Article

Zebrafish pax5 regulates development of the utricular macula and vestibular function.

Biology Department, Texas A&M University, College Station, Texas, USA.
Developmental Dynamics (impact factor: 2.54). 12/2006; 235(11):3026-38. DOI:10.1002/dvdy.20961 pp.3026-38
Source: PubMed

ABSTRACT The zebrafish otic vesicle initially forms with only two sensory epithelia, the utricular and saccular maculae, which primarily mediate vestibular and auditory function, respectively. Here, we test the role of pax5, which is preferentially expressed in the utricular macula. Morpholino knockdown of pax5 disrupts vestibular function but not hearing. Neurons of the statoacoustic ganglion (SAG) develop normally. Utricular hair cells appear to form normally but a variable number subsequently undergo apoptosis and are extruded from the otic vesicle. Dendrites of the SAG persist in the utricle but become disorganized after hair cell loss. Hair cells in the saccule develop and survive normally. Otic expression of pax5 requires pax2a and fgf3, mutations in which cause vestibular defects, albeit by distinct mechanisms. Thus, pax5 works in conjunction with fgf3 and pax2a to establish and/or maintain the utricular macula and is essential for vestibular function.

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Keywords

auditory function
 
cause vestibular defects
 
distinct mechanisms
 
essential
 
hair cell loss
 
Hair cells
 
mediate vestibular
 
Morpholino knockdown
 
Otic expression
 
otic vesicle
 
pax2a
 
pax5 disrupts vestibular function
 
saccular maculae
 
statoacoustic ganglion
 
two sensory epithelia
 
Utricular hair cells
 
utricular macula
 
variable number
 
vestibular function
 
zebrafish otic vesicle