SUBCELLULAR-LOCALIZATION OF CATALASE IN SEA-URCHIN (TETRAPIGUS-NIGER)GAMETES - IMPLICATIONS FOR PEROXISOME BIOGENESIS

Peroxisomes are essential subcellular organelles that appear to be der ived from pre existing organelles. To test the presence of peroxisomes in sea urchin (Tetrapigus niger) sperm and eggs, we performed biochem ical and morphological experiments to evaluate the subcellular distrib ution of catalase as the typical peroxisomal marker. In sea urchin spe rm, we found that catalase is localized in the cell cytosol. In contra st, sea urchin eggs contain sedimentable catalase, presumably containe d in peroxisome-like structures detected by immunomicroscopy and by cy tochemistry. Our results show, for the first time, evidence for the pr esence of peroxisome-like structures in sea urchin eggs and provide ev idence for the peroxisome biogenesis hypothesis by division of preexis ting organelles. (C) 1997 Elsevier Science Inc.