Telogen elongation in the hair cycle of ob/ob mice

Figures & data

Fig. 1. Identification of anagen hair follicles by HE staining (A) and immunohistochemistry for Ki67 (B).

Notes: Anagen follicles extended into the subcutaneous fat layer and the dermal papilla was enveloped with hair bulb. Lots of proliferative cells were observed in anagen follicles. hs: hair shaft, br: bulge region, hb: hair bulb, and sf: subcutaneous fat layer. Arrows indicate the Ki67-positive follicular cells. Bar = 300 μm in A and 100 μm in B.

Table 1. Histologically identified hair cycle phases and positivity for Ki67 in +/+ mice.

Age (weeks)	Replication	HE staining, number of follicles (%)							Ki67^b
		Total^a	Anagen		Catagen		Telogen
6	1	31	0	(0.0)	27	(87.1)	4	(12.9)	−
	2	31	0	(0.0)	16	(51.6)	15	(48.4)	−
	3	26	0	(0.0)	2	(7.7)	24	(92.3)	−
7	1	30	0	(0.0)	0	(0.0)	30	(100.0)	−
	2	24	0	(0.0)	0	(0.0)	24	(100.0)	−
	3	29	0	(0.0)	0	(0.0)	29	(100.0)	−
8	1	25	0	(0.0)	0	(0.0)	25	(100.0)	−
	2	27	0	(0.0)	0	(0.0)	27	(100.0)	−
	3	38	6	(15.8)	0	(0.0)	32	(84.2)	−
9	1	30	10	(33.3)	0	(0.0)	20	(66.7)	+/−
	2	25	25	(100.0)	0	(0.0)	0	(0.0)	+
	3	24	12	(50.0)	0	(0.0)	12	(50.0)	+/−
10	1	31	31	(100.0)	0	(0.0)	0	(0.0)	+
	2	25	25	(100.0)	0	(0.0)	0	(0.0)	+
	3	27	27	(100.0)	0	(0.0)	0	(0.0)	+

Notes:

^a Total number of follicles in which the morphologies of the dermal papilla and hair matrix can be clearly observed.

^b Positivity for Ki67 is shown as follows: +, all follicles were positive; +/−, A portion of follicles were positive; and −, all follicles were negative.

Table 2. Histologically identified hair cycle phases and Ki67 positivity in ob/ob mice.

Age (weeks)	Replication	HE staining, number of follicles (%)							Ki67^b
		Total^a	Anagen		Catagen		Telogen
6	1	33	33	(100.0)	0	(0.0)	0	(0.0)	+
	2	27	27	(100.0)	0	(0.0)	0	(0.0)	+
	3	41	41	(100.0)	0	(0.0)	0	(0.0)	+
7	1	42	10	(23.8)	32	(76.2)	0	(0.0)	+/−
	2	26	5	(19.2)	21	(80.8)	0	(0.0)	+/−
	3	31	3	(9.7)	28	(90.3)	0	(0.0)	+/−
8	1	27	0	(0.0)	27	(100.0)	0	(0.0)	−
	2	25	0	(0.0)	25	(100.0)	0	(0.0)	−
	3	21	0	(0.0)	21	(100.0)	0	(0.0)	−
9	1	26	0	(0.0)	5	(19.2)	21	(80.8)	−
	2	31	0	(0.0)	29	(93.5)	2	(6.5)	−
	3	34	0	(0.0)	2	(5.9)	32	(94.1)	−
10	1	19	0	(0.0)	0	(0.0)	19	(100.0)	−
	2	25	0	(0.0)	0	(0.0)	25	(100.0)	−
	3	22	0	(0.0)	0	(0.0)	22	(100.0)	−
11	1	15	0	(0.0)	0	(0.0)	15	(100.0)	−
12	1	46	0	(0.0)	0	(0.0)	46	(100.0)	−
13	1	26	0	(0.0)	0	(0.0)	26	(100.0)	−
14	1	23	0	(0.0)	0	(0.0)	23	(100.0)	−
15	1	16	0	(0.0)	0	(0.0)	16	(100.0)	−
	2	18	0	(0.0)	0	(0.0)	18	(100.0)	−
	3	16	0	(0.0)	0	(0.0)	16	(100.0)	−
16	1	21	0	(0.0)	0	(0.0)	21	(100.0)	−
17	1	19	0	(0.0)	0	(0.0)	19	(100.0)	−
18	1	35	20	(57.1)	0	(0.0)	15	(42.9)	+/−
	2	25	0	(0.0)	0	(0.0)	25	(100.0)	−
	3	21	0	(0.0)	0	(0.0)	21	(100.0)	−
19	1	23	0	(0.0)	0	(0.0)	23	(100.0)	−
20	1	20	0	(0.0)	0	(0.0)	20	(100.0)	−
21	1	27	12	(44.4)	0	(0.0)	15	(55.6)	+/−
22	1	31	0	(0.0)	0	(0.0)	31	(100.0)	−
23	1	22	0	(0.0)	0	(0.0)	22	(100.0)	−
	2	23	0	(0.0)	0	(0.0)	23	(100.0)	−
24	1	31	0	(0.0)	0	(0.0)	31	(100.0)	−
	2	22	0	(0.0)	0	(0.0)	22	(100.0)	−
	3	27	0	(0.0)	0	(0.0)	27	(100.0)	−

Notes:

^a Total number of the follicles in which the morphologies of the dermal papilla and hair matrix can be clearly observed.

^b Positivity for Ki67 is shown as follows: +, all follicles were positive; +/−, A portion of follicles were positive; and −, all follicles were negative.

Fig. 2. Anagen transition in +/+ and ob/ob mice.

Notes: (A)–(C): Macroscopic observation of the anagen transition, which is recognized as the skin pigmentation. Arrows indicate the abnormal pigmentation of skin in ob/ob mice. Bar = 1 cm. (D)–(E): Histological observation of hair follicles in the ob/ob mice shown in C. The anagen follicles and the catagen follicles were coexisted in the HE-stained skin tissue with pigmentation (D). The caudal tissue showed only the telogen follicles (E). Bar = 300 μm.