STUDIES OF A NOVEL RNA APPROACH THAT PROMOTES HEART DEV

促进心脏发育的新型 RNA 方法的研究

• 批准号: 6165082
• 负责人: LARRY F LEMANSKI
• 金额: $ 1.51万
• 依托单位: TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-15 至 2001-07-01
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6165082
• 关键词: RNA; Urodela; cardiac myocytes; cell differentiation; endoderm; gene deletion mutation; gene expression; genetic promoter element; genetic regulation; genetic transcription; genetically modified animals; in situ hybridization; invertebrate embryology; molecular cloning; myocardium; myofibrils; myogenesis; point mutation; polymerase chain reaction; tropomyosin

DESCRIPTION: (Adapted from Investigator's Abstract). The long term goal of the laboratory is to elucidate the cellular, molecular and genetic mechanisms that regulate myocardial cell differentiation and myofibrillogenesis in the developing heart. Ambystoma mixicanum is an intriguing model for studying heart development because it carries a mutation in gene c thought tot exert its effect via abnormal inductive processes from the anterior endoderm. The hearts of double recessive (c/c) mutant embryos do not beat, as they are deficient in tropomyosin and do not contain organized myofibrils. However, the defect can be corrected by culturing the mutant hearts in the presence of normal anterior endoderm tissue, medium conditioned by the anterior endoderm, or total RNA isolated from endoderm or the conditioned medium, each of which promotes myofibrillogenesis in the mutant hearts. A single clone (#4) has been identified from a cDNA library constructed from total conditioned medium RNA which can act as a template for the bioactive RNA capable of correcting the heart defect in organ culture as well as in vivo. The bioactive RNA can bind with a protein present in the embryonic axolotl heart and the bioactive RNA enters the cells of mutant hearts to effect rescue. It is hypothesized that the bioactive RNA is a regulatory molecules which up regulates tropomyosin synthesis in the mutant hearts for promoting myofibrillogenesis either directly or in complex with its binding protein. There are four Specific Aims to test this hypothesis: 1) The expression of the bioactive RNA will be examined in normal and mutant hearts at various stages of development using RT-PCR and in situ hybridization. Ectopic expression of sense and antisense RNA will be tested by creating transgenic axolotls; 2) In vitro mutagenesis of the clone #4 RNA will be performed to elucidate the mechanism of its rescuing activity as well as its binding ability to the newly-discovered binding protein; 3) Study up regulation of tropomyosin in the mutant hearts corrected by the cone #4 RNA; 4) The full length cDNA and the RNA and its mechanism by which its expression is regulated. It is anticipated that these studies will provide significant new information the mechanism of in vivo inductive interactions responsible for normal cardiac myocyte differentiation at the molecular level.

描述：（改编自研究者摘要）。的长期目标