The placenta of Galea musteloides (Caviomorpha): morphology and development

Abstract

The placental morphology of caviomorph rodents is closely related to the growth and development of precocial offspring. This study describes the placental morphology and histochemistry of the cuis Galea musteloides at three gestational stages, using material from a mammalogical collection. The placenta of G. musteloides is discoidal, lobulated and hemomonochorial. The main placenta and the subplacenta differentiate early during gestation. Changes potentially associated with embryonic/fetal growth and development were observed, including shifts in the relative proportions of the main placental components, remodelling of the maternal–embryonic/fetal barrier, and predominance of syncytiotrophoblast towards term. The yolk sac lacked a capsule and exhibited features consistent with substance exchange, and, together with the glands of the non-decidualised endometrium, showed temporal variations in the expression of specific glycosidic residues. The placentation of G. musteloides conforms to the caviomorph placental bauplan, although genus-level peculiarities were identified. This study expands current knowledge of the reproductive characteristics of the species and highlights placental plasticity throughout gestation. Moreover, it underscores the scientific value of biological collections for conducting diverse types of studies without the need to sacrifice new specimens.