title: Multiple responses to different photoperiods occur in the mouse, Peromyscus leucopus.
abstract: 1. Peromyscus leucopus exhibits multiple responses to different daylengths. The winter molt and gonadal regression are complete in populations chronically exposed to 12, 11, 10, or 9 h of light per day while hypertrophy of brown fat and occurrence of daily torpor were greater in mice on 9 or 10 h of light when compared to animals on 11 or 12 h photocycles. 2. A precise "critical" daylength is not observed in this species for gonadal regression, occurrence of daily torpor, or hypertrophy of brown fat. 3. Certain mice never exhibit a short-day response following 12 weeks exposure to 12, 11, 10, or 9 h of light per day.
authors.affiliation: Department of Biology, Wesleyan University, 06457, Middletown, CT, USA.
authors.forename: G Robert
authors.initials: GR
authors.lastname: Lynch
authors.affiliation: Department of Biology, Wesleyan University, 06457, Middletown, CT, USA.
authors.forename: Seth L
authors.initials: SL
authors.lastname: Gendler