Cellular Composition and Proliferation Levels in the Hematopoietic Tissue of Black Scorpionfish (Scorpaena porcus L.) Head Kidney and Spleen During the Spawning and Wintering Periods.

To identify cells and analyze proliferative activity of hematopoietic tissue, black scorpionfish head kidney and spleen cells were characterized by light microscopy and flow cytometry. Hematopoiesis of black scorpionfish head kidney was formed by the following series: erythropoietic, granulopoietic, lymphopoietic, and thrombopoietic. Flow cytometric analysis allowed dividing blood cells in hematopoietic organs into subpopulations differing by size, granularity, and proliferative activity. Three distinct subpopulations were observed during the wintering period. The number of small low-granulated cells, identified as lymphocytes and thrombocytes, was 41% ± 4% in both wintering and spawning fish. Proliferating subpopulation of blast (high-granulated) cells amounted to about 36% of the total cell count with 50% ± 5% of proliferating cells; the largest low-granulated cells (10% of total cells) comprised maturing white blood cells, monocytes, and macrophages. The spawning period was accompanied with an increase of maturing neutrophils and enhancement of blast cell proliferation. In the spleen three distinct subpopulations were observed. The subpopulation of small low-granulated cells comprised lymphocytes and thrombocytes similar to the head kidney and amounted 33% ± 4%. Other cells with larger diameter were identified as red blood cells. No proliferation was observed during the wintering period in the spleen, however, spawning induced cell proliferation of erythroblasts (small granulated cells) with the number of dividing cells 84% ± 1%. Anat Rec, 302:1136-1143, 2019. © 2018 Wiley Periodicals, Inc.

Black Scorpionfish (Scorpaena porcus) Hemopoiesis: Analysis by Flow Cytometry and Light Microscopy.

Cell suspensions of head kidney and spleen of black scorpionfish (Scorpaena porcus L.) have been studied using flow cytometry and light microscopy. On the basis of forward scatter (FS) and side scatter (SS) distribution and light microscopy, two main types of cells in the hemopoietic organs were identified: "small cells" (5.1-8.9 µm) and "large cells" (10.8-15.3 µm). Subpopulation of small cells was formed by thrombocytes, lymphocytes, and elements with functionally inactive nuclei. Euchromatin level in their nuclei was low and acidophilic cytoplasm corresponded to negligible nucleic acids content. No proliferative activity was observed using SYBR Green I fluorescence analysis. Morphological characteristics of these cells coincided with colony forming units of mammals. Large cells in head kidney consisted of two subpopulations of cells differing in granularity and DNA content. Proliferating blast cells and differentiating cells of all hemopoietic lines were identified among them. Macrophages and apoptotic cells were also detected in head kidney. In spleen large cells cluster mainly included aged red blood cells with extended lengthwise axis. Blast cells and differentiating elements in spleen were not observed. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:1993-1999, 2017. © 2017 Wiley Periodicals, Inc.