A spontaneous mouse mutation, mesenchymal dysplasia (mes), is caused by a deletion of the most C-terminal cytoplasmic domain of patched (ptc).
A recessive mouse mutation, mesenchymal dysplasia (mes), which arose spontaneously on Chromosome 13, causes excess skin, increased body weight, and mild preaxial polydactyly. Fine gene mapping in this study indicated that mes is tightly linked to patched (ptc) that encodes a transmembrane receptor protein for Shh. Molecular characterization of the ptc gene of the mes mutant and an allelism test using a ptc knockout allele (ptc(-)) demonstrated that mes is caused by a deletion of the most C-terminal cytoplasmic domain of the ptc gene. Since mes homozygous embryos exhibit normal spinal cord development as compared with ptc(-) homozygotes, which die around 10 dpc with severe neural tube defects, the C-terminal cytoplasmic domain lost in mes mutation is dispensable for inhibition of Shh signaling in early embryogenesis. However, compound heterozygotes of ptc(-) and mes alleles, which survive up to birth and die neonatally, had increased body weight and exhibited abnormal anteroposterior axis formation of the limb buds. These findings indicate that Ptc is a negative regulator of body weight and ectopic activation of Shh signaling in the anterior mesenchyme of the limb buds, and that the C-terminal cytoplasmic domain of Ptc is involved in its repressive action.
Makino
S
S
Mammalian Genetics Laboratory, National Institute of Genetics, Mishima, Shizuoka-ken 411-8540, Japan.
Masuya
H
H
Ishijima
J
J
Yada
Y
Y
Shiroishi
T
T
D000015:Abnormalities, Multiple / Q000235:genetics* / Q000473:pathology; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019521:Body Patterning; D002874:Chromosome Mapping; D005804:Genes, Lethal / Q000235:genetics; D005816:Genetic Complementation Test; D005838:Genotype; D053823:Hedgehog Proteins; D047908:Intracellular Signaling Peptides and Proteins; D018878:Limb Buds / Q000002:abnormalities / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics*; D008648:Mesoderm / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D018345:Mice, Knockout; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D009436:Neural Tube Defects / Q000235:genetics; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D017689:Polydactyly / Q000150:complications / Q000235:genetics; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D011956:Receptors, Cell Surface; D017384:Sequence Deletion / Q000235:genetics*; D015398:Signal Transduction; D012868:Skin Abnormalities / Q000150:complications / Q000235:genetics; D013116:Spinal Cord / Q000196:embryology / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism; D015430:Weight Gain / Q000235:genetics
D053823:Hedgehog Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; C000606240:Ptch1 protein, mouse; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D015534:Trans-Activators