Cleofina Elsa Bosco



The caviomorph rodent, O. degus posseses a special structure related to the placenta, called subplacenta (SP).  SP is composed only of cytotrophoblast (CT) cells. Previous data indicates that placentation in this species is similar to that in humans regarding the migration of the extrasubplacental-trophoblast (EST) to the uterine arteries.  The aim of this paper was to determine the origin of the placental barrier fine syncytium (FS), the origin of the coarse syncytium (CS), and to establish the presence of syncytial knots that will be deported to the maternal blood.

Eight pregnant degus were divided into two groups: day 27 and 84 of gestation, and their placentas were processed for histological analysis at optical and electron microscopy levels. Our results show that at day 27 the FS emerged from the central-basal zone of the SP and that the CS emerged from the inferior-lateral zone of the SP.  At pregnancy term, we evidenced the presence of syncytial knots in the FS that will be deported to the maternal space, as has been demonstrated to occur in humans and chinchilla. In this way, O. degu can be considered a potential animal model for studies related to human placental pathologies.

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