Spermatid

Spermatid

Infobox Anatomy
Name = Spermatid
Latin =
GraySubject = 258
GrayPage = 1243


Caption = "Germinal epithelium of the testicle."
1: basal lamina
2: spermatogonia
3: spermatocyte 1st order
4: spermatocyte 2nd order
5: spermatid
6: mature spermatid
7: Sertoli cell
8: tight junction (blood testis barrier)


Caption2 = Transverse section of a tubule of the testis of a rat. X 250.
System =
MeshName = Spermatids
MeshNumber = A05.360.490.890.860
The term spermatid refers to the haploid male gametid that results from division of secondary spermatocytes. As a result of meiosis, each spermatid contains only half of the genetic material present in the original primary spermatocyte.

Spermatids are connected together by cytoplasmic material and have superfluous cytoplasmic material around their nuclei.

When formed, "early round spermatids" must undergo further maturational events in order to develop into spermatozoa, a process termed spermiogenesis (also termed "spermeteliosis").

The spermatids begin to grow a tail, develop a thickened mid-piece where the mitochondria become localised and form an acrosome. Spermatid DNA also undergoes packaging, becoming highly condensed. The DNA is packaged firstly with specific nuclear basic proteins, which are subsequently replaced with protamines during spermatid elongation. The resultant tightly packed chromatin is transcriptionally inactive.


=Additional

External links

* - "Male Reproductive System: testis, early spermatids"
* - "Male Reproductive System: testis, late spermatids"
* [http://www.cvm.okstate.edu/instruction/mm_curr/histology/MR/HiMRp3.htm Histology at okstate.edu]


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Look at other dictionaries:

  • spermatid — spermatid. См. сперматида. (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.

  • spermatid — [spʉr′mə tid] n. [ SPERMAT(O) + ID] Zool. any of the four haploid cells formed by the two consecutive meiotic divisions of a primary spermatocyte, each of which develops into a spermatozoon …   English World dictionary

  • spermatid — noun Date: 1889 one of the haploid cells that are formed by the second division in meiosis of a spermatocyte and that differentiate into spermatozoa …   New Collegiate Dictionary

  • spermatid — n. [Gr. sperma, seed] One of four haploid cells of the male after the meiotic divisions; an immature spermatozoon …   Dictionary of invertebrate zoology

  • spermatid — /sperr meuh tid/, n. Cell Biol. one of the cells that result from the meiotic divisions of a spermatocyte and mature into spermatozoa. [1885 90; SPERMAT + ID3] * * * …   Universalium

  • spermatid — noun A haploid cell, produced by meiosis of a spermatocyte, that develops into a spermatozoon …   Wiktionary

  • spermatid — A cell in a late stage of the development of the spermatozoon; it is a haploid cell derived from the secondary spermatocyte and evolves by spermiogenesis into a spermatozoon. SYN: nematoblast. [spermat + id (2)] * * * sper·ma·tid spər mət əd …   Medical dictionary

  • spermatid — n. any of four haploid cells that develop into a sperm cell …   English contemporary dictionary

  • spermatid — [ spə:mətɪd] noun Biology an immature male sex cell formed from a spermatocyte, which may develop into a spermatozoon without further division. Derivatives spermatidal ˌspə:mə tʌɪd(ə)l adjective …   English new terms dictionary

  • spermatid —   Cell that differentiates and becomes a mature sperm …   Expanded glossary of Cycad terms

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