Fig. 1

Distribution of ESGs and HFs in the volar skin of C57BL/6 mice and SD rats. a–d Gross phenotype of the volar skin of mouse forefoot (a, n = 60), mouse hindfoot (b, n = 20), rat forefoot (c, n = 20), and rat hindfoot (d, n = 20). The right panels show magnified views of the boxes in the left panels. 30 mice and 10 rats were used. e–h Representative images of iodine-starch sweat test on mouse forefoot (e, n = 20), mouse hindfoot (f, n = 20), rat forefoot (g, n = 20), and rat hindfoot (h, n = 20). 10 mice and 10 rats were used. Black dots represent sweating spots. (e1, f1, g1, h1) and (e2, f2, g2, h2) are magnified views of the footpads and IFPs in the boxed area shown in (e, f, g, h), respectively. i–l Representative images of epidermal preparations from the volar skin of mouse forefoot (i, n = 10), mouse hindfoot (j, n = 10), rat forefoot (k, n = 10), and rat hindfoot (l, n = 10). 5 mice and 5 rats were used. (i1, j1, k1, l1) and (i2, i3, j2, j3, k2, k3, l2, l3) are magnified views of the footpads and IFPs in the boxed area shown in (i, j, k, l), respectively. ESG ducts stained with Nile Blue A are the elongated blue tubes emerging inside the footpads or IFPs. Oil Red O staining marks HF-related sebaceous glands (red). Red arrows indicate HFs, and black arrows indicate ESGs. Scale bar = 1 mm. Abbreviations: IFPs, inter-footpads; HFs, hair follicles; ESGs, eccrine sweat glands; SD, Sprague-Dawley