Table 1.
Specimens examined.
Fig 1.
Regions of yak body where skin specimens were obtained for this study.
1 forehead 2 cheek 3 dorsal neck 4 lateral neck 5 ventral neck 6 withers 7 scapula 8 brachia 9 thorax 10 lateral of forearm 11 medial of forearm 12 metacarpus 13 back 14 costal region 15 waist 16 buttock 17 thigh 18 abdomen 19 lateral of crus 20 inguinal region 21 medial of crus 22 metatarsus 23 nasolabial plate 24 hoof 25 axilla. Note: the axilla was not marked.
Table 2.
Primers used in this study.
Fig 2.
Histological characteristics of skin in yak.
E: epidermis, D: dermis, SEG: sebaceous gland, SW: sweat gland, AP: arrector pili, HF: hair follicle, HB: hair bulb.
Fig 3.
Histological structures of the epidermis in yak.
A. Structures of epidermis in hairy skin of yak, HE ×1000 B. Structures of epidermis in glabrous skin of yak, HE ×400. SC: stratum corneum, SG: stratum granulosum, SS: stratum spinosum, SB: stratum basale, SL: stratum lucidum.
Fig 4.
Histological structures of the dermis in yak.
A. Collagen fiber in dermis in yak, Masson’s trichrome ×100 B. Elastic fiber in dermis in yak, WVG ×200 C. Epidermal lamellae and dermal lamellae fit together in hoof in yak, Sacpic ×100 D. Capillary plexus in dermis in yak, Sacpic ×200 E. Adipose tissue in the deep dermis of hoof sphere, HE×40 F. Sweat gland and secretion in deep dermis in yak, AB-PAS ×200 G. Nasolabial glands distributed in the dermis of nasolabial plate, HE ×200 H. Sebaceous gland around the hair follicle in dermis, HE ×400 E: epidermis, D: dermis, CF: collagen fiber, EF: elastic fiber, HF: hair follicle, CP: capillary plexus, EL: epidermal lamellae, DL: dermal lamellae, HT: horn tubule, AC: adipose cell, SW: sweat gland, SD: striated duct, SA: serous alveoli, ID: intercalated duct, ILD: interlobular duct, SEG: sebaceous gland.
Fig 5.
Histological structures of hair follicle in yak.
A. Hair follicle group consisting of one primary follicle and some secondary follicles and sebaceous gland, HE ×100 B. Structures of hair follicle in yak, Sacpic ×400 SEG: sebaceous gland, SW: sweat gland, HF: hair follicle, CF: collagen fiber, CT: connective tissue, PF: primary follicle, SF: secondary follicle, DRS: dermal root sheath, ORS: outer root sheath, IRS: inner root sheath, HC: hair cortex.
Table 3.
Thickness of skin of body regions.
Table 4.
Rank order of thickness of skin according to age.
Table 5.
Age differences of thickness of epidermis, dermis and skin.
Fig 6.
Schema graphs showing thickness change of skin in adult yak (unit: mm).
Different colors show different thickness over body regions.
Fig 7.
The HSPs gene expressions in skin of yak during hair cycle.
A: HSP27 gene expression in skin. B: HSP70 gene expression in skin. C: HSP90 gene expression in skin. Different letters represent that the difference was significant (p<0.05), the same letter represents that the difference was no significant (p>0.05).
Fig 8.
Detection of HSP27, HSP70 and HSP90 expression in skin of yak during hair cycle by Western-blot.
Different letters represent that the difference was significant (p<0.05), the same letter represents that the difference was no significant (p>0.05).
Fig 9.
Immunohistochemical staining of HSP27 in skin of yak during hair cycle.
A, B: HSP27 expressed in the epidermis and the outer root sheath of secondary follicle. C. negative control. Arrows show the immunostained products as brown deposits. ×400.
Fig 10.
Immunohistochemical staining of HSP70 in skin of yak during hair cycle.
A, B: HSP70 expressed in the epidermis, sebaceous gland, sweat gland and the outer root sheath of hair follicle. C. negative control. Arrows show the immunostained products as brown deposits. ×400.
Fig 11.
Immunohistochemical staining of HSP90 in skin of yak during hair cycle.
A, B: HSP90 expressed in the epidermis, sebaceous gland and hair root sheath. C. negative control. Arrows show the immunostained products as brown deposits. ×400.
Fig 12.
The CGI-58 gene expressions in skin of yak during hair cycle.
Fig 13.
The KDF1 gene expressions in skin of yak during hair cycle.