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recessive spotting : a linked locus that interacts with W/Kit but is not allelic
Author(s) -
Bennett Dorothy C.,
Trayner Ian D.,
Piao Xianhua,
Easty David J,
Klüppel Michael,
Alexander Warren S.,
Wagner Erwin F.,
Bernstein Alan
Publication year - 1998
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1046/j.1365-2443.1998.00184.x
Subject(s) - biology , proto oncogene proteins c kit , stem cell factor , melanocyte , microbiology and biotechnology , pdgfra , locus (genetics) , receptor tyrosine kinase , tyrosinase , melanosome , complementary dna , tyrosine kinase , systemic mastocytosis , allele , gene , kinase , mast cell , genetics , cancer research , signal transduction , melanin , progenitor cell , stem cell , immunology , melanoma , enzyme , biochemistry , gist , stromal cell
Background The murine coat‐colour mutation recessive spotting ( rs ) maps very closely to the W/Kit locus, encoding the proto‐oncoprotein Kit, the protein tyrosine kinase receptor for stem cell factor. Kit is important in the development of melanocytes, germ cells, interstitial cells of Cajal (ICC) and haemopoietic lineages, including mast cells. rs has never been genetically separated from Kit , and interacts with Kit mutations, suggesting that it is a recessive allele of Kit . Here we have tested this possibility. We have shown previously that diploid rs / rs melanocytes proliferated more slowly than did +/+ melanocytes, as did an immortal line of rs / rs melanocytes, melan‐rs. Results The Kit mRNA level in rs / rs melanocytes was indistinguishable from that of other melanocyte lines. The Kit cDNA sequence from rs / rs melanocytes and the kinase activity of Kit in rs / rs mast cells appeared to be normal. No deficiency of mast cells or ICC was observed in rs / rs mice. Moreover, following the overexpression of a normal Kit cDNA, proliferation of rs / rs melanocytes was retarded further, but that of +/+ melanocytes was increased, indicating an intracellular interaction between rs and Kit . Of other closely linked tyrosine kinase genes, melanocytes and melanoblasts did not express mRNA for Pdgfra , Flk‐1 or Txk , but both expressed Tec , encoding a nonreceptor kinase that interacts with Kit. Conclusions rs is not a mutation in Kit , although we have confirmed that rs interacts with Kit . It seems unlikely that rs affects Pdgfra , Flk‐1 or Txk , but Tec remains a candidate for rs .