Elements of chromosome structure and function in fission yeast

Area of Science:

• * Molecular Biology
• * Genetics
• * Cell Biology

Background:

• * Fission yeast (S. pombe) chromosome structure and function research has progressed significantly.
• * Key elements like replication origins, telomeres, and centromeres have been isolated.
• * This has enabled the creation of minichromosomes and yeast artificial chromosomes (YACs).

Purpose of the Study:

• * To investigate chromosome segregation and behavior during mitosis and meiosis in fission yeast.
• * To utilize advanced techniques for detailed analysis of chromosomal elements.
• * To explore the functional similarities between fission yeast centromeres and those in larger eukaryotes.

Main Methods:

• * Isolation of replication origins, telomeres, and centromeres.
• * Development of minichromosomes and a YAC-like cloning system.
• * Application of fluorescent in-situ hybridization (FISH) in S. pombe.
• * Indirect immunofluorescence for detecting spindle and chromosomal proteins.

Main Results:

• * Identification of numerous mutants defective in chromosome segregation.
• * Localization of centromeres and telomeres during mitosis and meiosis using FISH.
• * Discovery of a heterochromatin-like structure mediating transcriptional repression at centromeres.
• * Reinforcement of similarities between fission yeast centromeres and those of larger eukaryotes.

Conclusions:

• * FISH, combined with immunofluorescence, is a powerful tool for advancing fission yeast chromosome research.
• * Fission yeast centromeres exhibit characteristics similar to those in higher eukaryotes.
• * Further study of these phenomena will facilitate genetic dissection of centromeric elements.