Exploratory comparative ovarian transcriptomic profiling in Dekalb White hens identified candidate signatures associated with egg-laying plateau persistence

The peak egg-laying plateau in poultry is regulated by complex genetic factors. To elucidate these, we performed a comparative ovarian transcriptome profiling (RNA-Seq) of Dekalb White hens with distinct egg production curves, using early-persistent (PP, n = 3) vs. late-degraded (DP, n = 3) birds selected by contrasting phenotypes from 60 birds per cohort at 49.5 weeks of age. PP hens showed earlier plateau onset (24 vs. 27 weeks), higher production (97.32% vs. 85.43%), lower body weight (1652.27 ± 26.19 vs. 1869.05 ± 32.18 g) and lower liver weight (34.85 ± 2.55 vs. 44.55 ± 1.10 g) than DP birds (p < 0.05). Suggestive shifts in hematological profiles (erythrocytes, hemoglobin, color index) were observed in the DP group (p < 0.05). Among 17,285 loci, 484 differentially expressed genes were identified (305 upregulated and 179 downregulated in PP). Functional enrichment analysis highlighted enzymatic activity and immune response pathways. Notably, PP hens exhibited upregulation of PNLIPRP1 (log2FC = 1.9, p = 0.001) and downregulation of PLTP (log2FC = −1.65, p = 0.015). Non-linear hierarchical approximation revealed a stochastic noise mode in DP (α = 45.05, p = 0.276). Network analysis identified a compact regulatory cluster (SFRP5, WNT5B, MMP13) linked to the Wnt pathway. RT-qPCR validated RNA-Seq trends for five candidate genes; SERPINB10B, MMP13 and LYG3 expression increased 3.86- to 16.00-fold in DP (p < 0.05). These signatures offer potential candidate molecular markers for future exploratory breeding programs targeting extended egg-laying plateaus.