Fig. 2

Hypothalamo-pituitary-gonadal axis networks. Ingenuity® Pathway Analysis (Qiagen, Valencia, CA) was used to generate networks to biologically interpret the expression data. Copyright permission has been obtained from QIAGEN for use of the images presented

(A) Hypothalamic network comparing gene expression in low egg producing hens (LEPH) and high egg producing hens (HEPH) during the preovulatory surge (PS) (RPKM> 0.2, P < 0.05, |fold change| > 1.5). Green represents genes up-regulated in LEPH, whereas red represents genes up-regulated in HEPH. (B) Pituitary network comparing HEPH gene expression outside and during the PS (RPKM> 0.2, P < 0.05, |fold change| > 1.5). Green represents genes up-regulated outside of the PS, whereas red represents genes up-regulated during the PS.