Gametogenesis

Gametogenesis

Gametogenesis is a process by which diploid or haploid precursor cells undergo cell division and differentiation to form mature haploid gametes. Depending on the biological life cycle of the organism, gametogenesis occurs by meiotic division of diploid gametocytes into various gametes or by mitotic division of haploid gametogenous cells. For example, plants produce gametes through mitosis in gametophytes. The gametophytes grow from haploid spores after sporic meiosis. The existence of a multicellular, haploid phase in the life cycle between meiosis and gametogenesis is also referred to as alternation of generations.

Gametogenesis in animals

Animals produce gametes directly through meiosis in organs called gonads. Males and females of a species that reproduces sexually have different forms of gametogenesis:

* spermatogenesis (male)
* oogenesis (female)

tages

However, before turning into gametogonia, the embryonic development of gametes is the same in males and females.

Common path

Gametogonia are usually seen as the initial stage of gametogenesis. However, gametogonia are themselves successors of primordial germ cells. During early embryonic development, primordial germ cells (PGCs) from the dorsal endoderm of the yolk sac migrate along the hindgut to the gonadal ridge. They multiply by mitosis and once they have reached the gonadal ridge they are called gametogonia. Gametogonia are not longer the same between males and females.

Individual path

From gametogonia, male and female gametes develop differently - males by spermatogenesis and females by oogenesis. However, by convention, the following pattern is common for both:

Gametogenesis in gametangia

Fungi, algae and primitive plants form specialized haploid structures called gametangia where gametes are produced through mitosis. In some fungi, for example zygomycota, the gametangia are single cells on the end of hyphae and acting as gametes by fusing into a zygote. More typically, gametangia are multicellular structures that differentiate into male and female organs:

* antheridium (male)
* archegonium (female)

Gametogenesis in flowering plants

In flowering plants, the male gamete is produced inside the pollen grain through the division of a generative cell into two sperm nuclei. Depending on the species, this can occur while the pollen forms in the anther or after pollination and growth of the pollen tube. The female gamete is produced inside the embryo sac of the ovule.


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  • gametogénesis — (plural gametogénesis) sustantivo femenino 1. Área: biología Proceso de formación de los gametos a partir de células germinativas que tiene lugar en las gónadas …   Diccionario Salamanca de la Lengua Española

  • gametogenesis — gametogenesis. См. гаметогенез. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • gametogénesis — Origen y maduración de los gametos, que se produce a través del proceso de meiosis. Diccionario Mosby Medicina, Enfermería y Ciencias de la Salud, Ediciones Hancourt, S.A. 1999 …   Diccionario médico

  • gametogenesis — [gə mēt΄ō jen′ə sis] n. the entire process of consecutive cell divisions and differentiation by which mature eggs or sperm are developed gametogenic [gə mēt΄ōjen′ik] adj. gametogenous [gam΄ə täj′ə nəs] gametogeny [gam΄ə täj′ənē] n …   English World dictionary

  • Gametogénesis — Este artículo o sección necesita referencias que aparezcan en una publicación acreditada, como revistas especializadas, monografías, prensa diaria o páginas de Internet fidedignas. Puedes añadirlas así o avisar …   Wikipedia Español

  • Gametogénesis — ► sustantivo femenino BIOLOGÍA Proceso de formación de los gametos, a partir de las células germinativas. IRREG. plural gametogénesis * * * gametogénesis (de «gameto» y « génesis») f. Biol. Formación de los gametos. * * * La gametogénesis es el… …   Enciclopedia Universal

  • gametogénesis — {{#}}{{LM G18664}}{{〓}} {{[}}gametogénesis{{]}} ‹ga·me·to·gé·ne·sis› {{◆}}(pl. gametogénesis){{◇}} {{《}}▍ s.f.{{》}} {{♂}}En algunos seres vivos,{{♀}} proceso de formación de los gametos: • En los animales superiores, la gametogénesis tiene lugar… …   Diccionario de uso del español actual con sinónimos y antónimos

  • Gametogenesis — The development and production of the male and female germ cells required to form a new individual. The male and female germ cells are called gametes. The gametes in human males are produced by the testes, two globe shaped reproductive organs… …   Medical dictionary

  • Gametogenesis — lytinių ląstelių susidarymas statusas T sritis gyvūnų raida, augimas, ontogenezė, embriologija atitikmenys: lot. Gametogenesis; Pro ontogenesis ryšiai: platesnis terminas – žinduolių reprodukcija siauresnis terminas – gametų brendimas siauresnis… …   Veterinarinės anatomijos, histologijos ir embriologijos terminai

  • Gametogenesis — lytinių ląstelių susidarymas statusas T sritis gyvūnų raida, augimas, ontogenezė, embriologija atitikmenys: lot. Gametogenesis ryšiai: platesnis terminas – pagrindiniai terminai siauresnis terminas – patelės lytinių ląstelių susidarymas… …   Veterinarinės anatomijos, histologijos ir embriologijos terminai

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