Harmonin (Ush1c) is required in zebrafish Müller glial cells for photoreceptor synaptic development and function.

Abstract

Usher syndrome is the most prevalent cause of hereditary deaf-blindness, characterized by congenital sensorineural hearing impairment and progressive photoreceptor degeneration beginning in childhood or adolescence. Diagnosis and management of this disease are complex, and the molecular changes underlying sensory cell impairment remain poorly understood. Here we characterize two zebrafish models for a severe form of Usher syndrome, Usher syndrome type 1C (USH1C): one model is a mutant with a newly identified ush1c nonsense mutation, and the other is a morpholino knockdown of ush1c. Both have defects in hearing, balance and visual function from the first week of life. Histological analyses reveal specific defects in sensory cell structure that are consistent with these behavioral phenotypes and could implicate Müller glia in the retinal pathology of Usher syndrome. This study shows that visual defects associated with loss of ush1c function in zebrafish can be detected from the onset of vision, and thus could be applicable to early diagnosis for USH1C patients.

• Authors: Jennifer B Phillips, Bernardo Blanco-Sanchez, Jennifer J Lentz, Alexandra Tallafuss, Kornnika Khanobdee, Srirangan Sampath, Zachary G Jacobs, Philip F Han, Monalisa Mishra, Tom A Titus, David S Williams, Bronya J Keats, Philip Washbourne, Monte Westerfield
• Journal: Disease models & mechanisms (Dis Model Mech) Vol. 4 Issue 6 Pg. 786-800 (Nov 2011) ISSN: 1754-8411 [Electronic] England
• PMID: 21757509 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Morpholinos
• Nerve Tissue Proteins
• Ush1c protein, zebrafish
• Zebrafish Proteins

Topics

• Animals
• Gene Expression Regulation, Developmental (drug effects)
• Gene Knockdown Techniques
• Hair Cells, Auditory (drug effects, metabolism)
• Hearing (drug effects)
• Larva (drug effects)
• Lateral Line System (drug effects, metabolism, physiopathology)
• Life Cycle Stages (drug effects)
• Molecular Sequence Data
• Morpholinos (pharmacology)
• Mutation (genetics)
• Nerve Tissue Proteins (genetics, metabolism)
• Neuroglia (metabolism)
• Photoreceptor Cells, Vertebrate (drug effects, metabolism, pathology, ultrastructure)
• Protein Transport (drug effects)
• Subcellular Fractions (drug effects, metabolism)
• Synapses (drug effects, metabolism, pathology, ultrastructure)
• Vision, Ocular (drug effects)
• Zebrafish (genetics, growth & development)
• Zebrafish Proteins (genetics, metabolism)