platelet and microparticle

[gocentral]

Hi

Platelets are not cells, they are a fragment of a cell. There is no term platelet, although there are terms for parts of platelets, would it be possible to have platelet as an is_a child to GO:0044464 cell part? (and parent to the platelet terms)

GO:0044464 cell part > is_a child platelet Definition: platelets are cell fragments created by the budding of long processes extended by megakaryocytes Ref GOC:BHF

> is_a child blood microparticle definition: these particles arise from the cellular components of blood and the endothelial lining of blood vessels, they are small (≤1.5 μm), expose the anionic phospholipid (PL) phosphatidylserine (PS) on the outer leaflet of their membrane, and bear surface membrane antigens reflecting their cellular origin. Ref GOC:BHF

>> is_a child endothelial microparticle definition:small cell membrane vesicles that are released from endothelial cells and can be found circulating in the blood Ref GOC:BHF

In addition the process of microparticle formation also needs to be created. GO:0048646 anatomical structure formation involved in morphogenesis > is_a child microparticle formation Definition: The process in which endothelial cells release small vesicles, microparticles, into the blood. Ref GOC:BHF

>> regulation child regulation of microparticle formation Ref GOC:BHF

>> > positive regulation child positive regulation of microparticle formation Ref GOC:BHF

Intend to use positive regulation endothelial microparticle for the annotation of mouse cd36 Q08857 based on PMID: 20978343.

Thanks

Ruth

Reported by: RLovering

Original Ticket: geneontology/ontology-requests/8085

[gocentral]

hmmm ... platelet is in the Cell Ontology (CL:0000233). I'll ask Terry to look at this item and comment

Original comment by: mah11

[gocentral]

Midori and Ruth,

Platelets are considered within the domain of the Cell Ontology, and have been from the start. Platelets have sufficient internal complexity and metabolism to be considered anucleated cells. It is of course possible to annotate to an internal structure of a platelet, such as a 'stored secretory granule' and coannoate in column 16 to 'platelet ; CL:0000233'.

Thanks,

Alex

Original comment by: addiehl

[gocentral]

reply from Terry:

"I'm inclined to label a platelet as a cell, but not to label microparticles as cell. Many people say platelet are not cells because they lack a nucleus and are produced as fragments of megakaryocytes. But there are other cell types with no nucleus (erythrocytes) and fragmentation is a misnomer as platelets are produced by a budding process. Platelets have internal structures (alpha and dense granules) that are enclosed by a plasma membrane. This fits the CARO definition of cell "Anatomical structure that has as its parts a maximally connected cell compartment surrounded by a plasma membrane." [CARO:MAH]". Platelets can be activated, secrete cytokines, change shape, migrate up a chemokine gradient, etc. These suggest platelets are not a passive storage unit, but a functional biological unit enclosed in a plasma membrane (another common definition of a cell). Also, the size of platelet 2-5-um is just slightly smaller than lymphocytes (6-um) and in the range of other small mammalian cells (sperm cell precursors, cerrebellum granular cells). Microparticles, to my limited knowledge, do not actively migrate, respond to signals nor have internal structures. They are also significantly smaller than other mammalian cells (less than 1.5 um).

Of course the important thing is not to have overlap between CL and GO!

terry"

In light of what Terry and Alex have said, I propose to add the requested microparticle terms, but not platelet, to GO CC.

m

Original comment by: mah11

[gocentral]

• assigned_to: nobody --> gomidori

Original comment by: mah11

[gocentral]

added blood microparticle GO:0072562 endothelial microparticle GO:0072563 blood microparticle formation GO:0072564 endothelial microparticle formation GO:0072565

regulation terms coming up soon

Original comment by: mah11

[gocentral]

• status: open --> open-accepted

Original comment by: mah11

[gocentral]

In the TermGenie pipeline:

id: GO:2000331 name: regulation of terminal button organization

id: GO:2000332 name: regulation of blood microparticle formation

id: GO:2000333 name: negative regulation of blood microparticle formation

id: GO:2000334 name: positive regulation of blood microparticle formation

id: GO:2000335 name: regulation of endothelial microparticle formation

id: GO:2000336 name: negative regulation of endothelial microparticle formation

id: GO:2000337 name: positive regulation of endothelial microparticle formation

Original comment by: mah11

[gocentral]

• status: open-accepted --> closed-accepted

Original comment by: mah11