104 



PIERRE H. GONSE 



Fig. 2. Difference spectra of Spisula spermatozoa at 25 °C. Cells in 

 SW-GG, pH 7.3, 37 X 10 s cells/ml. Sample S9. Solid line: (anaerobic) - 

 (aerobic, Amytal 10 mM). Dashed line: (anaerobic, CO) — (anaerobic). 



chrome c x absorption stands out at 554 itua. Cytochrome b absorption 

 bands are found at 562 ni/x and 430 m/A, while cytochrome b(d) ab- 

 sorbs at 564 m/A. A trough at 460 m/A is indicative of flavoproteins, 

 and absorption at 340 m/A of pyridine nucleotide, both in the reduced 

 state. The location of absorption bands has been checked and cor- 

 rected with reference to a sample of pure beef heart cytochrome c. 



Mann (1945, 1951) demonstrated the presence of cytochromes a B , 

 a, b, and c in spermatozoa of mammals and pointed out the greater 

 abundance of cytochrome oxidase. This feature is particularly strik- 

 ing if a comparison is made of the spectra of bull (Fig. 1) and Spisula 

 spermatozoa (Fig. 2) obtained also under anaerobic conditions. In 

 Spisula sperm, owing to the more common distribution of cyto- 

 chromes a and a 3 , the gamma bands of cytochromes c and (b) remain 

 distinct instead of fusing into the single peak at 445 m/A as is charac- 

 teristic of bull sperm. 



In Spisula spermatozoa, at 25°C, absorption bands at 603 and 440 

 m/A indicate the presence of cytochromes a and a 3 , the latter band 

 being shifted toward shorter wavelength by cytochrome (b) absorp- 

 tion at 430 m/A (Fig. 2). After treatment with carbon monoxide, an 

 fl 3 -CO compound is formed with absorption at 590 and 425 m/A. Cyto- 



