STUDIES OF SPERM FUNCTION IN MAMMALIAN FERTILIZATION

哺乳动物受精过程中精子功能的研究

基本信息

批准号：
6125618
负责人：
PATRICIA J OLDS-CLARKE
金额：
$ 20.73万
依托单位：
TEMPLE UNIV OF THE COMMONWEALTH
依托单位国家：
美国
项目类别：
财政年份：
1996
资助国家：
美国
起止时间：
1996-12-01 至 2001-11-30
项目状态：
已结题

项目摘要

DESCRIPTION (Adapted from the Investigator's Abstract): The t haplotypes of mouse sperm are a valuable model system for understanding the genetic and biochemical basis of mammalian sperm dysfunction. Sperm from mice carrying two t haplotypes have extremely poor sperm quality, are deficient in the ability to bind to the zona pellucida, and are unable to penetrate zona-free oocytes. The ultimate objectives of this research are to determine the biochemical mechanisms by which loci in the t haplotypes cause dysfunction in fertilization and to identify and characterize these loci. Gene sequences can then be used as probes to identify human homologs. The sterility of t/t males is caused by the interaction of three genetic factors, S1-S3, each located in a different chromosomal inversion. When homozygous, S1 enhances defects in motility and egg penetration caused by heterozygosity of S2. Aim I is to determine the type of mechanism underlying this enhancement and map the genes responsible to a region small enough for positional cloning. This can be done using Mus spretus-Mus domesticus chromosome 17 recombinant mice, since M. spretus contains noncomplementing alleles to the t haplotype loci affecting sperm, and M. spretus DNA is not inverted relative to M. domesticus. Biochemical defects associated with either S1 or S2 could be involved in zona-binding deficiency. Aim II is to determine which possibility is correct by mapping this deficiency within the t complex. These experiments have the potential to identify the molecular basis for reduced sperm-zona binding. The t haplotype causes an abnormality in the tyrosine phosphorylation of a specific subset of sperm proteins. Since these phosphorylation events are coupled with capacitation in wildtype sperm, the t haplotype-specific defect(s) that affect this pathway could be involved in pathways leading to defective motility and/or egg penetration. Aim III is to determine whether this is so by determining the requirements for the abnormal protein tyrosine phosphorylation, and by mapping the defect to a specific region of the t complex.

描述（改编自研究者的摘要）：t 单倍型小鼠精子是了解遗传和遗传的一个有价值的模型系统哺乳动物精子功能障碍的生化基础。小鼠携带的精子两个 t 单倍型的精子质量极差，缺乏能够与透明带结合，并且无法穿透无透明带卵母细胞。这项研究的最终目标是确定 t 单倍型中的基因座导致功能障碍的生化机制受精并识别和表征这些基因座。基因然后可以使用序列作为探针来鉴定人类同源物。 t/t雄性不育是由三种遗传相互作用引起的 S1-S3 因子，各自位于不同的染色体倒位。什么时候纯合子，S1 增强由以下原因引起的运动和卵子穿透缺陷 S2的杂合性。目标 I 是确定机制的类型在这种增强的基础上，绘制负责一个小区域的基因足以用于定位克隆。这可以使用 Mus spretus-Mus 来完成 Domesticus 17 号染色体重组小鼠，因为 M. spretus 含有影响精子的 t 单倍型基因座的非互补等位基因，以及 M. spretus DNA 相对于 M. Domesticus 来说不是倒置的。与 S1 或 S2 相关的生化缺陷可能涉及透明带结合缺陷。目标 II 是确定哪种可能性通过在 t 复合体中映射此缺陷来纠正。这些实验有潜力确定精子带减少的分子基础绑定。 t单倍型导致酪氨酸异常精子蛋白特定子集的磷酸化。由于这些磷酸化事件与野生型精子的获能相结合，影响该途径的单倍型特异性缺陷可能涉及导致运动性和/或卵子穿透缺陷的途径。目标三是通过确定以下要求来确定是否如此异常的蛋白质酪氨酸磷酸化，并通过将缺陷映射到 t复合体的特定区域。