Analysis of Nucleoli in Intact Peripheral Blood Lymphocytes in Different Species of Mammals
Analysis of NOR (nucleolar organizer regions) allows assessing the level of synthesis of 18S and 28S ribosomal RNA subunits, involved in protein biosynthesis, in cells. In order to develop a method of an express analysis of r-gene activity (ribosomal RNA genes) the NOR index study in species of domestic animals, differing in the number of genes clusters of ribosomal RNA (rRNA), is of interest. The coloring of peripheral blood lymphocytes was carried out with 50% solution of silver nitrate by the method of W. Howell, D. Black. From each animal 100 lymphocytes were analyzed, the proportion of cells with dyed NOR and the average number of NOR in the cell were determined. We studied three types of animals: nutria, American mink and domestic sheep. The number of ribosomal genes clusters in these species is 1, 2, and 5, respectively. When stained lymphocytes in blood smears with a solution of silver nitrate it was allocated two types of cells: resting lymphocytes and lymphocytes containing structure Ag+. The share of the latter was proportional to the number of rRNA genes clusters in the studied species. The proportion of cells, labeled by silver, in nutria was 40%, in mink-68% and in domestic sheep-91%. This allows considering the Ag+ structures of lymphocytes as the interphase nucleolus organizers and using them as a reporter system in the study of factors affecting the metabolism in animals.