Transcriptomic profiling of hypothalamic development in female rats.

The hypothalamic arcuate nucleus (ARC) and anteroventral periventricular nucleus (AVPV) are critical regulators of reproductive function, energy balance, stress, and neuromodulation. These regions undergo substantial changes in neural and glial populations over development that enable the acquisition of adult functions. Although previous studies have examined developmental changes in specific hypothalamic cell populations or gene families, to our knowledge, none has comprehensively compared unbiased/bulk transcriptional profiles across key developmental stages in both the ARC and AVPV. In this study, we used 3' targeted RNA sequencing to profile gene expression in the ARC and AVPV of female rats at infantile (P8), peripubertal (P30), and adult (P60) life stages. We conducted unbiased and a priori selected differential gene expression analyses, the latter genes selected for their roles in reproduction, metabolism, stress, and neuromodulation. We also measured serum hormones as an index of physiology. Developmental analyses revealed robust differential gene expression between the infantile and prepubertal periods in both the ARC and AVPV, with substantial transcriptional overlap between regions. Fewer and more region-specific transcriptional changes were observed during the transition to adulthood. Gene ontology (GO) analyses revealed coordinated developmental programming prior to puberty, including downregulation of developmental processes and upregulation of metabolic and regulatory pathways. In adulthood, the AVPV showed continued transcriptional remodeling, while the ARC remained comparatively stable. FSH emerged as the strongest hormonal correlate of a priori hypothalamic gene expression. These data provide a reference for understanding hypothalamic development and hormone-gene interactions across life stages in the female rat.