Mice homozygous for the cappuccino mutation have a severe dilution in coat color and diminished eye pigmentation. The BLOC-1 complex is disrupted and melanosome development appears arrested at an early stage. These homozygotes have significantly increased bleed times due to defective platelet aggregation. This mutation provides a model for Hermansky-Pudlak Syndrome.
The cappuccino mutation arose spontaneously in the C3H/HeJ inbred strain at The Jackson Laboratory. This mutation was backcrossed onto the C57BL/6J background for at least 10 backcross generations in the laboratory of Luanne Peters and sperm from homozygous males was cryopreserved in 2010.
|Gene Symbol and Name||Bloc1s4, biogenesis of lysosomal organelles complex-1, subunit 4, cappuccino|
|Strain of Origin||C3H/HeJ|
|Molecular Note||This allele comprises an 11 bp deletion that causes a frame shift that alters the C-terminal one third of the protein sequence. Expression and subcellular localization of the protein are not affected by this mutation. The mutation does affect the ability of the protein to form a complex with other lysosomal related proteins.|