The zebrafish gene claudinj is essential for normal ear function and important for the formation of the otoliths.
We have identified a mutation in the zebrafish gene claudinj generated by retroviral integration. Mutant embryos display otoliths severely reduced in size, no response to tapping stimulus, and an inability to balance properly suggesting vestibular and hearing dysfunction. Antisense in situ hybridization to the cldnj gene showed expression first in the otic placode and later asymmetric expression in the otic vesicle. Morpholino inhibition of claudinj expression showed similar defects in otolith formation. Phylogenetic analysis of claudin sequences from multiple species demonstrates that claudinj was part of a gene expansion that began in the common ancestor of fish and humans, but additional fish specific gene duplications must have also occurred.
Hardison
Amanda L
AL
Genome Technology Branch, National Human Genome Research Institute, NIH, Building 50, Room 5537, 50 South Drive, Bethesda, MD 20892-8004, USA.
Lichten
Lauren
L
Banerjee-Basu
Sharmila
S
Becker
Thomas S
TS
Burgess
Shawn M
SM
D000818:Animals; D030801:Animals, Genetically Modified; D057167:Claudins; D004423:Ear / Q000033:anatomy & histology / Q000196:embryology* / Q000502:physiology*; D004625:Embryo, Nonmammalian / Q000196:embryology; D018507:Gene Expression Regulation, Developmental; D006309:Hearing / Q000235:genetics / Q000502:physiology; D006801:Humans; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010802:Phylogeny; D012249:Rhombencephalon / Q000196:embryology / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism*
D057167:Claudins; D029961:Zebrafish Proteins; C509880:cldnj protein, zebrafish