Fig. 7.

Decline in cell proliferation during juvenile-to-aged period (a, c, e) and adult-to-aged period (b, d, f). a–d AgNOR assay. The analysis of interphase AgNORs was conducted with the morphometric (a, b) and counting (c, d) method according to the guidelines of the Committee on AgNOR Quantification. Correlation analysis within the combined horse group (Hucul and Anglo-Arabian breed) is shown. The number (c, d) of argyrophilic nucleolar proteins is decreased during horse development and aging. c n = 60, r = −0.38, p = 0.003; d n = 29, r = −0.1, p = 0.6. e, f Mitotic index (metaphase spreads per 100 cells) is diminished during horse development and aging. e n = 60, r = −0.3, p = 0.018; f n = 29, r = −0.32, p = 0.088