Assignment1 of the horse progesterone receptor (PGR) and estrogen receptor (ESR1) genes to horse chromosomes 7 and 31, respectively, by in situ hybridization

The steroid receptors, progesterone receptor (PR; gene symbol PGR) and estrogen receptor (ER; gene symbol ESR1), belong to a family of nuclear hormone receptors that function as transcription factors regulating gene activity which coordinate reproductive events in females (Parker, 1990). Mapping PGR and ESR1 to horse chromosomes provides comparative map information useful for determining the genome organization of the horse. Less than 50 type I anchor loci have been mapped in the horse. The human genes PGR mapped to HSA11q22.1→q22.3 (Rousseau-Merck et al., 1987) and ESR1 to HSA6q25.1 (Gosden et al., 1986; Menasce et al., 1993).