AJP - Endocrinology and Metabolism, Vol 253, Issue 6 E701-E704, Copyright © 1987 by American Physiological Society

ARTICLES

Definition of a prenatal sensitive period for maternal-fetal communication of day length

D. R. Weaver, J. T. Keohan and S. M. Reppert
Laboratory of Developmental Chronobiology, Massachusetts General Hospital, Boston 02114.

The duration of the nocturnal elevation of melatonin in the dam is a key feature in providing the Djungarian hamster fetus with a prenatal photoperiodic history. The developing animal compares the prenatal photoperiod with the photoperiod experienced during the postnatal period to properly time puberty. In the present report, we define the period during gestation when melatonin administered to the dam is effective in providing the fetus with a prenatal photoperiodic history. The administration of melatonin (50 ng delivered over 10 h at night) by timed infusions to pregnant, pinealectomized Djungarian hamsters for the last 4-7 days of gestation stimulated testicular weights of male pups reared in 14 h of light/day. Single 10-h melatonin infusions were ineffective in stimulating reproductive development (testes weights on day 34) of the male pups, irrespective of the gestational age of the fetus at the time of treatment. In contrast, two consecutive nightly 10-h infusions during gestation clearly stimulated testicular development. The gestational age of the fetus at the time of infusion strongly influenced the response, however. Treatments beginning between 6 and 3 days before birth were effective in stimulating postnatal reproductive development of the offspring. These results indicate that there is a well-delineated, sensitive period during prenatal development when melatonin can provide the fetus with a prenatal photoperiodic history.

This article has been cited by other articles:

				M. P. Butler, K. W. Turner, J. H. Park, J. P. Butler, J. J. Trumbull, S. P. Dunn, P. Villa, and I. Zucker Simulated natural day lengths synchronize seasonal rhythms of asynchronously born male Siberian hamsters Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2007; 293(1): R402 - R412. [Abstract] [Full Text] [PDF]

				M. P. Butler, J. J. Trumbull, K. W. Turner, and I. Zucker Timing of puberty and synchronization of seasonal rhythms by simulated natural photoperiods in female Siberian hamsters Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2007; 293(1): R413 - R420. [Abstract] [Full Text] [PDF]

				Z. M. Weil, L. M. Pyter, L. B. Martin II, and R. J. Nelson Perinatal photoperiod organizes adult immune responses in Siberian hamsters (Phodopus sungorus) Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2006; 290(6): R1714 - R1719. [Abstract] [Full Text] [PDF]

				A. K. Flynn, D. A. Freeman, I. Zucker, and B. J. Prendergast Testicular development in Siberian hamsters depends on frequency and pattern of melatonin signals Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2000; 279(4): R1182 - R1189. [Abstract] [Full Text] [PDF]