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F V Jotereau

Publications and source records attributed to F V Jotereau.

10 recordsLinked to original sources
PubMed1987

Evidence for a cyclic renewal of lymphocyte precursor cells in the embryonic chick thymus.

Experiments involving sequential transplantations of the chick embryonic thymus at E9 to E12 into a first 3-day host quail embryo and then into a second chick host allowed demonstration of the cyclic periodicity of hemopoietic cell seeding of the embryonic thymus. After a first wave of colonization occurring between E6.5 and E8, the thymus becomes refractory to hemopoietic cell entry for about 4 days. It resumes its capacity to be seeded by a second wave of blood-borne stem cells at E12. After a second period of non receptivity starting at E14, a third wave of incoming cells reaches the thymus around E18. Therefore, with a slightly different periodicity, the same cyclic mechanism regulates the renewal of lymphocytes in chick and quail embryos. Quail hemopoietic cells were immunostained in the chimeric thymuses, with a species specific monoclonal antibody (anti-MB1) which recognizes a common surface antigenic determinant on all endothelial and blood cells of the quail (except erythrocytes). Two steps could thus be distinguished in the seeding process. When the thymus becomes receptive for hemopoietic cells, the latter first accumulate in the intrathymic blood vessels before penetrating massively in the thymic parenchyma. The quail chick-chimera system combined with the use of a species- and cell-type-specific antibody provides a unique tool for studying thymic colonization by lymphocyte precursors.

Animals↗
PubMed1985

Tissue distribution and ontogenic appearance of a chicken T lymphocyte differentiation marker.

A monoclonal antibody, designated T10A6, was produced by immunizing mice with H.B14 chicken thymocytes. T10A6, when tested by immunofluorescence, labeled 80% of thymocytes, and a subset of peripheral T cells: 20% of spleen leukocytes, 10% of blood leukocytes, 8% of bone marrow cells but less than 1% of bursal lymphocytes. Tissue distribution on polyethylene glycol sections showed that in the thymus T10A6 stained most cortical thymocytes and a portion of medullary cells. In the spleen, the positive cells appeared scattered mainly in the T-dependent areas. Ontogenic studies revealed that the antigen recognized was found in the chick embryo thymus from day 11 onward and the expression of this antigen on thymocytes reached the adult level from day 13. The first positive cells were detected in the spleen on day 13 of embryonic life. T10A6 (IgG1) precipitated a 65-kDa material from thymocytes. This is the first description of a monoclonal antibody recognizing a peripheral T cell subpopulation in chicken.

Animals↗
PubMed1975

Tracing of cells of the avian thymus through embryonic life in interspecific chimeras.

Differences in the structure of the interphase nucleus between two species of birds, the Japanese quail (Coturnix coturnix japonica) and the chick (Gallus gallus) has been used to distinguish cells from different origins in interspecies combinations. This biological cell marking technique was applied to thymus histogenesis. Using various combinations between components of quail and chick thymic rudiments, the respective contribution of endodermal epithelium, mesenchyme, and blood-borne extrinsic elements to the histogenesis of thymus was analyzed. It was demonstrated that the whole lymphoid population of the thymus is derived from immigrant blood-borne stem cells which are chemically attracted by the endoderm of the 3rd and 4th pharyngeal pouch. The latter is determined to differentiate into thymic epithelial reticulum as soon as the 15-somite stage, and is able to attract blood stem cells even when transplanted in an heterotopic position such as the ventral body wall of the embryo. It was shown that the thymic mesenchyme originates from the neural crest mesectoderm which colonizes early the 3rd and 4th branchial arches. It participates in the formation of perivascular mesenchyme, but does not give rise to lymphocytes. From heterospecific transplantations of quail thymuses into chick embryo (and inversely) at various stages of development is appeared that the thymic rudiment becomes attractive for lymphoid stem cells at a precise stage of its evolution for each species. The attractivity period lasts about 24 h for the quail and 36 h for the chick. Then, the inflow of stem cells becomes very low until the end of the incubation period. At this time, a second wave of lymphocytoblasts invades the thymus and the primitive embryonic lymphoid population is completely renewed around the hatching time. Competent thymic stem cells are present in the blood before and after the period of physiological thymic attractivity. The identity of basophilic cells appearing in the thymus during its histogenesis and lymphoid stem cells has been demonstrated from the analysis of quail-chick chimeric thymuses.

Animals↗
PubMed1975

Origin of hemopoietic stem cells in embryonic bursa of Fabricius and bone marrow studied through interspecific chimeras.

The histogenesis of the bursa of Fabricius and of bone marrow was studied by a biological cell marking technique based on differences in the nuclear structure of two species of birds, Japanese quail (Coturnix coturnix japonica) and chick (Gallus gallus). In quail cells the nucleus contains a large amount of heterochromatin associated with the nucleolus. That makes it possible to distinguish them from chick cells after Feulgen-Rossenbeck staining and by electron microscopy. By grafting bursal rudiments and limb buds of quail into chick and inversely it was possible to demonstrate that the whole hemopoietic population of the bursa of Fabricius and of bone marrow is derived from bloodborne extrinsic stem cells. Neither endoderm nor mesoderm of the bursal rudiments is capable of differentiating into lymphoid cells. Combinations of quail bursal endoderm with chick homologous mesenchyme showed that the reticular cells of the follicles are the only endodermal derivatives of the bursa. The mesenchymal bursal component gives rise to the interfollicular connective cells. The contribution to bone marrow histogenesis of cells of vascular and blood origin, on one hand, and of the elements of the cartilaginous model, on the other hand, was analyzed. It appeared that osteoblasts, osteocytes, and stromal cells of marrow are derived from the perichondrium. In contrast, the endothelium of the vascular buds and the hemopoietic cells which invade the diaphysal cartilage during the endochondral ossification process do not belong to the mesenchymal bone primordium but have a fully extrinsic origin.

Animals↗
PubMedDate not supplied

Ontogeny of the avian thymus and bursa of Fabricius studied in interspecific chimeras.

Differences in the structure of the interphase nucleus between two species of birds, the Japanese quail (Coturnix coturnix japonica) and the chick (Gallus gallus) have been used to distinguish cells from different origins in interspecies combinations. This biological cell marking technique was applied to thymus and bursa of Fabricius histogenesis. Using various combinations between components of quail and chick thymic and bursic rudiments, the respective contribution of endodermal epithelium, mesenchyme and blood-borne extrinsic elements to the histogenesis of thymus and bursa was analyzed. It was demonstrated that the whole lymphoid population in these organs is derived from immigrant blood-borne stem cells. Thymus and bursa become attractive for stem cells at a precise stage of their development. In thymus the attractive period last about 24 hours in the quail and 36 hours in the chick. In the bursa of Fabricius the invasion lasts several days in both quail and chick embryos. The mechanisms which control the onset and the interruption of the stem cells inflow have been investigated.

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