Fig. 1

Evaluation of nail growth in Syrian hamsters. a Labeled nail in the fourth digit of the right forelimb of the Syrian hamster. b Measurement of nail growth by sequential labeling. Syrian hamster nails. The nails grew to 540 μm in 7 days in this case. Scale bar: 500 μm. c Nail growth of the fourth digit in one week in cold-acclimated (CA) hamsters. No differences in nail growth were observed between the right and left digits. Each point represents one digit, resulting two point from one individual in most cases. Nail growth in right digit: 73.0 ± 5.4 (N = 8), left digit: 60.6 ± 3.5 (N = 7), and sum of them: 67.2 ± 3.7 (n = 15 from total 8 animals). d Total nail growth during 1–3 weeks. The Y-axis indicates the sum of nail growth per week along the time-course labeling (X-axis) for each digit. Each point represents the nail length. e No correlation was found between body weight and nail growth per day. Each point represents one individual (N = 8). Nail growth per day was represented as a mean value of the right and left digit