Duper is a Cryptochrome 1 null mutation in Syrian hamsters

The duper mutation is a recessive mutation that shortens the period length of the circadian rhythm in Syrian hamsters. These animals show a large phase shift when responding to light pulses. Using two distinct ecotypes and a fast homozygosity mapping strategy, we identified duper as an early nonsense allele of Cryptochrome 1 (Cry1) leading to a short, unstable protein. Liver, cortex and SCN tissues from 4 duper and 4 wild type hamsters, were collected at CT15. For cortex and SCN, RNA extracted from the 4 hamsters of the same genotypes were pooled together before library preparations. For liver, RNA extracted from each hamster was used to prepare library separately. In total, 12 libraries (2x1 for cortex, 2x1 for SCN and 2x4 for liver) were pooled for sequencing.