E. DEPARTMENT OF INTEGRATED GENETICS
E-a. Division of Human Genetics - Hiroyuki Sasaki Group

RESEARCH ACTIVITIES

(1) Establishment and maintenance of genomic imprinting in the germline and in early embryos

Hiroyuki Sasaki, Masahiro Kaneda, Ryutaro Hirasawa, Kenichiro Hata, Maki Kusumi, Takashi Sado, Kenji Kumaki, Hiroyasu Furuumi, Masaki Okano¹, Naomi Tsujimoto², En Li², Tomohiro Suzuki³, Shigeharu Wakana³ and Toshihiko Shiroishi³ (¹CDB, RIKEN; ²Harvard Med. Sch.; ³GSC, RIKEN)

--DNA methylation serves as an important gene-marking mechanism for discrimination of the parental alleles of imprinted genes. Although de novo DNA methyltransferases of the Dnmt3 family are implicated in maternal imprinting, the lethality of conventional Dnmt3a and Dnmt3b knockout mice precluded further studies. We have disrupted Dnmt3a and Dnmt3b in male and female germ cells, leaving them intact in somatic cells, by conditional gene knockout technology^{2), 3)}. Offspring from the Dnmt3a conditional mutant females died in utero and lacked methylation and allele-specific expression at maternally imprinted loci. The Dnmt3a conditional mutant males showed impaired spermatogenesis and a lack of methylation at paternally imprinted loci in spermatogonia. Although these defects closely resembled those of Dnmt3L knockout mice, exact contribution of Dnmt3a and Dnmt3L to paternal imprinting varied from locus to locus. By contrast, the Dnmt3b conditional mutants and their offspring showed no phenotype. These results indicate that Dnmt3a is the critical enzyme responsible for both paternal and maternal imprinting^{2), 3)}. We also study how the primary imprints are maintained in preimplantation mouse embryos, and set out to screen ENU-treated mutant mouse stocks for mutations that affect the establishment of germline imprints in collaboration with a group in GSC, RIKEN.

(2) Comparative analyses of the distal imprinted domain on mouse chromnosome 7 and the orthologous domain on chicken chromosome 5

Hiroyuki Sasaki, Takaaki Yokomine, Wahyu Purbowasito¹, Hisao Shirohzu, Chikako Suda, Takashi Sado, Hisakazu Iwama, Kazuho Ikeo, Tetsuya Hori, Masaoki Tsuzuki², Shigeki Mizuno³, Yo-ichi Matsuda⁴, Chiyoko Sato⁵, Katsuzumi Okumura⁵, Tsunehiro Mukai⁶, Mohamad Zubair⁷, Ken Tsutsui⁸, Reiko Kato⁹, Atsushi Toyoda⁹, Masahira Hattori⁹ and Yoshiyuki Sakaki⁹ (¹Kyushu Univ.; ²Hiroshima Univ.; ³Nihon Univ.; ⁴Hokkaido Univ.; ⁵Mie Univ.; ⁶Saga Univ.; ⁷NIBB; ⁸Okayama Univ.; ⁹GSC, RIKEN)

--Genomic imprinting, an epigenetic gene-marking phenomenon in the germline, causes parent-of-origin-specific monoallelic expression of a subset of mammalian genes. Imprinted genes tend to form clusters in the genome (imprinted domains), which may be related to the mechanism of imprinting or to the evolution of imprinting. As a step to understand the structural and functional characteristics of the imprinted domains, we have cloned and sequenced a 1-Mb imprinted domain in mouse chromosome 7F4/F5 and its orthologous domain in chicken chromosome 5 (0.5 Mb). Using the mouse YAC clone that we have isolated, Cerrato et al. found that this domain is in fact composed of two autonomous subdomains¹⁾. We then found that the genes of the chicken domain are not imprinted and, furthermore, that the chicken domain lacks the unique tandem repeat cluster of 0.2 Mb, the H19 gene, and the imprinting control elements, all of which are present in the mouse. The results indicate that the mammalian imprinted genes were already clustered in the common ancestors of mammals and birds and that the imprinting mechanism, which can affect multiple genes in the cluster, came in later during mammalian evolution^{8), 9)}. We also mapped a total of 52 nuclear matrix attachment regions (MARs) in the imprinted mouse domain. We found that the MARs are unevenly distributed in the domain and that there is a large MAR cluster in the boundary region of two imprinted subdomains⁶⁾.

(3) Imprinting mechanisms of the mouse Igf2/H19 sub-domain

Hiroyuki Sasaki, Yuzuru Kato, Ko Ishihara¹, Melanie Ehrlich², Walter Reith³ and Mitsuyoshi Nakao¹ (¹Kumamoto Univ.; ²Tulane Univ.; ³Univ. Geneva)

--The imprinted mouse 7F4/F5 domain contains two linked imprinted genes Igf2 and H19 near its centromeric boundary: Igf2 is paternally expressed and H19 maternally expressed. It is known that the paternal-specific methylation of the differentially methylated region (DMR) upstream of H19 is the primary signal for the Igf2/H19 imprinting. We found that a winged-helix type DNA-binding protein called RFX1 or MDBP binds to the conserved sequences within the DMR. Interestingly, this protein binds to the target sequence preferentially when they are methylated at CpG sites. We are currently looking at RFX knockout mice to see whether these proteins play a role in Igf2/H19 imprinting. We also wrote a review on the interactions between the DMRs by chromatin looping¹⁰⁾.

(4) Computer-assisted search for sequence features common to imprinted DMRs

Hiroyuki Sasaki, Hisato Kobayashi, Takashi Abe and Toshimichi Ikemura¹ (¹SOKENDAI)

--Although the imprinted DMRs, which show differential methylation depending on parental origin, often play crucial roles in imprinting, features common to the DMRs have not been identified. We therefore set out to look for sequence features common to the DMRs by computer-assisted programs. We first located the DMR sequences on self-organizing maps (SOMs) produced from the mouse genome sequences for di-, tri- and tetra-nucleotides. We found that most DMRs are located in the periphery of the SOMs: they are more CpG-rich than most of the genome but less CpG-rich than the CpG islands. More detailed studies on the DMR sequences are ongoing.

(5) Molecular pathology of ICF syndrome

Hiroyuki Sasaki, Hiroyasu Furuumi, Tadashi Kajii, Tomohiro Kamoda¹, Nobuaki Iwasaki¹, Naomi Tobita¹, Nobuko Fujiwara¹, Akira matsui¹, Yu-ichi Goto² and Takeo Kubota² (¹Univ. Tsukuba; ²Yamanashi Univ.)

--We previously studied two Japanese families with ICF (immunodeficiency, centromeric instability, facial anomalies) syndrome, an autosomal recessive disorder with hypomethylation of satellite DNA, and found that they have mutations in the de novo DNA methyltransferase gene DNMT3B. We have now studied a new Japanese ICF case and found that this patient does not have any mutation in DNMT3B. This suggests that the molecular pathology of ICF syndrome is heterogeneous and that a gene other than DNMT3B can affect the methylation of pericentromeric satellite DNA⁴⁾.

(6) Development of a universal DNA chip system applicable to any organism

Hiroyuki Sasaki, Shin-ichi Mizuno¹, Tadafumi Iino¹, Hidetoshi Ozawa¹, Kosuke Tashiro¹ and Takashi Gojohbori (¹Kyushu Univ.)

--We carried out a collaborative research project with groups in Kyushu University to develop a universal DNA chip system that can be used to study expression of any gene in any organism. We established the basic chip design and protocols for this innovative chip system (patent application no. 2004-278122). Development of the universal DNA chip system for practical use is underway.

(7) Antisense regulation at the Xist locus

Takashi Sado, Tatsuya Ohhata¹, Yuko Hoki¹and Hiroyuki Sasaki (¹PRESTO, JST)

--Xist (X-inactive specific transcript), which does not encode a protein, is essential for X-inactivation to occur in cis. Expression of Xist is negatively regulated in cis by its antisense gene Tsix. Disruption of Tsix, therefore, induces upregulation of Xist in cis. We have been studying the molecular mechanism of how Tsix regulates Xist expression in a cis-limited manner by gene targeting technology. We examined chromatin at the Xist locus on the Tsix deficient X chromosome in embryos. We found that in the absence of Tsix, methylation levels of CpG sites were reduced and chromatin structure became open at the Xist locus. In addition, histones of this region were modified to be characteristic of active chromatin. These results suggest that Tsix plays a role in establishment of repressive chromatin at the Xist and silence the Xist gene.

(8) X-inactivation in mouse embryos deficient for histone methyltransferase G9a

Tatsuya Ohhata, Makoto Tachibana¹, Hiroyuki Sasaki, Yoichi Shinkai¹ and Takashi Sado (¹Kyoto Univ.)

--Accumulating evidence suggests that methylation of histone H3 at lysine 9 (K9) and 27 (K27) is implicated in X-inactivation. Histone methyltranferase G9a is the enzyme that catalyzes methylation of K9 and perhaps K27 in euchromatic region. We studied X-inactivation in mouse embryos deficient for G9a, which die around the early somite stage. RNA-FISH revealed that Xist was appropriately regulated in both males and females. Taking advantage of X-linked GFP transgenes, effects of functional loss of G9a on the maintenance of X-inactivation were analyzed. We did not observe reactivation of the hitherto inactivated GFP transgenes in both the embryonic and extraembryonic tissues, suggesting that X-inactivation is stably maintained in G9a-null embryos. The same result was obtained using X-linked LacZ transgenes located more distal to the X-linked GFP transgenes, indicating that inactive state of these transgenes was stably maintained regardless the distance from the X-inactivation center, from which X-inactivation initiates and spreads. The results suggest that the X-inactivation process is properly regulated in the absence of G9a⁵⁾. It is likely that methylation of histone H3 at K9 and K27 on the inactive X chromosome is mediated by an enzyme(s) other than G9a.

(9) Role of Dnmt3L in spermatogenesis and genomic imprinting during oogenesis

Kenichiro Hata, Maki Kusumi, En Li¹ and Hiroyuki Sasaki (¹Harvard Med. Sch.)

--Dnmt3L (DNA cytosine-5-methyltransferase 3-Like) encodes a protein of 421 amino acid residues and harbors a putative zing finger domain that shares a high degree of homology with the PHD-like domain of DNA methyltransferases Dnmt3a and Dnmt3b. The C-terminal part of Dnmt3L is related to DNA cytosine-5-methyltransferase, but it does not possess critical motifs for methyltransferase activity. We have generated Dnmt3L-deficient mice by gene targeting. While Dnmt3L^-/- female mice grew normally, all embryos from pregnant Dnmt3L ^-/- mothers died around E10.5. The maternally methylated imprinted genes, e.g. Igf2r and Peg1, were hypomethylated in embryos derived from Dnmt3L ^-/- females x Dnmt3L ^+/+ males, but paternally methylated imprinted genes were unaffected. Also, Dnmt3L^-/- male mice showed severe defects in spermatogenesis, which is similar to, but severer than, the phenotype displayed by Dnmt3a^-/- mice. We speculate that Dnmt3L functions via interactions with Dnmt3a and/or Dnmt3b to control DNA methylation in developing germ cells. Dnmt3L may be involved in not only the establishment of genomic imprinting but also DNA methylation of other regions.

PUBLICATIONS

Papers
1. Cerrato, F., Sparago, A., Zou, X., Dean, W., Bruggemann, M., Sasaki, H., Reik, W. and Riccio, A. (2005) The two domain hypothesis in Beckwith-Wiedemann syndrome: autonomous imprinting of the telomeric domain of the distal chromosome 7 cluster. Hum. Mol. Genet. (in press).
2. Kaneda, M., Okano, M., Hata, K., Sado, T., Tsujimoto, N., Li, E. and Sasaki, H. (2004). Essential role for de novo DNA methyltransferase Dnmt3a in paternal and maternal imprinting. Nature 429, 900-903.
3. Kaneda, M., Sado, T., Okano, M., Hata, K., Tsujimoto, N., Li, E. and Sasaki, H. (2004). Role of de novo DNA methyltransferases in initiation of genomic imprinting and X-chromosome inactivation. Cold Spring Harbor Symp. Quant. Biol. (in press).
4. Kubota, T., Furuumi, H., Kamoda, T., Iwasaki, N., Tobita, N., Fujiwara, N., Goto, Y., Matsui, A., Sasaki, H. and Kajii, T. (2004). .ICF syndrome in a girl with DNA hypomethylation but without detectable DNMT3B mutation. Am. J. Med. Genet. 129A, 290-293.
5. Ohhata, T., Tachibana, M., Tada, M., Tada, T., Sasaki, H., Shinkai, Y. and Sado, T. (2004). X-inactivation is stably maintained in mouse embryos deficient for histone methyltransferase G9a. Genesis 40, 151-156.
6. Purbowasito, W., Suda, C., Yokomine, T., Zubair, M., Sado, T., Tsutsui, K. and Sasaki, H. (2004). Large-scale identification and mapping of nuclear matrix-attachment regions in the distal imprinted domain of mouse chromosome 7. DNA Res. 11, 391-407.
7. Sado, T., Okano, M., Li, E. and Sasaki, H. (2004). De novo methylation is dispensable for the initiation and propagation of X chromosome inactivation. Development 131, 975-982.
8. Shirohzu, H., Yokomine, T., Sato, C., Kato, R., Toyoda, A., Purbowasito, W., Suda, C., Mukai, T., Hattori, M., Okumura, K., Sakaki, Y. and Sasaki, H. (2004). A 210-kb segment of tandem repeats and retroelements located between imprinted subdomains of mouse distal chromosome 7. DNA Res. 11, 325-334.
9. Yokomine, T., Shirohzu, H., Purbowasito, W., Toyoda, A., Iwama, H., Ikeo, K., Hori, T., Mizuno, S., Tsudzuki, M., Matsuda, Y., Hattori, M., Sakaki, Y. and Sasaki, H. (2005). Structural and functional analysis of a 0.5-Mb chicken region orthologous to the imprinted mammalian Ascl2/Mash2-Igf2-H19 region. Genome Res. (in press).

Reviews
10. Kato, Y. and Sasaki, H. (2005). Imprinting and looping: epigenetic marks control interactions between regulatory elements. BioEssays (in press).
11. 石原宏,佐々木裕之,中尾光善（2004）クロマチンインスレーターの構造と機能.わかる実験医学シリーズ 注目のエピジェネティクスがわかる63-70.
12. 金田正弘,佐渡敬,佐々木裕之（2004）遺伝子に刷り込まれた記憶―細胞分化とDNAのメチル化・ゲノムインプリンティング.生物の科学 遺伝58, 69-74.
13. 金田正弘,佐々木裕之（2004）HOT PRESS:DNAメチル化酵素Dnmt3aが生殖系列でゲノム刷り込み（インプリンティング）を行う.細胞工学23, 934-935.
14. 熊木健治,佐々木裕之.幹細胞とゲノムインプリンティング.バイオインダストリー（印刷中）.
15. 佐々木裕之（2004）エピジェネティクスと疾患.Molecular Medicine 41（増刊号）ヒトゲノム―ヒトの理解と疾病の克服332-338.
16. 佐々木裕之（2005）.ゲノムインプリンティング,新しい潮流をもたらしたスーパーモデル（Overview）.Molecular Medicine（印刷中）.
17. 佐渡敬（2004）X染色体遺伝子量補償.ゲノム医学4, 51-57.
18. 佐渡敬,大畑樹也（2005）.マウス胚体外組織におけるインプリント型X染色体不活性化.Molecular Medicine（印刷中）.
19. 秦健一郎,佐々木裕之（2005）:生殖系列におけるインプリント成立機構.Molecular Medicine（印刷中）.
20. 古海弘康,佐々木裕之（2004）シリーズ最新医学講座・転写因子12.エピジェネティクス制御とその異常.臨床検査48, 1673-1679.

Books
21. Sasaki, H. (2005). DNA methylation in epigenetics, development and imprinting. In: Encyclopedia of Genetics, Genomics, Proteomics and Bioinformatics (eds. Dunn, M., Jorde, L., Little, P. & Subramaniam, S.), John Wiley & Sons, Chichester (in press).
22. 佐々木裕之編（2004）Springer Reviews シリーズ―エピジェネティクス,シュプリンガー・フェアラーク東京.
23. 佐渡敬（2004）性染色体の遺伝子量補償.Springer Reviewsシリーズ―エピジェネティクス（佐々木裕之編）,pp.117-127,シュプリンガー・フェアラーク東京.
24. 秦健一郎（2004）生殖,発生の異常とエピジェネティクス.Springer Reviewsシリーズ―エピジェネティクス（佐々木裕之編）,pp.183-190,シュプリンガー・フェアラーク東京.
25. 平澤竜太郎,佐々木裕之.DNAメチル化.再生医療教科書シリーズ,第3巻「再生医療のための分子生物学（仲野徹・赤池敏宏監修）」（印刷中）.
26. 古海弘康,佐々木裕之（2004）哺乳類のメンデル遺伝するエピジェネティクス.Springer Reviewsシリーズ―エピジェネティクス（佐々木裕之編）,pp.129-134,シュプリンガー・フェアラーク東京.
27. 佐渡敬（2004）（日本語訳）Hall, I.M., Grewal, S.I.S. Structure and Function of Heterochromatin: Imprication fro Epigenetic Gene Silencing and Genome Organization. In “RNAi: A guide to gene silencing" (Ed. Hannon, G.J.)（日本語版監修 中村義一）,pp.199-223,メディカル・サイエンス・インターナショナル.

ORAL PRESENTATIONS

1. Sado, T., Okano, M., Li, E. and Sasaki, H.: De novo DNA methylation is dispensable for initiation and propagation of X chromosome inactivation. Keystone Symposia "Emerging Mechanisms of Epigenetic Regulation", Tahoe City, California, USA, January, 2004.
2. Sasaki, H.: Essential role for de novo DNA methyltransferase Dnmt3a in both paternal and maternal imprinting. PROBRAIN and CREST Symposium "DNA Methylation and Histone Modifications", Tokyo, February, 2004.
3. Sasaki, H., Kaneda, M., Sado, T., Okano, M., Hata, T., Tsujimoto, N. and Li, E.: Role of de novo DNA methyltransferases in initiation of genomic imprinting and X-chromosome inactivation. The 69th Cold Spring Harbor Symposium on Quantitative Biology "Epigenetics", Cold Spring Harbor, New York, USA, June, 2004.
4. Sasaki, H., Kaneda, M., Sado, T., Okano, M., Hata, T., Tsujimoto, N. and Li, E.: Role of de novo DNA methylation in initiation of genomic imprinting and X-chromosome inactivation. Cold Spring Harbor "Mouse Molecular Genetics Meeting", New York, USA, September, 2004.
5. Sasaki, H.: Essential role for de novo methyltransferase Dnmt3a in paternal and maternal imprinting. Satellite Symposium of the JSAR Annual Meeting 2004 "Current Status and Perspectives in Reproductive Biology and Biotechnology", Kyoto, September, 2004.
6. Sasaki, H., Kaneda, M., Sado, T., Okano, M., Hata, T., Tsujimoto, N. and Li, E.: Essential role for de novo methyltransferase Dnmt3a in paternal and maternal imprinting. Genomic Imprinting-2004 Workshop, Montpellier, France, September, 2004.
7. 佐々木裕之:配偶子形成とゲノムインプリンティング確立におけるde novoメチル化酵素の役割.公開シンポジウム「生殖細胞の発生プロセス・再プログラム化とエピジェネティクス」,京都,2004年2月.
8.佐渡敬:X染色体不活性化センター（Xic）から発現されるnon-coding RNA.理化学研究所井川特別研究室開設3周年記念シンポジウム,和光,2004年4月.
9. 佐渡敬:X染色体不活性化センターにおけるアンチセンス制御.第19回哺乳動物遺伝研究会,筑波,2004年6月.
10. 金田正弘,佐々木裕之:ゲノムインプリンティング確立におけるde novo DNAメチル化酵素Dnmt3a,Dnmt3bの役割.第19回哺乳動物遺伝研究会,筑波,2004年6月.
11. 佐渡敬,保木裕子,佐々木裕之:マウスXist遺伝子座におけるアンチセンス制御機構.日本RNA学会,熊本,2004年8月.
12. 佐渡敬:X染色体不活性化センターにおけるアンチセンス制御.国立遺伝学研究所研究会「DNAの高次構造とクロマチンに記された情報の理解に向けて」,三島,9月.
13. 佐々木裕之:エピジェネティクスと疾患.第11回日本遺伝子診療学会大会シンポジウム「ゲノム医科学1」,東京,2004年9月.
14. 佐渡敬:X染色体不活性化センターにおけるアンチセンス制御機構.第76回日本遺伝学会シンポジウム「発生遺伝学再考―脊椎動物篇」,大阪,2004年9月.
15. 佐々木裕之,金田正弘,岡野正樹,秦健一郎,佐渡敬,En Li:DNAメチル化酵素Dnmt3aが雌雄の生殖系列でゲノム刷り込みを行う.日本人類遺伝学会第49回大会,東京,2004年10月.
16. 秦健一郎,En Li,佐々木裕之:精子形成過程を司るエピジェネティクス機構.日本人類遺伝学会第49回大会,東京,2004年10月.
17. 金田正弘,秦健一郎,佐渡敬,岡野正樹,辻本直美,En Li,佐々木裕之:de novo DNAメチル化酵素Dnmt3aが雌雄の生殖系列においてインプリントを確立する.文部科学省科学研究費補助金特定領域研究公開シンポジウム「生殖細胞の発生プロセス・再プログラム化とエピジェネティクス」,吹田,2004年11月.
18. Sado, T., Hoki, Y. and Sasaki, H.: Antisense regulation at the Xist locus.第27回日本分子生物学会年会ワークショップ「DNAメチル化とヒストンメチル化による遺伝子発現制御」,神戸,2004年12月.
19. 佐々木裕之,金田正弘:ゲノムインプリンティングの確立と維持におけるDNAメチル化とヒストン修飾の使い分け.第27回日本分子生物学会年会ワークショップ「DNAメチル化とヒストンメチル化による遺伝子発現制御」,神戸,2004年12月.
20. 佐々木裕之:ゲノムインプリンティングの機構:マウスからのアプローチ.2004年度愛知県心身障害者コロニー発達障害研究所公開シンポジウム「ゲノムインプリンティングと発達障害」,春日井,2004年12月.

POSTER PRESENTATIONS

1. Kaneda, M., Hata, K., Sado, T., Okano, M., Li, E. and Sasaki, H.: Role of de novo DNA methyltransferases Dnmt3a and Dnmt3b in establishment of genomic imprinting. Keystone Symposia "Emerging Mechanisms of Epigenetic Regulation", Tahoe City, California, USA, January, 2004.
2. Hata, K., Li, E. and Sasaki, H.: Meiotic and epigenetic aberrations in Dnmt3L-deficient male germ cells. Cold Spring Harbor Laboratory "Germ Cell Meeting", Cold Spring Harbor, New Youk, USA, September, 2004.
3. Suzuki, T., Furuumi, H., Hashimoto, M., Kyouno, S., Nagashima, A., Kumaki, K., Kaneda, H., Gondo, Y., Noda, T., Wakana, S., Ishino, F., Sasaki, H. and Shiroishi, T.: Current Progress in Screening for Mutants Affecting Genomic Imprinting in the RIKEN-GSC Project. The 18th International Mouse Genome Conference 2004, Seattle, Washington, USA, October, 2004.
4. Hata, K., Li, E. and Sasaki, H.: Meiotic and epigenetic aberrations in Dnmt3L-deficient male germ cells.第17回内藤カンファレンス「幹細胞の維持と分化の分子基盤[�氈n」,葉山,2004年11月.
5. Ohhata, T., Tachibana, M., Tada, M., Tada, T., Sasaki, H., Shinkai, Y. and Sado, T.: X-inactivation is stably maintained in mouse embryos deficient for histone methyltransferase G9a.第27回日本分子生物学会年会,神戸,2004年12月.
6. 秦健一郎,久須美真紀,En Li,佐々木裕之:Dnmt3L-/-オス生殖細胞に認められる減数分裂とエピジェネティックな異常の解析.第27回日本分子生物学会年会, 神戸,2004年12月.
7. 金田正弘,秦健一郎,佐渡敬,岡野正樹,En Li,佐々木裕之:De novo DNAメチル化酵素Dnmt3a,Dnmt3bのインプリンティング確立における役割.第27回日本分子生物学会年会,神戸,2004年12月.
8. Kato, Y., Ishihara, K., Ehrlich, M., Reith, W., Nakao, M. and Sasaki, H.: Functional analysis of the mouse Igf2/H19 differentially methylated region.第27回日本分子生物学会年会,神戸,2004年12月.
9. 小林久人,阿部貴志,池村淑道,佐々木裕之:マウスインプリンティング遺伝子のDMRに共通な特徴の探索.第27回日本分子生物学会年会,神戸,2004年12月.
10. 鈴木智広,古海弘康,橋本昌和,京野志保,長嶋綾子,熊木健治,金田秀貴,権藤洋一,野田哲生,若菜茂晴,佐々木裕之,石野史敏,城石俊彦:体系的なマウス突然変異体プロジェクト（2004-7）.ゲノムインプリンティング.第27回日本分子生物学会年会,神戸,2004年12月.

EDUCATION

1. Prof. H. Sasaki was invited to give a seminar “Essential role for de novo DNA methyltransferase Dnmt3a in paternal and maternal imprinting" at the Hospital for Sick Children, Toronto, Canada, June, 2004.
2. 佐々木裕之:山梨大学医学部講義,玉穂町,2004年6月.
3. 秦健一郎:NHK高校講座「生物」,2004年10月放送.
4. 佐々木裕之:北海道大学医学部講義,札幌,2004年10月.
5. 佐々木裕之:北里大学理学部講義,相模原,2004年10月.

SOCIAL CONTRIBUTIONS AND OTHERS

1. 特許出願番号:2004-278122,発明の名称:核酸マイクロアレイ及び核酸プローブの設計方法並びに遺伝子検出方法,発明者:佐々木裕之他4名,出願人:九州大学,情報・システム研究機構.
2. 佐々木裕之:（財）遺伝学普及会評議員.
3. 秦健一郎,佐々木裕之:韮山高校生インターンシップ2名受け入れ,2004年7月.
4. 佐渡敬,佐々木裕之:夏休み体験入学プログラム1名受け入れ,2004年8月.
5. 佐々木裕之:静岡県立静岡がんセンター研究所遺伝子組換え実験安全委員会委員.