NDC10 - A GENE INVOLVED IN CHROMOSOME SEGREGATION IN SACCHAROMYCES-CEREVISIAE

A mutant, ndc10-1, was isolated by anti-tubulin staining of temperatur e-sensitive mutant banks of budding yeast. ndc10-1 has a defect in chr omosome segregation since chromosomes remain at one pole of the anapha se spindle. This produces one polyploid cell and one aploid cell, each containing a spindle pole body (SPB). NDC10 was cloned and sequenced and is identical to CBF2 (Jiang, W., J. Lechner. and J. Carbon. 1993. J. Cell Biol. 121:513-519) which is the 110-kD component of a centrome re DNA binding complex (Lechner, J., and J. Carbon. 1991. Cell. 64:717 -725). NDC10 is an essential gene. Antibodies to Ndc10p labeled the SP B region in nearly all the cells examined including nonmitotic cells. In some cells with short spindles which may be in metaphase, staining was also observed along the spindle. The staining pattern and the phen otype of ndc10-1 are consistent with Cbf2p/Ndc10p being a kinetochore protein, and provide in vivo evidence for its role in the attachment o f chromosomes to the spindle.