Protein Crosslinking by Transglutaminase Controls Cuticle Morphogenesis in Drosophila

Transglutaminase (TG) plays important and diverse roles in mammals, such as blood coagulation and formation of the skin barrier, by catalyzing protein crosslinking. In invertebrates, TG is known to be involved in immobilization of invading pathogens at sites of injury. Here we demonstrate that Drosophila TG is an important enzyme for cuticle morphogenesis. Although TG activity was undetectable before the second instar larval stage, it dramatically increased in the third instar larval stage. RNA interference (RNAi) of the TG gene caused a pupal semi-lethal phenotype and abnormal morphology. Furthermore, TG-RNAi flies showed a significantly shorter life span than their counterparts, and approximately 90% of flies died within 30 days after eclosion. Stage-specific TG-RNAi before the third instar larval stage resulted in cuticle abnormality, but the TG-RNAi after the late pupal stage did not, indicating that TG plays a key role at or before the early pupal stage. Immediately following eclosion, acid-extractable protein from wild-type wings was nearly all converted to non-extractable protein due to wing maturation, whereas several proteins remained acid-extractable in the mature wings of TG-RNAi flies. We identified four proteins—two cuticular chitin-binding proteins, larval serum protein 2, and a putative C-type lectin—as TG substrates. RNAi of their corresponding genes caused a lethal phenotype or cuticle abnormality. Our results indicate that TG-dependent protein crosslinking in Drosophila plays a key role in cuticle morphogenesis and sclerotization

A case of mucoepidermoid carcinoma arising in mature cystic teratoma

卵巣粘表皮癌は卵巣悪性腫瘍の中で極めてまれな組織型に分類される。今回、我々は成熟嚢胞性奇形種より発生した卵巣粘表皮癌の症例を経験したので報告する。症例は、69歳、女性、両側の成熟嚢胞性奇形腫を認めたが、SCC 高値とCT、MRI にて左側の腫瘍内に造影される充実性部分を認めたこと、小腸に浸潤を疑う所見を認めたこと、から悪性転化を疑い、手術を施行した。開腹時、両側卵巣腫瘍を認め、左卵巣腫瘍はS状結腸と強固に癒着していた。卵巣腫瘍充実性部分の迅速病理にて低分化癌と診断し、単純子宮全摘出術、両側付属器摘出術、S状結腸合併切除、骨盤リンパ節郭清術、大網切除術を施行した。病理組織学的には、左卵巣腫瘍の嚢胞壁肥厚部に皮膚付属器、脂肪織、軟骨組織、リンパ球集簇、卵巣間質を認め、充実成分に低分化な浸潤性扁平上皮癌を認めた。充実成分には、粘表皮癌に特徴的な、豊富な胞体粘液（PASおよびAlcian blue 染色陽性）を有する異型細胞が胞巣状~不完全な腺管状を呈する領域があり、成熟嚢胞性奇形腫より発生した卵巣粘表皮癌IIb期(pT2bN0M0)と診断した。術後補助化学療法としてDC（ドセタキセル、カルボプラチン）療法を施行し、術後1年8ヶ月現在、再発を認めない。雑誌掲載論

コナラにおける培養チロースの発達

小さな培養ブロックを用いると, 多数の培養チロースが一斉に発生し楕円体状に発達した。高温 (25-35℃) で培養すると, 培養チロースは急速に発達したが, 木化する前にしぼんでしまった。低温 (10-25℃) では発達に時間を要したが, 壁の木化段階まで観察できた。そこで, 20℃でチロースを培養し, チロースの発達の全段階を観察した。伸張中の培養チロース壁は一層からなっており, 未木化のprotective layerと連続していた。培養チロースの壁厚は0. 3-0. 5μmで, 伸張後の肥厚は認められなかった。また, 壁孔様構造も観察されなかった。チロース壁の木化は, 電顕観察によると, 壁の伸張終了後間もない時点から段階的に始まっていた。ゴルジ体, ER, ミトコンドリアはチロースの伸張段階に数を増したが, これらは発達の最終段階まで観察された

Osteoclast-Forming Suppressive Compounds from Makomotake, Zizania latifolia Infected with Ustilago esculenta

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Kinase activity of the dgk gene product is involved in the virulence of Streptococcus mutans

C-terminal deletion of the diacylglycerol kinase (Dgk) homologue of the cariogenic oral bacterium Streptococcus mutans resulted in loss of aciduricity. To confirm the role of the C terminus of the Dgk homologue in aciduricity, various mutants of S. mutans UA159 with a C-terminally truncated Dgk homologue were constructed. The deletion of one or two amino acid residues at the C terminus had no effect on the acid-tolerance properties of mutants. When further amino acid residues at the C terminus were removed, mutants became more acid-sensitive. The mutant with deletion of eight amino acid residues at the C terminus did not grow at pH 5.5, suggesting that the C-terminal tail of the Dgk homologue was indispensable for tolerance to acid stress in S. mutans. Kinase activity assays revealed that deletion of the C-terminal amino acids of Dgk led to a reduction of kinase activity for undecaprenol. A truncated mutant that had completely lost kinase activity was unable to grow at pH 5.5. These results suggest that the acid tolerance of S. mutans is closely related to kinase activity of the Dgk homologue. Additionally, the dgk deletion mutant exhibited markedly reduced levels of smooth-surface carious lesions in pathogen-free rats, despite there being no difference between the mutant and the parental organism in the extent of total smooth surface plaque. The results suggest that Dgk activity may play a direct role in the virulence of S. mutans