Physiological and genetic bases of coevolution of complex systems ectoparasitic vector—causative agent

Coevolutionary relationships of ticks of the Ixodes genus with causative agents pathogenic for human of viral, bacterial, and protozoan nature are considered using the method of polymerase chain reaction (PCR). Peculiarities of genotypic composition of ticks-vectors are analyzed, which differ in malate dehydrogenase and of which alleles are investigated by the polyacrylamide gel electrophoresis method. The inherited phenotypic differences of population composition of 2 tick species of the Ixodes genus differing by the presence of exoskeleton anomalies and the content of ions of heavy metals-pollutants accumulated in the tick body are investigated. The character of interaction of various tick-borne pathogens in the tick body and the degree of danger of these tocks depending on geno-and phenotypic properties of the populations throughout their area are determined.     

Zooplankters as indicators of ecosystem health: past findings and future directions

Both acute (ingestion, respiration) and chronic bioassays (reproduction, survival) have been used to identify sources of pollutants. A mass-balance analysis suggests that acute tests be paired, using important indicator species asDaphnia, Ceriodaphnia and potentially others, to estimate the impact of contaminants upon the zooplankton community. Eventually groups of community bioassays may be combined to approximate an ecosystem bioassay. Hormesis or the stimulation of a physiological process by a compound which is toxic at high concentrations is characteristic of several bioassays; in this paper the ecotoxicology community is challenged to keep detailed records of the species, toxic compound, and physiological response involving hormesis in order to understand it; and ultimately to use it to simplify interpretation of bioassays. Life history characteristics of the cladoceran zooplankton, including early reproduction, high net reproductive rates, and the potential for many parthenogenetic generations with constant genotypes and low mutation rates make good choices for environmental bioassays. In contrast, high mutation rates of rotifers make them questionable choices. Five innovations, one or more of which may improve our ability to detect and identify pollutants, are suggested for ecotoxicologists using zooplankton. These include (a) the use of strains of known genotype; (b) determination of the genetic adaptation of clones to common toxins; (c) the use of common behaviors, including responses to light in detection of non-lethal chemicals at ambient levels; (d) record keeping on occurrence of cladoceran tumors; and (e) the determination of precise toxins responsible for the inhibition of zooplankton function and behavior.