The Sec14 family glycerophospholipid-transfer protein is required for structural integrity of the spindle pole body during meiosis in fission yeast

Genes Cells. 2004 Dec;9(12):1275-86. doi: 10.1111/j.1365-2443.2004.00806.x.

Abstract

The fission yeast spo20+ gene encodes a glycerophospholipid-transfer protein. spo20 mutants are unable to assemble the forespore membrane properly. Here we studied the structural integrity of the spindle pole body (SPB) in spo20-H6 mutants during meiosis. Meiotic cells expressing a GFP-tagged SPB marker protein, Spo15-GFP, showed an excess number of SPBs, some of which were not localized to the spindle poles and were termed 'pseudo-SPBs'. Formation of spindles for meiosis I was significantly delayed in spo20-H6 cells, although the morphology of spindles and segregation of the sister chromatids seemed normal. The SPB of spo20-H6 contained meiosis-specific outer plaques, though outermost layers were less evident. Time-lapse studies of spo20-H6 cells showed that the pseudo-SPBs originated from normal SPBs at the spindle poles during meiosis I. Among the SPB components tested, Spo15, Spo13, Sad1 and Cut12 were localized to the pseudo-SPBs, but Sid4 was not always present. Alp4, a component of the gamma-tubulin complex, was also present in about 40% of the pseudo-SPBs. The forespore membranes initiated from both the SPBs and the pseudo-SPBs. We conclude that Spo20 plays a role in maintaining the structural integrity of the meiotic SPB, besides supplying membrane vesicles for forespore membrane assembly.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Base Sequence
  • Genetic Vectors
  • Glycerophospholipids / metabolism
  • Meiosis*
  • Molecular Sequence Data
  • Mutation
  • Phospholipid Transfer Proteins / genetics*
  • Phospholipid Transfer Proteins / physiology*
  • Plasmids
  • Schizosaccharomyces / cytology
  • Schizosaccharomyces / genetics
  • Schizosaccharomyces / ultrastructure*
  • Schizosaccharomyces pombe Proteins / genetics*
  • Schizosaccharomyces pombe Proteins / physiology*
  • Spindle Apparatus / chemistry
  • Spindle Apparatus / ultrastructure*

Substances

  • Glycerophospholipids
  • Phospholipid Transfer Proteins
  • Schizosaccharomyces pombe Proteins
  • Spo20 protein, S pombe