A proerythroblast (or rubriblast, or pronormoblast) is a
precursor cell
In cell biology, precursor cells—also called blast cells—are partially differentiated, or intermediate, and are sometimes referred to as progenitor cells. A precursor cell is a stem cell with the capacity to differentiate into only one cell ...
to the
normoblast (nucleated
red blood cell
Red blood cells (RBCs), referred to as erythrocytes (, with -''cyte'' translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, erythroid cells, and rarely haematids, are the most common type of blood cel ...
), as the earliest of four stages in its
development
Development or developing may refer to:
Arts
*Development (music), the process by which thematic material is reshaped
* Photographic development
*Filmmaking, development phase, including finance and budgeting
* Development hell, when a proje ...
.
In
histology
Histology,
also known as microscopic anatomy or microanatomy, is the branch of biology that studies the microscopic anatomy of biological tissue (biology), tissues. Histology is the microscopic counterpart to gross anatomy, which looks at large ...
, it is very difficult to distinguish it from the other "-blast" cells (
lymphoblast
__NOTOC__
A lymphoblast is a modified naive lymphocyte with altered cell morphology. It occurs when the lymphocyte is activated by an antigen and increased in volume by nucleus and cytoplasm growth as well as new mRNA and protein synthesis. The ly ...
,
myeloblast
The myeloblast is a unipotent white blood cell which differentiates into the effectors of the granulocyte series. It is found in the bone marrow. Stimulation of myeloblasts by G-CSF and other cytokines triggers maturation, differentiation, prolife ...
,
monoblast
Monoblasts are the committed progenitor cells that differentiated from a committed macrophage or dendritic cell precursor (MDP) in the process of hematopoiesis. They are the first developmental stage in the monocyte series leading to a macrophage. ...
, and
megakaryoblast). The
cytoplasm
The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell a ...
is blue in an
H&E stain
Hematoxylin and eosin stain ( or haematoxylin and eosin stain or hematoxylin–eosin stain; often abbreviated as H&E stain or HE stain) is one of the principal tissue stains used in histology. It is the most widely used stain in medical diag ...
, indicating that it is
basophilic
Basophilic is a technical term used by pathologists. It describes the appearance of cells, tissues and cellular structures as seen through the microscope after a histological section has been stained with a basic dye. The most common such dye ...
.
Proerythroblasts arise from the
CFU-e (colony-forming unit
erythroid) cells, and give rise to basophilic
erythroblasts. In the
mouse
A mouse (: mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus'' ...
, proerythroblasts are large committed
progenitors that express high levels of
transferrin receptor (iron acquisition receptor), the
erythropoietin receptor (EpoR), some
c-Kit (stem cell factor receptor), and are Ter119 (
cell surface molecule)-positive. Their proliferative capacity is more limited compared to the preceding stage, the CFU-e.
In vivo
Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, an ...
, starting with the proerythroblast stage, erythroid cells undergo several more
cell divisions while at the same time upregulating survival genes such as
Bcl-xL
B-cell lymphoma-extra large (Bcl-xL), encoded by the BCL2-like 1 gene, is a transmembrane molecule in the mitochondria. It is a member of the Bcl-2 family of proteins, and acts as an anti-apoptotic protein by preventing the release of mitochondr ...
, acquiring and storing large amounts of
iron
Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...
, ramping up the synthesis of
hemoglobin
Hemoglobin (haemoglobin, Hb or Hgb) is a protein containing iron that facilitates the transportation of oxygen in red blood cells. Almost all vertebrates contain hemoglobin, with the sole exception of the fish family Channichthyidae. Hemoglobin ...
and other erythroid genes (in large part a
GATA-1 dependent process that is augmented by the EpoR signaling) and decreasing in cell size, eventually removing their
nuclei and being released into the bloodstream as a
reticulocyte. There are several Nucleoli on the nucleus and it occupies most of the cell volume. the chromatins are consist of a network of fine red pink strands. The distinguished feature of pro erythroblast to its corresponding myeloblast in granulocytic series is that it carries more basophilic peripheral cytoplasm.
"Pronormoblast" vs. "proerythroblast"
Some sources consider the terms "pronormoblast" and "proerythroblast" to be
synonyms
A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...
. However, other sources
Proerythroblast
Dorland's Medical Dictionary consider "proerythroblast" to be a parent term, divided into the following two categories:
* "pronormoblast" - normal development
* "promegaloblast" - abnormal development
References
External links
* - "Bone Marrow and Hemopoiesis: bone marrow smear, erythroblast series with proerythroblast"
*
*
Image and description at purdue.edu
(pernicious anemia
Pernicious anemia is a disease where not enough red blood cells are produced due to a deficiency of Vitamin B12, vitamin B12. Those affected often have a gradual onset. The most common initial symptoms are Fatigue, feeling tired and weak. Other ...
)
Interactive image at usuarios.lycos.es
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Blood cells