AMPHIBIAN PLEURODELES-WALTL FIBRONECTIN - CDNA CLONING AND DEVELOPMENTAL EXPRESSION OF SPLICED VARIANTS

Partial cDNA clones encoding approximately the carboxy terminal half o f Pleurodeles fibronectin (FN) were isolated. They account for 4.7 Kbp of the 3' region of the FN mRNA. The cDNA nucleotide sequence compris es all three alternatively spliced segments designated EIIIA, EIIIB an d V-segment, respectively. All three segments are included in FN mRNA synthesized during early embryogenesis whereas, from the tailbud stage onward the V-region was partially excluded. The isolation of Pleurode les cDNA clones including the three different spliced EIIIA, EIIIB and V segment raises new possibilities for the study of the precise role of specific regions of FN in early amphibian development.