Related Experiment Video
Updated: Jun 25, 2026
Mouse Eye Enucleation for Remote High-throughput Phenotyping
Published on: November 19, 2011
Mice with mutations of Dock7 have generalized hypopigmentation and white-spotting but show normal neurological
Amanda L Blasius1, Katharina Brandl, Karine Crozat
1Departments of Genetics and Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Abstract:
The classical recessive coat color mutation misty (m) arose spontaneously on the DBA/J background and causes generalized hypopigmentation and localized white-spotting in mice, with a lack of pigment on the belly, tail tip, and paws. Here we describe moonlight (mnlt), a second hypopigmentation and white-spotting mutation identified on the C57BL/6J background, which yields a phenotypic copy of m/m coat color traits. We demonstrate that the 2 mutations are allelic. m/m and mnlt/mnlt phenotypes both result from mutations that truncate the dedicator of cytokinesis 7 protein (DOCK7), a widely expressed Rho family guanine nucleotide exchange factor. Although Dock7 is transcribed at high levels in the developing brain and has been implicated in both axon development and myelination by in vitro studies, we find no requirement for DOCK7 in neurobehavioral function in vivo. However, DOCK7 has non-redundant role(s) related to the distribution and function of dermal and follicular melanocytes.
Insights
Two mouse mutations, misty (m) and moonlight (mnlt), cause similar coat color changes due to defects in the dedicator of cytokinesis 7 (DOCK7) protein. DOCK7 is crucial for melanocyte function, not neurobehavior.
Area of Science:
- Genetics
- Developmental Biology
- Mammalian Genetics
Background:
- The recessive coat color mutation misty (m) in mice causes hypopigmentation and white spotting.
- A new mutation, moonlight (mnlt), on a different mouse background exhibits identical coat color phenotypes.
Purpose of the Study:
- To characterize the moonlight (mnlt) mutation and its genetic relationship to the misty (m) mutation.
- To investigate the molecular basis and in vivo function of the affected gene, dedicator of cytokinesis 7 (DOCK7).
Main Methods:
- Phenotypic analysis of mouse coat color mutations.
- Allele testing to determine genetic relationships between mutations.
- Molecular analysis to identify gene mutations and protein truncation.
- In vivo neurobehavioral testing.
Main Results:
- The moonlight (mnlt) mutation is allelic to the misty (m) mutation.
- Both mutations result in truncated dedicator of cytokinesis 7 (DOCK7) protein.
- DOCK7 is essential for normal melanocyte distribution and function.
- No requirement for DOCK7 in neurobehavioral function was observed in vivo.
Conclusions:
- The dedicator of cytokinesis 7 (DOCK7) protein plays a critical, non-redundant role in regulating dermal and follicular melanocyte distribution and function.
- Despite high expression in the brain and in vitro implications, DOCK7 is not essential for neurobehavioral function in vivo.
