Differential expression of a gene homologous to a G-alpha protein gene in neonatal mouse skin during development of hair follicles.
The development of mouse hair follicles depends on the proliferation, differentiation and migration of epithelial matrix cells in the follicle bulb. In particular, induction of the proliferation of epithelial cells is thought to be signalled by the dermal papilla at the base of the bulb. Neonatal mouse skin is useful for studying changes in gene expression during development of the follicles, as the mitotic activity of skin cells changes shortly after birth. Using RNA differential display, a 248-bp message has been identified, which is expressed in the skin, specifically on day 2 and day 3 but not on day 4 after birth. Confirmation of expression of this gene by ribonuclease protection assay showed that strong expression is seen on day 2 and day 3, but weak expression is also shown on day 1, day 4 and day 5. In situ hybridization data revealed that it is mainly localized in the dermal papilla. Analysis of its nucleotide sequence showed 99% identity between nucleotide 2 and 232 of the mouse uncoupled S49 cell mRNA for stimulatory GTP-binding protein (G(S)) alpha subunit, suggesting it is a segment of G(S)alpha. As the G(S)alpha subunit is involved in transducing extracellular signals across the cell, the finding of its expression in the papilla suggests it may be a molecular signal to the induction of epithelial proliferation in the follicle bulb. Evidence of strong expression on day 2, at the time when the mitotic activity of epithelial matrix cells starts to increase, also suggests that the G(S)alpha is a potential candidate for involvement in the initiation of follicle growth.
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Animal and Food Sciences Division, P.O. Box 84, Lincoln University, Canterbury, New Zealand. fssuhy@doh.gov.tw
Palmer
B R
BR
Wellby
M P
MP
Bickerstaffe
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R
Hickford
J G
JG
D000375:Aging / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development / Q000502:physiology*; D001483:Base Sequence / Q000235:genetics; D018076:DNA, Complementary / Q000302:isolation & purification; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D018859:Hair Follicle / Q000254:growth & development* / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid; D012879:Skin Physiological Phenomena; D014018:Tissue Distribution
D018076:DNA, Complementary; D019205:GTP-Binding Protein alpha Subunits, Gs