Author:
Butler Matthew P.,Turner Kevin W.,Park Jin Ho,Butler James P.,Trumbull Justin J.,Dunn Sean P.,Villa Philip,Zucker Irving
Abstract
Photoperiodism research has relied on static day lengths and abrupt transitions between long and short days to characterize the signals that drive seasonal rhythms. To identify ecologically relevant critical day lengths and to test the extent to which naturally changing day lengths synchronize important developmental events, we monitored nine cohorts of male Siberian hamsters ( Phodopus sungorus) born every 2 wk from 4 wk before to 12 wk after the summer solstice in a simulated natural photoperiod (SNP). SNP hamsters born from 4 wk before to 2 wk after the solstice underwent rapid somatic and gonadal growth; among those born 4–6 wk after the solstice, some delayed puberty by many weeks, whereas others manifested early puberty. Hamsters born eight or more weeks after the solstice failed to undergo early testicular development. The transition to delayed development occurred at long day lengths, which induce early puberty when presented as static photoperiods. The first animals to delay puberty may do so predominantly on the basis of postnatal decreases in day length, whereas in later cohorts, a comparison of postnatal day length to gestational day length may contribute to arrested development. Despite differences in timing of birth and timing of puberty, autumn gonadal regression and spring gonadal and somatic growth occurred at similar calendar dates in all cohorts. Incrementally changing photoperiods exert a strong organizing effect on seasonal rhythms by providing hamsters with a richer source of environmental timing cues than are available in simple static day lengths.
Publisher
American Physiological Society
Subject
Physiology (medical),Physiology
Reference47 articles.
1. Effects of photoperiod and androgen on pituitary function and neuropeptide staining in Siberian hamsters
2. Bronson FH. Mammalian Reproductive Biology. Chicago: University of Chicago Press, 1989.
3. Bronson FH, Rissman EF. The biology of puberty. Biol Rev 61: 157–195, 1986.
4. Butler MP, Trumbul JJ, Turner KW, Zucker I. Timing of puberty and synchronization of seasonal rhythms by simulated natural photoperiods in female Siberian hamsters. Am J Physiol Regul Integr Comp Physiol. May 9. 2007; doi:10.1152/ajpregu.00216.2007.
5. Christian JJ. Regulation of annual rhythms of reproduction in temperate small rodents. In: Testicular Development, Structure, and Function, edited by Steinberger A and Steinberger E. New York: Raven, 1980, p. 367–380.
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