Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (795 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
Male germ cells derived from the haploid secondary spermatocytes. Without further division, spermatids undergo structural changes and give rise to spermatozoa.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Spermatid; Spermatoblasts; Spermatoblast.
Where it fits in the MeSH classification
- Broader topics
- Spermatozoa
Related concepts
Research landscape
PubMed indexes 3,969 records tagged with the MeSH heading “Spermatids” (counts retrieved 2026-10-31). 369 of them (9.3%) were published from 2020 onward, and the busiest period so far is through 1999 with 1,842 records.
Reviews account for 169 records (4.3%) and meta-analyses for 1. Randomized controlled trials number 2 (0.1%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 1,842 |
| 2000-2009 | 964 |
| 2010-2019 | 794 |
| 2020 onward | 369 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 169 | 4.3% |
| Meta-analyses | 1 | 0.0% |
| Randomized controlled trials | 2 | 0.1% |
Method: PubMed query "Spermatids"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in anatomy and physiology
Anatomy describes how body structures are built and physiology describes how they normally work, so most findings here are descriptive or mechanistic rather than evidence about treatment. Much of what is known comes from dissection, imaging, tissue studies and experiments in animals, and measurements in healthy volunteers can differ from those in people with disease or at different ages. Normal ranges vary between individuals and populations. Check whether a result was measured in people or in another species, the age and health of the participants, and the method used.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| A putative de novo evolved gene required for spermatid chromatin condensation in Drosophila melanogaster | 2021 | Research article Design not recorded in structured metadata | 54 | cc by PMID 34478447 · DOI · PMC8445463 |
| Rat in vitro spermatogenesis promoted by chemical supplementations and oxygen-tension control | 2021 | Research article Design not recorded in structured metadata | 38 | cc by PMID 33568686 · DOI · PMC7875995 |
| Spermatid cyst polarization in Drosophila depends upon apkc and the CPEB family translational regulator orb2 | 2014 | Research article Design not recorded in structured metadata | 30 | cc by PMID 24830287 · DOI · PMC4022466 |
| The C-terminal ZZ domain of the Drosophila ORB2 RNA-binding protein is required for spermatid individualization | 2026 | Research article Design not recorded in structured metadata | 4 | cc by PMID 41172325 · DOI · PMC12774597 |
A putative de novo evolved gene required for spermatid chromatin condensation in Drosophila melanogaster [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Comparative genomics has enabled the identification of genes that potentially evolved de novo from non-coding sequences.
- Closing excerpt
- Altogether, this study provides insight into the integration of novel genes into biological processes, the links between genomic innovation and functional evolution, and the genetic control of a fundamental developmental process, gametogenesis.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (204 words)
Comparative genomics has enabled the identification of genes that potentially evolved de novo from non-coding sequences. Many such genes are expressed in male reproductive tissues, but their functions remain poorly understood. To address this, we conducted a functional genetic screen of over 40 putative de novo genes with testis-enriched expression in Drosophila melanogaster and identified one gene, atlas, required for male fertility. Detailed genetic and cytological analyses showed that atlas is required for proper chromatin condensation during the final stages of spermatogenesis. Atlas protein is expressed in spermatid nuclei and facilitates the transition from histone- to protamine-based chromatin packaging. Complementary evolutionary analyses revealed the complex evolutionary history of atlas. The protein-coding portion of the gene likely arose at the base of the Drosophila genus on the X chromosome but was unlikely to be essential, as it was then lost in several independent lineages. Within the last ~15 million years, however, the gene moved to an autosome, where it fused with a conserved non-coding RNA and evolved a non-redundant role in male fertility. Altogether, this study provides insight into the integration of novel genes into biological processes, the links between genomic innovation and functional evolution, and the genetic control of a fundamental developmental process, gametogenesis.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 34478447 · DOI · PMC8445463
Rat in vitro spermatogenesis promoted by chemical supplementations and oxygen-tension control [2]
Abstract reading summary — source excerpts
- Opening excerpt
- In vitro spermatogenesis (IVS) using air-liquid interphase organ culture method is possible with mouse testis tissues.
- Closing excerpt
- This is an important step towards successful IVS in many animal species, including humans.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (151 words)
In vitro spermatogenesis (IVS) using air-liquid interphase organ culture method is possible with mouse testis tissues. The same method, however, has been hardly applicable to animals other than mice, only producing no or limited progression of spermatogenesis. In the present study, we challenged IVS of rats with modifications of culture medium, by supplementing chemical substances, including hormones, antioxidants, and lysophospholipids. In addition, reducing oxygen tension by placing tissues in an incubator of lower oxygen concentration and/or applying silicone cover ceiling on top of the tissue were effective for improving the spermatogenic efficiency. Through these modifications of the culture condition, rat spermatogenesis up to round spermatids was maintained over 70 days in the cultured tissue. Present results demonstrated a significant progress in rat IVS, revealing conditions commonly favorable for mice and rats as well as finding rat-specific optimizations. This is an important step towards successful IVS in many animal species, including humans.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 33568686 · DOI · PMC7875995
Spermatid cyst polarization in Drosophila depends upon apkc and the CPEB family translational regulator orb2 [3]
Abstract reading summary — source excerpts
- Opening excerpt
- Mature Drosophila sperm are highly polarized cells--on one side is a nearly 2 mm long flagellar tail that comprises most of the cell, while on the other is the sperm head, which carries the gamete's genetic information.
- Closing excerpt
- Moreover, the proper execution of this orb2 autoregulatory pathway depends upon apkc.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (307 words)
Mature Drosophila sperm are highly polarized cells--on one side is a nearly 2 mm long flagellar tail that comprises most of the cell, while on the other is the sperm head, which carries the gamete's genetic information. The polarization of the sperm cells commences after meiosis is complete and the 64-cell spermatid cyst begins the process of differentiation. The spermatid nuclei cluster to one side of the cyst, while the flagellar axonemes grows from the other. The elongating spermatid bundles are also polarized with respect to the main axis of the testis; the sperm heads are always oriented basally, while the growing tails extend apically. This orientation within the testes is important for transferring the mature sperm into the seminal vesicles. We show here that orienting cyst polarization with respect to the main axis of the testis depends upon atypical Protein Kinase C (aPKC), a factor implicated in polarity decisions in many different biological contexts. When apkc activity is compromised in the male germline, the direction of cyst polarization within this organ is randomized. Significantly, the mechanisms used to spatially restrict apkc activity to the apical side of the spermatid cyst are different from the canonical cross-regulatory interactions between this kinase and other cell polarity proteins that normally orchestrate polarization. We show that the asymmetric accumulation of aPKC protein in the cyst depends on an mRNA localization pathway that is regulated by the Drosophila CPEB protein Orb2. orb2 is required to properly localize and activate the translation of apkc mRNAs in polarizing spermatid cysts. We also show that orb2 functions not only in orienting cyst polarization with respect to the apical-basal axis of the testis, but also in the process of polarization itself. One of the orb2 targets in this process is its own mRNA. Moreover, the proper execution of this orb2 autoregulatory pathway depends upon apkc.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 24830287 · DOI · PMC4022466
The C-terminal ZZ domain of the Drosophila ORB2 RNA-binding protein is required for spermatid individualization [4]
Abstract reading summary — source excerpts
- Opening excerpt
- ORB2 is the Drosophila ortholog of the human CPEB2-4 family of RNA-binding proteins, which include a conserved C-terminal Zinc-binding ('ZZ') domain.
- Closing excerpt
- We find that deletion of the ZZ domain does not affect spatial localization of the ORB2 protein; orb2ΔZZ flies are sterile and lack mature sperm; meiosis is mostly normal in orb2ΔZZ testes; individualization complexes are defective and spermatid individualization fails; proteins known to play a role in spermatid individualization-ORB, IMP, SOTI-are mislocalized; and the SOTI-dependent Cleaved Caspase-3 gradient no longer forms in orb2ΔZZ mutant testes.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (133 words)
ORB2 is the Drosophila ortholog of the human CPEB2-4 family of RNA-binding proteins, which include a conserved C-terminal Zinc-binding ('ZZ') domain. We have recently shown that this domain interacts with several translational co-repressors in the early embryo, and that deletion of this domain from the endogenous orb2 gene results in derepression of its target mRNAs. Here we assess the effect of deletion of the ZZ domain on spermatogenesis. We find that deletion of the ZZ domain does not affect spatial localization of the ORB2 protein; orb2ΔZZ flies are sterile and lack mature sperm; meiosis is mostly normal in orb2ΔZZ testes; individualization complexes are defective and spermatid individualization fails; proteins known to play a role in spermatid individualization-ORB, IMP, SOTI-are mislocalized; and the SOTI-dependent Cleaved Caspase-3 gradient no longer forms in orb2ΔZZ mutant testes.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41172325 · DOI · PMC12774597
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Chromatin dynamics during spermiogenesis [5]
- Research article The acrosome-acroplaxome-manchette complex and the shaping of the spermatid head [6]
- Research article Formation and function of the manchette and flagellum during spermatogenesis [7]
- Research article Transcriptional and translational regulation of gene expression in haploid spermatids [8]
- Research article A possible meiotic function of the peculiar patterns of gene expression in mammalian spermatogenic cells [9]
- Research article Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 1: background to spermatogenesis, spermatogonia, and spermatocytes [10]
References
- Rivard EL, Ludwig AG, Patel PH, Grandchamp A, Arnold SE, Berger A, et al.. A putative de novo evolved gene required for spermatid chromatin condensation in Drosophila melanogaster. . 2021. PMID 34478447 · DOI · PMC8445463
- Matsumura T, Sato T, Abe T, Sanjo H, Katagiri K, Kimura H, et al.. Rat in vitro spermatogenesis promoted by chemical supplementations and oxygen-tension control. . 2021. PMID 33568686 · DOI · PMC7875995
- Xu S, Tyagi S, Schedl P. Spermatid cyst polarization in Drosophila depends upon apkc and the CPEB family translational regulator orb2. . 2014. PMID 24830287 · DOI · PMC4022466
- Low TCH, Falk BL, Brill JA, Lipshitz HD. The C-terminal ZZ domain of the Drosophila ORB2 RNA-binding protein is required for spermatid individualization. . 2026. PMID 41172325 · DOI · PMC12774597
- Rathke C, Baarends WM, Awe S, Renkawitz-Pohl R. Chromatin dynamics during spermiogenesis. Biochim Biophys Acta. 2014. PMID 24091090 · DOI
- Kierszenbaum AL, Tres LL. The acrosome-acroplaxome-manchette complex and the shaping of the spermatid head. Arch Histol Cytol. 2004. PMID 15700535 · DOI
- Lehti MS, Sironen A. Formation and function of the manchette and flagellum during spermatogenesis. Reproduction. 2016. PMID 26792866 · DOI
- Steger K. Transcriptional and translational regulation of gene expression in haploid spermatids. Anat Embryol (Berl). 1999. PMID 10350128 · DOI
- Kleene KC. A possible meiotic function of the peculiar patterns of gene expression in mammalian spermatogenic cells. Mech Dev. 2001. PMID 11472831 · DOI
- Hermo L, Pelletier RM, Cyr DG, Smith CE. Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 1: background to spermatogenesis, spermatogonia, and spermatocytes. Microsc Res Tech. 2010. PMID 19941293 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-31.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.