How do they do that

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How do they do that ?
Approaches 1) Genetics (meiotic telomere
behavior mutants) 2) Molecular (telomeric
proteins)
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Maize Meiotic Mutants
desynaptic - precocious desynapsis desynaptic
(dy, only one allele) desynaptic-1 (dsy1-1,
dsy1-9101, dsy1-9307) desynaptic-2 (dsy2, only
one allele) asynaptic - fail to
synapse asynpatic-1 (as1, only one
allel) ameiotic - fail to go through
meiosis ameiotic-1 (am1-1, am1-2,
am1-pra) others absence of first division
(afd1) unpaired at metaphase I divergent
spindle (dv) incompletely paired at metaphase
I elongate (el1) male sterile (ms8, ms9, ms17,
ms22, ms23, ms28, ms41, ms43,
ms41) polymitotic (po)
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From Dernburg, Sedat, Cande, Bass
(1995) Cytology of Telomeres in Telomeres (CSHL)
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dsy1
DAPI
FITC
Rhod
3D Model
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DAPI
dsy1 at diakinesis Univalent Chromosome 2s are
detected by 5S rDNA FISH
FITC
Rhod
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dy
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Status of Mutant Analysis

• desynaptic and desynaptic1 have a telomeric
  mutant phenotype, evident by 3D FISH.(candidates
  for cloning)
• Some mutant have no bouquet.ameiotic-1 (arrests
  at onset of meiosis)absence of first division
  (bypasses bouquet)(candidates for DNA microarray
  analysis)

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Conclusions and Future Directions

• Telomeres have special functions in meiosis that
  are cytogenetically accessible in higher plants.
• Oat-maize chromosome addition lines provide ideal
  material for chromosome painting analysis.
• Some desynaptic mutants have telomere phenotypes.
• Identification of telomeric proteins will be
  valuable in understanding how meiotic telomeres
  function.

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Acknowledgements

• Florida State University
• George Koumbaris
• Stefano Bordoli
• Eric Foss
• Rachel Santarella
• Marion Goltz
• Support
• FSU Research Foundation

• University of California
• Zac Cande (UCB)
• John Sedat (UCSF)
• David Agard (UCSF)
• University of Minnesota
• Ron Phillips
• Howard Rines
• Evgueni Ananiev
• Oscar Riera-Lizarazu