Discovery of candidate genes and pathways regulating oviduct development in chickens

Estrogen is a key regulator in the development of the female reproductive system. It also stimulates oviduct development in immature chicks. We identified candidate genes and pathways associated with the development of chicken oviducts. A pellet containing the synthetic estrogen analog diethylstilbestrol (DES) was implanted subcutaneously in 1-wk-old female chicks for 10 days. The pellet was removed from half the group for 10 days, and an additional dose was given for a further 10 days. Total RNA was extracted from the oviducts of DES-treated and untreated chicks and subjected to an Affymetrix chicken GeneChip analysis. We found differential expression of 2290 and 1745 transcripts from the oviducts that were treated with DES once and twice, respectively. We also found a twofold or greater change in the expression of 77 and 390 transcripts between the two control and DES-treated time points, respectively, while we found a change in the expression of 10 transcripts that were common to all groups. Analyses of real-time PCR and in situ hybridization of selected genes confirmed the validity of the gene expression patterns observed in the microarray analysis. In particular, CCRN4L, FAM26F, HAS2, NELF, and NTM were up-regulated in the DES-treated chicken oviducts. High-throughput analysis revealed that the differentially expressed genes were related to tubular formation, epithelial differentiation, hormone interactions, nerve development, and tissue remodeling in the chicken oviduct. This study provides novel insights into candidate genes regulating oviduct development and differentiation via estrogen. The identified genes may serve as biomarkers of reproductive tract development in chicks.