Genetic control of different types of the aphid resistance in cereal crops

Inheritance of the two main types of the plant resistance to insects was investigated in the sorghum-greenbug (Schizaphis graminum Rond.) and wheat-bird cherry-oat aphid (Rhopalosiphon padi L.) interaction systems. The data obtained support the hypothesis that antixenosis (avoiding of the plant by the insect, given a choice) and antibiosis (adverse effect of the plant on the insect feeding on it) are pleiotropic manifestations of the same genes. This is confirmed by the following facts. (1) Identical patterns of segregation for antixenosis and antibiosis in different cases of sorghum resistance to the greenbug: monogenic control (gene Sgr4), digenic control (Sgr1, Sgr2 and Sgr7, Sgr8), and complementary action of the genes (Sgr9 and Sgr10). (2) Correlated changes in the levels of antibiosis and antixenosis during long-term reproduction of a greenbug clone on the resistant sorghum variety k-1206 (resistance controlled by one gene). (3) Simultaneous expression of antixenosis and antibiosis in F₃ wheat hybrid families to the bird cherry-oat aphid.     

An electron microscopic study of the macro- and microcysts of coccidia in the genus Sarcocystis from buffalo

Two sarcosporidian species from muscles of the water buffalo examined in Azerbaijan were studied. The one making macrocysts was identified as S. fusiformis, whereas the other producing microcysts appeared to be not S. levinei as it might have been expected. Indeed, the microcysts found in the muscles of the buffalo in the slaughterhouse [correction of slaughtery] of Baku differed essentially in morphology of the cyst wall from that of S. levinei, sooner resembling that of S. cruzi from cattle. The cyst wall of these microcysts was seen to make deep invaginations towards the ground substance of cysts. From these invaginations some curved channels were grown outlined with a filamentous material. The described pattern of cyst wall is not characteristic of the S. cruzi sarcocyst. No specification was achieved, and the sarcocysts found in the bubaline muscles are designated as Sarcocystis sp. from the buffalo.     

Current views on the life cycle of cyst-forming Coccidia (Eucoccidia, Sporozoa, Apicomplexa)]

The life cycles of cyst-forming coccidia of the genera Sarcocystis and Toxoplasma have been first analysed in terms of generally recognized biological phenomena, such as proliferation, differentiation, dedifferentiation, programmed cell death. The differences, existing between the respective obligatory heteroxenous (Sarcocystis) and facultatively heteroxenous (Toxoplasma) life cycles, have been found to involve the obvious differences in the degree of a zoite's differentiation, occurring in the course of asexual development in the intermediate host. In Sarcocystis spp., the degree of differentiation in merozoites, throughout their development, is much higher than in those of T. gondii. This level of merozoite differentiation in Sarcocystis is thought to determine the irreversible, one-directional way of both pre-cystic and cystic development of the pathogen, starting from the sporozoite stage and terminating in gamont formation within the tissue cyst. Unlike, in T. gondii, the level of merozoite differentiation is not so strong as in Sarcocystis spp., which may account for the reversible merozoite development in the former, which is clearly demonstrated by a ready conversion of pre-cystic tachyzoites into cystic bradyzoites, and the other way round. In the course of endogenous development, the pathogens adversely affect their environment (the infected cells and tissues), which, in its turn, may exert its influence on the particular parasites. Thus, both the parasite and the host represent a unique feed-bach regulatory system.     

Electron microscopic study of the process of intermediate cell division in the cyst of the coccidian Sarcocystis muris

The intermediate cell is a third definitely outlined morpho-functional type of cells within sarcocysts, in addition to the two other well known ones--metrocytes and merozoites (Fedoseenko, Levit, 1979; Beyer et al., 1981). The intermediate cell divides by endodyogeny, the nuclear division being accomplished by semi-closed pleuromitosis. In the dividing nuclei, centrioles and extranuclear bundle of microtubules connecting two pairs of centrioles are seen in addition to centrocones and associated semi-spindles. Pro-, ana- and telophases of mitosis have been followed. The microtubule organizing center (MTOC) seen in the cytoplasm of the intermediate cell is represented by the polar ring with microtubules originating from it. The MTOC is involved in the division of both the nucleus and the cytoplasm. The formation of the polar ring (MTOC) from the Golgi-adjunct has been first discovered and followed in the course of the intermediate cell division.     

Effect of pentoxyl, ibuprofen and acetylsalicylic acid on the thymus, spleen and adrenals in an experiment]

The effect of acetylsalicylic acid, ibuprofen and pentoxyl on the histological and morphometric pattern of the thymus and the weight of the thymus and spleen was studied in rats. There was decreased function of the thymus and its atrophy with acetylsalicylic acid and ibuprofen. Pentoxyl increased the secretory activity of the thymus. The effect of the drugs on the thymus and spleen was unidirectional.     

Effects of sulfalene on the thymus, spleen and adrenals in an experiment]

The effect of sulfalen on the weight and structure of the thymus, spleen and adrenal glands was studied. The findings were compared with the results observed in control rats. It was shown that after administration of sulfalen, the weight of the adrenal glands markedly decreased while their structure did not change. Thymus specimens showed a large number of hypertrophic epitheliocytes, in the medulla which was accompanied by a decrease in its weight.     

Identification of a new chitinase-like protein of the YM-1 subgroup in the rat olfactory epithelium

A novel protein with a molecular mass of around 43 kDa has been detected in the olfactory lining of rats exposed to pathophysiological conditions. The determination of the amino acid sequence has shown that this protein belongs to the YM-1 chitinase-like protein subgroup of the glycohydrolase family 18.