Estudo fenotípico da região Aorta-Gônada-Mesonefros, de embriões de galinhas Gallus gallus domesticus, com ênfase na aorta dorsal

Abstract

Nowadays it is known that firsts definitive hematopoietic progenitors arise from endothelium differentiation of dorsal aorta, at Aorta-Gonad-Mesonephros (AGM) site. In order to study those events and cells phenotype of dorsal aorta endothelium in this topographical site, fertilized eggs of Gallus gallus domesticus L. were incubated, from E16 to E25 and to be processed by histotechonology to obtain serial sections of the AGM site. After this, they were stained with Hematoxilin-Eosin, histochemistry to PAS, diastase PAS and Alcian Blue pH 1.0 and pH 2.5, to obtain a better overview and characterization from cells, also, histochemistry to fluorescein lectins and immunofluorescense to surface molecules, cytoeskeleton andextracellular matrix were performed. Our results showed endothelial hypertrophy of the aorta floor in the stages analyzed, which shown positive for PAS, with frequent appearance of PAS negatives basal vacuolizations and an occasional intravascular cell clusters arise of. It was also observed that cells which were separated from endothelium basal membrane shown progressively were more PAS positive which however in any time seems to be glycogen. Regard of glycosaminoglycans we noted the main presence of hialuronic acid for all the mesenchyme s site and in others structures like notochord periphery, neural tube and lateral mesoderm. It was observed fibronectin and smooth muscle α-actin co-expression on aorta surrounding walls, at vessel s ventral face. GFAP and BMP-4 are express between the cells of neural tube and surrounding it, as well as at embryo notochord. The lectins Abrus precatorius, Lens culinaris and Ricinus communis showed mostly positive expression on the sub endothelium site of the dorsal aorta floor at the stages analyzed in this work. Bandeiraea simplicifolia showed low expression on dorsal aorta and in Arachis hypogeae it was negative. Other structures of AGM s site also expressed sugar residues revealed by these lectins like: notochord, neural tube, mesenchyme, primitive gut and yolk sac.