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ABSTRACT. Mutant strain d48 and d12 cannot express serotype A. In d48, the A i-antigen gene is present in the micronucleus, but not in the macronucleus. It has recently been shown that d12 contains the A gene in its micronucleus, but its macronucleus lacks the gene. Micronuclear transplantations into enucleated cells were performed to analyze those mutants. Reciprocal transplantation between wild type and d48 confirmed that d48 contains the A gene in the micronucleus and its cytoplasm is defective. Wild type 51 enucleated cells into which were transplanted d12 micronuclei could not express A. Amiccronucleate d12 cells into which were transplanted normal micronuclei from 51 or d48 showed no expression of A. These results show that even if the micronucleus of d12 contains the A gene, it must be abnormal, and its cytoplasm is also defective the same as d48. Genetic analysis showed that heterozygote of d12 and wild type 51 or d48 caused a cure of the cytoplasmic defect of d48 and d12 during the development of macronuclei. 相似文献
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KIRSCHVINK JOSEPH L.; KIRSCHVINK ATSUKO KOBAYASHI 《Integrative and comparative biology》1991,31(1):169-186
Although the presence of geomagnetic sensitivity has been suspectedfor a long time in a variety of marine and terrestrial animals,many responses reported in the literature have been based onextensive statistical analysis of orientation results or relyon obscure behavioral activities (like cetacean strandings orhoney bee waggle dances.) None of these reports have yet approachedthe level of clarity and simplicity displayed in experimentswith the magnetotactic bacteria, which is the best example ofgeomagnetic sensitivity in any living organism. Furthermore,claims of magnetic effects on living organisms pervade the literatureof biomagnetism, but many have failed subsequent attempts atreplication. We need to develop simple and easily replicatedexperiments for marine and terrestrial animals which can bemodified to answer basic questions concerning the psychophysicsof any geomagnetic sensory system which might be present. Inthis paper, we report the first replication of the Walker-Bittermanmagnetic anomaly conditioning experiment in honey bees, as wellas one of our attempts to slightly alter their basic protocol.We also report our attempts to condition honey bees to magneticdirection in simple maze experiments, and the initial resultsof a pulse-remagnetization experiment designed to test the ferromagnetictransduction hypothesis. We conclude honey bees are sensitiveto the geomagnetic field, that the signal processing for itis more complex than previously thought, and that a ferromagnetictransducer is compatible with all known behavioral data. 相似文献
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SATORU KOBAYASHI HIDEKO MIZUNO MASUKICHI OKADA 《Development, growth & differentiation》1988,30(3):251-260
We describe the accumulation and distribution of poly (A)+ RNA during oogenesis and early embryogenesis as revealed by in situ hybridization with a radio-labeled poly (U) probe. The amount of poly (A)+ RNA in nurse cell cytoplasm continuously increased untill mid-vitellogenic stage (st. 10), then decreased with the rapid increase of poly (A)+ RNA in the oocyte (st. 11). The localization of poly (A)+ RNA at stage 10 was in the anterior region of the oocyte, where it is connected by cytoplasmic bridge to the nurse cells. These observations indicate that most of the poly (A)+ RNA synthesized in the nurse cells is transferred to the oocyte through the cytoplasmic bridges at stage 10–11. During the remainder of oogenesis (st. 11–14) and during preblastodermal embryogenesis, poly (A)+ RNA was evenly distributed over the cytoplasm of oocytes and embryos. At blastoderm stage, poly(A)+ RNA became concentrated in the peripheral region of embryos. Though the somatic nuclei of the blastoderm contained a detectable amount of poly (A)+ RNA, the pole cell nuclei did not. The cytoplasmic RNA visualised by acridine orange staining and the poly (A)+ RNA detected by hybridization with [3 H]poly (U) exhibited identical distributions during oogenesis and early embryogenesis. These observations provide a basis to assess the unique distributions of specific RNA sequences involved in early development. 相似文献
5.
Maternal Messenger RNA as a Determinant of Pole Cell Formation in Drosophila Embryos 总被引:1,自引:1,他引:0
Some polar plasm components are UV-sensitive. Messenger RNA extracted from oocytes or cleavage embryos can to induce pole cells in embryos that have been deprived of ability to form pole cells by UV-irradiation. This article reviews studies on the role of this mRNA in the developmental pathway leading to germ cell formation. 相似文献
6.
ABSTRACT. Water-soluble and 0.6 M KCl-soluble protein fractions prepared from Tetrahymena pyriformis , when inoculated into mice, could effectively induce activated macrophages having the ability to kill Toxoplasma gondii in vitro. This effect was not induced by other proteins tested, such as bovine serum albumin, pepsin from porcine stomach mucosa and chicken egg-white lysozyme, nor by muramyl dipeptide (MDP), a potent immunoadjuvant. Five fractions obtained by DEAE-Sephadex chromatography of the water-soluble protein fraction were compared with regard to induction of toxoplasmacidal activity in macrophages. The first peak was most effective for activation of macrophages. Five fractions obtained by chromatography of the 0.6 M KCl-soluble protein fraction were also examined and it was found that the first peak had the activity. No marked difference in activity was observed between the active fractions of water-soluble and 0.6 M KCl-soluble protein fractions. For practical use, we focused on the water-soluble active fraction. The minimum effective dose of the active fraction was 100 μg and the fraction could activate macrophages directly in vitro. Four fractions obtained by gel filtration of the active fraction on Sephadex G-200 were compared and the first peak had the activity. The first peak contained a single protein, revealed by SDS-polyacrylamide gel electrophoresis; its apparent molecular weight was 64,000. 相似文献
7.
Shuhei Takatsuka Takeshi Kubota Yuta Kurashina Sho Kurihara Motoki Hirabayashi Masato Fujioka Hirotaka James Okano Hiroaki Onoe 《Biotechnology and bioengineering》2023,120(8):2371-2377
Adeno-associated virus (AAV)-based gene therapy holds promise as a fundamental treatment for genetic disorders. For clinical applications, it is necessary to control AAV release timing to avoid an immune response to AAV. Here we propose an ultrasound (US)-triggered on-demand AAV release system using alginate hydrogel microbeads (AHMs) with a release enhancer. By using a centrifuge-based microdroplet shooting device, the AHMs encapsulating AAV with tungsten microparticles (W-MPs) are fabricated. Since W-MPs work as release enhancers, the AHMs have high sensitivity to the US with localized variation in acoustic impedance for improving the release of AAV. Furthermore, AHMs were coated with poly-l -lysine (PLL) to adjust the release of AAV. By applying US to the AAV encapsulating AHMs with W-MPs, the AAV was released on demand, and gene transfection to cells by AAV was confirmed without loss of AAV activity. This proposed US-triggered AAV release system expands methodological possibilities in gene therapy. 相似文献
8.
Limnology - The in-stream processing of nutrients plays an important role in the fluvial nutrient transport from lands to the ocean, but few empirical studies have addressed the temporal dynamics... 相似文献
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Ridwansyah Iwan Yulianti Meti Apip Onodera Shin-ichi Shimizu Yuta Wibowo Hendro Fakhrudin M. 《Limnology》2020,21(3):487-498
Limnology - The Cimanuk River with a total watershed area of 4010.8 km2 flowing from the Garut Regency to Indramayu Delta is the longest in West Java Province. However, the cumulative... 相似文献
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