Related Experiment Video

Updated: Jul 25, 2025

Transillumination-Assisted Dissection of Specific Stages of the Mouse Seminiferous Epithelial Cycle for Downstream Immunostaining Analyses
09:59

Transillumination-Assisted Dissection of Specific Stages of the Mouse Seminiferous Epithelial Cycle for Downstream Immunostaining Analyses

Published on: October 7, 2020

7.5K

Human Sperm Head Vacuoles Are Related to Nuclear-Envelope Invaginations

María José Gómez-Torres1,2, Javier Luna-Romero1, Pedro José Fernández-Colom3

  • 1Departamento de Biotecnología, Facultad de Ciencias, Universidad de Alicante, 03690 Alicante, Spain.

International Journal of Molecular Sciences
|June 28, 2023
PubMed

Insights

Human sperm head vacuoles are actually nuclear invaginations originating from the nuclear envelope. These structures contain perinuclear theca components, clarifying their physiological nature.

Area of Science:

  • Reproductive Biology
  • Spermatozoa Morphology
  • Cellular Ultrastructure

Background:

  • Nuclear vacuoles in human sperm have uncertain origins, debated as either pathological or physiological.
  • Previous studies linked sperm vacuoles to abnormal morphology, chromatin condensation, and DNA fragmentation.
  • The precise nature and origin of these structures remain unclear.

Purpose of the Study:

  • To investigate the incidence, position, morphology, and molecular content of human sperm vacuoles.
  • To elucidate the origin and cellular nature of nuclear vacuoles in spermatozoa.
  • To redefine the terminology for these sperm head structures.

Main Methods:

  • Transmission electron microscopy (TEM) for ultrastructural analysis.
  • Immunocytochemistry to determine molecular composition.
  • Analysis of 1908 sperm cells from 17 normozoospermic human donors.

Main Results:

  • Approximately 50% of analyzed sperm cells contained vacuoles, predominantly in the anterior head region (80%).
  • A positive correlation was observed between sperm vacuole and nucleus areas.
  • Vacuoles were identified as nuclear envelope invaginations containing cytoskeletal proteins and cytoplasmic enzymes, not of nuclear or acrosomal origin.

Conclusions:

  • Human sperm head vacuoles are cellular structures arising from nuclear invaginations.
  • These invaginations contain perinuclear theca (PT) components.
  • The term 'nuclear invaginations' is proposed instead of 'nuclear vacuoles' to accurately describe these findings.
Keywords:
TEMhuman spermimmunocytochemistrymorphologyultrastructurevacuoles

More Related Videos

Fluorimetric Techniques for the Assessment of Sperm Membranes08:58

Fluorimetric Techniques for the Assessment of Sperm Membranes

Published on: November 28, 2018

13.4K
Recording Electrical Currents across the Plasma Membrane of Mammalian Sperm Cells09:47

Recording Electrical Currents across the Plasma Membrane of Mammalian Sperm Cells

Published on: February 14, 2021

2.7K

Related Concept Videos

Fertilization01:38

Fertilization

During fertilization, an egg and sperm cell fuse to create a new diploid structure. In humans, the process occurs once the egg has been released from the ovary, and travels into the fallopian tubes. The process requires several key steps: 1) sperm present in the genital tract must locate the egg; 2) once there, sperm need to release enzymes to help them burrow through the protective zona pellucida of the egg; and 3) the membranes of a single sperm cell and egg must fuse, with the sperm...
71.2K
Spermatogenesis01:41

Spermatogenesis

Spermatogenesis is the process by which haploid sperm cells are produced in the male testes. It starts with stem cells located close to the outer rim of seminiferous tubules. These spermatogonial stem cells divide asymmetrically to give rise to additional stem cells (meaning that these structures “self-renew”), as well as sperm progenitors, called spermatocytes. Importantly, this method of asymmetric mitotic division maintains a population of spermatogonial stem cells in the male...
102.7K
Sperm Structure and Semen Composition01:22

Sperm Structure and Semen Composition

During ejaculation, males release around 2-5 milliliters of semen, which is a complex mixture of mature sperm and various fluids produced by accessory glands. The mature sperm cells measure approximately 60 micrometers in length and consist of a head, neck, midpiece, and tail. The head is flattened and tapered, measuring about 4 to 5 micrometers in length. It contains a nucleus with condensed chromosomes and an acrosome, a cap-like structure filled with enzymes essential for penetrating the...
3.0K
Intralumenal Vesicles and Multivesicular Bodies01:38

Intralumenal Vesicles and Multivesicular Bodies

Intraluminal vesicles (ILVs) are small vesicles 50-80 nm in diameter formed during the maturation of early endosomes. A specialized endosome containing numerous ILVs is called a multivesicular body (MVB). ILVs contain internalized molecules such as antigens, nucleic acids, proteins, and metabolites. Some of these molecules are released from the MVBs inside exosomes and are transported to other cells. Other MVBs contain molecules that are retained in the ILVs and are later degraded within the...
3.6K
Sperm Transport01:15

Sperm Transport

The journey of sperm from its origin to the point of ejaculation begins within the seminiferous tubules of the testis. Here, Sertoli cells produce fluid that propels non-motile sperm through a series of conduits, starting with the straight tubules leading to the rete testis. This interconnected network of tubules acts as the initial pathway for sperm, guiding them into the efferent ductules and then into the epididymis for maturation.
The maturation phase occurs in the epididymis, where sperm...
973
Meiosis I01:49

Meiosis I

Meiosis is a carefully orchestrated set of cell divisions, the goal of which—in humans—is to produce haploid sperm or eggs, each containing half the number of chromosomes present in somatic cells elsewhere in the body. Meiosis I is the first such division, and involves several key steps, among them: condensation of replicated chromosomes in diploid cells; the pairing of homologous chromosomes and their exchange of information; and finally, the separation of homologous chromosomes by...
193.8K