Bypass of Abasic Site-Peptide Cross-Links by Human Repair and Translesion DNA Polymerases.

DNA-protein cross-links remain the least-studied type of DNA damage. Recently, their repair was shown to involve proteolysis; however, the fate of the peptide remnant attached to DNA is unclear. Particularly, peptide cross-links could interfere with DNA polymerases.

Abasic site-peptide cross-links are blocking lesions repaired by AP endonucleases.

Apurinic/apyrimidinic (AP) sites are abundant DNA lesions arising from spontaneous hydrolysis of the N-glycosidic bond and as base excision repair (BER) intermediates. AP sites and their derivatives readily trap DNA-bound proteins, resulting in DNA-protein cross-links. Those are subject to proteolysis but the fate of the resulting AP-peptide cross-links (APPXLs) is unclear.

[Use of determination analysis for trophic connections in the water objects of Azov, Caspian and Kara gydrographic regions].

By determination analysis the study of contingencies between various components of freshwater biocoenoses in Don, Volga, Angara and Priazovye rivers is carried out. The positive contingency of phytoplankton and its divisions biomasses, and zooplankton biomasses is shown. The contingencies between zooplankton and Green, Pyrrophyta algae and cyanobacteria is the most valuable.

[Technical aspects of using rank distributions of phytoplankton abundance for the analysis of mass data of freshwater ecological monitoring. Approximate calculations].

Rank distribution parameters for the abundance of phytoplankton species was calculated based on long-term hydrobiological monitoring (1978-1997) of water bodies in the Azov, Caspian, and Kara hydrographic regions. Two model relationships between species abundance and the rank were used in data analysis: exponential and hyperbolic. Parameter variability related to changes in environmental quality in time and space was analyzed.

[Deterministic analysis as a tool to investigate the contingency of various components of biocenosis].

Specific application of deterministic analysis to investigate the contingencies of various components of natural biocenosis was illustrated by the example of fish production and biomass of phyto- and zooplankton. Deterministic analysis confirms the theoretic assumptions on food preferences of herbivorous fish: both silver and bighead carps avoided feeding on cyanobacteria. Being a facultative phytoplankton feeder, silver carp preferred microalgae to zooplankton.