Mice heterozygous for the sombre 4 Jackson allele have darker ears and tail than wild-type siblings.
This mutation arose spontaneously at The Jackson Laboratory in the strain B6.129S7-Ldlrtm1Her/J. Two backcrosses to C57BL/6J removed the Ldlrtm1Her allele and sperm was cryopreserved from heterozygous males.
|Allele Name||sombre 4 Jackson|
|Allele Type||Spontaneous (Constitutively active)|
|Gene Symbol and Name||Mc1r, melanocortin 1 receptor|
|Strain of Origin||B6.129S7-Ldlrtm1Her/J|
|Molecular Note||A spontaneous G-to-A change at chromosome 8 position 123,407,783 (GRCm38) results in the missense mutation p.E92K.|