Modification Expérimentale du Développement de l’Ovaire de Souris sous l’influence du Testicule Embryonnaire de Poulet

Abstract

ABSTRACT Mouse ovaries from foetuses 12–21 days of gestation were explanted in vitro in association with gonads of 6–10 days chick embryos. After 2-6 days of culture, the expiants were grafted into the coelom of young chick embryos. Grafts were removed when hosts were 12–19 days old (Plate 1, Figs. 1 and 2). In associations of mouse and chick ovaries, the two organs fused together forming chimeric organs (Plate 1, Fig. 3). The mouse gonad, containing numerous oocytes and primary follicles, lay in the medullary part of the chick gonad (Plates 1 and 2, Figs. 3–7). In associations of mouse ovary with chick testis, the development of the mouse ovary was inhibited (Plates 2 and 3, Figs. 8–14). Cortical structures were very sensitive to the testicular influence; and oocytes degenerated or failed to develop. Follicles when present had an abnormal appearance (Plate 2, Fig. 9). The degree of inhibition depended on the type of association and the age of the gonad when transplanted (Plate 2, Figs. 9 and 10). Some ‘medullary’ structures persisted in these inhibited ovaries. The rete ovarii, which looks like winding cords, was well developed and penetrated into the chick tissue where it established direct connection with testicular tubules (Plate 3, Fig. 16). In some expiants, in the vicinity of the rete, cords of testicular aspect which sometimes contained oocytes or degenerating follicles were observed (Plate 3, Fig. 13). These results demonstrate that mouse ovary associated with chick ovary can develop when transplanted to chick embryos. Oogenesis takes place, the oocytes grow and primary follicles develop.