Identification of differentially expressed Gnαs and Gnα11 in sheep (Ovis aries) skins associated with white and black coat colors.

Guanine nucleotide-binding protein subunit alpha-s (Gnαs) and guanine nucleotide-binding protein subunit alpha-11 (Gnα11) play an important role in coat color formation. To improve our understanding of Gnαs and Gnα11 expression levels and pattern in the skin of black sheep (Ovis aries) compared with white sheep, we analyzed the expression levels through quantitative real time PCR (qPCR) and Western blot, immunohistochemistry and immunofluorescence. qPCR and Western blot results suggested that Gnαs and Gnα11 were significantly expressed at high levels in black sheep skin compared with the white sheep skin. Gnα11 expression was higher than Gnαs expression in both skin colors, transcripts and protein exhibited the same expression pattern in white and black sheep skins. Immunohistochemical results revealed that Gnαs and Gnα11 were localized in the outer root sheath of hair follicle in sheep. Furthermore, the expression of Gnα11 in outer root sheath of hair follicle was stronger than that in Gnαs. Immunofluorescencence further demonstrated that signals of Gnαs and Gnα11 were detected in outer root sheath and hair papilla. These results provide a novel insight into the role of Gnαs and Gnα11 in the regulation of sheep coat color.