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Updated: Jul 14, 2026
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Collection of Human Follicular Fluid, Follicle Somatic Cells, and Immature Oocytes from Individuals Undergoing In Vitro Fertilization
Published on: October 24, 2025
Globular structure of human ovulatory cervical mucus.
Roberto Brunelli1, Massimiliano Papi, Giuseppe Arcovito
1Dipartimento di Scienze Ginecologiche, Perinatologia e Puericultura, Università di Roma La Sapienza, Italy.
Summary
Human cervical mucus structure changes with ovulation. Unfixed mucus reveals floating globules, not pores, facilitating sperm transit, with pH driving the shift from globular to fibrous states.
Area of Science:
- Biochemistry
- Reproductive Biology
- Biophysics
Background:
- Human cervical mucus is a complex mixture of mucin glycoproteins.
- Mucus properties change throughout the ovulatory cycle, impacting sperm transport.
- Previous studies on fixed samples suggested pore size changes governed sperm transit.
Purpose of the Study:
- To investigate the real-time structure of unfixed human cervical mucus during different ovulatory phases.
- To elucidate the mechanism governing sperm transit through cervical mucus.
- To identify the factors responsible for the structural transition between ovulatory and preovulatory mucus.
Main Methods:
- Atomic force microscopy (AFM) was used to examine unfixed cervical mucus samples.
- Analysis of the Mucin 5B (MUC5B) primary sequence.
- pH manipulation experiments to observe mucus structural changes.
Main Results:
- Unfixed ovulatory mucus is composed of floating mucin aggregate globules, not a network with varying pore sizes.
- The transition from ovulatory globular mucus to preovulatory fibrous mucus is pH-dependent.
- Mucin 5B exhibits pH-sensitive domains potentially involved in the structural switch.
Conclusions:
- The structure of cervical mucus is dynamic, with globules facilitating sperm transit during ovulation.
- pH is a critical regulator of cervical mucus structure and function.
- Specific domains within Mucin 5B may control the reversible aggregation of cervical mucus.
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