GPR1-AS (GPR1 antisense RNA) is exclusively and strongly expressed in the placenta and adult testis.
In four heterozygous human placental tissues only the paternal allele was detected (Kobayashi H et al, 2013).
In four of four informative placentas the GPR1-AS promoter was hypomethylated (≤25%) on the active
paternal allele and hypermethylated (≥75%) on the maternal allele. In contrast, the
promoter was biallelically methylated in blood lymphocytes (Kobayashi H et al, 2013).
GPR1-AS is homologous to mouse Zdbf2linc.