The Influence of quick-to-court Gene on Some Aspects of Mating Behavior in Drosophila melanogaster

Russian Journal of Genetics - quick-to-court (qtc) is a recently discovered gene involved in the regulation of the mating behavior of Drosophila melanogaster males. Previously, we obtained flies...     

The effect of phosphorylation on oxidative and CoA- and NAD+-independent turnover of pyruvate by pyruvate dehydrogenase complex in the brain

It was shown that in the presence of ATP and Mg2+ the phosphorylation of the partially purified pyruvate dehydrogenase complex and the enzyme in isolated brain mitochondria inhibited the oxidative activity of the pyruvate dehydrogenase complex. The phosphorylation did no affect essentially the nonoxidative decarboxylation of pyruvate to form CO2 and acetaldehyde. In native mitochondria from the bovine brain the nonoxidative activity of the pyruvate dehydrogenase complex reached about 10% as compared to the oxidative activity of enzyme.     

Different mechanisms of telomere length regulation

Eukaryotic chromosomes are linear and have their, ends formed by DNA-protein structures, telomeres. At present more and more facts demonstrate the diversity of telomere functions. Telomeres protect the chromosome ends from degradation, fusion, recombination, and from the repair system that recognizes nicks in DNA strands. As shown recently, shortening of the telomeres is a cause of cell aging. In most organisms, telomeres are elongated by means of a special ribonucleoprotein complex; however, in some insects this takes place by either gene conversion or transposition of mobile elements. Evolutionary relations between different types of telomeres are discussed.     

Particulate fatty acids in two small Siberian reservoirs dominated by different groups of phytoplankton

SUMMARY 1. We studied the composition of fatty acids (FAs) in the seston from two small freshwater reservoirs (Bugach and Lesnoi) with distinct periodicity of domination by cyanobacteria and eukaryotic algae during the growth season.
2. The diatoms in the both reservoirs were characterised by a high content of 14:0 and C16 unsaturated acids, whereas that of the essential FA 20:5ω3 [eicosapentanoic acid (EPA)] was low. The correlation between this polyunsaturated FA (PUFA) and diatom biomass was not significant in either reservoir. The percentage of 20:5ω3 in seston significantly correlated with the biomass of euglenophyta in Bugach and dinophyta in Lesnoi. Hence the diatoms, usually referred as a valuable food for zooplankton, were not an important source of the essential PUFA in these systems.
3. The dominant cyanobacteria in Bugach, and the green algae in Lesnoi, both contained the same marker acids: 18:3ω3 and 18:2ω6. Hence, a discrimination between these two phytoplanktonic groups on the basis of FA biomarkers may be difficult in some cases.
4. We found no significant correlation between the content of 20:5ω3 in seston and the biomass of the dominant daphniids in either reservoir. This is contrary to expectations, based on the literature, that EPA is generally important. Rather, the biomass of the two dominant Daphnia species in Bugach correlated strongly with the content of 18:3ω3 in the seston. The cyanobacteria were a probable source of this ω3 FA for Daphnia . We conclude that EPA is not always important for Daphnia populations although, in such cases, some other PUFA (e.g. 18:3ω3) might be related to their growth.