Cell type-specific deficiency of c-kit gene expression in mutant mice of mi/mi genotype.
The mi locus of mice encodes a novel member of the basic-helix-loop-helix-leucine zipper protein family of transcription factors (hereafter called mi factor). In addition to microphthalmus, osteopetrosis, and lack of melanocytes, mice of mi/mi genotype are deficient in mast cells. Since the c-kit receptor tyrosine kinase plays an important role in the development of mast cells, and since the c-kit expression by cultured mast cells from mi/mi mice is deficient in both mRNA and protein levels, the mast cell deficiency of mi/mi mice has been attributed at least in part to the deficient expression of c-kit. However, it remained to be examined whether the c-kit expression was also deficient in tissues of mi/mi mice. In the present study, we examined the c-kit expression by mi/mi skin mast cells using in situ hybridization and immunohistochemistry. Moreover, we examined the c-kit expression by various cells other than mast cells in tissues of mi/mi mice. We found that the c-kit expression was deficient in mast cells but not in erythroid precursors, testicular germ cells, and neurons of mi/mi mice. This suggested that the regulation of the c-kit transcription by the mi factor was dependent on cell types. Mice of mi/mi genotype appeared to be a useful model to analyze the function of transcription factors in the whole-animal level.
Isozaki
K
K
Department of Pathology, Medical School, Osaka University, Japan.
Tsujimura
T
T
Nomura
S
S
Morii
E
E
Koshimizu
U
U
Nishimune
Y
Y
Kitamura
Y
Y
D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism; D015672:Erythroid Precursor Cells / Q000378:metabolism; D005333:Fetus / Q000166:cytology / Q000378:metabolism; D015870:Gene Expression; D005838:Genotype; D005854:Germ Cells / Q000378:metabolism; D008297:Male; D008407:Mast Cells / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains / Q000235:genetics*; D009474:Neurons / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit; D012333:RNA, Messenger / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D016184:Receptors, Colony-Stimulating Factor / Q000235:genetics* / Q000378:metabolism; D012867:Skin / Q000166:cytology / Q000378:metabolism; D013737:Testis / Q000166:cytology / Q000378:metabolism
D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D016184:Receptors, Colony-Stimulating Factor; D019009:Proto-Oncogene Proteins c-kit; D020794:Receptor Protein-Tyrosine Kinases