TY - JOUR
T1 - Caenorhabditis elegans Ce-rdh-1/rad-51 functions after double-strand break formation of meiotic recombination
AU - Takanami, Takako
AU - Mori, Akiyuki
AU - Takahashi, Hideyuki
AU - Horiuchi, Saburo
AU - Higashitani, Atsushi
N1 - Funding Information:
We thank Drs MacQueen and Villeneuve for construction of the AV146 strain, Drs. Dernburg, McDonald, Moulder, Barstead, Dresser and Villeneuve for construction of the AV106 strain, Dr. Kohara for kindly supplying yk clones, the C. elegans Genetic center for kindly supplying these mutant strains, Ms. Izumi Chiba and Dr. Akira Yasui for help with X-ray irradiation and the C. elegans Genome Sequence Consortium for sequencing its complete genome of C. elegans. We are grateful to Ikuma Maeda and Asako Sugimoto for kindly teaching the in-situ hybridization methods. This work was supported by Yamada Science Foundation, Grants-in-Aid for Priority Areas Research C (cancer: 13214008 to A.H.) and for Basic Research (06274 to T. T. ) from the Ministry of Education, Science and Culture of Japan.
PY - 2003
Y1 - 2003
N2 - During meiotic prophase 1, homologous recombination is accompanied by dynamic chromosomal changes. The Ce-rdh-1/rad-51 gene is the only bacterial recA-like gene in the nematode C. elegans genome. Upon depletion of Ce-rdh-1/rad-51 using the RNA interference method, abnormal 'kinked' chromosomes can be observed in mature oocytes at diakinesis, whereas synapsis between homologous chromosomes during the pachytene stage is normal. Following fertilization, Ce-rdh-1/rad-51-depleted embryos die early in embryogenesis, and their nuclei exhibit abnormal chromosome fragments and bridges. From epistasis analyses with Ce-spo-11 defective mutant and ionizing radiation, it is indicated that Ce-rdh-1/rad-51 functions after double-strand break (DSB) formation of meiotic recombination. Under the Ce-chk-2 defective condition, whose meiotic synapsis and meiotic recombination between homologous chromosomes are completely inhibited, the Ce-rdh-1/rad51 is normally expressed in the gonadal cells. Moreover, it seems that exogenous DSBs in the Ce-chk-2 defective nuclei at the pachytene stage can be repaired between sister chromatids in a Ce-rdh-1/rad-51-dependent manner. These results indicate that Ce-rdh-1/rad51 functions after both endogenous and exogenous DSB formation during meiosis, but not as 'pairing centers' for meiotic synapsis.
AB - During meiotic prophase 1, homologous recombination is accompanied by dynamic chromosomal changes. The Ce-rdh-1/rad-51 gene is the only bacterial recA-like gene in the nematode C. elegans genome. Upon depletion of Ce-rdh-1/rad-51 using the RNA interference method, abnormal 'kinked' chromosomes can be observed in mature oocytes at diakinesis, whereas synapsis between homologous chromosomes during the pachytene stage is normal. Following fertilization, Ce-rdh-1/rad-51-depleted embryos die early in embryogenesis, and their nuclei exhibit abnormal chromosome fragments and bridges. From epistasis analyses with Ce-spo-11 defective mutant and ionizing radiation, it is indicated that Ce-rdh-1/rad-51 functions after double-strand break (DSB) formation of meiotic recombination. Under the Ce-chk-2 defective condition, whose meiotic synapsis and meiotic recombination between homologous chromosomes are completely inhibited, the Ce-rdh-1/rad51 is normally expressed in the gonadal cells. Moreover, it seems that exogenous DSBs in the Ce-chk-2 defective nuclei at the pachytene stage can be repaired between sister chromatids in a Ce-rdh-1/rad-51-dependent manner. These results indicate that Ce-rdh-1/rad51 functions after both endogenous and exogenous DSB formation during meiosis, but not as 'pairing centers' for meiotic synapsis.
KW - Ce-chk-2
KW - Homologous recombination
KW - Meiosis
KW - recA-like gene
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U2 - 10.1023/A:1022863814686
DO - 10.1023/A:1022863814686
M3 - Article
C2 - 12733639
AN - SCOPUS:0037271497
SN - 0967-3849
VL - 11
SP - 125
EP - 135
JO - Chromosome Research
JF - Chromosome Research
IS - 2
ER -