Photoperiodic regulation of reproductive development in male white-footed mice (Peromyscus leucopus) born at different phases of the breeding season

Publisher Website
Google Scholar
Abstract
Male white-footed mice were maintained from birth in chambers equipped with latitudinal timers programmed to stimulate the natural progression of daylengths at 42.degree. N latitude. Mice were born into photoperiods starting on April 1, July 15, Sept. 15 or Oct. 27. Testes and seminal vesicles of April- and July-born mice were mature at 60 days old; puberty was delayed by several mo. in animals born into the Sept. and Oct. photoperiods but these mice became fecund at about 3.5 mo. of age, independent of current photoperiod. Increasing daylengths of late winter do not appear to synchronize the reproductive development of overwintering juveniles born at different times during the previous breeding season.