Cloning and distribution of myosin 3B in the mouse retina: differential distribution in cone outer segments

Exp Eye Res. 2009 Aug;89(2):224-37. doi: 10.1016/j.exer.2009.03.011. Epub 2009 Mar 28.

Abstract

Class III myosins are important for the function and survival of photoreceptors and ciliary hair cells. Although vertebrates possess two class III myosin genes, myo3A and myo3B, recent studies have focused on Myo3A because mutations in the human gene are implicated in progressive hearing loss. Myo3B may compensate for defects in Myo3A, yet little is known about its distribution and function. This study focuses on Myo3B expression in the mouse retina. We cloned two variants of myo3B from mouse retina and determined that they are expressed early in retinal development. In this study we show for the first time in a mammal that both Myo3B and Myo3A proteins are present in inner segments of all photoreceptors. Myo3B is also present in outer segments of S opsin-immunoreactive cones but not M opsin dominant cones. Myo3B is also detected in rare cells of the inner nuclear layer and some ganglion cells. Myo3B may have diverse roles in retinal neurons. In photoreceptor inner segments Myo3B is positioned appropriately to prevent photoreceptor loss of function caused by Myo3A defects.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cloning, Molecular
  • Eye Proteins / genetics
  • Eye Proteins / immunology
  • Eye Proteins / metabolism*
  • Immune Sera
  • Mice
  • Mice, Inbred C57BL
  • Molecular Sequence Data
  • Myosin Heavy Chains / genetics
  • Myosin Heavy Chains / immunology
  • Myosin Heavy Chains / metabolism*
  • Myosin Type III / genetics
  • Myosin Type III / immunology
  • Myosin Type III / metabolism*
  • Retina / growth & development
  • Retina / metabolism*
  • Retinal Cone Photoreceptor Cells / metabolism
  • Retinal Ganglion Cells / metabolism
  • Retinal Photoreceptor Cell Outer Segment / metabolism
  • Tissue Distribution

Substances

  • Eye Proteins
  • Immune Sera
  • MYO3A protein, mouse
  • MYO3B protein, mouse
  • Myosin Type III
  • Myosin Heavy Chains