title: Maternal melatonin effects on clock gene expression in a nonhuman primate fetus.
abstract: In the adult mammal the circadian system, which allows predictive adaptation to daily environmental changes, comprises peripheral oscillators in most tissues, commanded by the suprachiasmatic nucleus (SCN) of the hypothalamus. The external environment of the fetus is provided by its mother. In primates, maternal melatonin is a candidate to entrain fetal circadian rhythms, including the SCN rhythms of metabolic activity. We found in the 90% of gestation capuchin monkey fetus expression of the clock genes Bmal-1, Per-2, Cry-2, and Clock in the SCN, adrenal, pituitary, brown fat, and pineal. Bmal-1, Per-2, and the melatonin 1 receptor (MT1) showed a robust oscillatory expression in SCN and adrenal gland, whereas a circadian rhythm of dehydroepiandrosterone sulphate was found in plasma. Maternal melatonin suppression changed the expression of Bmal-1, Per-2, and MT1 in the fetal SCN. These effects were reversed by maternal melatonin replacement. In contrast, neither maternal melatonin suppression nor its replacement had effects on the expression of Per-2 and Bmal-1 or MT1 in the fetal adrenal gland or the circadian rhythm of fetal plasma dehydroepiandrosterone sulphate. Our data suggest that maternal melatonin is a Zeitgeber for the fetal SCN but probably not for the adrenal gland.
authors.affiliation: Departamento de Ciencias Fisiológicas, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114D, Santiago, Chile.
authors.forename: C
authors.initials: C
authors.lastname: Torres-Farfan
authors.forename: V
authors.initials: V
authors.lastname: Rocco
authors.forename: C
authors.initials: C
authors.lastname: Monsó
authors.forename: F J
authors.initials: FJ
authors.lastname: Valenzuela
authors.forename: C
authors.initials: C
authors.lastname: Campino
authors.forename: A
authors.initials: A
authors.lastname: Germain
authors.forename: F
authors.initials: F
authors.lastname: Torrealba
authors.forename: G J
authors.initials: GJ
authors.lastname: Valenzuela
authors.forename: M
authors.initials: M
authors.lastname: Seron-Ferre
mesh_terms: D056930:ARNTL Transcription Factors; D000311:Adrenal Glands / Q000502:physiology; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics; D056926:CLOCK Proteins; D002428:Cebus; D002940:Circadian Rhythm / Q000235:genetics / Q000502:physiology; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D005260:Female; D005333:Fetus / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D006854:Hydrocortisone / Q000097:blood; D008550:Melatonin / Q000502:physiology*; D009687:Nuclear Proteins / Q000235:genetics; D011247:Pregnancy; D044122:Receptor, Melatonin, MT1 / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013493:Suprachiasmatic Nucleus / Q000502:physiology; D013696:Temperature; D015534:Trans-Activators / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics
chemical_list: D056930:ARNTL Transcription Factors; D051792:Basic Helix-Loop-Helix Proteins; D056926:CLOCK Proteins; D018076:DNA, Complementary; D019314:Dehydroepiandrosterone Sulfate; D006854:Hydrocortisone; D008550:Melatonin; D009687:Nuclear Proteins; D044122:Receptor, Melatonin, MT1; D015534:Trans-Activators; D014157:Transcription Factors