Cooperation of Nectin-1 and Nectin-3 Is Required for Maintenance of Epidermal Stratification and Proper Hair Shaft Formation in the Mouse

Figure 1

((a)–(f)) Expression of nectin-1 and nectin-3 in postnatal mouse epidermis and hair follicles. Sagittal sections of mouse skin at postnatal day 10 (P10), during first anagen, analysed by in situ hybridization. Both nectin-1 and nectin-3 are expressed in the spinous and granular layer of epidermis ((a) and (b)). In hair follicle, nectin-1 expression is observed in IRS, not in ORS (d). Nectin-3 expression is observed in ORS, not in IRS (e). Asterisk indicates nonspecific staining due to pigment of hair shaft. Dashed lines in (a), (b), and (c) indicate basement membrane (black) and border between granular and cornified layers (white) and in (d)–(f) they indicate outline of hair shaft and melanocytes (white) and border between ORS and IRS (black). Scale bars are 50 μm in (a), (b), and (c) and 20 μm in (d), (e), and (f). ((g)–(i)) Hair abnormality of the nectin-1−/−; nectin-3+/− compound mutants. Macroscopic appearance of one control and two nectin-1−/−; nectin-3+/− mice at P10. (g′), (h′), and (i′) show magnifications of (g), (h), and (i). The nectin-1−/−; nectin-3+/− mice are smaller in size compared with the control ((g)–(i)). The control mouse has thick hair and the long and straight guard hairs are visible in lateral inspection (arrowhead in (g′)). The density and length of hair varied among the nectin-1−/−; nectin-3+/− mutants, but the long guard hairs were not visible ((h′) and (i′)). Scale bar is 1 cm.