Amebocyte
Encyclopedia
An amebocyte or amoebocyte (uh-me´-buh-sīt´) is a mobile cell (moving like an amoeba
) in the body of invertebrate
s such as echinoderm
s, mollusks or sponges. They move by pseudopod
ia. Similarly to some of the white blood cell
s of vertebrate
s, in many species amebocytes are found in the blood or body fluid and play a role in the defense of the organism against pathogen
s. Depending on the species, it may also digest and distribute food, dispose of wastes, form skeletal fibers, fight infections, and change into other cell types. Also known as explosive cells.
Limulus amebocyte lysate
, an aequous extract of amebocytes from the horseshoe crab
(Limulus polyphemus), is commonly used in a test to detect bacteria
l endotoxin
s.
In sponges, amebocytes or archaeocyte
s are cells found in the mesohyl
that can transform into any of the animal's more specialized cell types.
In old literature, the term amebocyte is sometimes used as a synonym of phagocyte
.
Amoeba
Amoeba is a genus of Protozoa.History=The amoeba was first discovered by August Johann Rösel von Rosenhof in 1757. Early naturalists referred to Amoeba as the Proteus animalcule after the Greek god Proteus, who could change his shape...
) in the body of invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s such as echinoderm
Echinoderm
Echinoderms are a phylum of marine animals. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone....
s, mollusks or sponges. They move by pseudopod
Pseudopod
Pseudopods or pseudopodia are temporary projections of eukaryotic cells. Cells that possess this faculty are generally referred to as amoeboids. Pseudopodia extend and contract by the reversible assembly of actin subunits into microfilaments...
ia. Similarly to some of the white blood cell
White blood cell
White blood cells, or leukocytes , are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a...
s of vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
s, in many species amebocytes are found in the blood or body fluid and play a role in the defense of the organism against pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
s. Depending on the species, it may also digest and distribute food, dispose of wastes, form skeletal fibers, fight infections, and change into other cell types. Also known as explosive cells.
Limulus amebocyte lysate
Limulus Amebocyte Lysate
Limulus amebocyte lysate is an aqueous extract of blood cells from the horseshoe crab, Limulus polyphemus. LAL reacts with bacterial endotoxin or lipopolysaccharide , which is a membrane component of Gram negative bacteria...
, an aequous extract of amebocytes from the horseshoe crab
Horseshoe crab
The Atlantic horseshoe crab, Limulus polyphemus, is a marine chelicerate arthropod. Despite its name, it is more closely related to spiders, ticks, and scorpions than to crabs. Horseshoe crabs are most commonly found in the Gulf of Mexico and along the northern Atlantic coast of North America...
(Limulus polyphemus), is commonly used in a test to detect bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
l endotoxin
Endotoxin
Endotoxins are toxins associated with some Gram-negative bacteria. An "endotoxin" is a toxin that is a structural molecule of the bacteria that is recognized by the immune system.-Gram negative:...
s.
In sponges, amebocytes or archaeocyte
Archaeocyte
Archaeocytes or amoebocytes are amoeboid cells found in sponges. They are totipotent and have varied functions depending on the species.-Location:...
s are cells found in the mesohyl
Mesohyl
The mesohyl, formerly known as mesenchyme, is the gelatinous matrix within a sponge. It fills the space between the external pinacoderm and the internal choanoderm...
that can transform into any of the animal's more specialized cell types.
In old literature, the term amebocyte is sometimes used as a synonym of phagocyte
Phagocyte
Phagocytes are the white blood cells that protect the body by ingesting harmful foreign particles, bacteria, and dead or dying cells. Their name comes from the Greek phagein, "to eat" or "devour", and "-cyte", the suffix in biology denoting "cell", from the Greek kutos, "hollow vessel". They are...
.