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Comparative aspects of circulating erythrocytes in the trophic and reproductive phases of European eel. Ultrastructure and cytochemistry
Author(s) -
Barni S.,
Gerzeli G.
Publication year - 1985
Publication title -
biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 85
eISSN - 1768-322X
pISSN - 0248-4900
DOI - 10.1111/j.1768-322x.1985.tb00402.x
Subject(s) - biology , cytochemistry , japanese eel , chromatin , cytoplasm , golgi apparatus , prophase , nucleus , microbiology and biotechnology , ultrastructure , organelle , osmium tetroxide , biochemistry , dna , endoplasmic reticulum , japonica , electron microscope , anatomy , botany , meiosis , physics , gene , optics
Different cytochemical and morphological parameters were used to compare the functional patterns of the erythrocytes in the transition from the trophic (yellow eel) to the reproductive (silver eel) phases of European eel (Anguilla anguilla L.). Data on the nucleus were obtained by microdensitometric (Feulgen reaction) and cytofluoremetric (propidium iodide and Hoechst 33342 fluorochromization) evaluations of DNA staining intensity. In the silver eel, chromatin condensation was more heterogeneous and chromatin also appeared to be looser. The fluorochromes provided information on the different degrees of organization of the chromatin filament, with regard to both primary and higher order DNA structure. In the silver eel, the fine structure showed a higher number of erythrocytes with large euchromatinic areas and the heterochromatinic component was occasionally present in scattered clumps. As for the cytoplasm, in the silver eel a positive correlation could be established between the presence of intact cytoplasmic organelles (mitochondria, Golgi complexes, ribosomes, etc.) and the high fluorescence intensity. This aspect is revealed through the detection of definite membrane components such as glycoconjugates and primary amino groups (PAS reaction and fluorescamine staining, respectively). All these findings allowed us to establish that the transition from the trophic to the premigratory reproductive phase is marked by a higher heterogeneity of the erythrocytes, due to different cell maturation levels. This fact can be ascribed to different metabolic requirements as well as to a more intense erythropoiesis, typical of the most active phase of the eel's life.