|
|
|
|
|
|
|
||
J. Cell Biol.,
Volume 145, Number 6, June 14, 1999 1233-1250
* Kansai Advanced Research Center, Communications Research Laboratory, Kobe 651-2401, Japan; and Meiotic recombination requires pairing of
homologous chromosomes, the mechanisms of which
remain largely unknown. When pairing occurs during
meiotic prophase in fission yeast, the nucleus oscillates between the cell poles driven by astral microtubules.
During these oscillations, the telomeres are clustered at
the spindle pole body (SPB), located at the leading
edge of the moving nucleus and the rest of each chromosome dangles behind. Here, we show that the oscillatory nuclear movement of meiotic prophase is dependent on cytoplasmic dynein. We have cloned the gene
encoding a cytoplasmic dynein heavy chain of fission
yeast. Most of the cells disrupted for the gene show no
gross defect during mitosis and complete meiosis to
form four viable spores, but they lack the nuclear movements of meiotic prophase. Thus, the dynein
heavy chain is required for these oscillatory movements. Consistent with its essential role in such nuclear
movement, dynein heavy chain tagged with green fluorescent protein (GFP) is localized at astral microtubules and the SPB during the movements. In dynein-disrupted cells, meiotic recombination is significantly
reduced, indicating that the dynein function is also required for efficient meiotic recombination. In accordance with the reduced recombination, which leads to
reduced crossing over, chromosome missegregation is
increased in the mutant. Moreover, both the formation
of a single cluster of centromeres and the colocalization
of homologous regions on a pair of homologous chromosomes are significantly inhibited in the mutant.
These results strongly suggest that the dynein-driven
nuclear movements of meiotic prophase are necessary
for efficient pairing of homologous chromosomes in fission yeast, which in turn promotes efficient meiotic recombination.
Department of
Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado 80309-0347
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
