The Effects of Light on the Onset of Puberty

Abstract

The earliest reported experiment on the reproductive effects of altering photoperiods was that of Bissonnette (1935b) on immature male ferrets (Mustela putorius). He maintained one group of three animals on a period of 8½ hours of light, starting on 10 November (Northern hemisphere) and a second group of three on normal daylight plus 9 hours of artificial light (added after sundown) starting from the same date. Puberty was delayed in his ‘long-day’ animals and hastened in two of the ‘short-day’ ferrets, but delayed in the third. These results suggested that light did have some effect on puberty, but the small sample precluded any major conclusions. A considerable amount of research since Bissonnette’s report has confirmed the importance of the light regime on puberty attainment, and much of this is reviewed below.