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931.
Vitamin A induced homeotic hindlimb formation on dorsal and ventral sides of regenerating tissue of amputated tails of Japanese brown frog tadpoles
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When anuran tadpoles are treated with vitamin A after tail amputation, hindlimb‐like structures can be generated instead of the lost tail part at the amputation site. This homeotic transformation was initially expected to be a key to understanding the body plan of vertebrates. Unfortunately, homeotic limb formation has been reproduced in only some Indian frog species and a European species, but not in experimental anurans such as Xenopus laevis or Rana catesbeiana. Consequently, this fascinating phenomenon has not been well analyzed, especially at the molecular level. In addition, the initial processes of ectopic limb development are also unclear because morphological changes in the early phases have not been analyzed in detail. In this study, we report the induction of homeotic transformation using Japanese brown frogs and present a detailed morphological analysis. Unexpectedly, the ectopic limbs developed not only at the ventral sites, but also at the dorsal sites of the tail regenerates of vitamin A‐treated tadpoles. The relationship between position and axial orientation of ectopic limbs suggested the double duplication of positional value order along the rostral‐caudal axis and the dorsal‐ventral axis of the tail regenerates. 相似文献
932.
Takeshi Higa Satoshi Hasegawa Yoshio Hayasaki Yutaka Kodama Masamitsu Wada 《Journal of plant research》2017,130(4):779-789
Chloroplast photorelocation movement, well-characterized light-induced response found in various plant species from alga to higher plants, is an important phenomenon for plants to increase photosynthesis efficiency and avoid photodamage. The signal for chloroplast accumulation movement connecting the blue light receptor, phototropin, and chloroplasts remains to be identified, although the photoreceptors and the mechanism of movement via chloroplast actin filaments have now been revealed in land plants. The characteristics of the signal have been found; the speed of signal transfer is about 1 µm min?1 and that the signal for the accumulation response has a longer life and is transferred a longer distance than that of the avoidance response. Here, to collect the clues of the unknown signal substances, we studied the effect of temperature on the speed of signal transmission using the fern Adiantum capillus-veneris and found the possibility that the mechanism of signal transfer was not dependent on the simple diffusion of a substance; thus, some chemical reaction must also be involved. We also found new insights of signaling substances, such that microtubules are not involved in the signal transmission, and that the signal could even be transmitted through the narrow space between chloroplasts and the plasma membrane. 相似文献
933.
Michiyo Tsuru Michio Sata Maki Tanaka Hideaki Umeyama Yoshio Kodera Mieko Shiwa Norikazu Aoyagi Kaori Yasuda Kei Matsuoka Takaaki Fukuda Hideaki Yamana Kensei Nagata 《Translational oncology》2017,10(6):998-1007
Patients who undergo surgical extirpation of a primary liver carcinoma followed by radiotherapy and chemotherapy leading to complete remission are nevertheless known to develop cancerous metastases 3–10 years later. We retrospectively examined the blood sera collected over 8 years from 30 patients who developed bone metastases after the complete remission of liver cancer to identify serum proteins showing differential expression compared to patients without remission. We detected a novel RGD (Arg-Gly-Asp)-containing peptide derived from the C-terminal portion of fibrinogen in the sera of metastatic patients that appeared to control the EMT (epithelial-mesenchymal transition) of cancer cells, in a process associated with miR-199a-3p. The RGD peptide enhanced new blood vessel growth and increased vascular endothelial growth factor levels when introduced into fertilized chicken eggs. The purpose of this study was to enable early detection of metastatic cancer cells using the novel RGD peptide as a biomarker, and thereby develop new drugs for the treatment of metastatic cancer. 相似文献
934.
935.
Seiji Murakami Daisuke Iwaki Hiroaki Mitsuzawa Hitomi Sano Hiroki Takahashi Dennis R Voelker Toyoaki Akino Yoshio Kuroki 《The Journal of biological chemistry》2002,277(9):6830-6837
Pulmonary surfactant protein A (SP-A) plays an important role in modulation of the innate immune system of the lung. Peptidoglycan (PGN), a cell wall component of Gram-positive bacteria, is known to elicit excessive proinflammatory cytokine production from immune cells. In this study we investigated whether SP-A interacts with PGN and alters PGN-elicited cellular responses. Binding studies demonstrate that PGN is not a ligand for SP-A. However, SP-A significantly reduced PGN-elicited tumor necrosis factor alpha (TNF-alpha) secretion by U937 cells and rat alveolar macrophages. The inhibitory effect on TNF-alpha secretion was dependent upon SP-A concentrations in physiological range. Coincubation of SP-A and PGN with human embryonic kidney 293 cells that had been transiently transfected with the cDNA of Toll-like receptor 2 (TLR2), a cell signaling receptor for PGN, significantly attenuated PGN-induced nuclear factor-kappaB activity. SP-A directly bound to a soluble form of the recombinant extracellular TLR2 domain (sTLR2). Coincubation of sTLR2 with SP-A significantly reduced the binding of sTLR2 to PGN. These results indicate that the direct interaction of SP-A with TLR2 alters PGN-induced cell signaling. We propose that SP-A modulates inflammatory responses against the bacterial components by interactions with pattern-recognition receptors. 相似文献
936.
Toshikazu Takino Hiroyuki Yasui Akira Yoshitake Yoshio Hamajima ·Rokuji Matsushita Jitsuya Takada Hiromu Sakurai 《Journal of biological inorganic chemistry》2001,6(2):133-142
A new vanadyl complex, bis(5-iodopicolinato)oxovanadium(IV), VO(IPA)2, with a VO(N2O2) coordination mode, was prepared by mixing 5-iodopicolinic acid and VOSO4 at pH 5, with the structure characterized by electronic absorption, IR, and EPR spectra. Introduction of the halogen atom on to the ligand enhanced the in vitro insulinomimetic activity (IC50 = 0.45 mM) compared with that of bis(picolinato)oxovanadium(IV) (IC50 = 0.59 mM). The hyperglycemia of streptozotocin-induced insulin-dependent diabetic rats was normalized when VO(IPA)2 was given by daily intraperitoneal injection. The normoglycemic effect continued for more than 14 days after the end of treatment. To understand the insulinomimetic action of VO(IPA)2, the organ distribution of vanadium and the blood disposition of vanadyl species were investigated. In diabetic rats treated with VO(IPA)2, vanadium was distributed in almost all tissues examined, especially in bone, indicating that the action of vanadium is not peripheral. Vanadyl concentrations in the blood of normal rats given VO(IPA)2 remain significantly higher and longer than those given other complexes because of its slower clearance rate. VO(IPA)2 binds with the membrane of erythrocytes, probably owing to its high hydrophobicity in addition to its binding with serum albumin. The longer residence of vanadyl species shows the higher normoglyceric effects of VO(IPA)2 among three complexes with the VO(N2O2) coordination mode. On the basis of these results, VO(IPA)2 is indicated to be a preferred agent to treat insulin-dependent diabetes mellitus in experimental animals. 相似文献
937.
Yoshifumi Sawada Keitaro Kato Tokihiko Okada Michio Kurata Yoshio Mukai Shigeru Miyashita Osamu Murata Hidemi Kumai 《Ichthyological Research》1999,46(3):245-257
The growth and morphological development of larval and juvenileEpinephelus bruneus were examined in a hatchery-reared series. Average body length (BL) of newly-hatched larvae was 1.99 mm, the larvae growing
to an average of 3.96 mm by day 10, 6.97 mm by day 20, 12.8 mm by day 30, 22.1 mm by day 40 and 24.7 mm by day 45 after hatching.
Newly-hatched larvae had many mucous cells in the entire body epidermis. By about 4 mm BL, the larvae had developed pigment
patterns peculiar to epinepheline fishes, including melanophores on the dorsal part of the gut, on the tips of the second
dorsal and pelvic fin spines, and in a cluster on the ventral surface of the tail. Spinelets on the second dorsal and pelvic
fin spines, the preopercular angle spine and the supraocular spine, had started to develop by about 6 mm BL. The notochord
tip was in the process of flexion in larvae of 6–8 mm BL, by which time major spines, pigments and jaw teeth had started to
appear. Fin ray counts had attained the adult complement at 10 mm BL. After larvae reached 17 mm BL, elements of juvenile
coloration in the form of more or less densely-pigmented patches started to appear on the body. Squamation started at 20 mm
BL. Major head spines had disappeared or became relatively smaller and lost their serrations by 20–25 mm BL. 相似文献
938.
Satoshi Katayama Yoshio Sugawara Michio Omori Akihiro Okata 《Ichthyological Research》1999,46(1):7-18
Pond smelt,Hypomesus nipponensis McAllister, in Lake Ogawara demonstrate alternative life history strategies, as evidenced by the coexistence of anadromous
and resident fish. However, it is unknown if anadromous and resident groups interbreed. In this study, maturation and spawning
processes were examined and compared between anadromous and resident groups. Histological observations indicated negligible
variation in the maturational stage composition of oocytes, the frequency of oocyte diameter being unimodal for all specimens
at different maturational stages. Oocytes were absent in the ovaries of spent fish. Accordingly, the species can be considered
a semelparous spawner with unimodal oocyte diameter distribution. Temporal changes in the proportion of spent fish were compared
between anadromous and resident groups. Spawning of both groups began in late March and peaked over April 8–12. Although both
groups did not differ significantly in the period of peak spawning, anadromous fish finished spawning earlier than resident
ones. Anadromous fish were not able to spawn upon migration into Lake Ogawara, and quickly matured after immigration, contrasting
with resident fish. 相似文献
939.
Tissue-Specific Somatic Mosaicism in Spinal and Bulbar Muscular Atrophy Is Dependent on CAG-Repeat Length and Androgen Receptor–Gene Expression Level
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Fumiaki Tanaka Matthew F. Reeves Yasuhiro Ito Michiyo Matsumoto Mei Li Shigeru Miwa Akira Inukai Masahiko Yamamoto Manabu Doyu Mari Yoshida Yoshio Hashizume Shin-ichi Terao Terunori Mitsuma Gen Sobue 《American journal of human genetics》1999,65(4):966-973
The factors influencing the tissue-specific pattern of somatic mosaicism in CAG-repeat diseases have not yet been fully resolved. We performed a detailed analysis of the degree of somatic mosaicism in various tissues from 20 patients with spinal and bulbar muscular atrophy (SBMA), including 4 who were deceased. The most outstanding feature was the prominent somatic mosaicism observed in the cardiac and skeletal muscles, composed predominantly of postmitotic cells, and in the skin, prostate, and testis. The CNS tissues, liver, and spleen showed the least mosaicism. The tissue distribution of somatic mosaicism in patients with SBMA was markedly different from that in patients with Huntington disease (HD) and from that in patients with dentatorubral-pallidoluysian atrophy (DRPLA). The degree of somatic mosaicism correlated with the CAG-repeat number but not with age at examination. Furthermore, tissues with a higher mosaicism level corresponded well to those with a higher expression level of androgen receptor protein. The tissue-specific pattern of somatic mosaicism related not only to cell composition with different cell turnover rates but to repeat size and gene expression levels, and postnatal cell division is unlikely to be a major cause of somatic mosaicism probably because of the relative stability of CAG repeat in SBMA. 相似文献
940.