Houillon C, Dournon C
Reprod Nutr Dev (1980). 1986;26(5A):1115-35.
Chimeric grafts of the embryos of the urodele amphibian (Pleurodeles waltlii Michah.) produced viable, double-bodied animals having two pairs of genital glands of the same sex [homosexual chimeras: anterior testes--posterior testes (male----male) and anterior ovaries--posterior ovaries (female----female)] or of different sex [(heterosexual chimeras: anterior ovaries--posterior testes (female----male) and anterior testes--posterior ovaries (male----female)]. 115 chimeras aged 5 months to 15 years were analysed. Gonadal development in a same animal was observed at different times by exploratory laparotomy. The testes of heterosexual chimeras were removed in order to prevent their inhibitory effect on the ovaries (freemartin effect). The 115 experimental animals were classified according to gonadal development as follows: 47 male----male chimeras (41%), 26 female----female chimeras (23%), 13 female----male chimeras (11%), 29 male----female chimeras (25%). As a rule, male----male chimeras only developed three normal testes. The fourth testis, always situated in the anterior part of the chimera, remained vestigial; nevertheless, it could attain a normal size if the other three testes were removed. female----female chimeras usually had four ovaries; the times of vitellogenesis and of sexual maturity were synchronous in all four ovaries. The anterior ovaries of female----male chimeras were always inhibited and the posterior testes were always normal. male----female chimeras always had normal anterior testes but their posterior ovaries were often weakly inhibited. The high number of male----male chimeras and the low number of female----female ones could be due to a phenotypic reversal of the anterior ovaries in some of the female----male chimeras. The number of male----female chimeras (corresponding to the theoretical number) suggests that the phenotypic sex of the posterior ovaries was not reversed. The freemartin effect in double-bodied heterosexual chimeras depended on the location of the ovaries in relation to the testes. The effect was more significant on the anterior ovaries when posterior testes were present. No or weak freemartin effect was observed when the posterior ovaries developed facing the anterior testes; in about 60% of cases, a reciprocal inhibition or an equilibrium between gonads of different sex occurred.(ABSTRACT TRUNCATED AT 400 WORDS)
有尾两栖动物（Pleurodeles waltlii Michah.）胚胎的嵌合体移植产生了有活力的双头动物，这些动物具有两对同性的生殖腺[同性嵌合体：前部睾丸——后部睾丸（雄性——雄性）和前部卵巢——后部卵巢（雌性——雌性）]或不同性别的生殖腺[异性嵌合体：前部卵巢——后部睾丸（雌性——雄性）和前部睾丸——后部卵巢（雄性——雌性）]。对115只年龄在5个月至15岁之间的嵌合体进行了分析。通过剖腹探查在不同时间观察同一动物的性腺发育情况。为了防止异性嵌合体的睾丸对卵巢产生抑制作用（弗里马丁效应），将其睾丸切除。115只实验动物根据性腺发育情况分类如下：47只雄性——雄性嵌合体（41%），26只雌性——雌性嵌合体（23%），13只雌性——雄性嵌合体（11%），29只雄性——雌性嵌合体（25%）。通常，雄性——雄性嵌合体只发育出三个正常的睾丸。第四个睾丸总是位于嵌合体的前部，仍处于退化状态；不过，如果切除其他三个睾丸，它可以发育到正常大小。雌性——雌性嵌合体通常有四个卵巢；所有四个卵巢的卵黄生成和性成熟时间是同步的。雌性——雄性嵌合体的前部卵巢总是受到抑制，而后部睾丸总是正常的。雄性——雌性嵌合体总是有正常的前部睾丸，但其后部卵巢常常受到轻微抑制。雄性——雄性嵌合体数量多而雌性——雌性嵌合体数量少可能是由于一些雌性——雄性嵌合体中前部卵巢出现了表型逆转。雄性——雌性嵌合体的数量（与理论数量相符）表明后部卵巢的表型性别没有逆转。双头异性嵌合体中的弗里马丁效应取决于卵巢相对于睾丸的位置。当存在后部睾丸时，对前部卵巢的影响更为显著。当后部卵巢朝着前部睾丸发育时，未观察到或仅观察到轻微的弗里马丁效应；在大约60%的情况下，不同性别的性腺之间会发生相互抑制或平衡。（摘要截选至400字）
