Phenylalanine Rich Diet (Vicia faba L.) Enhances the Expression of Dopamine Receptor D3 (DRD3) Gene in Rabbits

Dopamine is a neurotransmitter hormone for pleasure and reward. It is synthesized only in the brain cells of human and animals and responsible for the regulation of behavior, mood, memory, cognitive, flexible movement, the body weight, and other important functions. The Dopamine Receptor D3 (DRD3) is the most important receptor for dopamine. In this investigation, expression of DRD3 gene was studied in rabbits fed on supplemented diet of dry and fresh faba bean (Vicia faba L. Sakha 3). DRD3 gene (≈ 1200 bp) in control and treated rabbits were PCR amplified, sequenced and aligned with reference gene (Acc. No XM_017346708.1). High genetic similarity values were detected among all sequences. DRD3 gene sequences of control, fresh and dry faba bean fed rabbits were deposited in the GenBank with accession numbers MZ714134, MZ714135 and MZ714136 respectively. Direct estimation of blood phenylalanine (Phe) amino acid indicated that feeding rabbits on dry faba bean reflected the highest level of Phe in the rabbit’s blood. Quantitative RT-qPCR analysis showed that DRD3 gene was over expressed after feeding rabbits on dry faba bean form compared with feeding on green form and control. Thus, diet rich with phenylalanine like Sakha3 (dry and fresh forms) enhance gene expression of DRD3 gene. However, diet doesn't affect the DRD3 gene sequence and structure. In a conclusion, our findings indicated a direct effect of faba bean supplemented diet on increasing DRD3 expression levels which improve the life quality for human.