STUDIES ON MAMMALIAN OOCYTES (AND SPERMATOCYTES)

本申请中的研究建议研究减数分裂 成年雄性和雌性土耳其仓鼠的特征 冬眠前，冬眠和复发在短时间内 光周期/冷环境。 减数分裂关键步骤分析 进展将与相关的 内分泌和体温测定。 在男性中， 建议研究减数分裂阶段的动力学，并分析 前细线期DNA合成和复制子 特色 粗线期精母细胞染色粒分析 地图，联会复合体和Z-DNA位点的建议。 通过交叉评估的重叠将在双线期进行 精母细胞，单个二价体鉴定， 染色粒图谱 重组蛋白的提取和测定 将作为潜在遗传正常性的一个指标， 重组 中期I和II的染色体补体 精母细胞提供早期阶段的保真度的测量， 诱发畸变 在规定的光周期/温度下的研究重点 雌性土耳其仓鼠卵子发生的条件将是确定 体外成熟卵母细胞的非整倍体和结构异常 和体内。 还建议评估受精卵母细胞， 可能引起的传染性异常。 研究精子发生复发的能力 以及卵母细胞成熟的后期阶段， 条件使用降低的温度，已知的扰动器， 减数分裂，作为一个探针，提出了一个独特的系统，分析 哺乳动物生殖细胞发育的基本阶段， 这些与内分泌因素有关。 的可行性 这些研究已经在对男性的初步研究中得到证实， 金黄中仓鼠

The investigations in this application propose to study the meiotic characteristics of the adult male and female Turkish hamster during prehibernation, hibernation and recrudescence in a short photoperiod/cold environment. Analysis of key steps in meiotic progression will be carried out simultaneous with relevant endocrine and thermal determinations. In the male, it is proposed to study the kinetics of meiotic stages, and analyze the duration of preleptotene DNA synthesis and replicon characteristics. Analysis of pachytene spermatocyte chromomere maps, synaptonemal complexes and Z-DNA sites is proposed. Recombination as assessed by chiasma will be done in diplotene spermatocytes with identification of individual bivalents by chromomere maps. Extraction and assay of recombination proteins will be made as one index of the normalcy of underlying genetic recombination. Chromosomal complements at metaphase I and II spermatocytes provide measures of fidelity of earlier stages and induced aberrations. The focus of investigation under defined photoperiod/temperature conditions in female Turkish hamster oogenesis will be to identify aneuploidy and structural abnormalities in oocytes matured in vitro and in vivo. It is also proposed to assess fertilized oocytes for transmissible abnormalities which may have been induced. The capability for studying the recrudescence of spermatogenesis and the later stages of oocyte maturation in a physiological condition using reduced temperature, a known perturbator of meiosis, as a probe presents a unique system for analyzing essential stages of germ cell development in mammals and correlating these with endocrine factors. The feasibility of the such studies has been demonstrated in a preliminary study with male Mesocricetus auratus.