High homology between a trophoblastic protein (trophoblastin) isolated from ovine embryo and α-interferons

AbstractOvine trophoblastic protein B (oTPB), an embryonic protein, is a 20 kDa secretory protein which is synthesized by the ovine conceptus from days 12 to 22 of pregnancy. oTPB was purified by HPLC using ion-exchange chromatography on a DEAE column and was subsequently chromatographed on a reversed-phase column. Automated Edman degradation was then used to determine the N-terminal amino acid sequence up to 45 residues. The sequence data reveal a significant homology between oTPB and bovine interferons α of class II: 64% of the amino acids are identical and 75% are homologous. A highly conserved region including residues 23–44 exhibits 82% homology. Identity between oTPB and either HuIFN-α.9 or MuIFNα. 1 is 55%. These alignments between oTPB and IFNs occur at the N-terminus of the mature proteins and proceed without deletion. These results suggest that oTPB is an embryonic interferon

Place de la microscopie dans l'etude des conditions de l'implantation chez les ruminants

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Le developpement embryonnaire normal avant l'implantation

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Blastocyst development and implantation

chap. 20International audienc

Developpement et implantation du blastocyste

chap. 20National audienc

Organisation cellulaire des cellules trophoblastiques dans l'élongation du conceptus ovin

International audienceWe present a computational approach to analyze the cellular organization during the elongation process of the ovine conceptus. First, we selected a set of mathematical descriptors to quantify cell geometry and cell neighborhood within the external epithelial layer of the conceptus: the trophoblast. Second, we established a hybrid image segmentation framework, and analyzed the extracted features with statistical tools to describe and compare the spatio-temporal dynamics of cellular organization within this epithelium. The main results indicated that the average geometry and neighborhood of the trophoblast cells are relatively stable from a sampling position to another and from a stage of development to another. Further, their elongation axes are randomly distributed. The cellular organization fits the Poisson's process. Moreover, no clustering structures or grid-like regular point patterns are found inside the studied cell population. This suggests that the trophoblast elongation observed in ruminants is not due to the geometrical change of cell shape but might be the consequence of cell addition associated with peculiar plans of cell division or intercalation.L'objectif de cette étude est une approche statistique de l'organisation cellulaire au cours de l'élongation du conceptus ovin. Nous avons sélectionné un ensemble de descripteurs mathématiques pour quantifier la géométrie et la topologie des cellules ainsi que des outils de la statistique spatiale permettant d'évaluer la dynamique spatio-temporelle d'organisation des cellules au niveau d'un tissu. Les analyses montrent une relative stabilité de la forme et de la topologie des cellules trophoblastiques au cours de l'élongation du conceptus. Aucune orientation particulière des cellules n'a pu être démontrée. L'organisation spatiale des cellules correspond bien à un processus de Poisson et aucune forme d'agrégation ou de dispersion régulière des cellules n'a été observée. Ceci suggère que l'élongation du conceptus observée chez les ruminants n'est pas due au changement des formes mais pourrait être la conséquence d'adjonction de cellules selon des plans de divisions particuliers ou des patrons coordonnés d'intercalation des cellules

Cellular localization of an embryonic interferon, ovine trophoblastin and its mRNA in sheep embryos during early pregnancy

International audienc

Co-expression of the proto-oncogene FOS (c-fos) and an embryonic interferon (ovine trophoblastin) by sheep conceptuses during implantation

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A hybrid segmentation framework using level set method for confocal microscopy images

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