Gametogenesis in the context of Gametocytes

A gametocyte is a eukaryotic germ cell that divides by mitosis into other gametocytes or by meiosis into gametids during gametogenesis. Male gametocytes are called spermatocytes, and female gametocytes are called oocytes.

In biology and genetics, the germline is the population of a multicellular organism's cells that develop into germ cells. In other words, they are the cells that form gametes (eggs and sperm), which can come together to form a zygote. They differentiate in the gonads from primordial germ cells into gametogonia, which develop into gametocytes, which develop into the final gametes. This process is known as gametogenesis.

Germ cells pass on genetic material through the process of sexual reproduction. This includes fertilization, recombination and meiosis. These processes help to increase genetic diversity in offspring.

Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testicle. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubules. These cells are called spermatogonial stem cells. The mitotic division of these produces two types of cells. Type A cells replenish the stem cells, and type B cells differentiate into primary spermatocytes. The primary spermatocyte divides meiotically (Meiosis I) into two secondary spermatocytes; each secondary spermatocyte divides into two equal haploid spermatids by Meiosis II. The spermatids are transformed into spermatozoa (sperm) by the process of spermiogenesis. These develop into mature spermatozoa, also known as sperm cells. Thus, the primary spermatocyte gives rise to two cells, the secondary spermatocytes, and the two secondary spermatocytes by their subdivision produce four spermatozoa and four haploid cells.

Spermatozoa are the mature male gametes in many sexually reproducing organisms. Thus, spermatogenesis is the male version of gametogenesis, of which the female equivalent is oogenesis. In mammals it occurs in the seminiferous tubules of the male testes in a stepwise fashion. Spermatogenesis is highly dependent upon optimal conditions for the process to occur correctly, and is essential for sexual reproduction. DNA methylation and histone modification have been implicated in the regulation of this process. It starts during puberty and usually continues uninterrupted until death, although a slight decrease can be discerned in the quantity of produced sperm with increase in age (see Male infertility).

A gametangium (pl.: gametangia) is a sex 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.

An oocyte (/ˈoʊəsaɪt/, oöcyte, or ovocyte) is a female germ cell involved in sexual reproduction. An oocyte is an immature ovum, an immature egg cell produced in a female fetus in the ovary during gametogenesis. During oogenesis, the oogonia become primary oocytes. An oocyte is a form of genetic material that can be collected for cryopreservation.

In medicine, precocious puberty is puberty occurring at an unusually early age. In most cases, the process is normal in every aspect except the unusually early age and simply represents a variation of normal development. There is early development of secondary sex characters and gametogenesis also starts earlier. Precocious puberty is of two types: true precocious puberty and pseudoprecocious puberty. In a minority of children with precocious puberty, the early development is triggered by a disease such as a tumor or injury of the brain.

Even when there is no underlying disease, unusually early puberty can have adverse effects on social behavior and psychological development (having more mature knowledge than one's peers, feeling inadequate, trying to attend and establish friendships with older people, depression). Affected children also face shorter adult height potential and possible lifelong health risks. Central precocious puberty can be treated by suppressing the pituitary hormones that induce sex steroid production. The opposite condition is delayed puberty.

A gametid is a complementary gamete to the gamete that gives rise to a zygote after conception. During meiosis, four gametes, or haploid cells, are the products of diploid cell division. Two gametes, one egg and one sperm, unite during conception, yielding a zygote. For each gamete that makes a zygote, there is a complementary gamete, or gametid. There are gametids for both egg and sperm gametes.

Another word for a gametid is a nontransmitted gamete. These gametids come from the same primary gametocyte that yields the gamete that fuses to form the zygote. Gametids do not always develop into mature gametes. A common example of a gametid that does not develop into a mature gamete is a polar body. Gametogenesis is the process by which mature gametes are produced. In sequential order, gametes develop from primary gametocytes, to secondary gametocytes, to gametids, and then finally to gametes.