Effect of bisphenol A on the ovarian expressions of estrogen-related receptor gene and protein in queen honey bee (Apis mellifera)

Estrogen-related receptors (ERRs) belong to a large class of orphan receptors in the nuclear receptor (NR) family. Bisphenol A (BPA) is known as an endocrine disruptor and xenoestrogen with a high affinity for the human estrogen-related receptor (ERRγ). Insects lack estrogen receptors (ER), and their ERR is orthologous to ERRγ. This study was intended to examine whether BPA does not affect the ovarian expression of orphan nuclear ERR in queen honey bees (Apis mellifera L.). The amERR gene was amplified by polymerase chain reaction (PCR) from the cDNA of bees. The amERR protein was harvested and purified with the recombinant vector amERR/pET-32a. Using RT-qPCR and Western blot (WB), the levels of amERR gene and protein expression in the ovaries of control and treated bees were determined. The results indicated that both 3 µg and 10 µg doses suppressed the ovarian expression of amERR, with 6H inhibition being the most significant. Furthermore, AutoDockVina was utilized for simulating molecular docking between the tertiary structure of amERR predicted by I-TASSER and BPA. It hinted that BPA could conjugate with the ligand-binding pocket (LBP) of amERR. Thus, BPA might arrest amERR activation through binding. The results showed that BPA might impact the transcription and protein expression levels of the amERR gene. It may be correlated with the potential specific binding of BPA and amERR.