Analysis of Meiotic Telomere Functions

Florida State University, Tallahassee FL

Investigators

Abstract

Sexual reproduction in most organisms requires two major processes that change the number of chromosome sets (ploidy level), meiosis and fertilization. Meiosis converts diploid somatic cells into haploid gamete cells, the sperm or egg cells. At fertilization, the union of chromosomes from the sperm and egg nuclei restores the diploid state. Not only is meiosis therefore essential for genome maintenance through reproduction, but it is also the stage at which chromosome shuffling and recombination occurs, producing genetic diversity. Although the role of meiosis in establishing the rules of inheritance is well understood and conserved across most higher organisms, relatively little is known about the molecular processes that govern the shuffling and assortment of genetic material during meiosis. The specialized ends of linear chromosomes, the telomeres, cluster together on the nuclear envelope at meiosis in an arrangement now referred to as the bouquet. The work summarized here uses maize (Zea mays, corn) as a model system to investigate the role of telomeres in meiosis. Genetic mutants are being screened by telomere-staining microscopy to permit examination of the relationship between telomere clustering and chromosome segregation during meiosis. This project will result in the identification and characterization of telomere-binding proteins from maize. These telomeric proteins are likely to mediate some aspects of meiotic chromosome behavior. The genes encoding maize telomeric proteins will be molecularly cloned and analyzed for information related to their possible function at meiosis. The proteins encoded by these cloned DNA segments will be tested for their ability to bind specifically to double-stranded telomeric DNA. This work will advance knowledge of the basic mechanisms of meiosis and the biological function of telomeres.