Lecture 33: Homologous Recombination

loss of heterozygosity

A condition where one allele of a gene is lost in a diploid organism, resulting in a cell that is homozygous for a certain gene. This often occurs during cancer development and can affect tumor suppressor genes

mechanisms leading to LOH

chromosome loss, deletion, unbalanced translocation, loss and reduplication, mitotic recombination, point mutation

crossover

• the exchange of genetic material between homologous chromosomes during meiosis

• two chromosomes, normally two homologous instances of the same chromosome, break and then reconnect but to the different end piece

Rb gene

A tumor suppressor gene that plays a critical role in regulating the cell cycle. The Rb gene, when mutated or lost, is often associated with various cancers, particularly retinoblastoma