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cell or organ in which gametes develop

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/06/11 22:19:51」(JST)

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A gametangium (plural: gametangia) is an organ or cell in which gametes are produced that is found in many multicellular protists, algae, fungi, and the gametophytes of plants. In contrast to gametogenesis in animals, a gametangium is a haploid structure and formation of gametes does not involve meiosis.

Types of gametangia

Depending on the type of gamete produced in a gametangium, several types can be distinguished.

Female

Female gametangia are most commonly called archegonia. They produce egg cells and are the sites for fertilization. Archegonia are common in algae and primitive plants as well as gymnosperms. In flowering plants, they are replaced by the embryo sac inside the ovule.

Male

The male gametangia are most commonly called antheridia. They produce sperm cells that they release for fertilization. Antheridia producing non-motile sperm (spermatia) are called spermatangia. Some antheridia do not release their sperm. For example, the oomycete antheridium is a syncytium with many sperm nuclei and fertilization occurs via fertilization tubes growing from the antheridium and making contact with the egg cells. Antheridia are common in the gametophytes in "lower" plants such as bryophytes, ferns, cycads and ginkgo. In "higher" plants such as conifers and flowering plants, they are replaced by pollen grains.

Isogamous

In isogamy, the gametes look alike and cannot be classified into "male" or "female." For example, in zygomycetes, two gametangia (single cells at the end of hyphae) form upon good contact with each other and fuse into a zygospore.

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English Journal

Pedogamy in Neidium (Bacillariophyceae).

Poulícková A1.
Folia microbiologica.Folia Microbiol (Praha).2008;53(2):125-9. doi: 10.1007/s12223-008-0018-x. Epub 2008 May 25.
Single (unpaired) vegetative cells of freshwater pennate diatom Neidium cf. ampliatum differentiated into gametangia and produced a single zygote (auxospore) via a pedogamic process. The gametic nuclei fused after auxospore expansion had begun. The auxospore expanded in parallel to the apical axis o
PMID 18500631

Search, encounter rates, and the evolution of anisogamy.

Cox PA, Sethian JA.
Proceedings of the National Academy of Sciences of the United States of America.Proc Natl Acad Sci U S A.1984 Oct;81(19):6078-9.
We describe analytical and numerical models to study gamete encounters in two and three dimensions between differently sized gametes without assuming pre-existing mating types. Our results indicate that an isogamous population can be successfully invaded by a gametangium if it produces gametes of a
PMID 6592603

The effect of actinomycin D on the formation of gametangia and mitosporangia in Allomyces.

Youatt J.
Archives of microbiology.Arch Microbiol.1976 Aug;109(1-2):163-6.
The effect of actinomycin on gametangium and mitosporangium production in Allomyces arbuscula and A. macrogynus has been investigated. Male gametangium production was not more sensitive to actinomycin than female development. Actinomycin at 20 mug/ml added at the commencement of induction was comple
PMID 986792