Also found in: Dictionary, Thesaurus, Medical, Wikipedia.


A male germ cell immediately before assuming its final typical form.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



a developing male sexual cell during spermatogenesis. Spermatids are formed in groups of four from secondary spermatocytes as a result of the second meiotic division. They are haploid and do not divide. After passing through a cycle of structural changes, they develop into spermatozoa.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
However, no significant difference was observed in the number of spermatogonia (A and B), spermatocyte, round and long spermatids, and Sertoli cells between the experimental groups.
The control negative group (200x; H&E) has normal cyto-architecture, reveal interstitial tissues (IT) and seminiferous tubules (ST) with sustentacular cells and the normal developing germ cells: spermatogonia (Sp), spermatocytes I (SPI), spermatids (Spt), spermatozoa (Spz) with flagellum.
This condition explains the elevated frequency of the I-VI stage of the spermatogenisis of the pubertal animals in this study, because it is in the stage that occurs the greatest presence of young and mature spermatids.
Category 9 denotes many end-stage spermatids, value 8 less than five spermatozoa and few late-stage spermatids.
For these purposes, there are two methods to characterize stages of the seminiferous epithelium cycle: (1) based on tubular morphology and (2) based on development of the acrosomic system and nuclear morphology of developing spermatids.
A) Primary spermatocytes (40X); B) Secondary spermatocytes (40X); C) Spermatids (40X); D) Spermatozoa (40X); E) Spermatozeugmata (20X).
Homogenization-resistant testicular spermatids (stage 19 of spermiogenesis) and sperm in the caput/corpus epididymis and cauda epididymis were assessed as described previously by Robb, Amann, and Killian (1978), with adaptations of Fernandes et al.
Some abundant spermatocytes, ripe oocytes with a large smaller spermatids, and nucleus may be observed ripe spermatozoa with free in the lumen.
Testicular spermatogenesis comprises a precisely timed and synchronized development of several generations of germ cells involving spermatogonial mitosis (proliferative phase); spermatocyte in which genetic material is recombined and segregated (meiotic phase); morphological transformation of the undifferentiated spermatids into highly specialized motile sperms (spermiogenic phase) [5].
(1) Abbreviations: Int, uncharacterized interstitial cells; Lc, Leydig cell; Sc, Sertoli cell; Spg, spermatogonia; Spc, spermatocyte; Spd, spermatid; Spz, spermatozoa; E, epithelium.
"Actin binding proteins, spermatid transport and spermiation," Seminars in Cell & Developmental Biology 30; 75-85.
Recent immunohistochemical studies in tissues from rat testes showed that MARCH7 is highly expressed in developing rat spermatids, colocalizing with [beta]-actin.