RT Conference Proceedings T1 Poster 2 - Quantification of the extracellular vesicles and progesterone levels in boar sperm commercial AI doses. A1 Álvarez Rodríguez, Manuel A1 Vicente Carrillo, Alejandro A1 Gala, Nerea A1 Martinez Alborcia, Maria José A1 Nieto Cristobal, Helena A1 De Mercado, Eduardo AB Abstract Commercial boar sperm artificial insemination (AI) doses contain seminal plasma (SP) and its components: extracellular vesicles (EVs) and progesterone (P4), modulating intracellular calcium, acrosome reaction and motility patterns. In this study, we aimed to quantify the concentration of EVs and P4 levels in commercial AI doses. Twenty homospermic AI-doses from animals with good fertility outcomes (Large White, LW; n=10 and Swedish Landrace, LD; n=10) diluted to 2.4×109 total spermatozoa/dose (80 mL; Magapor, Zaragoza, Spain), were centrifuged at 1500×g for 10 min (twice) to recover a sperm-free supernatant. The analysis of sperm motility, kinetics and morphology was performed by using the IA Station (SPERMTECH). P4 levels (ng/µL) were assessed using a species-specific (porcine) ELISA kit (P4-DE1561, Demeditec Diagnostics GmbH, Germany), by analyzing 25 µL of SP. Two hundred fifty µL of the SP-supernatant were used for EVs isolation (EQULTRA-20A-1, System Biosciences) and quantification (EXOCET96A-1, System Biosciences). Parametric data (mean ± standard error of the mean, SEM) were analyzed through a t-test and Pearson correlation (GraphPad Prism 8), the significance levels being set at P sensitive enough to detect changes due to the season or storage, and they could be differently and independently affected by these factors. Further research will focus on determining the usefulness of these parameters in discriminating boars. Supported by RTI2018-095183-B-I00 and DIN2020-011558 funded by MCIN/AEI/10.13039/ 501100011033, by “ERDF A way of making Europe” and “European Union NextGenerationEU/PRTR”, and LE023P20 funded by Junta de Castilla y León (Consejería de Educación/ERDF, EU). M. Rojo received a Collaborator Grant (Ministry of Education, Spain). Thanks to AIM/Topigs-Norsvin, M. de Prado and G. Rivas SN 0378-4320 YR 2025 FD 2025 LK https://hdl.handle.net/20.500.14352/124159 UL https://hdl.handle.net/20.500.14352/124159 LA eng NO Álvarez-Rodríguez, M., Vicente-Carrillo, A., Gala, N., Martinez-Alborcia, M: J., Nieto-Cristobal,H., de Mercado,E. (2025) Poster 2 - Quantification of the extracellular vesicles and progesterone levels in boar sperm commercial AI doses, Animal Reproduction Science, V. 278, Supplement, 107907. https://doi.org/10.1016/j.anireprosci.2025.107907. DS Docta Complutense RD 17 dic 2025