抄録
RecQ helicases are involved in the process of DNA replication, recombination and repair. Arabidopsis genome contains seven RecQ like genes. Recently, Hartung et al reported RecQl4A and RecQl4B knockout mutant in Arabidopsis. AtRecQl4A mutant showed enhanced frequency of homologous recombination compare with that of wild type. In contrast, AtRecQl4B mutant showed reduced frequency of HR. Furthermore, AtRecQl4A mutant showed sensitivity to DNA damaging agents, but AtRecQl4B mutant did not. In monocotyledon model plant, rice had been reported to have seven RecQ homologues. Interestingly, in contrast to Arabidopsis, rice has a single RecQl4-like gene. We cloned the full length OsRecQl4 cDNA, which is 3.5 kb in length and encodes an open reading frame of 1174 amino acid. It has a HRDC (Helicase and RNase D C-terminal) domain, which shows function of dissolution of double Holliday junctions (Wu L. et al. 2005). In addition, we characterized T-DNA and Tos17 insertion mutant of RecQl4 in rice.
