No abstract

This study brings the first evidence for the interclonal variation in the expression of predator‐induced morphological defence in ciliates. The degree of response to the ciliate predator Stylonychia mytilus was compared in 18 clones of Euplotes octocarinatus. Although all the examined clones were inducible, they attained similar level of the response at a different “dose” of inducing factor. One of the clones maintained the “induced form” permanently, i.e. in the absence of any predator. Furthermore, comparing the effects of two different predators S. mytilus and a turbellarian Stenostomum sp. revealed differences among closely related clones in their relative responses to these predators. The degree of response in a given clone to one predator species did not preclude its response level to the other one suggesting that the expression of the defence to different predators might change independently. Our findings indicate that there is genetic variation for sensitivity to the inducing factors in Euplotes and hence the possibility for selection on this variation.

Genlisea is a terrestrial carnivorous plant which occurs mainly in nutrient-poor soil. It has been known that individuals of ciliates Paramecium caudatum are trapped and digested by this plant. Our observations show that Gen/isea can trap not only Protozoa but also bigger animals, that their prey depend on the kind of available organisms and that prey were trapped passively. In the laboratory, Genlisea traps contained a variety of organisms: bacteria, algae, protozoans, nematodes, rotifers, annelids, tardigrades, crustaceans and mites.

The fibrinolytic system was studied in normal human plasma containing increasing concentrations of acetone up to 23.4 mmol l-1. Fibrinolytic activity measured as euglobulin clot lysis time [ECLT] and amidase activities toward chromogenic peptide substrates H-D-Valyl-L-Leucyl-L-Lysine-p-nitroanilide 2 HCl [S-2251], designed for plasmin determination, H-D-Valyl-L-Phenylalanyl-L-Lysine-p-nitroanilide 2 HCl [S-2390], designed for the determination of t-PA in plasma via plasminogen activation and H-D-Prolyl-L-Phenyl-Alanyl-L-Arginine-p-nitro-anilide 2 HCl [S-2302], designed for the determination of kallikrein and activated Hageman factor, increased when 15.7 mmol l-1 concentration of acetone was reached. A parallel increase of esterolytic [substrate: naphthol-AS-acetate] activity was observed in euglobulin fractions. Crossed immunoelectrophoresis [CIE] revealed changes in fibrinogen profiles of plasma enriched with acetone as compared to native plasma. These findings suggest that acetone present in plasma in concentrations comparable to those found in some pathological states might activate fibrinolytic system.