Abstract
Previous experiments 1 , 2 have demonstrated that the regenerating anal fin of adult P. maculatus females injected with testosterone propionate forms a clearly male-like structure but fails to form the typical gonopod characteristic of the male. The 3,4,5 complex remains short and differentiation of the various specialized structures within the complex is atypical. In seeking further factors which must be controlled in order experimentally to produce typical gonopod formation in the female, it seemed necessary to determine whether the nature of the morphogenetic agent itself, i. e., of the injected androgen, is of any influence in determining the character of the response. Therefore, equal dosages by weight (2 mg/cc) of androsterone,† dehydroandrosterone, androstenedione, testosterone, methyl testosterone, and ethinyl testosterone have been tested on the regenerating fin and the induced responses compared with one another and with that obtained with testosterone propionate.
The technics employed were in all cases similar to those previously described. 1 , 2 The anal fins were cut away across the bases of the rays and intraperitoneal injection was begun on the 9th or 10th day of regeneration. Each animal received 0.05 cc of sesame oil solution containing the appropriate androgen every fifth to seventh day until the response was complete. In most cases a concentration of 2 mg/cc was given. In the case of androsterone, however, several additional groups were run at higher and lower dosages (0.5-5 mg/cc). A total of 67 females were used, 35 receiving androsterone, 10 dehydroandrosterone, 6 ethinyl testosterone, 6 methyl testosterone, 5 testosterone, and 5 androstenedione. Controls received plain sesame oil.
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