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D Hernandez-Verdun

Publications and source records attributed to D Hernandez-Verdun.

83 records · Page 5Linked to original sources
PubMed1979

Localization of a gene: the nucleolar organizer.

Nucleolus differentiates around the nucleolus organizer regions of the chromosomes or NORs. In the interphasic nucleoli the fibrillar centers are now considered as the NORs. The purpose of this editorial is to review the experimental data which allowed such identification. Our current concepts regarding this point result from three lines of evidence: 1) specific localization during nucleologenesis, 2) in situ hybridization with labeled ribosomal RNA or DNA, and 3) specific staining with silver.

Cell Cycle↗
PubMed1978

[Ultrastructural identification of the nucleolus organizer by the silver staining technic].

The nucleolus organizer regions can be selectively stained in metaphase chromosome preparations by the Goodpasture and Bloom's technique which was adapted to electron microscopy analysis of cells during interphase. Using this technique, a selective accumulation of silver grains was observed over nucleolus light areas. This selective accumulation allows the identification of the interphase fibrillar centers as the nucleolus organizer regions. Ultrastructural relationships between fibrillar centers and dense fibrillar component are discussed.

Cell Nucleolus↗
PubMed1975

In vitro study of chorionic and ectoplacental trophoblast differentiation in the mouse.

Mouse chorioallantoic pre-placental structures alone or in association with the embryo were explanted during the 9th day of gestation (7-somite stage) and cultured in a static medium for 24 to 48 h. From the subsequent morphological study of trophoblast differentiation, using both light and electron microscopy, we draw the following conclusions. 1. The allantoic mesoderm cells migrate inside the trophoblastic population but they do not differentiate a capillary network and trophoblast cells phagocytose the existing foetal erythrocytes. 2. In the absence of allantoic mesoderm, chorionic trophoblast cells remain undifferentiated. 3. The development of the chorionic trophoblast is modified in that chorionic trophoblast cells fail to establish close junctions with ectoplacental trophoblast, and some chorionic cells initiate the formation of multinucleated syncytia. The genesis of these syncytia is discussed.

Animals↗