#513 plant gametangium
Plant gametangium was part of the existing tracker for archegonium, antheridium, and gametangium (https://sourceforge.net/tracker/index.php?func=detail&aid=3109542&group_id=76834&atid=835555), but I think it needs to be in a separate tracker to prevent confusion.
Existing def'n from POC meeting on 3-22-11, plus meeting between DWS, MAG and RLW:
plant gametangium (PO:0025124): A plant organ that produces one or more gametes that are located in it and is part of a whole plant in the
gametophytic phase.
participates in gametophytic phase, only_in_taxon bryophytes plus pteridophytes plus gymnosperms (=never_in_taxon angiosperms)
Comment: The embryo sac and pollen replace the function of gametangia of producing gametes in gymnosperms (for antheridia) and angiosperms (for both
antheridia and archegonia).
(This definition of gametangium works for algae. Could add a child term oogonium.)
We decided at the POC meeting 11-20-12 that this definition was circular and needed to be revised.
Note: in some green algae such as Ulva, the gametangia are single cells (Raven et al, (1992) Biology of plants, 5th ed.) so can this still be a plant organ?
Also, the gametes are not always contained in the gametangium.
Raven definition: "A cell or organ in which gametes are formed." In this case we would have to make it a plant structure.
The only other way to deal with this is create two terms for the two types of plant gametangia: multicellular plant gametangium (is a plant organ) and unicellular plant gametangium (is_a plant cell).
Propose revised name and def'n: multicellular plant gametangium (PO:0025124): A plant organ (PO:0009008) that produces one or more gametes (PO:0025006) and is part of a whole plant (PO:0000003) in the gametophyte development stage (PO:0028003).
unicellular plant gametangium (new PO:ID): A plant cell (PO:0009002) that produces one or more gametes (PO:0025006) and is part of a whole plant (PO:0000003) in the gametophyte development stage (PO:0028003).
gametangium would be a broad synonym for both terms.
After discussion on the POC call 12-4-12 (http://wiki.plantontology.org/index.php/POC_Conf._Call_12-4-12), the following definition was accepted:
multicellular plant gametangium (PO:0025124)
A plant organ (PO:0009008) that produces one or more gametes (PO:0025006) that produces one or more gametes (PO:0025006) and participates in the gametophyte development stage (PO:0028003).
revised comment: The multicellular plant gametangium; an archegonium (PO:0025126) and/or an antheridium (PO:0025125), occurs in bryophytes, pteridophytes and gymnosperms, but never in angiosperms.
Closing this tracker
After discussion on the POC call 12-4-12 (http://wiki.plantontology.org/index.php/POC_Conf._Call_12-4-12), the
following definition was accepted:
unicellular plant gametangium (PO:0025521): A plant cell (PO:0009002) that produces one or more gametes (PO:0025006) and participates in the gametophyte development stage (PO:0028003).
Revised comment: Occurs in some green alga, such as Ulva. Participates in the gametophyte development stage (PO:0028003).
Comment: The embryo sac and pollen replace the function of gametangia of producing gametes in gymnosperms (for antheridia) and angiosperms (for both
antheridia and archegonia).
This is not strictly true. The Embryo-Sac and pollen are reduced gametangia, that is specialized gametangia.
Moved to be is_a native plant cell and updated the def'ns:
unicellular plant gametangium (PO:0025521): A native plant cell (PO:0025606) that produces one or more gametes (PO:0025006) and participates in the gametophyte development stage (PO:0028003).