Development of ocular mucin: scanning EM analysis

Area of Science:

• Ophthalmology
• Developmental Biology
• Microscopy

Background:

• Ocular surface mucins are vital for tear film stability and eye protection.
• Understanding the timeline of mucin development is key to addressing ocular surface disorders.

Purpose of the Study:

• To investigate the initial development and morphology of ocular mucin in mouse pups.
• To determine the presence of mucin before the mouse eye opens.

Main Methods:

• Utilized scanning electron microscopy for high-resolution imaging.
• Employed a picric acid-paraformaldehyde-glutaraldehyde (PA-P-G) fixative optimized for ocular mucin.

Main Results:

• Ocular mucin was detected on the cornea and conjunctiva of mouse pups by postnatal day 10.
• The early mucus exhibited scant, strand-like, and granular morphology, differing from adult patterns.
• Mucin presence precedes eye opening (postnatal day 14-15).

Conclusions:

• Ocular mucin is present on the surface of the developing mouse eye well before it opens.
• This early mucin is essential for maintaining tear film stability and corneal wettability.
• The presence of ocular mucin likely contributes to protecting the eye from microbial infections.