The jerker mutation causes degeneration of cochlea and vestibular sensory hair cells in mice. A frame-shift mutation in the actin bundling gene Espin (Espn) leads to hair bundle defects by disrupting the actin filament assembly in stereocilia. Previously, jerker was mapped to distal mouse chromosome 4. Here, analyzing 2536 informative meioses derived from two intersubspecific intercrosses, we localize jerker to a 0.51+/-0.14 cM interval on chromosome 4. The following order and distances of genes and markers were determined: D4Mit180-0.44+/-0.13 cM-Hes2, Espn(je)-0.08+/-0.06 cM-D4Mit356-0.28+/-0.1 cM-D4Mit208. A 300kb physical bacterial artificial chromosome (BAC) contig was generated containing the Espn(je) locus. The human homologous region maps to 1p36.31. We present a detailed high-resolution genetic and physical map of markers located at distal chromosome 4 and demonstrate concordance of Espn with jerker. (C) 2002 Elsevier Science (USA). All rights reserved.