PRESENCE OF DIFFERENT COLLAGENS AND COLLAGEN MESSENGER-RNAS DURING EMBRYOGENESIS AND IN ADULT TISSUES OF THE SEA-URCHIN PARACENTROTUS-LIVIDUS

The presence of four different collagen genes had been previously desc ribed in the sea urchin genome and four different cDNAs had been clone d and sequenced. Two of them code for 140 and 300 KDaltons proteins, b elonging to the fibrillar collagens, and the other two families code f or two type IV collagens with a molecular weight of about 210 KDaltons . In this paper immunological evidence is provided for the presence in the developing P. lividus sea urchin embryo of at least seven major c ollagen proteins. Western blot analyses, carried out by means of speci fic polyclonal antibodies, show a series of collagenase sensitive band s, with molecular weights ranging from 55 to 200 KDaltons, which are p resent from eggs to plutei. Northern blot analyses show the presence o f the previously described 6 and 9 Kb RNA bands from oocytes till plut ei; in the later stages two other collagen RNAs are detected. The pres ence of two sets of coding for the 6 Kb mRNAs, differentially expresse d during development, is also discussed. Immunofluorescence histologic al analyses show the location of collagen in gonads, oocytes, eggs, em bryos and adult tissues.