NON-MENDELIAN INHERITANCE OF MACRONOCLEAR TRAITS

宏观清晰性状的非孟德尔遗传

• 批准号: 3467963
• 负责人: JAMES D FORNEY
• 金额: $ 10.8万
• 依托单位: PURDUE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-12-01 至 1994-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3467963
• 关键词: DNA; Paramecium; RNA; centrifugation; chromosome aberrations; extrachromosomal DNA; gene deletion mutation; gene expression; gene mutation; gene rearrangement; genome; laboratory rabbit; microinjections; micronucleus; microorganism genetics; molecular cloning; molecular genetics; mutagen testing; nucleic acid hybridization; nucleic acid sequence; nucleolus; radionuclides; surface antigens

The broad aim of this proposal is to elucidate the molecular details of an unusual type of non-Mendelian inheritance in Paramecium tetraurelia. We will combine molecular biology and genetics to study a mutant cell line (d48) that contains a complete copy of the A type variable surface antigen gene in the micronucleus but not in the macronucleus. Wild type cytoplasm allows the incorporation of these sequences into the macronucleus, but in d48 cytoplasm the chromosome is broken incorrectly and the A gene is deleted. Recent experiments have shown that macronuclear transformation of d48 with a recombinant clone containing the A antigen gene (pSA14SB) leads to the correct processing of the micronuclear A gene sequences during the formation of the next macronucleus (K. Aufderheide, personal communication). By microinjecting specific fragments of pSA14SB into the d48 macronucleus we will define the DNA sequences necessary for the correct processing of the A gene. Further experiments will be performed to determine if RNA products from these sequences are important for their function. Micronuclear DNA from the d48 and wild type cell lines will be isolated and used to compare the organization of the micronuclear sequences surrounding the chromosome breakage sites. Additional non-Mendelian mutants have recently been isolated that affect expression of the B surface antigen gene (J. Preer, personal communication). We will clone the B gene and determine if similar molecular mechanisms are involved in these mutations. We believe this research will advance the understanding of developmentally controlled DNA rearrangements in eukaryotes, and perhaps reveal novel aspects of nucleic acid processing.

这一建议的主要目的是阐明一种蛋白质的分子细节