Cloning, characterization, and localization of mouse and human SPO11

Spo11 is a meiosis-specific protein in yeast that has been found covalently bound to DNA double-strand breaks (DSBs) during the early stages of meiosi s. These DSBs initiate homologous recombination, which is required for prop er segregation of chromosomes and the generation of genetic diversity durin g meiosis. Here we report the cloning, characterization, tissue expression, and chromosomal localization of both mouse and human homologues of Spo11. The putative mouse and human proteins are 82% identical and share approxima tely 25% identity with other family members. Northern blot analysis reveale d testis-specific expression for both genes, but RT-PCR results showed ubiq uitous expression of at least a portion of Spo11 in mouse. Human SPO11 was also detected in several somatic tissues. Mouse Spo11 was localized to chro mosome 2H4, and human SPO11 was localized to chromosome 20q13.2-q13.3, a re gion amplified in some breast and ovarian tumors.