• Comment: The unsourced issue still remains. X (talk) 16:20, 13 October 2024 (UTC)
  • Comment: Significant part of this article is unsourced. Please provide citation for each statement/paragraphs. Thank you. X (talk) 04:30, 2 May 2024 (UTC)

An immature sperm is an early-stage cell in the process of spermatogenesis that has not yet fully developed into mature, functional spermatozoon.[1][2] It can be a spermatogonium, a spermatocyte, or a spermatid. A spermatocyte, in turn, can be either primary or secondary, depending on how far it has come in its process of meiosis.

Cell type ploidy chromatids Process
Spermatogonium diploid/46 2C Spermatocytogenesis (mitosis)
Primary spermatocyte diploid/46 4C Spermatidogenesis (meiosis 1)
Secondary spermatocyte haploid/23 2C Spermatidogenesis (meiosis 2)
Spermatid haploid/23 1C Spermiogenesis
Spermatozoon haploid/23 1C Capacitation

Spermatogonium

edit

Spermatogonia are the earliest identifiable immature male germ cells. They are diploid stem cells located in the seminiferous tubules of the testes. They are classified into two types: Type A, which undergo mitosis to replenish themselves, ensuring the continuous supply of germ cells; and Type B, which differentiate into primary spermatocytes during spermatocytogenesis, marking the initiation of spermatogenesis.[3]

Spermatocyte

edit

Primary spermatocyte

edit

Primary spermatocytes are the immediate descendants of spermatogonia. They are diploid cells that undergo meiosis I to produce secondary spermatocytes. Meiosis I reduces the chromosome number by half, resulting in two equal haploid cells.

Secondary spermatocyte

edit

Secondary spermatocytes are haploid cells formed as a result of meiosis I. They contain half the number of chromosomes found in somatic cells. They quickly undergo meiosis II to produce four equal haploid spermatids.

Spermatid

edit

Round spermatid

edit

Round spermatids are the first stage of sperm development to exhibit the characteristic head and tail of mature spermatozoa. They are haploid cells with condensed nuclei and are located within the seminiferous tubules. They undergo a series of morphological changes to become elongated spermatids.

Elongated spermatid

edit

Elongated spermatids are the intermediate stage between round spermatids and mature spermatozoa. During spermiogenesis, elongated spermatids undergo extensive morphological changes, including elongation of the nucleus and development of acrosome and flagellum. The Golgi apparatus and mitochondria also play crucial roles in the differentiation of elongated spermatids into mature spermatozoa.[4]

Spermatozoon

edit

Spermatozoa are the final product of spermatogenesis. They are highly specialized cells with a distinct morphology optimized for fertilization. Mature spermatozoa consist of a head containing an elongated haploid nucleus and acrosome, a midpiece packed with mitochondria for energy production, and a flagellum for sperm motility. Spermatozoa are released from the testes into the epididymis, where they undergo further maturation and capacitation.[5]

References

edit
  1. ^ Griswold, Michael D. (January 2016). "Spermatogenesis: The Commitment to Meiosis". Physiological Reviews. 96 (1). American Physiological Society: 1–17. doi:10.1152/physrev.00013.2015. ISSN 0031-9333. PMC 4698398. PMID 26537427.
  2. ^ O’Donnell, Liza; O’Bryan, Moira K. (2014-06-01). "Microtubules and spermatogenesis". Seminars in Cell & Developmental Biology. Regulation of Spermatogenesis Part II & DNA Replication. 30: 45–54. doi:10.1016/j.semcdb.2014.01.003. ISSN 1084-9521. PMID 24440897.
  3. ^ Alberts, Bruce (2017-08-07). Molecular Biology of the Cell. Garland Science. ISBN 978-1-317-56375-4.
  4. ^ Van Der Schoot, P.; Elger, W. (June 1993). "Perinatal development of gubernacular cones in rats and rabbits: Effect of exposure to anti-androgens". The Anatomical Record. 236 (2): 399–407. doi:10.1002/ar.1092360214. ISSN 0003-276X. PMID 8338243.
  5. ^ de Kretser, D. M.; Baker, H. W. G. (1999-10-01). "Infertility in Men: Recent Advances and Continuing Controversies*". The Journal of Clinical Endocrinology & Metabolism. 84 (10): 3443–3450. doi:10.1210/jcem.84.10.6101. ISSN 0021-972X. PMID 10522977.