Duke University School of Medicine
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Dr. Andrews, MD, PhD
Research

Identification of a Gene Involved in Inner Ear Development

While mapping iron modifiers, we generated a chromosome substitution strain (CSS)
with an SWR/J chromosome 14 on a C57BL/10J genomic background

chromosome mapping
Upon intercrossing these animals, we discovered that a subset of the progeny exhibit circling behavior due to malformation of the inner ear. Circling mice are always homozygous SWR on chromosome 14 chromosome 14

inner ear

Within the inner ear, three semicircular canals (SCC) provide information about rotational movement of the head. Our circling animals display malformation of the lateral SCC.

 

Circling is the result of an epistatic interaction between a recessive gene on chromosome 14 derived from SWR/J and three modifier genes derived from C57BL/10J.

This phenotype is unrelated to iron.

Cryns et al. Genome Res. 2002; 12: 613-617

probeWe used our CSS to map the chr14 circling gene

Our 430Kb candidate interval contains a novel EST expressed in the inner ear. Sequencing of this gene revealed that a 5.5Kb endogenous retrovirus disrupts the first intron in SWR/J but not in C57BL/10J.

Additional studies are being conducted to elucidate the effect of this retroelement and the function of our gene.