Abstract: The present invention provides isolated nucleic acid molecules comprising a polynucleotide encoding either of two alternative splice variants of human sel-10, one of which is expressed in hippocampal cells, and one of which is expressed in mammary cells. The invention also provides isolated sel-10 polypeptides and cell lines which express them in which A&bgr; processing is altered.

Abstract: Disclosed is a method of identifying genes whose gene products cause chromosome missegregation. The method involves transfecting a mammalian gene being assessed into a cell and then assessing whether the progeny cells have increased aneuploidy or increased chromosome breaks or translocations compared with cells that have not been transfected with the gene. Genes identified in this manner are likely to be involved in causing diseases such as cancer and Alzheimer's Disease, which result from improper chromosome segregation. Also disclosed is a method of identifying agents which can be used in the treatment of diseases caused by improper chromosome segregation. The method involves treating cells that have been transfected with a gene whose gene product causes improper chromosome segregation with an agent being assessed.