[Morphofunctional parameters of the nucleoli during development of polyploid nutrient cells of gonads from the snail Succinea lauta].
Ag-protein contents, integral area and number of nucleoli in polyploidizing nuclei of gonadal nutrient cells of the snail Succinea lauta were estimated on the squashed preparations by means of morphometry and cytophotometry. 8 NORs of different size were found in haploid chromosome set of prophase spermatocytes (n = 22), but usually 1-2 nucleoli per 2c DNA are present in the nutrient cell nuclei. During genome multiplication from 2c to 32c-64c the Ag-proteins content of nucleoli increased proportionally to gene dosage, but irregularly: before 8c-level the coefficient of increasing in each endocycle was more than 2; from 8c to 16c it was 2; after 16c-level it usually decreased to 1.6-1.3. This dynamics reflects the effects of several factors on nucleolar activity: endomitotic polyploidy (gene dosage effect), differentiation and rhythmic functioning of tissue. Increasing indexes of integral area and the number of nucleoli during polyploidization were significantly less, than increasing index of Ag-proteins. The lag of nucleolar area for 4 cycles (2c-32c) was 32%, and number of nucleoli per diploid set decreased from 2 to 1. It may be due to NOR aggregation corresponding chromosomes. The photometric index of Ag-protein content more adequately reflects in the nucleolar activity during development and functioning of tissues.
Anisimova
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AA
Far East State University, Vladivostok. nez@bio.dvgu.ru
Anisimov
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AP
D000818:Animals; D002466:Cell Nucleolus / Q000378:metabolism / Q000502:physiology*; D004247:DNA / Q000378:metabolism; D006372:Helix, Snails / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D008297:Male; D011123:Polyploidy; D012708:Sertoli Cells / Q000378:metabolism / Q000648:ultrastructure*
D004247:DNA
Morfofunktsional'nye parametry iadryshek v razvitii poliploidnykh pitaiushchikh kletok gonady ulitki iantarki Succinea lauta.