Gene expression and RNA interference phenotypes were investigated for a Caenorhabditis elegans homologue (Ce-RCQ-5) of human RecQ5 protein. Expression of the mRNA was observed by in situ hybridization from earliest embryogenesis and gradually decreased during late embryogenesis. Ce-RCQ-5 was immuno-localized in the nuclei of embryos, germ cells, and oocytes and also in the nuclei of various somatic cells of larvae and adults. Despite ubiquitous expression in postembryonic cells, RCQ-5 protein expression was highest in intestinal cells, which was confirmed by tagging the gene expression with green fluorescence protein. When endogenous Ce-rcq-5 gene expression was inhibited by RNA interference, no clear phenotypes were observed during development. However, C. elegans life span was reduced by 37% due to RNA interference of rcq-5 gene, suggesting its possible role in maintenance of genomic stability, as has been ascribed to other RecQ family DNA helicases. In addition, C. elegans became significantly more sensitive to ionizing radiation after inhibition of rcq-5 gene expression, indicating an involvement of C. elegans RCQ-5 in a cellular response to DNA damage, possibly in DNA repair.
Bibliographical noteFunding Information:
We thank Dr. Alan Coulson (Sanger Center) for the E03A3 cosmid clone, Andrew Fire (Carnegie institute) for pPD95.75 vector, and Robert Barstead (Oklahoma Medical Research Foundation) for RB835 strain. N2, RB835, CB1597 C. elegans strains were obtained from C. elegans Genetics Center (St. Paul, MN), which is supported by the National Center for Research Resources. This work was supported by the Life Phenomena & Function Research Grant [01-J-LF-01-B-83] and Atomic Energy Basic Research Grant [98-f-12] from the Korean Ministry of Science and Technology to H.-S. Koo.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology