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VOL. 75 (3), 419-466, 2009 DIFERENCIACIÓN SEXUAL: EL FACTOR DE JOST

transplanted in the abdominal cavity of male or female rats which
are castrated at birth. The latter can be examined by the response of
lordosis of female rats with plain sexual differentiation in front of
the male. The different brain regions containing estrogen receptors
have been localized.

Fetal testes regulate gonadal differentiation through two
hormones; testosterone an anti-Müllerian hormone. Testosterone
differentiates Wolff channels in deferent vessels, epididimus and
seminal vesicles, and AMH induces the regression of Müller channels
in the genetically male embryo, in which testes are previously
differentiated in the last fetal stage of gonad development. In the
female, with no testosterone or AMH, the Wolff channels undergo
involution and those of Müller spontaneously differentiate to uterus,
Fallopian trumps and upper part of vagina.

The credit for the knowledge of these matters should be given
to Prof. Alfred Jost (Paris, 1947-50), who discovered AMH in rabbit
fetuses. Currently, AMH has been endowed with many biological
functions, the most important being the involution of Müllerian
channels in genetically male fetuses. AMH is a biomarker of diseases
such as ovarian tumors and abnormal steroid synthesis in ovary and
its finding helped explain a heterogeneous number of sexual-related
pathologies.

AMH gene has been cloned and anti-AMH monoclonal antibodies
obtained. Since AMH has been associated with the transforming-
growth factor beta (TGF-ß) family, whose members are involved in
cancer processes, its biological functions and potential therapeutic
applications are currently and will certainly be subject of intense
studies.

Key words: Genes; Testes; Wolff and Müller ducts; Testosterone;
Hypothalamus; Anti-Müllerian hormone (AMH).

1. PALABRAS PREVIAS

Actualmente, está completamente establecida la interacción, du-
rante el desarrollo de los mamíferos, entre factores ambientales y
genoma para la proliferación celular y diferenciación de órganos

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