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31.
根癌农杆菌介导的叶用莴苣基因转化系统的建立 总被引:2,自引:0,他引:2
以叶用莴苣微茎尖为试材,在含有BA和NAA的MS液体培养基上旋转培养,诱导出大量愈伤组织;进一步分化培养,获得大量不定芽并生根;将愈伤组织碎块与根癌农杆菌共培养,对经卡那霉素筛选后所得到的再生植株进行X-Gluc染色,蓝色反应阳性率为80%,表明建立了叶用莴苣愈伤组织基因转化系统。 相似文献
32.
Reduced immunogenicity of beta-lactoglobulin by conjugation with carboxymethyl dextran differing in molecular weight 总被引:2,自引:0,他引:2
Kobayashi K Hirano A Ohta A Yoshida T Takahashi K Hattori M 《Journal of agricultural and food chemistry》2001,49(2):823-831
To reduce the immunogenicity of beta-lactoglobulin (beta-LG), two beta-LG-carboxymethyl dextran (CMD) conjugates (Conj. 40 and Conj. 162) were prepared by using water-soluble carbodiimide (EDC). The molar ratios of beta-LG to CMD in Conj. 40 and Conj. 162 were 8:1 and 7:1, respectively. Each conjugate maintained approximately 50% of the retinol binding activity of beta-LG. Structural analyses by intrinsic fluorescence, CD spectra, and ELISA with monoclonal antibodies indicated that the surface of beta-LG in each conjugate was covered by CMD without great disruption of native conformation. By conjugation with CMD, the antibody response to beta-LG was reduced in BALB/c, C3H/He, and C57BL/6 mice, which was eminent in Conj. 162. The results of B cell epitope scanning using overlapping synthesized peptides showed that the linear epitope profiles of the conjugates were similar to those of beta-LG, whereas the antibody response to each epitope was reduced, which was eminent in Conj. 162. It was concluded that conjugation with CMD of higher molecular weight is effective in reducing the immunogenicity of beta-LG and that masking of epitopes by CMD is responsible for the reduced immunogenicity. 相似文献
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ABSTRACT Xanthomonas oryzae pv. oryzae, the causal agent of bacterial leaf blight of rice, was subjected to transposon mutagenesis to generate mutants defective in pathogenicity. A novel mutant 74M913 was attenuated in virulence but retained its ability to cause the hypersensitive response in leaf blight-resistant rice and tomato. Cloning and sequence analysis revealed that the transposon in 74M913 was inserted in a gene homologous to the phosphoglucose isomerase (pgi) gene of X. axonopodis pv. citri. Growth of the mutant in a synthetic medium containing fructose or xylose as a sole carbohydrate source was much reduced, indicating the transposon disrupted pgi function. The interaction between expression of pgi and hypersensitive response and pathogenicity (hrp) genes was investigated because we had demonstrated previously that expression of hrp genes of X. oryzae pv. oryzae is induced in a synthetic medium containing xylose. However, pgi and the hrp gene (hrcU) were expressed independently. This study suggests that PGI is involved in pathogenicity of X. oryzae pv. oryzae. 相似文献
36.
Full-term development of offspring using round spermatids produced ectopically from fetal male germ cells 总被引:8,自引:0,他引:8
The continuous production of mammalian sperm is maintained by the proliferation and differentiation of spermatogonial stem cells, which originate from primordial germ cells in the early embryo. Previously, we reported that the transplantation of fetal male gonadal tissue into the recipient testis was effective obtaining functional sperm. This transplantation technique is a promising new approach for the preservation of testicular function in a mutant animal with embryonic lethality. In the present study, we examined whether spermatogenesis from fetal male germ cells is induced under ectopic conditions in male and female recipients. Nine to 10 weeks after the transplantation of male gonads prepared from embryos at 12.5 or 16.5 days post gestation, male germ cell differentiation occurred under the skin of male and female recipient nude mice. Histological analyses revealed that grafted gonads contained haploid germ cells such as round or elongated spermatids. Furthermore, we succeeded in obtaining normal progeny by injecting the ectopically produced round spermatids into the cytoplasm of oocytes, even when the male germ cells had been generated in female recipients. These results indicate that the transplantation of fetal male gonads under the skin of recipient mice is a useful technique for obtaining functional male gametes. 相似文献
37.
Yasunaga Y Takeuchi T Shimokawa T Nabeta M Matsuu A Asano A Ohta Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(6):805-808
Sugar expressions were examined on the epithelium of both the middle portion of the vagina and the vaginal portion of the cervical canal (CC) in pregnant mice to understand the pathogenesis of bacterial infection in the female reproductive organ by using a panel of lectins. As a result, N-acetylglucosamine was positive before pregnant day (P) 7 but negative after P10 and at diestrus on both the vagina and the CC. In addition, some differences in sugar expressions were seen between them. These results suggest that sugar expressions on the mucosal surface would change not only site-specifically but also time-dependently, and these sugar differences indicate the possibility of the alteration of the settled bacterial species on the vaginal mucosa in pregnancy. 相似文献
38.
Kimura S Sasase T Ohta T Sato E Matsushita M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(1):103-105
The Spontaneously Diabetic Torii-Lepr(fa) (SDT-fa/fa) rat, a model of obese type 2 diabetes, shows obesity, hyperglycaemia and low bone mineral density (BMD). The objective of this study is to evaluate the effects of parathyroid hormone (1-34) [PTH(1-34)] on BMD and glucose metabolism in the SDT-fa/fa rat. SDT-fa/fa rats showed obesity with hyperglycaemia and decreased serum osteocalcin levels and the tibial BMD. A 4-week treatment of PTH(1-34) (20 μg/kg/day) increased the serum osteocalcin levels and the tibial BMD, and decreased the serum glucose levels without changing the serum insulin levels. These findings indicate that PTH(1-34) improved not only BMD but also glucose metabolism in SDT-fa/fa rats. This study suggests that PTH(1-34) is a novel agent for the treatment of diabetic osteoporosis. 相似文献
39.
K Nakamura M Yamasaki T Osaki H Ohta N Sasaki K Aoshima T Kimura M Takiguchi 《Journal of the American Animal Hospital Association》2012,48(5):327-330
Bilateral segmental aplasia of the uterine horns with unilateral pyometra and uterine horn torsion were diagnosed in a Pomeranian bitch that presented with chronic abdominal distension and an acute onset of anorexia and lethargy. Because radiographic and ultrasonographic findings revealed the presence of markedly enlarged bilateral uterine horns filled with fluid in the caudal abdomen, a tentative diagnosis of either pyometra or hydrometra with uterine horn torsion was made. Exploratory laparotomy showed bilateral, segmentally distended uterine horns with unilateral uterine horn torsion. Ovariohysterectomy was performed, and bilateral segmental aplasia of the uterine horns with the development of unilateral uterine horn torsion was diagnosed histopathologically. To the authors' knowledge, this is the first report of uterine horn torsion in conjunction with segmental aplasia of the uterine horn in a bitch. 相似文献
40.
Kazumasa Ohta Kazuhiko Hoshizaki Katsunori Nakamura Akihiko Nagaki Yoichi Ozawa Aoi Nikkeshi Akifumi Makita Kazumi Kobayashi Osamu Nakakita 《Journal of Forest Research》2012,17(4):360-368
During the last few decades, pine wilt disease has spread to cool-climate regions in Japan and, more recently, the potential risk of it spreading into the European midwest has also become a concern. In a coastal pine stand (84.7?ha) in Akita, near the northern limit of pine wilt disease in Japan, we investigated seasonal variations in the incidence of damage caused by the disease to trees and oviposition by the disease’s insect vector, Monochamus alternatus, during a two-year period. Foliage discoloration occurred throughout each year, and its seasonal variation showed a bimodal pattern in Pinus thunbergii (a higher peak in May–June and a smaller peak in October) and a clear peak in June in P. densiflora, which differed from the patterns in seasonal variation seen for warm-climate regions. Oviposition scars by M. alternatus were found in 40–45% of the trees damaged each year. The percentage of trees that had oviposition scars was higher in P. thunbergii than in P. densiflora. This appeared to reflect the difference in seasonal discoloration pattern between the two species. Analysis of the oviposition risk showed that trees that exhibited discoloration starting between July and October had a significantly higher risk or significantly higher oviposition scar densities, particularly for those that became discolored between August and September (2.5–14.6-fold higher risk than during other months). Oviposition scar densities per damaged tree were similar within the period of higher oviposition risk. Considering both oviposition risks and scar densities, we concluded that trees with discoloration that become apparent between July and October are important targets for preventing the spread of pine wilt disease in Akita. 相似文献