biostudies-literatureUnknown29Yu YCoccidiosis, which is primarily caused by Eimeria spp., poses a persistent challenge to poultry health and production worldwide. The emergence and spread of drug-resistant strains have significantly compromised the efficacy of anticoccidial therapies. We previously used RNA-seq to demonstrate that ribosomal protein L27 is differentially expressed in drug-sensitive and maduramicin-resistant strains of E. tenella (EtRPL27). In the present study, an RT-qPCR analysis showed that its expression is stage-specific, with the highest levels in sporozoites and second-generation merozoites. Immunofluorescence revealed both the cytoplasmic and partial surface localization of EtRPL27. Notably, EtRPL27 transcript levels were significantly elevated in a maduramicin-resistant strain relative to the drug-sInternational journal for parasitology. Drugs and drug resistance100615https://www.ebi.ac.uk/biostudies/studies/S-EPMC12509730biostudies-literatureRibosomal protein L27 contributes to virulence and maduramicin resistance in Eimeria tenella.PMC12509730Huilin GGuan GDong HZhao QZhao FHan HLi LWang JYu YZhu SfalseRibosomal protein L27 contributes to virulence and maduramicin resistance in Eimeria tenella.Coccidiosis, which is primarily caused by Eimeria spp., poses a persistent challenge to poultry health and production worldwide. The emergence and spread of drug-resistant strains have significantly compromised the efficacy of anticoccidial therapies. We previously used RNA-seq to demonstrate that ribosomal protein L27 is differentially expressed in drug-sensitive and maduramicin-resistant strains of E. tenella (EtRPL27). In the present study, an RT-qPCR analysis showed that its expression is stage-specific, with the highest levels in sporozoites and second-generation merozoites. Immunofluorescence revealed both the cytoplasmic and partial surface localization of EtRPL27. Notably, EtRPL27 transcript levels were significantly elevated in a maduramicin-resistant strain relative to the drug-s2025-01-01T00:00:00Z2025 Sep2026-06-04T09:20:24.203Z2026-05-07T03:12:55.31ZS-EPMC125097304100493310.1016/j.ijpddr.2025.100615