DEFECTS IN MULLERIAN DUCT REGRESSION

在狗的两种不同的遗传综合征中，苗勒管持续存在于 睾丸组织的存在：XX性反转和持续性 米勒管综合征(PMDS)。这些是唯一已知的动物模型 在压抑方面具有一致和特定的遗传缺陷 到目前为止所描述的米勒管道系统。将这些模型保存为 进一步的研究完全取决于这一建议，因为没有其他建议 用来维持这些动物的资金。它们的意义不仅在于 它们是人类发育障碍的模型。他们是一个重要的 了解苗勒氏抑制物质(MIS)作用的资源 在哺乳动物的生殖发育和功能中。尽管这种基因 MI已被克隆，其作用的生化机制已被研究 提出的研究结果表明，目前尚未鉴定出MISR。这些型号应该 从而更详细地了解基因控制、结构、 和管理信息系统的作用机制。在这两种综合征中，我们都证明了 穆勒回归的失败不太可能是因为缺乏 由于我们最近显示了患病狗的睾丸组织 胚胎大鼠苗勒管在器官培养中退化的原因 生物化验。我们在这项研究中的目标是确定 穆勒系统对管理信息系统的明显不敏感是由于 管理信息系统的时间或数量。分泌物或与MIS受体的缺陷有关。 这些假设将通过以下方式进行检验：1)确定合成和 患病犬的MISmRNA和MIS值的时序与正常相当 雄性产仔数，以及2)比较位置、浓度和管理信息系统 患病犬和正常犬的MISR结合特性 一窝产仔。 患有XX性反转(可卡犬)和经前综合症(迷你雪纳瑞)的狗 将通过培育这些常染色体隐性遗传的已知携带者而产生 特征。正常人睾丸组织中MISmRNA的产生及细胞定位 受影响的窝产仔将通过Northern印迹进行定量和比较， 原位杂交和免疫组织化学技术。管理信息系统级别 正常和受影响的产仔仔的睾丸将由Western 印迹分析。MLS受体将首先通过抗独特型进行鉴定 抗体和随后通过与代谢标记的管理信息系统结合 稳定转染重组人MISs的细胞系产生 吉恩。

In two separate hereditary syndromes in the dog, Mullerian ducts 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.