaster lifespan has been analyzed.Methods. Virgin flies of dNOS4 transgenic strain were used for the experiment. This strain contains non-functional additional copies of nitric oxide synthase (NOS) gene under heat shock promoter.  For promoter activation, transgenic flies on their second day of life were exposed to heat shock (37°C) for an hour. After heat shock, flies were maintained on standard medium temperatures at 25°C, with females separate from males. Two types of control were used: Oregon R wild-type strain and Oregon R strain exposed to heat shock. The average lifespan was evaluated.Results. It was revealed that the longevity of females was significantly higher than males in each series of experiments (p < 0.05). The survival rate of females and males was similar in the first month of their life, but in the second month the mortality among males was much higher than among females in all series of experiments. The average lifespan of dNOS4 imago was 31 days (34 days for females and 28 days for males), maximum lifespan was 63 days. In controls, the average lifespan of Oregon R flies was 54 days (58 days for females and 50 days for males), and the maximum lifespan was 94 days. The average lifespan of Oregon R flies exposed to heat shock was 45 days (48 days for females and 41 days for males), and the maximum lifespan was 72 days. The difference between average lifespan in all studied groups is statistically significant (p < 0.05).Conclusion. Thus, NOS-transgene activation results in formation of non-functional  dNOS4-transcripts and NO deficiency. In turn, NO deficiency decreases dNOS4 imago lifespan.

The Investigations of Nitric Oxide Influence on Lifespan of Fruit Fly D. melanogaster Transgenic Strain dNOS4

Introduction. Aging and longevity control are among the greatest problems in biology and medicine. The fruit fly Drosophila melanogaster is a nice model organism for longevity investigations because of its biological features. Many D. melanogaster genes have their orthologs, similar in other eukaryotes, including human. The role of nitric oxide (NO) in the D. melanogaster lifespan has been analyzed. Methods. Virgin flies of dNOS4 transgenic strain were used for the experiment. This strain contains non-functional additional copies of nitric oxide synthase (NOS) gene under heat shock promoter.  For promoter activation, transgenic flies on their second day of life were exposed to heat shock (37°C) for an hour. After heat shock, flies were maintained on standard medium temperatures at 25°C, with females separate from males. Two types of control were used: Oregon R wild-type strain and Oregon R strain exposed to heat shock. The average lifespan was evaluated. Results. It was revealed that the longevity of females was significantly higher than males in each series of experiments (p < 0.05). The survival rate of females and males was similar in the first month of their life, but in the second month the mortality among males was much higher than among females in all series of experiments. The average lifespan of dNOS4 imago was 31 days (34 days for females and 28 days for males), maximum lifespan was 63 days. In controls, the average lifespan of Oregon R flies was 54 days (58 days for females and 50 days for males), and the maximum lifespan was 94 days. The average lifespan of Oregon R flies exposed to heat shock was 45 days (48 days for females and 41 days for males), and the maximum lifespan was 72 days. The difference between average lifespan in all studied groups is statistically significant (p < 0.05). Conclusion. Thus, NOS-transgene activation results in formation of non-functional  dNOS4-transcripts and NO deficiency. In turn, NO deficiency decreases dNOS4 imago lifespan

Homozygosity mapping in the Kazakh national dog breed Tazy

Abstract The Tazy is a breed of sighthound common in Kazakhstan. The identification of runs of homozygosity (ROH) is an informative approach to assessing the history and possible patterns of directional selection pressure. To our knowledge, the present study is the first to provide an overview of the ROH pattern in the Tazy dogs from a genome-wide perspective. The ROH of the Tazy was found to be mainly composed of shorter segments (1–2 Mb), accounting for approximately 67% of the total ROH. The estimated ROH-based inbreeding coefficients (FROH) ranged from 0.028 to 0.058 with a mean of 0.057. Five genomic regions under positive selection were identified on chromosomes 18, 22, and 25. The regions on chromosomes 18 and 22 may be breed specific, while the region on chromosome 22 overlaps with regions of hunting traits in other hunting dog breeds. Among the 12 candidate genes located in these regions, the gene CAB39L may be a candidate that affects running speed and endurance of the Tazy dog. Eight genes could belong to an evolutionarily conserved complex as they were clustered in a large protein network with strong linkages. The results may enable effective interventions when incorporated into conservation planning and selection of the Tazy breed