异性孪生不育研究进展

Progress in the Freemartin Syndrome

本文综述了当前的异性孪生不育生物学、诊断和非牛物种发生状况的研究。异性孪生胎儿胎盘间血管发生联系导致XX/XY间性嵌合体,而雌性胎儿生殖器发生雄性化导致不孕。异性孪生不育是最常见的牛间性形式,偶尔其他物种。建立早期诊断异性孪生不育的新的诊断方法的基础上检测Y染色体DNA片段的聚合酶链反应较常规核型分析和临床检查显示灵敏度和效率的改善,异性孪生不育检测有较大的经济重要性。新的异性孪生不育主要在异性孪生嵌合体形成机理、缪勒氏管抑制物(MIS)抗癌应用、移植免疫学和致突变致畸形研究领域。

This review considers the current state of knowledge of freemartin biology, incidence, experimental models, diagnosis, uses for freemartins in cattle herds, occurrence in non-bovine species. Freemartins arise when vascular connections form between the placenta of developing heterosexual twin foeti, XX/XY chimerism develops, and ultimately there is masculinisation of the female tubular reproductive tract to varying degrees. The freemartin condition represents the most frequent form of intersexuality found in cattle, and occasionally other species. There will be greater economic importance to establish early diagnosis of the freemartin and the detection of the less common single born freemartin. New diagnostic methods based on the detection of Y- chromosome DNA segments by polymerase chain reaction show improved assay sensitivity and efficiency over karyotyping and clinical examination. Potential new research areas are discussed, such as detection of foetal DNA in maternal circulation for prenatal diagnosis, discussion of the mechanism of freemartin, application of the anti-tumour properties of Mullerian inhibiting substance （MIS） and investigation of the trans-plantation immunology and teratology.