A New Function of the DRD1 Gene: GnRH Secretion Regulation in Sheep Hypothalamic Neurons.

Abstract

Background: Dopamine (DA) is an important neurotransmitter that is widely present in the central nervous system. DA plays a crucial regulatory role in mammalian emotion, endocrine function, and reproduction through the activation of dopamine receptors. We compared the transcriptomes of hypothalamic tissues from Kazakh sheep during the nonbreeding season of anoestrus and during the nutrient-induced nonbreeding season of oestrus. Our research findings suggest that the dopamine receptor D1 (DRD1) gene may be a candidate gene for the regulation of sheep oestrus. However, the underlying mechanism through which DRD1 regulates sheep oestrus is still poorly understood.

Methods: In the present study, the expression of DRD1 mRNA in the hypothalamus of oestrous Kazakh sheep was significantly greater than that in the anoestrous phase. Immunohistochemical staining revealed that DRD1 was more widely expressed in hypothalamic tissue and was more highly expressed during oestrus than during anoestrus. Hypothalamic neuron experiments further indicated that DRD1 affects the expression of GnRH through dopamine synapses and calcium signalling pathways.

Results: moreover, the overexpression of the DRD1 gene promoted the secretion of GnRH, while knocking down the DRD1 gene reduced the secretion of GnRH.

Conclusions: The present study revealed that the DRD1 gene plays a crucial regulatory role in the secretion of the hormone GnRH in the hypothalamus of Kazakh sheep.