The Asian swamp eel (
Monopterus albus
) is one of the most economically important freshwater fish in East Asia, but data on the immune genes of
M. albus are scarce compared to other commercially important fish. A better understanding of the eel's immune responses may help in developing strategies for disease management, potentially improving yields and mitigating losses. In mammals, interferon regulatory factors (IRFs) play a vital role in both the innate and adaptive immune system; though among teleosts
IRF4 and
IRF10 have seldom been studied. In this study, we characterized
IRF4 and
IRF10 from
M. albus (
maIRF4 and
maIRF10) and found that
maIRF4 cDNA consists of 1 716 nucleotides encoding a 451 amino acid (aa) protein, while
maIRF10 consists of 1 744 nucleotides including an open reading frame (ORF) of 1 236 nt encoding 411 aa. The
maIRF10 gene was constitutively expressed at high levels in a variety of tissues, while
maIRF4 showed a very limited expression pattern. Expression of
maIRF4 and
maIRF10 in head kidney, and spleen tissues was significantly up-regulated from 12 h to 48 h post-stimulation with polyinosinic: polycytidylic acid (poly I:C), lipopolysaccharide (LPS) and a common pathogenic bacteria
Aeromonas hydrophila
. These results suggest that IRF4 and IRF10 play roles in immune responses to both viral and bacterial infections in
M. albus.