Raw data from allantoic and amniotic fluids collected during gestation in ovine species.

Gestational success in ruminants depends on the maintenance of a dynamic maternal–fetal microenvironmentintrauterine microenvironment, resulting from complex interactions among the conceptus, extraembryonic membranes, maternal tissues,the maternal endometrium, and gestational fluids. This study performed a comparative and longitudinal proteomic characterization of allantoic and amniotic fluids throughout pregnancy in sheep, aiming to elucidate the molecular mechanisms involved in maternal–fetal communication and embryonic development. Samples of allantoic and amniotic fluids aseptically collected from extraembryonic compartments after uterine opening following animal slaughter,were collected directly from the uterus after animal slaughter and allocated into three gestational groups according to fetal development: early gestation (0–50 days; n = 6), mid gestation (50–100 days; n = 3), and late gestation (100–150 days; n = 5). After centrifugation and protein quantification using the Bradford method, standardized aliquots were subjected to in-solution protein digestion and analyzed by nano-LC–ESI-Q-TOF mass spectrometry. A total of 201 proteins were identified in the allantoic fluid and 159 proteins in the amniotic fluid, with five proteins showing significant differences across gestational stages. In the allantoic fluid, differentially abundant proteins included alpha-2-macroglobulin, gelsolin, basement membrane–specific heparan sulfate proteoglycan core protein, and alpha-globin chain. In the amniotic fluid, changes were observed in peroxiredoxin-2, mucin-5AC, fetuin-B, cystatin domain–containing protein, and globin domain–containing protein. Multivariate analyses revealed progressive remodeling of the fetal extraembryonic microenvironmentfetal microenvironment, associated with proteolytic control, tissue remodeling, redox homeostasis, epithelial protection, and metabolic processes. Collectively, these findings reinforce the active role of fetal extraembryonic fluids in gestational physiology and highlight their potential as sources of biomarkers associated with reproductive success in sheep.