著者

Keito Mineta Junya Hirota Kesuke Yamada Takashi Itoh Poyu Chen Hidekazu Iwakawa Hirotomo Takatsuka Yuji Nomoto Masaki Ito

出版者

Japanese Society for Plant Biotechnology

雑誌

Plant Biotechnology (ISSN:13424580)

巻号頁・発行日

vol.40, no.4, pp.353-359, 2023-12-25 (Released:2023-12-25)

参考文献数

20

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Although it is well known that hierarchical transcriptional networks are essential for various aspects of plant development and environmental response, little has been investigated about whether and how they also regulate the plant cell cycle. Recent studies on cell cycle regulation in Arabidopsis thaliana identified SCARECROW-LIKE28 (SCL28), a GRAS-type transcription factor, that constitutes a hierarchical transcriptional pathway comprised of MYB3R, SCL28 and SIAMESE-RELATED (SMR). In this pathway, MYB3R family proteins regulate the G2/M-specific transcription of the SCL28 gene, of which products, in turn, positively regulate the transcription of SMR genes encoding a group of plant-specific inhibitor proteins of cyclin-dependent kinases. However, this pathway with a role in cell cycle inhibition is solely demonstrated in A. thaliana, thus leaving open the question of whether and to what extent this pathway is evolutionarily conserved in plants. In this study, we conducted differential display RT-PCR on synchronized Nicotiana tabacum (tobacco) BY-2 cells and identified several M-phase-specific cDNA clones, one of which turned out to be a tobacco ortholog of SCL28 and was designated NtSCL28. We showed that NtSCL28 is expressed specifically during G2/M and early G1 in the synchronized cultures of BY-2 cells. NtSCL28 contains MYB3R-binding promoter elements, so-called mitosis-specific activator elements, and is upregulated by a hyperactive form of NtmybA2, one of the MYB3R proteins from tobacco. Our study indicated that a part of the hierarchical pathway identified in A. thaliana is equally operating in tobacco cells, suggesting the conservation of this pathway across different families in evolution of angiosperm.

著者

Makoto MIZUSHIMA Masaki ITO Noriyuki FUJIMA Haruto UCHINO Taku SUGIYAMA Miki FUJIMURA

出版者

The Japan Neurosurgical Society

雑誌

Neurologia medico-chirurgica (ISSN:04708105)

巻号頁・発行日

pp.2023-0008, (Released:2023-04-20)

参考文献数

22

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Although postoperative neurological events due to brain compression by the swollen temporal muscle are a rare complication, the chronological volume changes of the temporal muscle pedicle and their clinical impact have not yet been documented. This prospective observational study aimed to investigate the chronological volume changes in the temporal muscle pedicle in Moyamoya disease (MMD). Eighteen consecutive combined revascularization procedures using the temporal muscle were performed for symptomatic MMD in 2021. The postoperative pedicle volume was quantified using repeated computed tomography images on postoperative days (PODs) 0, 1, 7, 14, and 30. Postoperative neurological events with radiological evaluations and collateral development evaluated using magnetic resonance angiography obtained 6 months after surgery were studied. On average, the postoperative temporal muscle pedicle volume was most significantly increased by as much as 112% ± 9.6% on POD 7 (P < 0.001) and decreased by as little as 52% ± 21% on POD 30 (P < 0.0001) relative to POD 0. One exceptional patient (overall incidence, 5.6%) demonstrated postoperative transient neurological events due to brain compression by the swollen temporal muscle with decreased focal cerebral blood flow in the adjacent cortical area. The postoperative collateral development via direct and indirect revascularizations was confirmed in 16 (89%) and 12 (67%) hemispheres, respectively. All patients, except for one rebleeding case, showed independent outcomes at the mean latest follow-up period on 290 ± 96 days after surgery. Our observations confirmed the temporal profile of muscle pedicle volume changes after combined revascularization. Through routine attempts to avoid the unfavorable effects of temporal muscle swelling, combined revascularization can provide favorable outcomes in symptomatic MMD.

著者

Hirotomo Takatsuka Yuji Nomoto Satoshi Araki Yasunori Machida Masaki Ito

出版者

Japanese Society for Plant Biotechnology

雑誌

Plant Biotechnology (ISSN:13424580)

巻号頁・発行日

vol.38, no.2, pp.269-275, 2021-06-25 (Released:2021-06-25)

参考文献数

21

被引用文献数

4

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MYB3R family transcription factors play a central role in the regulation of G2/M-specific gene transcription in Arabidopsis thaliana. Among the members of this family, MYB3R3 and MYB3R5 are structurally closely related and are involved in the transcriptional repression of target genes in both proliferating and quiescent cells. This type of MYB3R repressor is widespread in plants; however, apart from the studies on MYB3Rs in Arabidopsis thaliana, little information about them is available. Here we isolated tobacco cDNA clones encoding two closely related MYB3R proteins designated as NtmybC1 and NtmybC2 and determined the nucleotide sequences of the entire coding regions. Phylogenetic analysis suggested that NtmybC1 and NtmybC2 can be grouped into a conserved subfamily of plant MYB3Rs that also contains MYB3R3 and MYB3R5. When transiently expressed in protoplasts prepared from tobacco BY-2 cells, NtmybC1 and NtmybC2 repressed the activity of target promoters and blocked promoter activation mediated by NtmybA2, a MYB3R activator from tobacco. Unlike MYB3R3 and MYB3R5, NtmybC1 and NtmybC2 showed cell cycle-regulated transcript accumulation. In synchronized cultures of BY-2 cells, mRNAs for both NtmybC1 and NtmybC2 were preferentially expressed during the G2 and M phases, coinciding with the expression of NtmybA2 and G2/M-specific target genes. These results not only broadly confirm our fundamental view that this type of MYB3R protein acts as transcriptional repressor of G2/M-specific genes but also suggest a possible divergence of MYB3R repressors in terms of the mechanisms of their action and regulation.

著者

Reira Suzuki Takashi Ueda Takuji Wada Masaki Ito Takashi Ishida Shinichiro Sawa

出版者

Japanese Society for Plant Biotechnology

雑誌

Plant Biotechnology (ISSN:13424580)

巻号頁・発行日

vol.38, no.1, pp.1-8, 2021-03-25 (Released:2021-03-25)

参考文献数

45

被引用文献数

5

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Root-knot nematodes (RKN; Meloidogyne incognita) are phytoparasitic nematodes that cause significant damage to crop plants worldwide. Recent studies have revealed that RKNs disrupt various physiological processes in host plant cells to induce gall formation. However, little is known about the molecular mechanisms of gall formation induced by nematodes. We have previously found that RNA expression levels of some of genes related to micro-RNA, cell division, membrane traffic, vascular formation, and meristem maintenance system were modified by nematode infection. Here we evaluated these genes importance during nematode infection by using Arabidopsis mutants and/or β-glucronidase (GUS) marker genes, particularly after inoculation with nematodes, to identify the genes involved in successful nematode infection. Our results provide new insights not only for the basic biology of plant–nematode interactions but also to improve nematode control in an agricultural setting.