Intact testosterone receptor complex does not induce RNA synthesis of Tfm-nuclei in multinucleated urethral muscle fibres of mosaic mice

Daudi supernatant, unlike other H-Y antigen sources, exerts a sex-reversing effect on embryonic chick gonad differentiation

In vitro cultures of intact chick gonads (organ cultures) and reaggregation cultures of dispersed gonad cells (roller cultures) were made. Gonads or gonad cells from 7-day-old chick embryos, at the stage when sex-specific differentiation begins, were cultured in the presence of presumed H-Y antigen-containing supernatants, or co-cultured in the presence of H-Y antigen-producing cell lines. The H-Y antigen-producing cells tested were of human, mouse, bovine and chicken origin. During organ culture, addition of supernatant of the human lymphoma cell line Daudi, or co-culture with Daudi cells, stimulated a clear proliferation of the germinal epithelium in male gonads, indicating feminization. A similar effect was obtained by treatment with estradiol. In reaggregation culture, the increase in nuclear size of germ cells was chosen as a parameter for feminization. A significant increase of germ cell nuclear size was observed in gonads cultured in the presence of Daudi supernatant. In both organ cultures and reaggregation cultures, other tested H-Y antigen sources and semi-purified H-Y antigen fractions did not exert significant effects on differentiation of the gonads or on the average area of the germ cell nuclei. These findings suggest that it is not H-Y antigen, but another protein produced by Daudi cells, that might be responsible for the sex-reversing effects.

Androgen receptor-deficient Tfm cells in the mosaic epididymis of sex-reversed mice heterozygous for Tfm: an autoradiographic study with [3H]-dihydrotestosterone and [3H]-estradiol

Testicular feminization (Tfm) in the mouse is characterized by androgen insensitivity of the target cells. We describe the presence of androgen-insensitive Tfm cells in the epididymis of mosaic mice produced by converting female carriers of the Tfm mutation (XTfm/X+) to males via the sex reversal factor (Sxr). The mosaic arises by random X-inactivation. In the epididymal duct, flat undifferentiated Tfm cells are interspersed between high columnar wild-type cells. By thaw-mount autoradiography we show that after injection of [3H]dihydrotestosterone, radioactivity is concentrated in the nuclei of high columnar wild-type cells, whereas the nuclei of the low cuboid Tfm cells remain free of nuclear radioactivity. After injection of [3H]estradiol, both Tfm and wild-type cells show nuclear labeling. Our observations demonstrate that Tfm cells in the mosaic epididymis selectively lack nuclear dihydrotestosterone-binding sites, whereas estradiol-binding sites are intact.

Cytosolic androgen receptor in skeletal muscle from normal and dystrophic mice

The cytosolic androgen receptor was studied in skeletal muscle of normal mice and of mice with hereditary muscular dystrophy (129/ReJ-dy). Mouse muscle contains a cytosolic androgen receptor with high affinity (KD 0.6 nM) and low capacity (Bmax 3fmol/mg protein). Dystrophic muscle contains a receptor with similar binding properties. The receptors from muscle of dystrophic and normal mice bind to DNA-cellulose affinity columns and are eluted with similar patterns. The reported failure of androgens to alleviate the clinical signs of murine muscular dystrophy is probably not due to decreased androgen responsiveness of the affected muscles.