Mast cells in spotted mutant mice ( W Ph mi )

Abstract

Mast cells derived from haematopoietic tissue are deficient in numbers in spleen, stomach and skin of Harwell mice doubly mutant at the spotting W locus: seven viable combinations of four mutants. Most combinations have variably impaired viability, anaemia and infertility; but homozygous W sh W sh are normal in these respects yet still lack mast cells. The effect of the W gene on mast cells acts in recessive fashion. Effects of doubly mutant W genes on mast cells and coat colour, the latter usually regarded as dominant, appear more closely related than other pleiotropic effects. The spotting gene Ph , closely linked to W , has but marginal effects on mast cells, whereas mi , another spotting gene, quite unrelated to W affects mast cells in the spleen in a dominant way. Thus, splenic mast cells may be a special category of a heterogeneous population. Peptic ulceration, recorded in W/W v mice of Jackson stock, was not seen in Harwell mice. We suggest that this lesion is due to genetic complementation or environmental causes.