Different seminal ejaculated fractions in artificial insemination condition the protein cargo of oviductal and uterine extracellular vesicles in pig

The seminal plasma (SP) is the liquid component of semen that facilitates sperm transport through the female genital tract. SP modulates the activity of the ovary, oviductal environment and uterine function during the periovulatory and early pregnancy period. Extracellular vesicles (EVs) secreted in the oviduct (oEVs) and uterus (uEVs) have been shown to influence the expression of endometrial genes that regulate fertilization and early embryo development. In some species, semen is composed of well-separated fractions that vary in concentration of spermatozoa and SP composition and volume. This study aimed to investigate the impact of different accumulative fractions of the porcine ejaculate (F1, composed of the sperm-rich fraction, SRF; F2, composed of F1 plus the intermediate fraction; F3, composed of F2 plus the post-SRF) on oEVs and uEVs protein cargo. Six days after the onset of estrus, we determined the oEVs and uEVs size and protein concentration in pregnant sows by artificial insemination (AI-sows) and in non-inseminated sows as control (C-sows). We also identified the main proteins in oEVs and uEVs, in AI-F1, AI-F2, AI-F3, and C-sows. Our results indicated that although the size of EVs is similar between AI- and C-sows, the protein concentration of both oEVs and uEVs was significantly lower in AI-sows (p < 0.05). Proteomic analysis identified 38 unique proteins in oEVs from AI-sows, mainly involved in protein stabilization, glycolytic and carbohydrate processes. The uEVs from AI-sows showed the presence of 43 unique proteins, including already-known fertility-related proteins (EZR, HSPAA901, PDS). We also demonstrated that the protein composition of oEVs and uEVs differed depending on the seminal fraction(s) inseminated (F1, F2, or F3). In conclusion, we found specific protein cargo in oEVs and uEVs according to the type of semen fraction the sow was inseminated with and whose functions these specific EVs proteins are closely associated with reproductive processes

Artificial insemination of all ejaculated sperm fractions accelerates embryo development and increases the uterine vascularity in the pig

© 2024 The Authors. This manuscript version is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by/4.0/ This document is the Published version of a Published Work that appeared in final form in Theriogenology. To access the final edited and published work see https://doi.org/10.1016/j.theriogenology.2024.02.017The semen of boar is characterized by ejaculation in well-differentiated fractions with specific concentration, composition, and volume. The ‘sperm-rich fraction' (SRF), the most concentrated seminal fraction, is habitually collected in insemination centers to make artificial insemination (AI) doses. The absence of the other fractions in AI doses could alter the uterine reaction to AI and not trigger essential responses that could maximize fertility. Thus, there is an urge to ascertain the impact of different ejaculate fractions on the uterus after AI to optimize the semen doses. This work analyzed specific parameters related to fertility in pregnant artificially inseminated sows (n = 15) with ac-cumulative fractions of the semen of boars (n = 6): F1, composed of the sperm-rich fraction (SRF); F2, composed of F1 plus the intermediate fraction; F3, composed of F2 plus the post-SRF. Non-inseminated sows (n = 5) were included as control (C). The different types of seminal dose did not affect the number of ovulated follicles (CL; corpora lutea, p > 0.05) but did affect the embryo development (p 0.05). Independently of the type of seminal dose (F1, F2, or F3), we observed by immunohistochemistry that AI significantly increased uterine vascularization, although with some anatomical differences. The cranial region of the uterine horns was significantly more vascularized in AI-F1 or AI-F2 sows (26.7 ± 2.3 and 28.6 ± 2.0%, respectively), and AI-F3 showed significantly less vascularization at that point (17.8 ± 1.6%, p < 0.05). To summarize, the synergistic effect of all ejaculate fractions accelerates embryo development, at least during the preimplantation period, and increases the uterine reaction to AI in certain parts of the uterus

Perception of stress by students who teach guided practices in Veterinary Physiology

Resúmenes IV Congreso VetDoc de Docencia Veterinaria, León 2017 (6-7 de Julio)[ES] Desde el curso 2010-11, empleamos en las asignaturas Fisiología Veterinaria I y II las prácticas guiadas o dirigidas como recurso docente. Esta actividad permite al estudiante profundizar en la comprensión de los conceptos de la asignatura de Fisiología y desarrollar otras competencias transversales como la expresión oral, la organización del tiempo, el trabajo en equipo, uso de recursos audiovisuales, etc. Sin embargo, el “estudiante-profesor” que imparte la práctica asume un rol en el que no tiene experiencia y el aumento en su nivel de ansiedad puede tener un impacto negativo en la realización de esta actividad

EFECTO DEL PROTOCOLO DE PREPARACIÓN DE LOS ESPERMATOZOIDES BOVINOS SOBRE EL PATRÓN DE REACCIÓN ACROSÓMICA

The acrosome reaction of bovine frozen-thawed semen samples, under different preparation processes, was analysed by the lectin binding staining. The addition of heparin and caffeine to the medium significantly increased the number of sperm with acrosome reaction. When sperm was selected by the use of a Percoll gradient column, the process of acrosome reaction was accelerated. These data confirm that the sperm preparation for the in vitro fertilisation has an effect on the capacitation and acrosome reaction pattern, and it could be determinant for the fertilisation process.En este trabajo se ha analizado el proceso de reacción acrosómica mediante la tinción con lectinas de muestras de semen bovino congelado que han sido sometidos a diferentes tratamientos de preparación. La adición de heparina y cafeína supone un aumento significativo del número de espermatozoides con los acrosomas reaccionados. Al seleccionar los espermatozoides en un columna de Percoll se acelera el proceso de reacción acrosómica. Estos datos confirman que la preparación de los espermatozoides para la fecundación in vitro afecta al patrón de capacitación y reacción acrosómica, de manera que pueden ser determinantes para el proceso de fecundación