Transcriptional Profiling of Common Carp: A Microarray-Based Framework for Aquaculture Research

The common carp Cyprinus carpio L. is a cornerstone aquaculture species, yet transcriptome interpretation is complicated by its paleotetraploid genome and extensive alternative splicing. A species-tailored oligonucleotide microarray was developed to deliver reproducible, gene-level expression profiling. Probe design was anchored to the SPL01 reference and implemented on an Agilent platform using a gene-level strategy that collapsed transcripts to genes, selected the longest isoform, and placed 3'-anchored 60-mer probes. The workflow incorporated embedded technical controls and a standardized two-color pipeline to ensure stable measurements across arrays. Baseline functional organization of the head kidney was defined using 614 C. carpio L. -Danio rerio orthologs and complementary enrichment tools. Coherent signatures emerged for hemoglobin-mediated oxygen transport, heme and porphyrin metabolism, antioxidant defense driven by peroxiredoxin and thioredoxin systems, including hydrogen peroxide detoxification, protease regulation through SERPIN, SPINK, and WFDC families, and elements of innate and humoral immunity. Targets bearing c-Myc motifs showed a modest positive bias consistent with ongoing hematopoiesis. These resolved baseline modules provide a reference against which infection- or exposure-induced programs such as interferon-stimulated genes, chemokines and chemotaxis, complement activation, and degranulation can be detected and quantified. The platform complements RNA-seq by offering cost-efficient, rapid, and comparable measurements suited to large cohorts and longitudinal designs. Anticipated applications include host-pathogen studies for viral and bacterial agents and the assessment of chemical contaminants in aquaculture surveillance, supporting standardized, cross-study decision-making in research and health monitoring.