WDR1 expression in the normal and noise-damaged chick vestibule

Area of Science:

• Oto-neurology
• Molecular Biology
• Regenerative Medicine

Background:

• Avian cochlear hair cells regenerate post-acoustic overstimulation, a stark contrast to mammals.
• The WDR1 gene is a candidate for mediating this avian regenerative capacity.
• Previous research indicated WDR1 over-expression in the chick cochlea after noise exposure.

Purpose of the Study:

• To investigate and compare WDR1 gene expression in the chick vestibule before and after acoustic overstimulation.
• To determine if WDR1 plays a role in vestibular hair cell regeneration.

Main Methods:

• Seven-day-old chicks were exposed to loud white noise (120 dB SPL) for 5-6 hours.
• Groups included normal, immediate damage, and 2-day regeneration.
• Immunohistochemistry and quantitative real-time RT-PCR were used to measure WDR1 protein and mRNA levels in vestibular organs (utricle, saccule, semicircular canals).

Main Results:

• WD40 repeat protein 1 expression significantly increased (P=0.001) in semicircular canals and utricle two days post-stimulation.
• WDR1 mRNA levels showed a non-significant 1.34-fold increase in the regeneration group.
• The saccule was an exception, showing no increase in WDR1 expression.

Conclusions:

• Elevated WDR1 expression in the avian vestibule post-acoustic overstimulation suggests a potential role in hair cell regeneration.
• A conserved hair cell regeneration mechanism may operate in both the avian cochlea and vestibule.
• WDR1 warrants further investigation as a key factor in avian auditory and vestibular regeneration.