DEFECTS IN MULLERIAN DUCT REGRESSION

在两个独立的遗传综合症的狗，穆勒二重奏 持续存在睾丸组织：XX性逆转和 持续性苗勒管综合征（PMDS）。 这些是唯一的 具有一致和特异性遗传缺陷的已知动物模型 迄今为止描述的苗勒管系统的抑制。 保存这些模型以供进一步研究完全取决于 由于没有其他资金可以维持， 这些动物。 它们的意义不仅在于 人类发育障碍的模型。 他们是一个重要的 了解缪勒管抑制作用的资源 物质（MIS）在哺乳动物生殖发育和功能。 尽管MIS的基因已经被克隆和生化 已经提出了其作用机制，MIS受体具有 未被确认。 这些模型应该导致一个更详细的 了解遗传控制，结构和机制， MIS的作用。 在这两种综合征中，我们已经表明， 无MIS不太可能导致Mullerian回归 因为我们最近发现， 狗导致胚胎大鼠苗勒管退化的器官 培养物生物测定 本研究的目的是 确定缪勒管的明显不敏感性 从系统到MIS是由于MIS的时间或数量上的缺陷。 分泌或MIS受体的缺陷。 这些假设 将通过以下方式进行测试：1）确定是否合成和定时 受影响犬的MIS mRNA和MIS与受影响犬的MIS mRNA和MIS相当。 正常的雄性同窝仔，和2）比较位置， 浓度和MIS受体的MIS结合特性 在患病犬和正常同窝仔中。 XX性反转犬（可卡犬）和PMDS（小型） 雪纳瑞）将通过繁殖这些已知的载体产生 常染色体隐性遗传 的产生和细胞定位 正常和受累同窝仔睾丸中的MIS mRNA将被 通过北方印迹，原位杂交， 和免疫组织化学技术。 正常人睾丸MIS水平 受影响的同窝仔将通过蛋白质印迹法测定 分析. MlS受体将首先通过以下方法鉴定： 抗独特型抗体，随后通过结合 稳定细胞系产生的代谢标记MIS 用重组人MIS基因转染。

In two separate hereditary syndromes in the dog, Mullerian duets persist in the presence of testicular tissue: XX sex reversal and the persistent Mullerian Duct Syndrome (PMDS). These are the only known animal models with consistent and specific inherited defects in repression of the Mullerian duct system described to date. Preservation of these models for further study depends entirely upon this proposal, since there is no other funding to maintain these animals. Their significance is not only that they are models of human developmental disorders. They are an important resource for understanding the role of Mullerian Inhibiting Substance (MIS) in mammalian reproductive development and function. Although the gene for MIS has been cloned and biochemical mechanisms of its action have been proposed, the MIS receptor has not been identified. These models should lead to a more detailed understanding of the genetic control, structure, and mechanisms of action of MIS. In both syndromes, we have shown that failure of Mullerian regression is unlikely to result from an absence of MIS since we have recently shown that testicular tissue of affected dogs causes regression of embryonic rat Mullerian ducts in an organ culture bioassay. Our objective in the present study is to determine whether the apparent insensitivity of the Mullerian system to MIS is due to a defect in timing or amount of MIS. secretion or to a defect in the MIS receptor. These hypotheses will be tested by: 1) Determine whether the synthesis and timing of MIS mRNA and MIS in affected dogs is comparable to that in normal male littermates, and 2) Comparing the location, concentration, and MIS binding characteristics of the MIS receptor in affected dogs and normal littermates. Dogs with XX sex reversal (Cocker Spaniels) and PMDS (Miniature Schnauzers) will be produced by breeding known carriers of these autosomal recessive traits. Production and cellular location of MIS mRNA in testes of normal and affected littermates will be quantitated and compared by Northern blot, in situ hybridization, and immunohistochemical techniques. MIS levels in testes of normal and affected littermates will be determined by Western blot analysis. The MlS receptor will first be identified by antiidiotypic antibodies and subsequently by binding to metabolically-labelled MIS produced by stable cell lines transfected with the recombinant human MIS gene.