Eukaryotic Cell doi:10.1128/EC.00246-07
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.
Multiple modes of chromatin configuration at natural meiotic recombination hotspots in fission yeast
Kouji Hirota*,
Walter W. Steiner,
Takehiko Shibata,
and
Kunihiro Ohta
Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan; Shibata Distinguished Senior Scientist Laboratory, RIKEN Discovery Research Institute, Wako-shi, Saitama 351-0198, Japan; Department of Biology, P.O. Box 2032, Niagara University, Lewiston, New York 14109
* To whom correspondence should be addressed. Email:
khirota{at}postman.riken.jp.
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Abstract |
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The ade6-M26 meiotic recombination hotspot of fission yeast is defined by a cAMP-responsive element (CRE)-like heptanucleotide sequence 5'-ATGACGT-3', which acts as a binding site for the Atf1/Pcr1 heterodimeric transcription factor required for hotspot activation. We previously demonstrated that the local chromatin around the M26 sequence motif alters to exhibit higher sensitivity to micrococcal nuclease before the initiation of meiotic recombination. In this study, we have examined whether or not such alterations in chromatin occur at natural meiotic DNA double-strand break (DSB) sites in S. pombe. At one of the most prominent DSB sites, mbs1 (meiotic break site1), the chromatin structure has a constitutively accessible configuration at or near the DSB sites. The establishment of the open chromatin state and DSB formation are independent of the CRE-binding transcription factor, Atf1. Analysis of the chromatin configuration at CRE-dependent DSB sites revealed both differences and similarities to mbs1. For example, the tdh1+ locus, which harbors a CRE-consensus sequence near the DSB site, shows a meiotically induced open chromatin configuration, similar to ade6-M26. In contrast, cds1+ locus is similar to mbs1 in that it exhibits a constitutive open configuration. Importantly, Atf1 is required for the open chromatin formation in both tdh1+ and cds1+. These results suggest that CRE-dependent meiotic chromatin changes are intrinsic processes related to DSB formation in fission yeast meiosis. In addition, the results suggest that the chromatin configuration in natural meiotic recombination hotspots can be classified into at least three distinct categories: (1) Atf1•CRE-independent constitutively open chromatin configuration, (2) Atf1•CRE-dependent meiotically induced open chromatin configuration, and (3) Atf1•CRE-dependent constitutively open chromatin configuration.
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