Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Lampbrush Chromosomes01:51

Lampbrush Chromosomes

8.2K
In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, Rückert observed LBCs in shark egg cells and coined the term "lampbrush chromosomes" because they looked like brushes used to clean kerosene lamps.
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops...
8.2K
Spermatogenesis01:41

Spermatogenesis

105.7K
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...
105.7K
Development of the Sexual Organs in the Embryo and Fetus01:15

Development of the Sexual Organs in the Embryo and Fetus

1.8K
Development of the reproductive organs in an embryo starts from a bipotential state. This means the early embryo can develop either male or female reproductive organs. The formation of these organs begins with the growth of gonadal ridges that arise from the intermediate mesoderm during the fifth week of development.
Near the gonadal ridges, two duct systems are present: the mesonephric ducts (Wolffian ducts) and paramesonephric ducts (Müllerian ducts). These ducts form the basis for the...
1.8K
Fertilization01:38

Fertilization

74.3K
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...
74.3K
Accessory Ducts of the Male Reproductive System01:25

Accessory Ducts of the Male Reproductive System

1.9K
The male reproductive system is a complex network of organs and tissues that work together to produce and transport sperm. The epididymis, vasa deferens, ejaculatory ducts, and urethra are the accessory ducts involved in sperm maturation and transportation. These ducts play a critical role in the production and transportation of sperm from the testes to the urethra, where it is then released during ejaculation.
The epididymis is a small, comma-shaped organ located at the back of each testicle....
1.9K
Accessory Glands of the Male Reproductive System01:16

Accessory Glands of the Male Reproductive System

2.2K
The accessory ducts involved in sperm maturation and transportation include the epididymides, vasa deferentia, ejaculatory ducts, and urethra. These ducts play a critical role in the maturation, storage, and transportation of sperm from the testes to the urethra, where it is then released during ejaculation.
The epididymis is a small, comma-shaped organ located at the back of each testicle. The epididymis can be divided into three main parts: the head, body, and tail. The head of the epididymis...
2.2K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

ALLOPLUS: allogeneic hematopoietic stem cell transplantation in children and adult people living with human immunodeficiency virus, a retrospective study of the SFGM-TC.

Bone marrow transplantation·2026
Same author

Creation of a Multidisciplinary Cycling Medicine Clinic: Analysis of the First 9 Years.

Current sports medicine reports·2026
Same author

Pervasive convergent evolution of sperm conjugation across the Arthropoda tree of life.

Nature communications·2026
Same author

Arterial Switch Operation in the First 2 Days of Life.

The Annals of thoracic surgery·2026
Same author

Host plant nutrition drives fitness outcomes in the cactus specialist Drosophila mettleri.

PloS one·2026
Same author

Independent origin of sperm heteromorphism in the Drosophilidae.

Journal of evolutionary biology·2026

Related Experiment Video

Updated: Oct 15, 2025

Ex vivo Culture of Drosophila Pupal Testis and Single Male Germ-line Cysts: Dissection, Imaging, and Pharmacological Treatment
08:35

Ex vivo Culture of Drosophila Pupal Testis and Single Male Germ-line Cysts: Dissection, Imaging, and Pharmacological Treatment

Published on: September 11, 2014

17.6K

Sperm Cyst "Looping": A Developmental Novelty Enabling Extreme Male Ornament Evolution.

Zeeshan A Syed1, Romano Dallai2, Negar Nasirzadeh3,4

  • 1Center for Reproductive Evolution, Department of Biology, Syracuse University, Syracuse, NY 13244, USA.

Cells
|October 23, 2021
PubMed
Summary

A novel sperm development process, sperm cyst looping, allows fruit flies to produce long sperm in short testes. This adaptation evolves long sperm but reduces male lifespan.

Keywords:
energetic constraintfemale reproductive tractheterochronylife-historypostcopulatory sexual selectionsaltansspermatogenesistrait diversificationwillistoni

More Related Videos

Organ Culture and Whole Mount Immunofluorescence Staining of Mouse Wolffian Ducts
09:16

Organ Culture and Whole Mount Immunofluorescence Staining of Mouse Wolffian Ducts

Published on: January 13, 2017

11.0K
Cytological Analysis of Spermatogenesis: Live and Fixed Preparations of Drosophila Testes
10:30

Cytological Analysis of Spermatogenesis: Live and Fixed Preparations of Drosophila Testes

Published on: January 20, 2014

26.8K

Related Experiment Videos

Last Updated: Oct 15, 2025

Ex vivo Culture of Drosophila Pupal Testis and Single Male Germ-line Cysts: Dissection, Imaging, and Pharmacological Treatment
08:35

Ex vivo Culture of Drosophila Pupal Testis and Single Male Germ-line Cysts: Dissection, Imaging, and Pharmacological Treatment

Published on: September 11, 2014

17.6K
Organ Culture and Whole Mount Immunofluorescence Staining of Mouse Wolffian Ducts
09:16

Organ Culture and Whole Mount Immunofluorescence Staining of Mouse Wolffian Ducts

Published on: January 13, 2017

11.0K
Cytological Analysis of Spermatogenesis: Live and Fixed Preparations of Drosophila Testes
10:30

Cytological Analysis of Spermatogenesis: Live and Fixed Preparations of Drosophila Testes

Published on: January 20, 2014

26.8K

Area of Science:

  • Evolutionary biology
  • Reproductive biology
  • Genetics

Background:

  • Postcopulatory sexual selection drives rapid evolution of reproductive traits.
  • Sperm length and female sperm-storage organ size often co-evolve.
  • In Drosophila, testes longer than sperm were considered a constraint on sperm length evolution.

Purpose of the Study:

  • To investigate a novel spermatogenic mechanism in Drosophila.
  • To understand the evolutionary implications of sperm cyst looping.
  • To identify the constraints and costs associated with extreme sperm length evolution.

Main Methods:

  • Comparative analysis of spermatogenesis across Drosophila species groups.
  • Observation of sperm development and testis morphology.
  • Evolutionary and physiological analyses.

Main Results:

  • Discovery of sperm cyst looping in saltans and willistoni species groups.
  • Sperm cyst looping enables production of relatively long sperm in short testes.
  • This mechanism removes allometric constraints on sperm length, allowing rapid evolution.
  • Sperm cyst looping incurs energetic costs and reduces male lifespan.

Conclusions:

  • Sperm cyst looping is an evolutionary innovation allowing rapid sperm length evolution in Drosophila.
  • This adaptation balances the benefits of long sperm with physiological costs.
  • Ecological pressures may drive the evolution and maintenance of this unique trait.