310
L. GALLIEN
{iii) Reptiles. Δ
5
-3β-ο1 DH is revealed in the interrenal tissue of Lacerta
sicula at the fifteenth and seventeenth days of incubation (Chieffi, 1965).
(iv) Birds. In the chick, Δ
5
-3β-ο1 DH has been demonstrated in the
gonads at the eighth and tenth days of incubation, and in the adrenal
glands from the fifth day (Chieffi et al., 1964; Narbaitz and Kolodny,
1964; Narbaitz and Teitelman, 1965).
(v) Mammals. Δ
5
-3β-ο1 DH has been identified very early in a series of
species in interrenal tissue and gonads (reviewed in Deane and Rubin,
1965; Price and Ortiz, 1965). Mouse: at the fifteenth day in the testes
(Hitzeman, 1962); guinea pig: at the thirty-first day in the testes and
adrenal glands (Price ei al., 1963, 1964); man (Cavallero et al., 1965;
Deane and Rubin, 1965).
Labeled steroids and autoradiography have been used to analyze the
localization of hormones in the course of sex reversal in the teleost, 0.
latipes (Hishida, 1965). These techniques open up the study of steroid
activity, even to the level of the genes participating in the differentiation
of sex.
In conclusion, the analysis of the initial reactions that control the biosynthesis and metabolism of the steroid hormones at the beginning of sexual
differentiation, and the elucidation of the enzyme systems appearing as
precursors of these hormones have constituted a particularly active field of
research in recent years. The most outstanding result is that very early, in
most cases even at the time of differentiation of the gonads or slightly
thereafter, the reproductive glands are the seat of active secretion of steroid
hormones. These facts strongly suggest that they play an active role in the
control of sexual organogenesis in embryonic stages.
F. Summary
The experimental studies undertaken in vertebrates in order to understand the freemartin effect analyzed by Lillie (1917) have involved various
methods.
In the first place, there is the demonstration of the neutral sexual state,
that is, the differentiation of the aggregate of somatic sexual characteristics
when an organism develops in the absence of hormones, after early ablation
of the gonadal primordia. A certain reservation must be made in order to
allow for the eventual influence of the embryonic hypophysis or adrenal
cortex.
The mass of information obtained has been largely confirmed by methods
of embryonic grafting and of culture of organs of the reproductive tract and
their primordia. Cultures have been carried out in the presence or absence of
hormones.
The administration of steroid hormones from adult gonads has estab-
L. GALLIEN
{iii) Reptiles. Δ
5
-3β-ο1 DH is revealed in the interrenal tissue of Lacerta
sicula at the fifteenth and seventeenth days of incubation (Chieffi, 1965).
(iv) Birds. In the chick, Δ
5
-3β-ο1 DH has been demonstrated in the
gonads at the eighth and tenth days of incubation, and in the adrenal
glands from the fifth day (Chieffi et al., 1964; Narbaitz and Kolodny,
1964; Narbaitz and Teitelman, 1965).
(v) Mammals. Δ
5
-3β-ο1 DH has been identified very early in a series of
species in interrenal tissue and gonads (reviewed in Deane and Rubin,
1965; Price and Ortiz, 1965). Mouse: at the fifteenth day in the testes
(Hitzeman, 1962); guinea pig: at the thirty-first day in the testes and
adrenal glands (Price ei al., 1963, 1964); man (Cavallero et al., 1965;
Deane and Rubin, 1965).
Labeled steroids and autoradiography have been used to analyze the
localization of hormones in the course of sex reversal in the teleost, 0.
latipes (Hishida, 1965). These techniques open up the study of steroid
activity, even to the level of the genes participating in the differentiation
of sex.
In conclusion, the analysis of the initial reactions that control the biosynthesis and metabolism of the steroid hormones at the beginning of sexual
differentiation, and the elucidation of the enzyme systems appearing as
precursors of these hormones have constituted a particularly active field of
research in recent years. The most outstanding result is that very early, in
most cases even at the time of differentiation of the gonads or slightly
thereafter, the reproductive glands are the seat of active secretion of steroid
hormones. These facts strongly suggest that they play an active role in the
control of sexual organogenesis in embryonic stages.
F. Summary
The experimental studies undertaken in vertebrates in order to understand the freemartin effect analyzed by Lillie (1917) have involved various
methods.
In the first place, there is the demonstration of the neutral sexual state,
that is, the differentiation of the aggregate of somatic sexual characteristics
when an organism develops in the absence of hormones, after early ablation
of the gonadal primordia. A certain reservation must be made in order to
allow for the eventual influence of the embryonic hypophysis or adrenal
cortex.
The mass of information obtained has been largely confirmed by methods
of embryonic grafting and of culture of organs of the reproductive tract and
their primordia. Cultures have been carried out in the presence or absence of
hormones.
The administration of steroid hormones from adult gonads has estab-