Intragenic vectors for gene transfer without foreign DNA     

Anthony J. Conner  Philippa J. Barrell  Samantha J. Baldwin  Annemarie S. Lokerse  Pauline A. Cooper  Astrid K. Erasmuson  Jan-Peter Nap  Jeanne M. E. Jacobs 《Euphytica》2007,154(3):341-353

The intragenic vector system involves identifying functional equivalents of vector components from the genome of a specific crop species (or related species to which it can be hybridised) and using these DNA sequences to assemble vectors for transformation of that plant species. This system offers an attractive alternative to current genetic engineering strategies where vectors are based on DNA sequences that usually originate from bacteria. The construction of intragenic vectors enables the well-defined genetic improvement of plants with all transferred DNA originating from within the gene pool already available to plant breeders. In this manner genes can be introgressed into elite cultivars in a single step without linkage drag and without the incorporation of foreign DNA. The resulting plants are non-transgenic, although they are derived using the tools of molecular biology and plant transformation. The use of intragenic vectors for the transfer of genes from within the gene pools of crops may help to alleviate some of the major public concerns over the deployment of GM crops in agriculture, notably the ethical issue associated with the transfer of DNA across wide taxonomic boundaries. This paper reviews the progress toward the development and use of intragenic vectors and the implications of their use for the genetic improvement of crops. Dedicated to the late Hans Sandbrink for his enthusiasm in helping to develop intragenic vectors  相似文献   

Maternofetal inflammation induced for 2 wk in late gestation reduced birth weight and impaired neonatal growth and skeletal muscle glucose metabolism in lambs     

Robert J Posont  Caitlin N Cadaret  Joslyn K Beard  Rebecca M Swanson  Rachel L Gibbs  Eileen S Marks-Nelson  Jessica L Petersen  Dustin T Yates 《Journal of animal science》2021,99(5)

Intrauterine stress impairs growth and metabolism in the fetus and offspring. We recently found that sustained maternofetal inflammation resulted in intrauterine growth-restricted (MI-IUGR) fetuses with asymmetric body composition, impaired muscle glucose metabolism, and β-cell dysfunction near term. These fetuses also exhibited heightened inflammatory tone, which we postulated was a fetal programming mechanism for the IUGR phenotype. Thus, the objective of this study was to determine whether poor growth and metabolism persisted in MI-IUGR lambs after birth. Polypay ewes received serial lipopolysaccharide or saline injections in the first 2 wk of the third trimester of pregnancy to produce MI-IUGR (n = 13) and control (n = 12) lambs, respectively. Lambs were catheterized at 25 d of age. β-Cell function was assessed at 29 d, hindlimb glucose metabolism at 30 d, and daily blood parameters from day 26 to 31. Glucose metabolism was also assessed in flexor digitorum superficialis (FDS) muscle isolated at necropsy on day 31. Asymmetric body composition persisted in MI-IUGR neonates, as these lambs were lighter (P < 0.05) than controls at birth and 31 d, but body and cannon bone lengths did not differ at either age. FDS muscles from MI-IUGR lambs were smaller (P < 0.05) and exhibited reduced (P < 0.05) glucose oxidation and Akt phosphorylation but similar glucose uptake compared with controls when incubated in basal or insulin-spiked media. Similarly, hindlimb glucose oxidation was reduced (P < 0.05) in MI-IUGR lambs under basal and hyperinsulinemic conditions, but hindlimb glucose utilization did not differ from controls. Circulating urea nitrogen and cholesterol were reduced (P < 0.05), and triglycerides, high-density lipoprotein cholesterol, and glucose-to-insulin ratios were increased (P < 0.05) in MI-IUGR lambs. Glucose and insulin concentrations did not differ between groups during basal or hyperglycemic conditions. Although circulating monocyte and granulocyte concentrations were greater (P < 0.05) in MI-IUGR lambs, plasma tumor necrosis factor α (TNFα) was reduced (P < 0.05). FDS muscle contained greater (P < 0.05) TNF receptor 1 (TNFR1) and IκBα protein content. These findings indicate that maternofetal inflammation in late pregnancy results in fetal programming that impairs growth capacity, muscle glucose oxidation, and lipid homeostasis in offspring. Inflammatory indicators measured in this study appear to reflect heightened cytokine sensitivity in muscle and compensatory systemic responses to it.  相似文献   

Protected areas and frugivorous fish in tropical rivers: Small-scale fisheries,conservation and ecosystem services     

Paula Nagl  Gustavo Hallwass  Luís H. Tomazoni-Silva  Pedro P. Nitschke  Anais R. P. Rowedder  Astrid Tatiana Romero-Martinez  Renato A. M. Silvano 《水产资源保护:海洋与淡水生态系统》2021,31(10):2752-2771

1. Frugivorous fish provide often conflicting ecosystem services of seed dispersal and food provisioning in tropical rivers. Fishing may reduce the size and abundance of frugivorous fish, thus affecting their potential as seed dispersers, which could affect the conservation of these fish and of floodplain forests.
2. The goal of this study was to assess the influence of co-managed protected areas in the form of extractive reserves (RESEX) and small-scale fisheries on frugivorous fish in the Tapajós and Negro rivers, in the Brazilian Amazon. The study examined whether: (i) frugivorous fish are important for fisheries and selectively caught; and (ii) frugivorous fish abundance, size and fisheries catch per unit of effort are higher inside the RESEX than outside.
3. The analyses included fisheries-dependent data (3,753 fish landings) and independent data (12,730 sampled fish) collected in 16 fishing communities (eight for each river). In both rivers, frugivorous fish are among the 10 species caught the most and frugivorous biomass was proportionately higher in landings than in samplings, indicating fisheries selectivity towards these fishes.
4. In both rivers, catches of frugivorous fish were higher outside the RESEX than inside. Catch per unit effort and the proportion of frugivores in the catch were higher outside the RESEX in the Tapajós River but did not vary between sites inside and outside the RESEX in the Negro River. Frugivorous fish were larger inside the RESEX in the Negro, but smaller inside the RESEX in the Tapajós.
5. The results indicated that the ecosystem services of seed dispersal and food source provided by frugivorous fish are not in conflict in the tropical rivers studied. Therefore, these clearwater and blackwater rivers in the Brazilian Amazon show a balance between fisheries and conservation of frugivorous fish, which play an essential role in the functioning of tropical floodplain forest ecosystems.

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The effect of cutting direction on aroma compounds and respiration rate of fresh-cut iceberg lettuce (Lactuca sativa L.)     

Karla M. Deza-Durand  Mikael Agerlin Petersen 《Postharvest Biology and Technology》2011,61(1):83-90

The purpose of this research was to investigate whether cutting direction and storage temperature could influence aroma formation and respiration rates in minimally processed lettuce. Lettuce was cut both longitudinally and transverse to the mid-rib and stored at 6 and 10 °C for 4 and 5 days. The experiment was performed in January and March 2008. Changes in respiration rate were analyzed during storage, and aroma analysis was carried out after 4 and 5 days of storage in January and March, respectively. Respiration rates increased with increasing storage temperatures. Transverse cuts to the rib were strongly related with volatiles of the lipoxygenase (LOX) pathway i.e. cis-3-hexenal, cis-3-hexenol and trans-2-hexenol, while longitudinal cutting enhanced formation of volatiles from other metabolic routes. Aroma formation was also influenced by storage temperature, where higher storage temperatures resulted in increases in α-longipinene, 2-methylbutanal and 3-methylbutanal. Our results demonstrate that cutting the lettuce transverse to the mid-rib caused more severe damage to the tissue than longitudinal cutting, based on aroma production of LOX volatiles.  相似文献   

Accurate determination of oosporein in fungal culture broth by differential pulse polarography     

Michelitsch A  Rückert U  Rittmannsberger A  Seger C  Strasser H  Likussar W 《Journal of agricultural and food chemistry》2004,52(6):1423-1426

A simple and accurate differential pulse polarographic method has been developed for the determination of oosporein in the culture broth of the fungus Beauveria brongniartii. This hydroxybenzoquinone derivative is the only major secondary metabolite secreted by this entomopathogenic fungus, which is used as biological pest control agent (BCA) against Melolontha melolontha larvae. It can be found in the host organism as well as in the formulated product. The polarographic behavior of oosporein was examined in various buffer systems over the pH range 3-10. In Britton-Robinson buffer/methanol solution (3:7 v/v, pH 5.5) the differential pulse polarograms exhibited reproducible peaks at E(p) = -0.18 V vs silver/silver chloride/potassium chloride (3 M). Under these conditions, a plot of peak height vs concentration of oosporein was found to be linear over the range 5.9 x 10(-)(7) to 2.5 x 10(-)(5) M (0.18-7.74 microg mL(-)(1); r = 0.9998). The detection limit was calculated to be 54 ng mL(-)(1). To evaluate the concentration of oosporein, the standard addition method was applied. The analysis of oosporein in the culture broth led to a mean value of 524.9 microg mL(-)(1) broth with a relative standard deviation (S(rel)) of +/-2.6%. The proposed polarographic method is accurate, not time-consuming, and it is of low cost because no separation steps are necessary.  相似文献   

The effect of increasing amount of glucogenic precursors on reproductive performance in young postpartum range cows     

Mulliniks JT  Kemp ME  Cox SH  Hawkins DE  Cibils AF  Vanleeuwen DM  Petersen MK 《Journal of animal science》2011,89(9):2932-2943

Supplementing CP and propionate salts (PS) may improve economic returns in young range beef cows by increasing the dietary supply of glucogenic precursors. A 3-yr study conducted at Corona Range and Livestock Research Center (Corona, NM) from February to mid-July in 2005 (n = 80), 2006 (n = 81), and 2007 (n = 80) evaluated days to first estrus, calf weaning weight, BW change, and metabolic responses in 2- and 3-yr-old postpartum cows grazing native range. Cows were individually fed one of three 36% CP supplement treatments after parturition, with increasing glucogenic potential (GP) supplied by RUP and PS. Supplements were isoenergetic and fed at a rate of 908 g/cow per day twice weekly. Supplementation was initiated 7 d after calving and continued for an average of 95 d. Supplement treatments provided 1) 328 g of CP, 110 g of RUP and 0 g of PS (PS0); 2) 328 g of CP, 157 g of RUP, and 40 g of PS (PS40); or 3) 329 g of CP, 158 g of RUP, and 80 g of PS (PS80). Ultimately, PS0, PS40, and PS80 provided 44, 93, and 124 g of GP, respectively. Body weight was recorded weekly and serum was collected twice weekly for progesterone analysis to estimate days to first estrus. Cows were exposed to bulls for 60 d or less beginning in mid-May. Days to first estrus exhibited a quadratic (P = 0.06) response to GP resulting from the fewest days to first estrus with the consumption of PS40. Pregnancy rates were 88, 96, and 94% for cows fed PS0, PS40, and PS80, respectively (P = 0.11). Total kilograms of calf weaned per cow exposed to bulls for the supplementation and following year increased quadratically (P = 0.09). However, supplement did not affect milk composition or yield (P ≥ 0.53). Serum acetate half-life decreased linearly (P = 0.08) with increasing GP in 2007. Predicted margins were the greatest (quadratic; P = 0.03) for cows fed PS40. Even though supplement costs were greater for PS40 and PS80, cows fed PS40 had increased profits ($33.47/cow) compared with cows fed PS0 and PS80. This study implies that young postpartum cows fed additional glucogenic precursors may have improved reproductive efficiency and may wean more calf weight per cow exposed to breeding.  相似文献   

Golden perspective: application of laser-generated gold nanoparticle conjugates in reproductive biology     

Barchanski A  Taylor U  Klein S  Petersen S  Rath D  Barcikowski S 《Reproduction in domestic animals》2011,46(Z3):42-52

The current demand for female calves has grown rapidly and controlling the sex of offspring provides an economically flexible management for the livestock producer. The only functioning method of efficiently producing separate populations of X and Y sperm in mammals is based on relative DNA differentiation by high-speed flow cytometry. In this context, gold nanoparticles conjugated to sex chromosome-specific moieties display promising application as novel fluorophor-alternative for the high-throughput screening, since they feature no photo bleaching, high quantum yield, good biocompatibility and the possibility of non-destructive membrane penetration. Especially, gold nanoparticles fabricated by pulsed laser ablation are in the recent focus of interest, due to excellent biocompatibility, fabrication-dependent, tuneable particle size as well as surface charge and ease of (bio)-functionalization with a remarkably strong ligand binding. For the purpose of our studies functionalized gold nanoparticles may be used as novel markers for sex-sorting of mammalian sperm and, depending on the selected probe, also for the selection of sperm with heritable DNA-sequences interesting for animal breeding.  相似文献   

Herb feeding increases n−3 and n−6 fatty acids in cow milk     

M.B. Petersen  K. Søegaard  S.K. Jensen 《Livestock Science》2011,141(1):90-94

Most work dealing with the impact of species-rich herbage on milk fatty acid content has hitherto been carried out in alpine areas or semi-natural grasslands. The main objective of the present study was to examine the effect of herbs sown and intensively managed in a lowland sward on the concentration of n−3 and n−6 fatty acids and vitamins in cows' milk compared to clover grass and total mixed ration (TMR) feeding. Twelve cows were housed in tie-stall and randomly allocated to three diets fed ad libitum for 14 days: HERBS (mixture of fresh herbs); CLOVER (mixture of fresh white clover and ryegrass); or TMR (total mixed ration based on silage and concentrate). n−3 fatty acid (FA) content was similar between the three diets, while n−6 FA content was highest in the TMR diet. A twofold increase in n−3 FA concentration in milk was observed when feeding HERBS compared to CLOVER and TMR (0.8, 0.4 and 0.3 g/kg milk, respectively). n−6 FA concentration increased as well when feeding HERBS (1.4, 0.9 and 1.0 g/kg milk for HERBS, CLOVER and TMR, respectively). Transfer efficiency from feed to milk was doubled for n−3 FA when feeding HERBS and for transfer efficiency of n−6 FA from feed to milk an increase of 28% was observed for HERBS compared to CLOVER. Retinol content was highest in HERBS milk, while there was no difference in α-tocopherol and ß-carotene milk content between the three diets. The results thus support previous findings on the effect of herbs on the milk fatty acid profile, but it will require further research to understand the effect of herbs on n−3 and n−6 FA concentration in milk. In conclusion, milk content of polyunsaturated fatty acids (PUFA), like n−3 and n−6 FA, was significantly increased when herbs constituted the major part of the herbage, despite lower or similar dietary content of n−3 and n−6 FA in herbs compared to clover grass- and TMR diets.  相似文献   

The treatment of insertion desmopathy in the metatarsus of horses     

R Tscheuschner  W Richter  O Dietz  R Petersen 《Tier?rztliche Praxis》1991,19(2):163-166

Metacarpal or metatarsal exostoses were diagnosed in 112 horses used for sport purposes between January 1976 to December 1987. Fourteen of these patients were treated surgically by subperiosteal removal of the exostosis. All animals which could be followed up had returned to their original use. The average time of use after discharge from the clinic was 38.4 months. Surgery was successful in completely removing the exostoses in 58.3% of these horses. The indications for anaesthesia and resection of the ulnar nerve are discussed.  相似文献   

Nitrogen cycling in organic farming systems with rotational grass–clover and arable crops     

J. Berntsen    R. Grant    J. E. Olesen    I. S. Kristensen    F. P. Vinther    J. P. Mølgaard  & B. M. Petersen 《Soil Use and Management》2006,22(2):197-208

Organic farming is considered an effective means of reducing nitrogen losses compared with more intensive conventional farming systems. However, under certain conditions, organic farming may also be susceptible to large nitrogen (N) losses. This is especially the case for organic dairy farms on sandy soils that use grazed grass–clover in rotation with cereals. A study was conducted on two commercial organic farms on sand and loamy sand soils in Denmark. On each farm, a 3‐year‐old grass–clover field was selected. Half of the field was ploughed the first year and the other half was ploughed the following year. Spring barley (Hordeum vulgare L.) was sown after ploughing in spring. Measurements showed moderate N leaching during the pasture period (9–64 kg N ha^?1 year^?1) but large amounts of leaching in the first (63–216 kg N ha^?1) and second (61–235 kg N ha^?1) year after ploughing. There was a small yield response to manure application on the sandy soil in both the first and second year after ploughing. To investigate the underlying processes affecting the residual effects of pasture and N leaching, the dynamic whole farm model farm assessment tool (FASSET) was used to simulate the treatments on both farms. The simulations agreed with the observed barley N‐uptake. However, for the sandy soil, the simulation of nitrate leaching and mineral nitrogen in the soil deviated considerably from the measurements. Three scenarios with changes in model parameters were constructed to investigate this discrepancy. These scenarios suggested that the organic matter turnover model should include an intermediate pool with a half‐life of about 2–3 years. There might also be a need to include effects of soil disturbance (tillage) on the soil organic matter turnover.  相似文献