Abstract

Hepcidin is a multifunctional peptide involved in innate immunity and iron homeostasis, yet its earliest developmental regulation in sturgeons remains poorly understood. Here, we investigated maternal loading and embryonic expression patterns of hepcidin transcripts (hamp) in Siberian sturgeon (Acipenser baerii). RT-qPCR detected hamp transcripts in all 17 unfertilized egg (UFE) batches examined; however, maternally loaded transcript abundance varied markedly among batches, with up to a 14.8-fold difference, indicating substantial heterogeneity in the molecular starting state of embryos. In contrast, female traits, including age, body weight, and condition factor, as well as fertilization rate and hatching success, were not significantly correlated with UFE hamp transcript abundance (Spearman’s rank correlation with BH-FDR adjustment; q > 0.05). Developmental expression analysis from UFE to first hatch was then performed using five developmental series (DevSeries 1–5) that represented relatively high, intermediate, and low UFE baseline levels within the statistically differentiated UFE dataset (Welch ANOVA/Games–Howell post hoc, p < 0.05). The developmental dataset showed significant DevSeries, stage, and DevSeries × stage effects, indicating that embryonic hamp expression profiles differed among DevSeries (two-way ANOVA, p < 0.05). High-loading DevSeries (DevSeries 2 and 4) showed prolonged early persistence followed by later re-elevation, whereas low-loading DevSeries (DevSeries 3 and 5) maintained lower overall abundance but displayed more evident stage-linked increases during embryogenesis. Collectively, these findings show that maternally loaded hamp transcripts are associated with embryonic expression profiles and support the view that maternal transcript abundance provides an initial baseline that should be considered when interpreting early developmental expression profiles of immune- and iron-regulation-related genes in this chondrostean species.

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