In vivo analysis of synaptonemal complex formation during yeast meiosis.
During meiotic prophase a synaptonemal complex (SC) forms between each pair of homologous chromosomes and is believed to be involved in regulating recombination. Studies on SCs usually destroy nuclear architecture, making it impossible to examine the relationship of these structures to the rest of the nucleus. In Saccharomyces cerevisiae the meiosis-specific Zip1 protein is found throughout the entire length of each SC. To analyze the formation and structure of SCs in living cells, a functional ZIP1::GFP fusion was constructed and introduced into yeast. The ZIP1::GFP fusion produced fluorescent SCs and rescued the spore lethality phenotype of zip1 mutants. Optical sectioning and fluorescence deconvolution light microscopy revealed that, at zygotene, SC assembly was initiated at foci that appeared uniformly distributed throughout the nuclear volume. At early pachytene, the full-length SCs were more likely to be localized to the nuclear periphery while at later stages the SCs appeared to redistribute throughout the nuclear volume. These results suggest that SCs undergo dramatic rearrangements during meiotic prophase and that pachytene can be divided into two morphologically distinct substages: pachytene A, when SCs are perinuclear, and pachytene B, when SCs are uniformly distributed throughout the nucleus. ZIP1::GFP also facilitated the enrichment of fluorescent SC and the identification of meiosis-specific proteins by MALDI-TOF mass spectroscopy.
White
Eric J
EJ
Department of Microbiology and Molecular Genetics, UMDNJ-Graduate School of Biomedical Sciences, UMDNJ-New Jersey Medical School, International Center for Public Health, Newark, New Jersey 07101-1709, USA.
Cowan
Carrie
C
Cande
W Zacheus
WZ
Kaback
David B
DB
D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism; D002875:Chromosomes / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000502:physiology*; D005838:Genotype; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007700:Kinetics; D013058:Mass Spectrometry; D008540:Meiosis; D008856:Microscopy, Fluorescence; D009154:Mutation; D009687:Nuclear Proteins; D049471:Pachytene Stage; D010641:Phenotype; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013573:Synaptonemal Complex / Q000737:chemistry*; D013997:Time Factors
D005656:Fungal Proteins; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; C090118:Zip1 protein, S cerevisiae; D049452:Green Fluorescent Proteins; D004247:DNA