On the C57BL/6 background, homozygotes have a white coat color while heterozygotes have a black coat. Clinically, heterozygotes have variable amounts of pigment in the retina with a normal optic cup and retinal vessels. Homozygotes have an iris coloboma, a large optic cup and poor or no retinal vessels. Homozygotes show some pigment in the iris, which does not dilate.
The MitfMi-Mee allele (initially named MitfMi-2J) was identified in a transgenic line but is found in mice not bearing this transgene. The trangene originated in an FVB background and was outcrossed to C57BL/6. In 1996 mice not carrying the transgene but bearing the Mitf mutation were imported into The Jackson Laboratory from Dr. Wendy Synder at Mass Eye and Ear. They were at backcross generation N5 to C57BL/6. They were backcrossed another two generations and then maintained by sibling mating primarily heterozygotes x homozygotes.
|Allele Name||microphthalmia, Massachusetts Eye and Ear Infirmary|
|Allele Type||Spontaneous (Not Specified)|
|Gene Symbol and Name||Mitf, melanogenesis associated transcription factor|
|Strain of Origin||C57BL/6 x FVB/N|
|Molecular Note||This allele is defined by a noncomplementation test with Mitfmi.|
When using the microphthalmia, Massachusetts Eye and Ear Infirmary mouse strain in a publication, please cite the originating article(s) and include JAX stock #003046 in your Materials and Methods section.