By molecular genetic approach using polymorphic DNA markers which detect allelic deletion at specific chromosomal loci, we analyzed 30 human stomach cancers for possible loss of chromosomal heterozygosity. We analyzed 25 loci on 18 different chromosomes covering regions frequently deleted in several types of cancers. Loss of chromosomal heterozygosity was observed only in five of 30 cases exami...

Sex chromosomes and their evolution have captivated researchers since their discovery. For more than 100 years, the dominant model of sex chromosome evolution has held that differentiated sex chromosomes, such as the X and Y chromosomes of mammals or the Z and W chromosomes of birds, evolved from ordinary autosomes, primarily through the degeneration of the sex-specific Y or W chromosome. At th...

Hybrids constructed with the murine fibroblasts IT22 and either human lymphoid cells or human melanoma cells retain the human chromosomes 1, 14, and 21 and lose the human chromosome 2. The human lymphocyte-mouse fibroblast hybrids preferentially retain the human chromosome 11, while the human melanoma-murine fibroblast hybrids preferentially retain the human chromosome 8 and lose the human chro...

In humans and other mammals with XX females and XY males, the Y bears a gene (SRY) that induces testis differentiation in the embryo and switches on hormones that masculinize it. The human X has more than 1500 genes, but the tiny Y is a genetic wasteland and bears only 45 protein-coding genes, most active only in testis. To discover how human sex chromosomes got to be so weird, we compared the ...