Morphogenesis of blood cell lineages in channel catfish

Abstract

The morphogenesis of blood cell lineages in channel catfish Ictalurus punctatus, from head and trunk kidney and spleen imprints as well as from blood smears of bled and control fish, showed that early maturation stages resembled those in higher vertebrates. The erythroid lineage consisted of the proerythroblast, erythroblasts (basophilic, polychromatic, orthochromic), young erythrocyte and erythrocyte. The rare bilobed erythrocyte seemed to be a cell in apoptosis while old erythrocytes and erythroplastids represented remnants of this process. Maturation stages of neutrophils and basophils encompassed the granuloblast, young progranulocyte, progranulocyte and metagranulocyte. The basophilic lineage was regularly present in kidneys, rare in spleen and absent from blood. It contained large Sudan Black and PAS-negative, water soluble granules and small PAS-positive ones. Lymphocytes with azurophilic granulation occured regularly in kidneys and spleen. Monoblasts and promonocytes in kidneys preceded monocytes. A phagocytic lineage devouring apoptotic blood cell remnants was present in kidneys and spleen. Its youngest identified stage (promacrophage) resembled more a granuloid cell without granules than a monocytoid one. The larger, young macrophages contained a few to several ingestions and the very large mature macrophages were loaded with them. The latter two stages corresponded to cells in melano-macrophage centres (macrophage aggregates). Precursor stages of the thrombocyte were not identified.

Cell composition of the head kidney of European chub (Squalius cephalus L. )

“…Basic hematopoietic structures and mechanisms in fishes are similar to those operating in other vertebrates (Fijan 2002a(Fijan , 2002b, and all hematopoietic cell types are very similar to those of mammals (Chen and Zon 2009). Hematopoiesis is a complex process in which haematopoietic stem cells (HSCs), the most immature elements of the hematopoietic hierarchy, proliferate and differentiate into various classes of hematopoietic progenitor cells.…”

“…Five hundred blood cells were identified, counted, and their relative abundance was calculated for each fish. The cells were identified according to terminology in Fijan (2002a) and Kondera (2011).…”

“…Hematopoiesis is a complex process in which haematopoietic stem cells (HSCs), the most immature elements of the hematopoietic hierarchy, proliferate and differentiate into various classes of hematopoietic progenitor cells. These progenitor cells further have been shown to be able to differentiate into mature blood cells: erythrocytes, lymphocytes, thrombocytes, granulocytes, and monocytes (Peters and Schwarzer 1985, Zuasti and Ferrer 1989, W³asow and D¹browska 1989, Fijan 2002a, 2002b, Kobayashi et al 2006, Som et al 2009). All vertebrates (including fish) have primitive and definitive waves of hematopoiesis, but HSCs are only produced by the definitive wave.…”

“…Head kidney tissue is known to be sensitive to various impacts because of its high cell turnover rate (Kondera and Witeska 2013), so it can be used as a bioindicator, and it can provide early warning signs of environmental degradation. According to Fijan (2002aFijan ( , 2002b, Soldatov (2005), and Gangopadhyay and Homechaudhuri (2011), the pronephros, or head kidney, is a basic organ forming the blood elements, and it is also the reservoir of blood cells. The head kidney is also an important endocrine organ, homologous to mammalian adrenal glands, releasing catecholamines, corticosteroids, and other hormones.…”

The effect of thermal shock on morphological characteristics of blood cells in Siberian sturgeon (Acipenser baerii) triploids

“…A decreased size of erythrocytes in the peripheral blood of fish is a stage in morphological changes in the final phase of a cell's life, during apoptosis (Fijan 2002). It can be supposed that large erythrocytes of triploids are too difficult to be phagocytosed and therefore have to be divided.…”