Bisphenol A (BPA) and phthalate diesters are ubiquitous environmental contaminants. While these compounds have been reported as reproductive toxicants, their effects may partially be attributed to metabolites. The aim of this study was to examine reproductive organ development in chicken embryos exposed to the BPA metabolite, 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene (MBP; 100 µg/g egg) or a human-relevant mixture of 4 phthalate monoesters (85 µg/g egg). The mixture was designed within the EU project EDC-MixRisk based upon a negative association with anogenital distance in boys at 21 months of age in a Swedish pregnancy cohort. Chicken embryos were exposed in ovo from an initial stage of gonad differentiation (embryonic day 4) and dissected two days prior to anticipated hatching (embryonic day 19). No discernible effects were noted on reproductive organs in embryos exposed to the mixture. MBP-treated males exhibited retention of Müllerian ducts and feminization of the left testicle, while MBP-administered females displayed a diminished the left ovary. In the left testicle of MBP-treated males, mRNA expression of female-associated genes was upregulated while the testicular marker gene SOX9 was downregulated, corroborating a feminizing effect by MBP. Our results demonstrate that MBP, but not the phthalate monoester mixture, disrupts both male and female reproductive organ development in an avian embryo model.

中文翻译：

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建议的双酚A代谢物（MBP）会干扰鸡胚生殖器官的发育，而与人有关的邻苯二甲酸单酯混合物则没有这种作用。

双酚A（BPA）和邻苯二甲酸二酯是普遍存在的环境污染物。虽然这些化合物已被报告为生殖毒物，但其作用可能部分归因于代谢产物。这项研究的目的是检查暴露于BPA代谢物，4-甲基-2,4-双（4-羟苯基）戊-1-烯（MBP; 100 µg / g鸡蛋）或鸡胚中的鸡胚的生殖器官发育。与人有关的4种邻苯二甲酸单酯（85 µg / g鸡蛋）的混合物。该混合物是在欧盟项目EDC-MixRisk中设计的，该模型基于瑞典怀孕队列中21个月大男孩的生殖器距离与负相关。从性腺分化的初始阶段（胚胎第4天）开始将卵暴露在卵内，并在预期的孵化前两天进行解剖（胚胎第19天）。没有发现对暴露于混合物的胚胎中生殖器官有明显影响。接受MBP治疗的雄性小鼠表现出缪勒氏管的保留和左侧睾丸的女性化，而接受MBP治疗的女性表现出左侧卵巢的缩小。在用MBP治疗的男性的左睾丸中，女性相关基因的mRNA表达上调，而睾丸标记基因SOX9下调，从而证实了MBP的女性化作用。我们的结果表明，MBP而不是邻苯二甲酸单酯混合物会破坏禽类胚胎模型中男性和女性生殖器官的发育。在用MBP治疗的男性的左睾丸中，女性相关基因的mRNA表达上调，而睾丸标记基因SOX9下调，从而证实了MBP的女性化作用。我们的结果表明，MBP而不是邻苯二甲酸单酯混合物会破坏禽类胚胎模型中男性和女性生殖器官的发育。在用MBP治疗的男性的左睾丸中，女性相关基因的mRNA表达上调，而睾丸标记基因SOX9下调，从而证实了MBP的女性化作用。我们的结果表明，MBP而不是邻苯二甲酸单酯混合物会破坏禽类胚胎模型中男性和女性生殖器官的发育。