of many sharks, is provided with an abundance 

 of yolk material. A Saline extract of the dogfish 

 yolk material was tested in addition to the sera 

 from numerous adult dogfish; this extract also 

 failed to react with any of the antisera used in 

 this study. The lack of reactivity observed here 

 with yolk materials from females of dogfish or 

 lampreys appears to reflect the phylogenetic 

 gap between the teleosts and these more primi- 

 tive vertebrates. 



The vitellin substances of the advanced tele- 

 osts that stimulate production of the broadly 

 cross-reactive antisera appears to be biochemi- 

 cally and antigenically more complex than those 

 of the more primitive teleosts. It is evident 

 from figure 1 and table 3 that only a small 

 fraction of the total number of anti-RM anti- 

 bodies react with SM vitellin; the major anti- 

 genic vitellin component of SM is detected, 

 however, by the anti-RM reagent (Figure 2). 

 Possibly the vitellin antigens of more primitive 

 teleost species have been retained in certain 

 advanced species without extensive modifica- 

 tion during the evolution of additional vitellin 

 substances. 



This study further demonstrates the useful- 

 ness of serological methods to determine ma- 

 turity in oviparous vertebrates. The results are 

 also of significance in systematics. The exist- 

 ence of antigens in the sera of maturing fe- 

 males which do not occur in the sera of males 

 and immature females must be taken into ac- 

 count in studies that attempt to apply serology 

 to problems of taxonomy. These antigens them- 

 selves, as was demonstrated here, also offer 

 additional materials for more detailed examina- 

 tions of systematic relationships. 



LITERATURE CITED 



Gushing, John E. 



1964. The blood groups of marine animals. Adv. 

 Mar. Biol. 2: 85-131. 



Drilhon, a., and J. M. Fine. 



1963. Dimorphisme sexuel dans les proteines se- 

 riques de Salmo salar: Etude electrophoretique 

 Compt. Rend. Soc. Biol. 157(9): 1897-2000. 



Fine, J. M., G. A. Boffa, and A. Drilhon. 



1964. Etude electrophoretique et immunologique 

 des proteines seriques de la lamproie marine 

 (Petromyzoon marinus L.) Compt. Rend. Soc. 

 Biol. 158 (10) : 2021-2025. 



Ho, F. Ghung-Wai, and W. E. Vanstone. 



1961. Effect of estradiol monobenzoate on some 

 serum constituents of maturing sockeye salmon 

 (Oncorhynchus ncrka). J. Fish. Res. Bd. Can. 

 18: 859-864. 



Jukes, T. H., and H. D. Kay. 



1932. Egg-yolk proteins. J. Nutr. 5: 81-101. 

 NUTTALL, G. H. F. 



1904. Blood immunity and blood relationship. 

 Cambridge Univ. Press, New York, 444 pp. 

 Olivereau, Madeleine, and George Ridgway. 



1962. Cytologie hypophysaire et antigene serique 

 en relation avec la maturation sexuelle chex 

 Oncorhynchus species. Compt. Rend. Seances 

 Acad. Sci. 254: 753-755. 



Ridgway, George J. 



1964. Salmon serology. In U.S. Bureau of Com- 

 mercial Fisheries, Report on the Investigations 

 by the United States for the International North 

 Pacific Fisheries Commission-1962, pp. 107-110. 

 Int. N. Pac. Comm. Annu. Rep. 1962. 

 Ridgway, George J., G. W. Klontz, and C. Matsumoto. 

 1962. Intraspecific differences in serum antigens 

 of red salmon demonstrated by immunochemical 

 methods. Int. N. Pac. Fish Comm., Bui. 8: 1-13. 

 Urist, Marshall R., and Arne 0. Schjeide. 



1961. The partition of calcium and protein in the 

 blood of oviparous vertebrates during estrus. J. 

 Gen. Physiol. 44: 743-756. 

 Utter, Fred M., and George J. Ridgway. 



1967. A serologically detected serum factor as- 

 sociated with maturity in English sole, Paro- 

 phyrys vetulus, and Pacific halibut, Hippoglos- 

 sus stenolepis. U.S. Fish. Wildl. Serv., Fish. 

 Bull. 66: 47-58. 

 Vanstone, W. E., W. A. Maw, and R. H. Common. 

 1955. Levels and partition of the fowl's serum 

 proteins in relation to age and egg production. 

 Can. J. Biochem. Physiol. 33(6): 891-903. 



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