CHAPTER 2 



SPERM-EGG INTERACTING SUBSTANCES, I 



The spermatozoa and eggs of many animals and plants contain or 

 produce substances which have well-defined effects on the gametes 

 of the opposite sex and, in some instances, on those of the same 

 sex. These substances are sometimes known as Gamones (= 

 gamete hormones), though this word is not in general use. They 

 have also been given other names: F. R. LilHe (1912a) published 

 the first systematic account of one of these substances, derived 

 from unfertilized eggs, which he called Fertilizin. In certain 

 circumstances a solution of fertilizin agglutinates spermatozoa 

 of the same species. The substance on the head of the spermato- 

 zoon with which fertilizin reacts is known as Antifertilizin ; it was 

 first extracted from spermatozoa by Frank (1939) and Tyler 

 (1939), while later, Tyler (1940a) also extracted it from eggs. The 

 biological and chemical characteristics of sperm-egg interacting 

 substances are summarized in Table i, which also contains a list 

 of their various names. 



Reciprocal induction of spawning. Among aquatic organisms it 

 has been known for many years that a spawning female often 

 induces males and other females of the same species to shed their 

 gametes, and vice versa. For example, spawning females of the 

 acorn worm, Saccoglossus horsti Brambell & Goodhart, induce 

 males of the same species to spawn (Burdon-Jones, 195 1), while 

 the spawning of a male sea-urchin may stimulate every other male 

 urchin in an aquarium tank to start shedding its spermatozoa, to 

 the dismay of the biologist hoping to work with this material. This 

 phenomenon is put to commercial use in the oyster industry, the 

 gonads of some hundreds of oysters being thrown into oyster-beds 

 to stimulate mass spawning, and thereby increase the oyster popu- 

 lation (Quayle, 1940). So far as the induction of spawning is con- 

 cerned, the nature of the responsible substances has been mainly 

 investigated in oysters, in particular by Nelson & Allison (1937), 

 Galtsoff (1940) and Nelson (1941). Although the results of these 

 studies are not particularly encouraging from the point of view of 

 isolating one compound with specific stimulatory activity, there 



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