Molecular characterization and analysis of the porcine gene.

Orphan receptor NURR1 (also termed NR4A2) belongs to the nuclear receptor superfamily and functions as a regulatory factor of differentiation, migration, maturation and maintenance of mesencephalic dopaminergic neurons. NURR1 plays an important role in nigrostriatal dopamine neuron development and is therefore implicated in the pathogenesis of neurodegenerative diseases linked to the dopamine system of the midbrain. Here we report the isolation and characterization of porcine cDNA. The cDNA was RT-PCR cloned using NURR1-specific oligonucleotide primers derived from sequences. The porcine cDNA encodes a polypeptide of 598 amino acids, displaying a very high similarity with bovine, human and mouse (99%) NURR1 protein. Expression analysis revealed a differential mRNA expression in various organs and tissues. transcripts could be detected as early as at 60 days of embryo development in different brain tissues. A significant increase in transcript in the cerebellum and a decrease in transcript in the basal ganglia was observed during embryo development. The porcine gene was mapped to chromosome 15. Two missense mutations were found in exon 3, the first coding exon of . Methylation analysis of the porcine gene body revealed a high methylation degree in brain tissue, whereas methylation of the promoter was very low. A decrease in DNA methylation in a discrete region of the promoter was observed in pig frontal cortex during pig embryo development. This observation correlated with an increase in transcripts. Therefore, methylation might be a determinant of expression at certain time points in embryo development.