Exploring OR2H1-Mediated Sperm Chemotaxis: Development and Application of a Novel Microfluidic Device

Area of Science:

• Reproductive Biology
• Sperm Physiology
• Olfactory Receptor Function

Background:

• Sperm chemotaxis is crucial for fertilization.
• Microfluidic devices offer precise control for studying sperm behavior.
• Olfactory receptors (ORs) mediate sperm chemotaxis.

Purpose of the Study:

• To develop and validate a novel microfluidic device for human sperm analysis.
• To identify new olfactory receptors involved in sperm chemotaxis.
• To investigate the role of methional and its receptor OR2H1 in sperm function.

Main Methods:

• Design and validation of a user-friendly microfluidic device.
• Utilizing the Atlas database to identify candidate receptors.
• Assessing sperm migration, motility, and intracellular calcium levels upon methional stimulation.
• Computer-assisted sperm analysis (CASA) to evaluate sperm kinematics.

Main Results:

• The microfluidic device reliably assessed human sperm chemotaxis.
• OR2H1 was identified as a candidate receptor expressed in human spermatozoa.
• Methional, a ligand for OR2H1, significantly enhanced sperm migration and progressive motility.
• Methional increased intracellular calcium levels and improved sperm linearity and straightness.

Conclusions:

• Methional promotes human sperm chemotaxis through the OR2H1 receptor.
• The study identifies a novel mechanism influencing sperm function.
• Findings suggest a potential role for the vaginal microbiome in human fertility.