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kfas, vol. 57, no. 3, pp.239-252, June, 2024 DOI. https://doi.org/10.5657/KFAS.2024.0239

Molecular Characterization and Ontogenetic Expression Patterns of

Recombination Activating Genes (RAG1/2) in Marine Medaka Oryzias

dancena

김태수·박주환·남윤권·김찬희*
국립부경대학교 수산생명과학부 양식응용생명과학전공

ABSTRACT

Recombination activating genes (RAGs) play a crucial role in initiating V(D)J recombination, which is essential for developing adaptive immunity in vertebrates. In this study, we cloned and characterized RAG1/2 cDNA from the marine medaka Oryzias dancena (OdRAG1/2) and investigated their mRNA expression patterns during ontogenetic developmental stages. The OdRAG1 and OdRAG2 cDNA contained open reading frames (ORFs) encoding proteins containing 1,078 and 531 amino acids, respectively. Multiple sequence alignment and phylogenetic analysis revealed that OdRAG1 and OdRAG2 are highly conserved with their corresponding orthologs, featuring distinct core and noncore regions. Notably, expression analysis showed that, in contrast to other fish RAGs studied, OdRAG1/2 expression peaked at 0 days post-hatching (DPH). Additionally, for the expression of T and B cell differentiation markers, CD3γ and CD20, also peaked at 0 DPH. Collectively, adaptive immunity in O. dancena potentially begins during embryonic development, which is critical for V(D)J recombination and essential immune component development, suggesting the early ontogenetic stage interactions between innate and adaptive immunity.
Keyword

Recombination activating genes (RAGs), Gene expression, Ontogeny, Oryzias dancena, Immune system