MOLECULAR CHARACTERIZATION OF TELOMERES IN HUMAN SPERM

描述：(改编自申请者的摘要)这项计划的长期目标 建议对端粒的组织结构进行表征 精子发生。一个主要的重点是定义与之相关的分子 人类精子的端粒染色体结构域。中的一个组件 端粒结合蛋白复合体(HsTBP)-与DS具有结合亲和力 六核苷酸重复序列(TTAGGG)端粒DNA已被鉴定并提出 参与端粒与核膜的连接。一 在hsTBP的组成成分中，称为spH2B，被认为是 体细胞组蛋白H_2B。HsRBP的另一个成分是一种新的50 kDa蛋白质 被鉴定为p50。基于这些数据，申请人提出隔离， Sph2B和p50的克隆和进一步鉴定。这一方法将 使人类能够鉴定hsTBP的其他成分 生精细胞和精子。使用原子力显微镜进行的其他研究 和整体安装电子显微镜包括结构分析 端粒DNA似乎保留了其核小体样的组织。这个 以后的研究将探索最近报道的T环的一个变体 用原位技术观察体细胞端粒的特征 精子的交联型端粒DNA制剂。建议进行的研究包括 被认为是调节端粒酶活性的重要因素 减数分裂前期和后期的同源染色体配对和重组 受精后有秩序地提取染色体。

DESCRIPTION: (Adapted from the applicant's abstract) The long-term goal of this proposal is to characterize the organization of the telomere during spermatogenesis. A major emphasis is to define the molecules associated with the telomere chromosomal domains in human sperm. A component of the telomere-binding protein complex (hsTBP) - with binding affinity to the ds hexanucleotide repeat (TTAGGG) telomere DNA - has been identified and proposed to participate in the attachment of the telomeres to the nuclear envelope. One of the components of hsTBP, called spH2B, is regarded as a subtype of the somatic histone H2B. Another component of hsRBP is a novel 50 kDa protein identified as p50. Based on these data, the applicant proposes the isolation, cloning, and further characterization of spH2B and p50. This approach will enable the identification of additional components of hsTBP in human spermatogenic cells and sperm. Additional studies using atomic force microscopy and whole mount electron microscopy include a structural analysis of the telomeric DNA that appears to retain its nucleosomal-like organization. The latter studies will explore whether a variation of the recently reported t-loop characteristic of the telomere in somatic cells is observed using in situ cross-linked telomeric DNA preparations of sperm. The proposed studies are regarded as important for the regulation of telomerase activity during homologous chromosomal pairing and recombination during meiotic prophase and ordered chromosome withdrawal after fertilization.