Fig. 4

Beta-estradiol as an upstream regulator. Activation z-score calculated by Ingenuity® Pathway Analysis (Qiagen, Valencia, CA) for beta-estradiol based on differentially expressed genes (DEGs) (RPKM> 0.2, P < 0.05, |fold change| > 1.5). The top panel shows the calculated z-score for beta-estradiol based on DEGs between low egg producing hens (LEPH) and high egg producing hens (HEPH), both outside (basal) and during (surge) the preovulatory surge (PS). The bottom panel shows the calculated z-score for beta-estradiol based on DEGs between outside and during the PS in LEPH and HEPH individually. Significant predicted activation (z-score ≥ 2) or inhibition (z-score ≤ − 2) of beta-estradiol is denoted with an asterisk (*)