Trophic positions and niche segregation of two anuran species in the ecosystem of a forest lake

Hydrobiologia - Different species of amphibians often breed in the same water bodies and their diets overlap. Theoretically, this might lead to a competitive elimination of either one but there are...     

Radioimmunoanalytic study of the kinetics of lambda phage structural protein synthesis

The kinetics of the lambda-phage major structural protein syntheses was determined during the lytic development by radioimmunoassay. For this purpose, the individual structural proteins such as pE, pV and pD were isolated in polyacrylamide gel by the preparative SDS-electrophoresis. The proper monospecific antisera were obtained. All the proteins were labelled with 125J in vitro by a chloramine method. The degree of nativity for iodinated proteins was determined by the electrophoretic and immunochemical methods. The concentrations of proteins pE, pV and pD were measured in lysates of E. coli W3350 cells infected with the phage lambda C1857 at various time intervals after infection using a competitive radioimmunoassay. The concentrations of all three proteins turned out to increase sharply between 20 and 40 minutes after infection, then the rate of synthesis of structual proteins declined gradually. On a cell basis the accumulation of major proteins of the head such as pE and pD exceeded by a factor of 10 or 20 the amount required for collection of the infected progeny or pahge; at the same time the primary component of the tail pV accumulated to a lesser extent. The autonomic regulation of the syntheses of major phage proteins is assumed to be exercised as a translation level in the lytic development of the phage lambda.     

Modern state of the diversity of Coregonids from Onega Lake and the problems of their species identification

The revision was made of all forms of the whitefish Coregonus lavaretus and of the European vendace C. albula that exist in Onega Lake up to the present time. The available data indicate that the entire diversity of coregonid forms has been retained: C. albula is represented by two forms (usually a small form and a large form—kilets); all nine forms were found in C. lavaretus. Various taxonomic approaches for the determination of the systematic status of these forms are discussed.     

The fish Perccottus glenii: history of introduction to western regions of Eurasia

The fish,Perccottus glenii, appeared in western regions of Eurasia in 1916 and has several centres of invasion. Ways of distribution are discussed. Uncontrolled distribution of this fish leads to significant negative changing of freshwater ecosystems.