[The search for the sexual process or its equivalents in the Trypanosomatidae]. / Poiski polovogo protsessa ili ego ékvivalentov u tripanosomatid.

Literary evidence on searching for the sexual process in the life cycles of the trypanosomatids are reviewed. Based on the data provided, a; conclusion is made that the stable well-accepted viewpoint on the absence of any genetic exchanges in these flagellates is to be rejected. However, forms and mechanisms of the discovered phenomena are investigated insignificantly. The results reported in the number of publications suggest the presence of the sexual process, at least, in Trypanosoma brucei. But the existence of other forms of genetic exchanges, both in this and in other species, is also possible. The species problem in the trypanosomatids is discussed.

[Presence of genetic exchange in Crithidia oncopelti (Trypanosomatidae) studied with drug resistance markers]. / Issledovanie nalichiia geneticheskogo obmena u Crithidia oncopelti (Trypanosomatidae) s pomoshch'iu markerov lekarstvennoi rezistentnosti.

Strains resistant to 100 mkg/ml of cycloheximide (ChxR100) and to 2.5 mg/ml of chloramphenicol (CapR2.5) were used in studies for the presence of genetic interchange in C. oncopelti. Phenotypes of these strains were stable on the nonselective medium and specific. Strains ChxR100 and CapR2.5 were mixed in equal proportions, cultivated during 7 days and tested. Under consecutive effect of inhibitors the culture of strains mixture and clones isolated from it exhibited double resistance. Phenotypes of recombinant clones were stable on the nonselective medium during, at the minimum, 70 to 90 cell generations. At the same conditions control cultures of parental strains and clones did not exhibit resistance that excludes the possibility of origin of cells resistant to both antibiotics from Crithidia of one of the parental strains as a result of secondary mutation. Thus, the results obtained show convincingly the presence of genetic interchange between flagellates of ChxR100 and CapR2.5 strains.

[Crithidia oncopelti (Kinetoplastmonada) strains resistant to cycloheximide and chloramphenicol]. / Shtammy Crithidia oncopelti (Kinetoplastmonada) ustoichivye k tsiklogeksimidu i khloramfenikolu.

By gradual (during several months) increase of the concentrations of cycloheximide (C) and chloramphenicol (Ch) in cultural medium there were obtained strains of C. oncopelti resistant to the effect of 20, 50, 100 mkg/ml and 2.5 mg/ml Ch. During 38, 28, 19 and 12 subculturings (that corresponds to 160, 120, 80 and 50 cell generations, respectively) on media without inhibitors parasites preserve their resistance to corresponding concentrations of C and Ch without essential changes. Cross resistance between obtained strains of Crithidia was missing. Therefore, the characters of resistance to C and Ch are rather specific, genetically specified and can be used as genetical markers.

[Effect of biologically active agents on the feeding response of Dileptus anser]. / Vliianie biologicheski aktivnykh veshchestv na pishchevuiu reaktsiiu khishchnoi infuzorii Dileptus anser.

A study was made of the effects of pharmacological agents--adrenaline, noradrenaline, serotonine, dibenamine, theophylline, and emidazole--on the phagocytar activity of Dileptus anser. These effects were estimated in terms of food response changes towards chemical food models (CFM) made in cysteine, lecithine or tween-40 solutions. The above pharmacological agents were also tested as phagocytosis inductors. Of these, only adrenalin appeared to be an effective inductor of the food response. The CFM, made in adrenaline, was stimulated by 10(-6) M theophylline, and inhibited with 10(-4)--10(-8) M imidazole. The addition of 10(-3)--10(-12) M adrenaline or 10(-8)--10(-10) M serotonine to the Dileptus-containing medium stimulated phagocytosis of CFM. 5.10(-6) M dibenamin decreased phagocytotic intensity of CFM. 10(-6) M theophylline stimulated, while 10(-4) M inhibited the food response. It is proposed that protozoans have receptors capable of accepting hormones. A possible role of the system of cyclic AMP in transporting hormonal and food stimules in protozoans is discussed.