The coronavirus membrane (M) protein acts as a dominant immunogen and is a major player in virus assembly. In this study, we prepared two monoclonal antibodies (mAbs; 1C3 and 4C7) directed against the transmissible gastroenteritis virus (TGEV) M protein. The 1C3 and 4C7 mAbs both reacted with the native TGEV M protein in western blotting and immunofluorescence (IFA) assays. Two linear epitopes, 243YSTEART249 (1C3) and 243YSTEARTDNLSEQEKLLHMV262 (4C7), were identified in the endodomain of the TGEV M protein. The 1C3 mAb can be used for the detection of the TGEV M protein in different assays. An IFA method for the detection of TGEV M protein was optimized using mAb 1C3. Furthermore, the ability of the epitope identified in this study to stimulate antibody production was also evaluated. An immunodominant epitope in the TGEV membrane protein endodomain was identified. The results of this study have implications for further research on TGEV replication.

Avian reovirus (ARV) infections pose a significant and evolving threat to China’s poultry industry, the world’s largest. Diverse farming systems—ranging from modern intensive operations to traditional waterfowl-poultry polyculture—foster a unique ecological niche for ARV, defined by complex serotypic and genotypic diversity, marked regional variations, potential interspecies transmission between chickens and waterfowl, and recurrent co-infections. Collectively, these factors undermine the efficacy of conventional diagnostic approaches. This review systematically outlines the current epidemic landscape of ARV in China, highlighting the molecular characteristics of prevailing strains (particularly those from waterfowl) and their roles in diagnostic evasion. We critically assess the performance and limitations of existing diagnostic techniques (virus isolation, ELISA, PCR/qPCR) within the Chinese epidemiological setting. Furthermore, we discuss innovative technologies—including multiplex qPCR, CRISPR-Cas systems, and next-generation sequencing (NGS)—that offer potential for developing next-generation diagnostics tailored to China’s specific challenges. Finally, we propose future directions, with an emphasis on standardization, data sharing, and interdisciplinary collaboration to bridge the gap between cutting-edge innovation and on-farm application for precise ARV control.