DEFECTS IN MULLERIAN DUCT REGRESSION

苗勒管回归缺陷

• 批准号: 3316647
• 负责人: VICKI N MEYERS-WALLEN
• 金额: $ 16.67万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-04-01 至 1995-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3316647
• 关键词: Mullerian duct inhibiting substance; autosomal recessive trait; confocal scanning microscopy; congenital reproductive system disorder; cytogenetics; dogs; electron microscopy; embryo /fetus; genetic regulation; genital secretion; hermaphroditism; histogenesis; histology; in situ hybridization; messenger RNA; molecular pathology; northern blottings; organ culture; pseudohermaphroditism; sex chromosomes; testicular feminization; testis disorder

In two separate hereditary syndromes in the dog, Mullerian ducts persist in the presence of testicular tissue: Persistent Mullerian Duct Syndrome (PMDS) and XX sex reversal (XXSR). These are the only known animal models with consistent and specific inherited defects in regression 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 proposed, the MIS receptor (MIS-R) has only been indirectly identified. These models should lead to a more detailed understanding of the genetic control, structure, and mechanism of action of MIS. In both syndromes, we have shown that failure of Mullerian duct regression is unlikely to result from MIS absence, since testicular tissue of affected neonatal 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 resistance of the Mullerian duct system to MIS is due to a defect in timing or amount of MIS secretion or to a defect in the MIS-R. These hypotheses will be tested by: 1) Determining whether the synthesis and timing of MIS and MIS mRNA in affected embryos is comparable to that of normal male littermates, 2) Identifying the MIS- R in normal and affected embryos during the period of Mullerian duct regression, and 3) Comparing the density, location, concentration, and MIS binding characteristics of the MIS-R in affected and normal littermates. Dogs with PMDS and XXSR will be produced by breeding known carriers of these autosomal recessive traits. Production, cellular location, and biological activity of MIS will be compared in testes of normal and affected embryos by immunohistochemical methods and bioassay. Production and cellular location of MIS mRNA in testes of normal and affected littermates will be compared by Northern blot analysis and in situ hybridization. The MIS-R will first be identified in normal embryos by confocal imaging microscopy. Characteristics of the MIS-R in affected and normal embryos will be compared by competitive binding studies with radiolabeled recombinant human MIS and radiolabeled antiidiotypic antibodies.

在狗中的两个单独的遗传综合症中，穆勒人的管道坚持不懈 在存在睾丸组织的情况下：持续的Mullerian管道综合征 （PMD）和XX性逆转（XXSR）。 这些是唯一已知的动物 在回归中具有一致且特定遗传缺陷的模型 迄今为止描述的穆勒管系统。 保存这些 进一步研究的模型完全取决于此建议，因为 没有其他资金来维护这些动物。 它们的意义不是 只是它们是人类发育障碍的模型。 他们是一个 理解穆勒（Mullerian）抑制作用的重要资源 哺乳动物生殖发育和功能中的物质（MIS）。 尽管MIS基因已被克隆和生化机制 提出的作用是，MIS受体（MIS-R）仅间接是 确定。 这些模型应导致更详细的理解 MIS的遗传控制，结构和机理。 在 这两种综合征，我们都表明穆勒风管的失败 由于缺席而不太可能导致，因为 受影响的新生儿狗会导致胚胎大鼠穆勒风管的回归 在器官文化生物测定中。 我们在本研究中的目标是 确定穆勒风管系统的明显电阻 MIS是由于定时或分泌量的缺陷或 MIS-R中的缺陷。 这些假设将通过：1）确定 是否在受影响的胚胎中的MIS和MIS mRNA的合成和时机是否 与正常男性同窝仔相媲美，2）确定错误 在穆勒风管时期的正常和受影响的胚胎的R 回归，3）比较位置，浓度和 MIS-R在受影响和正常的MIS-R的MIS结合特征 同窝工人。 具有PMD和XXSR的狗将通过已知的繁殖而产生 这些常染色体隐性特征的载体。 生产，细胞 位置和MIS的生物活性将在睾丸中比较 通过免疫组织化学方法和生物测定法正常和受影响的胚胎。 MIS mRNA在正常睾丸中的生产和细胞位置 将通过北印迹分析和在 原位杂交。 MIS-R将首先在正常胚胎中识别 通过共聚焦成像显微镜。 MIS-R受影响的特征 和正常胚胎将通过竞争性结合研究与 放射标记的重组人类MIS和放射标记的抗替代型 抗体。