Pj. Morgan et al., OPER1 IS AN EARLY RESPONSE GENE UNDER PHOTOPERIODIC REGULATION IN THEOVINE PARS TUBERALIS, Journal of neuroendocrinology, 10(5), 1998, pp. 319-323
Mammalian Per1 (or RIGUI) is a recently described putative clock gene
that is expressed in the suprachiasmatic nucleus. It is also expressed
in the pars tuberalis (PT) of the pituitary, where melatonin appears
to drive its expression. This study examines the regulation of Per1 ex
pression, In ovine PT cells, oPer1 is an early response gene transient
ly expressed after stimulation with forskolin, but melatonin has no in
dependent effect on its expression. In sheep, PT tissue photoperiodic
background influences the magnitude or timing of expression of oPer1 2
h after lights-on. These data demonstrate that oPer1 mRNA is elevated
in the PT following the decline in night-time melatonin, and that the
amplitude or timing of this elevation is dependent upon the duration
of the nocturnal melatonin signal.