Screening for novel genes involved in TLS in mammalian cells

Because TLS is an inherently mutagenic process, it is under tight regulation to avoid an escalation in mutation frequency. We are performing genetic screens designed to identify novel genes that are involved in mammalian TLS. We are currently using a two-stage siRNA screening approach: The first stage is a screen based on UV sensitivity under conditions in which TLS plays a role more important than under normal conditions. Candidates from the first stage are then screened in the second more specific stage, using a TLS-specific high throughput assay that we have developed. This study is done in collaboration with Prof. Eytan Domany’s group (Physics faculty). Screening of over 1100 genes comprising several targeted gene libraries led to the identification of several novel TLS genes, which are currently being analyzed.