title: Molecular cloning, expression and  variation analyses of the dopamine D2 receptor gene in pig breeds in China.
abstract: The  dopamine D2 receptor (DRD2) is a crucial mediator for normal physiological  processes. We cloned the pig DRD2 gene, investigated its distribution in  tissues and identified polymorphisms by RT-PCR, quantitative real-time PCR and  direct sequencing. Two Yorkshire pigs from Guangdong Academy of Agricultural  Sciences (Guangzhou, China) were selected to clone the gene and investigate its  expression; 16 individuals from four pig breeds (Yorkshire, Landrace, small-ear  spotted, and Xinchang) were used to scan the variations. The two transcripts (DRD2L and DRD2S), obtained through insertion or deletion of exon 5 and  part of 3'UTR, were found to encode 444- and 415-amino acid proteins,  respectively. The 574-bp indel in 3'UTR comprises five miRNA targeting sites,  based on bioinformatics predictions. The pig DRD2 gene expresses  predominantly in the pituitary gland, and then in oviducts and the  hypothalamus. Both DRD2L and DRD2S mRNA were detected in  cerebrum, cerebellum, hypothalamus, pituitary gland, back muscle, oviduct,  uterus, and testis tissues; DRD2L was more abundant than DRD2S.  The DRD2 gene is located on chromosome 9 and contains seven exons.  Sixty-one different sequences were identified in this gene; among seven in the  coding region, only one altered the encoded amino acid. These findings will  help us understand the functions of the DRD2 gene in pigs.
authors.affiliation: Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China.
authors.forename: H P
authors.initials: HP
authors.lastname: Xu
authors.forename: X M
authors.initials: XM
authors.lastname: He
authors.forename: M X
authors.initials: MX
authors.lastname: Fang
authors.forename: Y S
authors.initials: YS
authors.lastname: Hu
authors.forename: X Z
authors.initials: XZ
authors.lastname: Jia
authors.forename: Q H
authors.initials: QH
authors.lastname: Nie
authors.forename: X Q
authors.initials: XQ
authors.lastname: Zhang
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D020029:Base Pairing / Q000235:genetics; D001483:Base Sequence; D001665:Binding Sites; D001947:Breeding; D002681:China; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D014644:Genetic Variation; D016678:Genome / Q000235:genetics; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D009928:Organ Specificity / Q000235:genetics; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011485:Protein Binding / Q000235:genetics; D017448:Receptors, Dopamine D2 / Q000737:chemistry / Q000235:genetics*; D017384:Sequence Deletion / Q000235:genetics; D034421:Sus scrofa / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; D018076:DNA, Complementary; D035683:MicroRNAs; D017448:Receptors, Dopamine D2