Structure and ovarian expression of the oxytocin gene in sheep.

In sheep, the oxytocin gene is highly up-regulated in the ovarian corpus luteum as well as in the hypothalamus. This expression is already elevated on Day 2 of the oestrous cycle, representing 1% of all transcripts in this tissue, and it declines thereafter to low levels after Day 6 of the cycle. In order to study the mechanisms involved in luteal oxytocin gene expression, we have cloned and sequenced the oxytocin gene from the sheep. This gene is closely homologous to other known mammalian oxytocin genes, especially the bovine one, and comparison of the gene promoter regions highlights several blocks of putative control elements.