In JoVE (1)

Other Publications (2)

Articles by M. Angélica Bello in JoVE

 JoVE Biology

Scanning Electron Microscopy (SEM) Protocols for Problematic Plant, Oomycete, and Fungal Samples

1Biodiversity and Conservation Department, Real Jardín Botánico, CSIC, 2Research Support Unit, Real Jardín Botánico, CSIC, 3Mycology Department, Real Jardín Botánico, CSIC, 4Division of Glycoscience, AlbaNova University Center, Royal Institute of Technology (KTH)

JoVE 55031

Other articles by M. Angélica Bello on PubMed

Placentation in the Degu (Octodon Degus): Analogies with Extrasubplacental Trophoblast and Human Extravillous Trophoblast

Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology. Apr, 2007  |  Pubmed ID: 16448832

This study examined the placentation in the degu, the origin of the extrasubplacental trophoblast (EST) (extravillous trophoblast in human), and the activity of Na+/K+ ATPase in the placental barrier during different gestational ages, as part of a wider effort to understand the reproductive biology of this species. Fifteen degus at the first stage of gestation, midgestation and at term of pregnancy were studied. At day 27 of gestation, the subplacenta is formed under the wall of the central excavation. Simultaneously, the outermost trophoblast of the ectoplacental cone differentiated into secondary trophoblast giant cells that lie on the outside of the placenta, forming an interface with the maternal cells in the decidua. These giant cells immunostained positive for cytokeratin (CK) and placental lactogen (hPL) until term. During this period, the EST merged from the subplacenta to the decidua and immunostained negative for CK, but at term, immunostained for CK and hPL in the maternal vessels. The vascular mesenchyme of the central excavation invaded the chorioallantoic placenta during this period, forming two fetal lobules of labyrinthine-fine syncytium, the zone of the placental barrier. The activity of Na+/K+ ATPase in the placental barrier was constant during the gestational period. The residual syncytium at the periphery of the placental disc and between the lobules was not invaded by fetal mesenchyme and formed the marginal and interlobular labyrinthine syncytium that immunostained first for CK, and later for hPL, as in the labyrinthine fine syncytium. The presence of intracytoplasmic electron-dense material in the interlobular labyrinthine syncytium suggested a secretory process in these cells that are bathed in maternal blood. Placentas obtained from vaginal births presented a large, single lobe, absence of the subplacenta, and a reduced interlobular labyrinthine syncytium. At day 27, the inverted visceral yolk sac is observed and its columnar epithelium immunostained for CK and hPL. This suggests that the yolk sac is an early secretory organ. The epithelium of the parietal yolk sac covers the placenta. The origin of the EST in the degu placenta and its migration to maternal vessels allows us to present this animal model for the study of pregnancy pathologies related to alterations in the migration of the extravillous trophoblast.

Floral Development and Evolution of Capitulum Structure in Anacyclus (Anthemideae, Asteraceae)

Annals of Botany. Nov, 2013  |  Pubmed ID: 23287557

Most of the diversity in the pseudanthia of Asteraceae is based on the differential symmetry and sexuality of its flowers. In Anacyclus, where there are (1) homogamous capitula, with bisexual, mainly actinomorphic and pentamerous flowers; and (2) heterogamous capitula, with peripheral zygomorphic, trimerous and long-/short-rayed female flowers, the floral ontogeny was investigated to infer their origin.

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