Worm Breeder's Gazette 15(5): 39 (February 1, 1999)

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.

Characterization of an ATM-like gene Ce-atl-1

Hidetoshi Aoki1, Shusei Sato2, Takeshi Ishihara3, Isao Katsura3, Hideyuki Takahashi1, Atsushi Higashitani1,4

1 Institute of Genetic Ecology, Tohoku University, 2-1-1 Katahira, Sendai, 980-8577, Japan
2 Kazusa DNA Research Institute, 1532-3 Yana, Kisarazu, 292-0812, Japan
3 National Institute of Genetics, 1-111 Yata, Mishima, 411-8540, Japan
4 ahigashi@ige.tohoku.ac.jp

We are interested in check point controls after meiotic recombination and mitotic DNA damage. In 1995 human ataxia telangiectasia mutated (ATM) gene was isolated and characterized by Savitsky, K. et al. (Science 268, 1749-1753). The ATM protein contains a PI-3 kinase domain in its C-terminal region. This feature is shared with a group of proteins including Rad3 in S. pombe, MEC1(ESR1) and TEL1 in S. cerevisiae, MEI-41 in D. melanogaster, and ATR and DNA-dependent protein kinase in human and mouse. The ATM protein plays key roles in checkpoint control of mitosis and meiosis. The phenotype of knockout mouse in this gene is pleiotropic as human ATM deficient patiant is (Barlow et al., Cell 86, 159-171, 1996).

From blast search of a C. elegans database, a homolog of ATM was identified in the cosmid clone T06E4.3. We named the gene Ce-ATL-1 (C. elegans ATM like 1). The primary structure of the cDNA was determined by sequencing the RT-PCR products of total mRNA and the yk76g7 cDNA clone isolated by Dr. Yuji Kohara (NIG, Japan). The total length of the cDNA is 7711bp and the putative gene product consists of 2514 amino acid residues (accession # AB018598). A PI-3 kinase motif was located in its C-terminal region. Comparison of amino-acid sequences of this motif indicated that the CeATL1 sequence is much closer to Mec1(Esr1), Tel1, Mei-41, than to bovine p110 which is the catalytic subunit of PI-3 kinase. By using RT-PCR, it was found that the level of mRNA of Ce-atl-1 was increased about 5 fold in the adult stage, while it was expressed in all stages.

To study the function of the Ce-atl-1 gene, we carried out RNAi to repress its expression. The phenotype of the F1 progenies was extremely pleiotropic. We could classify the phenotypes into various categories such as dead egg, L1 and L2 lethal (irregular L1 and L2), protruding vulva, abnormal gonad, irregular oocyte, dpy or small size, burst from vulva, abnormal intestine and high incidence of males. It suggests that the Ce-atl-1 is an essential gene. We are now attempting to identify novel gene(s) interacting with the Ce-atl-1 by using yeast two-hybrid system.