The entire coding sequence of the Rcc1 locus has been deleted and replaced with sequence that encodes the wild-type Hsap\RCC1 coding sequence tagged at the N-terminal end with mScarlet-I (allowing expression of the tagged Hsap\RCC1 protein under the control of Rcc1 regulatory sequences). A Avic\GFP3xP3.cUa marker has also been inserted, downstream of the Hsap\RCC1 coding sequence.