Characteristics of glyphosate inhibition of growth in soybean and tobacco callus cultures

Callus cultures or tobacco (Nicotiana tabacum L. cv. While Gold and N. glauca-langsdorffii, a tumour-forming amphidiploid hybrid) and soybean Glycine max L., cv. Chippewa) were used lo study the effect of glyphosate [N-(phosphonnmethyl) glycine) un growth and interactions with growth hormones. Glyphosate inhibited growth both in the dark and light but showed a greater toxicity in the dark. This was contrary to its effect on chlorophyll degradation which was accelerated by light. The inhibition of growth was not reversed by simultaneous addition of aromatic amino acids to the medium. Thus the results suggest a multiple glyphosate action. The tobacco callus tissue was more sensitive to glyphosate than the soybean callus tissue, confirming a difference in tolerance between plant species. Despite the inhibitory effect of glyphosate. the treated tissue revived after being transferred to a glyphosate-free medium. The glyphosate-induced growth inhibition in soybean and tumour-forming tobacco callus cultures also was reversible by high levels of indole-3-acetic acid (IAA), which itself was inhibitory Theglyphosate-IAA interaction in the tissues which were sensitive to IAA suggests that the inhibition of growth by glyphosate was related to auxin levels in these tissues.     

Fermentation of eastern gamagrass (Tripsacum dactyloides [L.] L.) by mixed cultures of ruminal microorganisms with or without supplemental corn

Five dual-flow fermentors (700 mL) were used to determine the effects of eastern gamagrass (Tripsacum dactyloides [L.] L.) diets on microbial metabolism by mixed rumen cultures. Fermentors were incubated with filtered ruminal contents and allowed to adapt for 4 d to diets followed by 3 d of sample collection. Five dietary treatments were tested: 1) gamagrass hay (GH) + no corn (GHNC), 2) gama grass silage (GS) + no corn (GSNC), 3) GS + low corn (GSLC), 4) GS + medium corn (GSMC); and 5) GS + high corn (GSHC). The experiment was conducted as a randomized complete block design with five treatments and three replications. Total VFA concentrations were not affected by diets. Corn addition linearly decreased (P < 0.001) molar proportion of acetate. In contrast, molar proportion of propionate was reduced in GSLC (cubic effect, P < 0.001) but remained similar across other diets. Corn supplementation linearly increased molar proportion of butyrate (P < 0.001). The acetate + butyrate-to-propionate ratio was highest in cultures offered GSLC (cubic effect, P < 0.001) but similar across other diets. Feeding GSNC resulted in a higher ruminal pH compared with GHNC (P < 0.03). Increasing the level of corn supplementation in GS linearly decreased culture pH (P < 0.001). All diets resulted in similar methane production, with the exception of GSMC, which lowered methane output (quadratic effect, P < 0.004). Total substrate fermented to VFA and gas tended to be greater with GHNC than with GSNC (P < 0.06) and linearly increased with the addition of corn (P < 0.004). Neutral detergent fiber digestibility was similar between GH and GS and was not affected by supplemental corn. Microbial N flow increased in cultures offered GSHC (quadratic effect, P < 0.02). Corn supplementation at the medium and high level linearly decreased C 18:0 (P < 0.02) and increased trans-C18:1 (P < 0.004). Including corn at the high level with GS did not have a detrimental effect on fermentation in dual-flow fermentors.     

Inhibition of diacylglycerol acyltransferase by alkamides isolated from the fruits of Piper longum and Piper nigrum

Pharmacological inhibition of acyl CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) has emerged as a potential therapy for the treatment of obesity and type 2 diabetes. Bioassay-guided isolation of CHCl3 extracts of the fruits of Piper longum and Piper nigum (Piperaceae), using an in vitro DGAT inhibitory assay, lead to isolation of a new alkamide named (2E,4Z,8E)-N-[9-(3,4-methylenedioxyphenyl)-2,4,8-nonatrienoyl]piperidine (2), together with four known alkamides: retrofractamide C (1), pipernonaline (3), piperrolein B (4), and dehydropipernonaline (5). Compounds 2-5 inhibited DGAT with IC50 values of 29.8 (2), 37.2 (3), 20.1 (4), and 21.2 (5) microM, respectively, but the IC50 value for 1 was more than 900 microM. This finding indicates that compounds possessing piperidine groups (2-5) can be potential DGAT inhibitors.     

Development and characterization of mouse monoclonal antibodies reactive with chicken CD83

This study was carried out to develop and characterize mouse monoclonal antibodies (mAbs) against chicken CD83 (chCD83), a membrane-bound glycoprotein belonging to the immunoglobulin superfamily that is primarily expressed on mature dendritic cells (DCs). A recombinant chCD83/IgG4 fusion protein containing the extracellular region of chCD83 was expressed in Chinese Hamster Ovary (CHO) cells and isolated from the spent cell culture medium by protein G affinity chromatography. The extracellular region of the chCD83 protein was purified and used to immunize mice. A cell fusion was performed, from which 342 hybridomas were screened for mAbs to chCD83. Two mAbs, chCD83-159 and chCD83-227, stained the greatest percentage of chCD83-transfected CHO cells and were selected for further characterization. By flow cytometry, both mAbs reacted with a chicken macrophage cell line, HD11. Both mAbs also recognized a single 53 kDa protein on Western blots of lysates from lipopolysaccharide-stimulated spleen mononuclear cells or unstimulated HD11 cells. Immunostaining of chicken secondary lymphoid organs identified chCD83(+) cells with morphologic and subtissue localization properties comparable to mammalian DCs. In vitro stimulation of spleen mononuclear cells with concanavalin A (Con A) decreased the percentage of chCD83(+) cells compared with cells treated with medium alone. Interestingly, spleen cells treated with Con A in the presence of chCD83-227 mAb exhibited decreased percentage of MHCII(+) cells compared with cells treated with an isotype-matched negative control mAb. These chCD83 mAbs may be useful for future investigations of chicken immune cell maturation and mechanisms of action.     

Potential of auxotrophic Edwardsiella tarda double-knockout mutant as a delivery vector for DNA vaccine in olive flounder (Paralichthys olivaceus)

To evaluate potential of an auxotrophic Edwardsiella tarda mutant (Δalr Δasd E. tarda) as a delivery vehicle for DNA vaccine in fish, olive flounder (Paralichthys olivaceus) were immunized with the E. tarda mutant harboring plasmids (pG02-ASD-CMV-eGFP) for eukaryotic expression of the enhanced green fluorescent protein (eGFP) gene through either intraperitoneal (i.p.) or oral route, and the expression of eGFP in the internal organs and generation of antibody against eGFP in fish were analyzed. In fish i.p. injected with 2×10(7)CFU/fish of Δalr Δasd E. tarda harboring pG02-ASD-CMV-eGFP, expression of eGFP was detected in liver, kidney, and spleen from 1 day to 28 days post-injection. In fish orally administered with 1×10(9)CFU/fish of the bacteria, the eGFP band was detected in liver, kidney, and spleen from 1 day to 14 days post-administration, whereas, in intestine, the band was detected only at 1 day post-administration. Either oral or i.p. immunization of olive flounder with recombinant E. tarda that carried eGFP-expressing eukaryotic plasmids was successful to induce humoral adaptive immunity against not only E. tarda that was used as a delivery vehicle but also eGFP that was used as the reporter protein of DNA vaccine, suggesting attenuated E. tarda-vectored DNA vaccine has a potential to be used as a combined vaccine against infectious diseases in fish.     

韩国棕头鸦雀种群的卵色多态性及其比例的地理变化(英文)

了解一个物种种群内多态性的发生及其进化,是进化生物学的挑战之一。鸟类卵色的多态性是其中一个重要例子,分裂选择被认为是鸟类卵色多态性进化的机制。我们对韩国境内的棕头鸦雀(Paradoxornis webbianus)种群的卵色变化进行了调查,采用光纤光谱仪来确定纯蓝和纯白卵色的出现比率。结果表明,不同地理种群的鸦雀的蓝、白卵色的比率不同,高纬度地区蓝色卵的比例较少,而随着纬度南移,蓝色卵的比例逐渐增多。种群之间的卵色比率变化模式与种群内卵色的比率变化不同。本文探讨了棕头鸦雀卵色多态性进化的理论假设。     

Chemerin analog regulates energy metabolism in sheep

Accumulating data suggest a relationship between chemerin and energy metabolism. Our group previously described gene cloning, expression analysis and the regulatory mechanism of chemerin and its own receptor in mice and cattle. The objective of the present study was to investigate the physiological effect of chemerin on endocrine changes and energy metabolism in sheep using a biologically stable chemerin analog. The chemerin analog was intravenously administrated (100 or 500 µg/head) to sheep, and plasma insulin and metabolites (glucose, nonesterified fatty acids (NEFA), triglyceride, total cholesterol and high‐density lipoprotein (HDL) cholesterol) were analyzed. The chemerin analog dramatically increased the insulin levels, and glucose levels were decreased. NEFA levels were slightly decreased at 20 min but then increased gradually from 60 to 180 min after analog administration. In addition, injection of the chemerin analog immediately increased triglyceride and total cholesterol but not HDL levels. These results suggested that chemerin analog regulated insulin secretion related to glucose metabolism and the release of triglycerides in sheep in vivo. This study provides new information about endocrine and metabolic changes in response to chemerin in sheep.     

Distribution and characterization of class 1 integrons in Salmonella enterica serotype Gallinarum biotype Gallinarum

Fowl typhoid caused by Salmonella enterica subsp. enterica serotype Gallinarum biotype Gallinarum is the most important chicken disease in Korea. Due to appearance of new or multiple antibiotics resistances in the recently isolated strains, it was difficult to control the disease using antibiotics in our country. Therefore, the prevalence and genetic contents of class 1 integrons in biotype Gallinarum isolated between 1992 and 2001 were investigated by PCR and direct sequencing, respectively. Out of 90 strains, 35 (39%) carried class 1 integrons. The 1.0, 1.6 and 2.0kbp amplicons were amplified in 32 strains (36%), 2 strains (2%) and 1 strain (1%), respectively. The 1.0, 1.6 and 2.0 kbp amplicons contained one (aadA1a), two (aadB-aadA1b) and three cassettes (dhfrXII-orfF-aadA2), respectively, providing resistances against aminoglycosides (aadA1a, aadA1b, aadB, and aadA2) and trimethoprim (dhfrXII). The integron-carrying strains of biotype Gallinarum appeared in 1996 and acquired additional cassettes in 2000. Although the resistances to ampicillin, tetracycline and chloramphenicol are unrelated to class 1 integrons, relatively high prevalence of integron in biotype Gallinarum may be a dormant threat to the chemotherapy of the disease in the near future because of potency to acquire additional antibiotics resistances.     

Modulatory effects of functional rice cultivars giant embryo and Aranghyangchal on the body weight and lipid metabolism in mice fed with a high fat diet

The effects of the functional rice cultivars giant embryo and Aranghyangchal on the body weight and lipid metabolism in male C57BL/6N mice under high fat diet conditions were investigated. The animals were randomly placed into four dietary groups: normal control (NC group), high fat (HF group), and high fat supplemented with giant embryo (HF-GE group) or Aranghyangchal (HF-AR group). After 8weeks, a marked increase in the body weight and plasma triglyceride and total cholesterol concentrations were found in the HF mice relative to the control group. However, the addition of the functional rice samples in the high fat diet reduced the body weight gain and significantly decreased the lipid levels through inhibition of lipogenesis and regulation of adipokine production. The results demonstrate that the functional rice grains giant embryo and Aranghyangchal may both be useful as biomaterials in the development of functional food with therapeutic potential against high fat diet-induced hyperlipidemia.