noun, plural: lymphoblasts
Hematopoiesis is the process of forming new blood cellular elements in vertebrates. In this regard, lymphopoiesis is a hematopoiesis leading to the formation of lymphocytes. It begins with a multipotent stem cell, a hemocytoblast, which gives rise to a common myeloid progenitor cell. The progenitor cell, in turn, gives rise to colony forming unit (particularly, CFU-L) fated to become lymphocytes. In the lymphocytic series, the first cell stage is referred to as lymphoblast. This cell gives rise to the prolymphocyte, which is a cell that ultimately develops into a mature lymphocyte. Nevertheless, unlike other blood cell –blast precursors, the lymphoblast may also be derived from certain lymphocytes. Therefore, a lymphoblast may be regarded as well as a cell that undergoes further differentiation of a lymphocyte, particularly T or B cell, depending on antigenic stimulation. This means that a mature lymphocyte, either T cell or B cell, may yield lymphoblasts by reentering the S phase of the cell cycle and subsequently, mitogenesis.
A lymphoblast can be recognized from a lymphocyte by having one or two nucleoli, lacking azurophilic granules, and with more mRNA and ribosomes. When stained with conventional dyes, the cytoplasm renders a intermediate blue color with darker blue border.
Word origin: Greek blastos ("germ", "sprout")
- lymphoblastic (adjective)
- Lymphoblastic Leukemia