Placental glycotype of the caviomorph rodent Lagostomus maximus and its evolution within Eutheria

Abstract

The main evolutionary milestone in the oviparity-viviparity transition is placentation.The placenta is an organ with great morphological diversity among eutherians. The expression of different glycosidic residues (Gr) in the near-term placenta constitutes its glycotype. In this study, the expression of different Gr was determined by lectin histochemistry in early, midterm, and near-term placentas of the plains viscacha (Lagostomus maximus), a caviomorph rodent with the highest poliovulatory rate and embryonic resorption rate among eutherians. Besides, a matrix with the expression of each Gr in the exchange trophoblast of viscacha and other eutherians was constructed to map and infer phylogenetic and evolutionary relationships. Between early, midterm, and near-term placentas, variations in the pattern expression of Gr were observed. The glycotype of the near-term placenta is composed of a high diversity of Gr. Reconstruction of the ancestral state for each Gr present in the nearterm placenta showed a diverse scenario: some sugars were common to the species of Placentalia included in this study. In the analyzed species with synepitheliochorial and epitheliochorial placentas, no differential glycosylation patterns between them were observed. In species with invasive placentas, such as the endotheliochorial placentas of Carnivora, some common Gr were detected among them, while others were species-specific. In species with hemochorial placenta, the same Gr are shared.Particularly, in the viscacha greater differences with species of the Hominidae and even Muridae families were observed. Nevertheless, greater similarities with other caviomorph rodents were detected. Placental glycotype of each species constitutes an excellent tool to achieve phylogenetic and evolutionary inferences among eutherians.

Term alpaca placenta glycosylation profile and its correlation with pregnancy maintenance and fetal survival

“…In the human trophoblastic basement membrane, the expressed mannose (positive by Con A, LCA) and galactose (strongly positive by ECL, RCA 120 ) were evident; however, they did not react with lectins from the GlcNAc group or the fucose-lectin group. Finally, Acuña et al (2023) indicated that WGA positivity is the ancestral condition for Placentalia.…”

“…Glycosylated residues of α-mannose and α-glucose that bind to Con A are presented in the placental vessel endothelium in swine and a coinciding result with that found in human placentas from normal pregnancy, demonstrating mild expression of α-mannose in placental vessels ( Jones et al, 1997 ). Con A positivity is the plesiomorphic condition for Placentalia and is preserved in all species ( Acuña et al, 2023 ).…”

“…This result differs from our study in alpacas, in which a very strong labeling was present in fetal blood capillaries, suggesting the importance of this e-PHA lectin during labor in the mentioned species. e-PHA positivity is the ancestral condition for Placentalia and is preserved in species except for Lama glama ( Acuña et al, 2023 ).…”

“…This difference in the glycosylation profile is more evident in chorionic cells, varying during different gestational stages in camelids, such as alpaca and camels, other domestic animals, and in humans ( Majewska et al, 2011 ). The expression of glycosidic residues shows the evolutionary history of the placenta among eutherians and the phylogenetic relationships between species of different taxa ( Acuña et al, 2023 ).…”