title: Respiration capacity of mitochondria isolated from unfertilized and fertilized sea urchin eggs.
abstract: Mitochondria were isolated from unfertilized and fertilized eggs of the sea urchin, Strongylocentrotus purpuratus. Both preparations exhibited coupled adenosine 5'-diphosphate (ADP)-dependent) oxidation of flavin and pyridine-linked substrates and both yielded the expected P:O ratios with these substrates. Highest respiratory control indices (greater than 4.0) were observed when succinate or pyruvate + malate were used as substrates. Mitochondria from unfertilized and fertilized eggs exhibited sensitivity to respiratory and phosphorylation inhibitors and uncouplers and both preparations exhibited cross-over points at sites I, II and III of the respiratory chain. Low-temperature difference spectra revealed a normal complement of cytochromes c, b and aa3, although cytochrome c from unfertilized eggs appears to be more subject to extraction during the course of mitochondrial isolation than does cytochrome c from fertilized eggs. An unidentified pigment absorbing at approx. 570 nm was visible in low-temperature spectra of unfertilized eggs and unfertilized egg mitochondria.
mesh_terms: D000818:Animals; D002458:Cell Fractionation; D003580:Cytochromes / Q000378:metabolism; D005260:Female; D008297:Male; D008928:Mitochondria / Q000378:metabolism* / Q000648:ultrastructure; D010063:Ovum / Q000378:metabolism*; D010101:Oxygen Consumption; D012617:Sea Urchins; D015053:Zygote / Q000378:metabolism*
chemical_list: D003580:Cytochromes