Evidence for estrogen receptor expression in the bursal epithelial cells of chicks

The aim of the present study was to demonstrate estrogen receptor (ER) α (ER-α) and ER-β expression in the bursa of Fabricius and cultured bursal epithelial cells (CBEC) by reverse transcription (RT)-polymerase chain reaction (PCR) using a primer set design based on the sequences of chicken ER-α complementary DNA (cDNA) and chicken ER-β-cDNA. In the case of ER-α, RT-PCR products of the expected size (698 base pairs (bp)) were amplified from cDNA derived from the bursa and CBEC, and from the oviduct, which was used as a positive control. All of the products were cleaved into two fragments of 476 bp and 222 bp by treating the products with restriction nuclease Hind III, indicating that these RT-PCR products from the bursa, CBEC and genital organs were the same. In contrast, in the case of ER-β, PCR products of the expected size (303 bp) were not detected in the bursa of Fabricius or CBEC, or in the oviduct and ovary. These results indicate that ER-α is expressed in the bursa of Fabricius and in CBEC, but ER-β is not expressed in the bursa or CBEC, or in the female genital organs of chickens.