Worm Breeder's Gazette 16(2): 38
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
|1||International Institute of genetics and Biophysics -CNR - 10, Via Marconi 80125 Naples Italy|
|2||Dipartimento di Genetica e Biologia Generale e Molecolare, Facolta' di Scienze, Universita' di Napoli "Federico II"- 8, Via Mezzocannone 80134 Naples, Italy|
Eukaryotic genes, defective in the repair of DNA damage, were isolated
in yeast and shown to be involved both meiotic recombination and recombinatorial
repair of double strand breaks (DSBs) on DNA. They belong to the RAD52
homologous recombination pathway. The Rad51 protein in particular is structurally
and functionally related to the RecA gene product of Escherichia coli.
It catalizes strand transfer between homologous DNA molecules, mutations
in this gene lead to enhanced sensitivity to genotoxic agents (like X-
and gamma-radiation that induce DSBs), reduction
of mitotic recombination and impaired meiosis.
We have cloned the RAD51 homolog in C. elegans (Rinaldo et al. 1998) . Using a CeRAD51 promoter fusion with the reporter gene LacZ in Andy Fire's vector pPD96.04, we have been observed, that the C. elegans RAD51 promoter is activated after gamma-irradiation.
The construct was injected in lin-15 adult hermaphrodites using the lin-15 wild type gene as transformation marker. We obtained 5 independent transformed lines. The expression pattern observed was consistent in the different lines: about 30 % of lin-15+ animal express the reporter LacZ gene in a limited number of cells varying in quantity and type between different animals and stages.
A population of transgenic hermaphrodite worms was syncronized and samples at different stages were subjected to gamma-irradiations (12000 rad with a Cs137 source). The treatment results in an overall enhancement in the expression of the reporter gene, LacZ, driven by the CeRAD51 promoter, and in an increse in the number of animals expressing the transgene in the population. Statistical analysis based on the number of worms expressing LacZ before and after induction is summarized in the following table.
Rinaldo C., Ederle S., Rocco V., and Volpe A. L. (1998) The Caenorhabditis
elegans RAD51 homolog is transcribed into two alternative mRNAs potentially
encoding proteins of different sizes. Mol. Gen. Genet. 260 : 289-294.