PRODUCTION OF GROWTH FACTORS BY EARLY MAMMALIAN EMBRYOS

早期哺乳动物胚胎生长因子的产生

• 批准号: 3320510
• 负责人: A. ANGIE RIZZINO
• 金额: $ 8.83万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-04-01 至 1989-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3320510
• 关键词: amnion; bioassay; early embryonic stage; embryo /fetus; embryo /fetus culture; embryo /fetus preservation; embryo /fetus transplantation; epidermal growth factor; fibroblast growth factor; growth media; histogenesis; mammalian embryology; microscopy; mixed tissue /cell culture; platelet derived growth factor; transforming growth factors; trophoblast; vitelline membrane

The roles of hormones and growth factors during the early stages of mammalian development are poorly understood. During the past decade, it has become apparent that embryos at several stages of development produce growth factors, some of which exhibit the properties of transforming growth factors (TGFs). TGFs are assayed by their ability to induce the soft agar growth of non-transformed cells, such as normal rat kidney (NRK) cells. The TGF-like growth factors from embryos were initially observed in extracts prepared from mouse embryos at mid and late stages of gestation. Recently, we have determined that embryos cultured from the blastocyst stage release growth factors that induce the soft agar growth of NRK cells. Although the precise developmental stage when production of these factors begins has not been established, the data suggest that these factors are released by cell types associated with early postimplantation embryos. However, it has not been determined whether these factors are released at earlier stages of development. Furthermore, the assay employed, although relatively sensitive, could not unambiguously identify the growth factors involved. This application proposes to address several important questions concerning TGF-like growth factors released by early mouse embryos: 1) What are their identities? 2) When are they first produced? 3) Is their release modified by conditions that interfere with development? 4) Are these factors produced by specific embryonic tissues? These questions will be addressed by employing a battery of bioassays that permit the identification of TGFs and related growth factors. The work proposed in this application will help to clarify the roles of growth factors during early development and help determine whether further study of embryonic growth factors is likely to yield assays suitable for monitoring normal preimplantation development.

激素和生长因子在早期阶段的作用 人们对哺乳动物的发育知之甚少。 在过去的十年里，它 已经很明显的是，处于几个发育阶段的胚胎会产生 生长因子，其中一些表现出转化生长的特性 因子（TGF）。 通过 TGF 诱导软琼脂的能力进行测定 非转化细胞的生长，例如正常大鼠肾（NRK）细胞。 来自胚胎的 TGF 样生长因子最初是在 从妊娠中期和晚期的小鼠胚胎中提取的提取物。 最近，我们确定从囊胚培养的胚胎 阶段释放诱导 NRK 软琼脂生长的生长因子 细胞。 尽管生产这些产品时的精确发展阶段 因素开始尚未确定，数据表明这些 因子由与植入后早期相关的细胞类型释放 胚胎。 但尚未确定这些因素是否 在开发的早期阶段发布。 此外，该测定 受雇者虽然相对敏感，但无法明确识别 所涉及的生长因子。 该应用程序建议解决几个问题 关于早期释放的 TGF 样生长因子的重要问题 小鼠胚胎：1）它们的身份是什么？ 2）他们什么时候第一次 生产？ 3) 它们的释放是否受到干扰条件的影响 发展？ 4）这些因子是由特定的胚胎组织产生的吗？ 这些问题将通过采用一系列生物测定来解决 允许鉴定 TGF 和相关生长因子。 工作 本申请中提出的建议将有助于阐明增长的作用 早期发育过程中的因素，有助于确定是否进一步研究 胚胎生长因子的分析可能会产生适合于 监测正常的植入前发育。