A molecular basis for natural selection at the timeless locus in Drosophila melanogaster     

Sandrelli F  Tauber E  Pegoraro M  Mazzotta G  Cisotto P  Landskron J  Stanewsky R  Piccin A  Rosato E  Zordan M  Costa R  Kyriacou CP 《Science (New York, N.Y.)》2007,316(5833):1898-1900

Diapause is a protective response to unfavorable environments that results in a suspension of insect development and is most often associated with the onset of winter. The ls-tim mutation in the Drosophila melanogaster clock gene timeless has spread in Europe over the past 10,000 years, possibly because it enhances diapause. We show that the mutant allele attenuates the photosensitivity of the circadian clock and causes decreased dimerization of the mutant TIMELESS protein isoform to CRYPTOCHROME, the circadian photoreceptor. This interaction results in a more stable TIMELESS product. These findings reveal a molecular link between diapause and circadian photoreception.  相似文献   

Chemical characterization of Klason lignin preparations from plant-based foods     

Bunzel M  Schüssler A  Tchetseubu Saha G 《Journal of agricultural and food chemistry》2011,59(23):12506-12513

To analyze the accuracy of the Klason lignin method as applied for the determination of lignin contents in plant based-food products, Klason lignin preparations from curly kale, pears, whole wheat grains, and corn bran were chemically characterized. Characterization included routine ash and protein determinations and the extraction of fat/waxes as well as cutin/suberin depolymerization and extraction of the liberated monomers. Fat/wax and cutin/suberin amounts in the Klason lignin preparations were determined gravimetrically, and their compositions were analyzed by using GC-MS. Typical fat, wax, and cutin (and suberin) constituents such as saturated and unsaturated fatty acids, hydroxy and/or epoxy fatty acids, and phenolic acids were identified in all samples, whereas the detection of long-chain hydrocarbons, alcohols, and ketones, sterols, stanols, and dioic acids was dependent on the sample analyzed. Estimation of the contribution of non-lignin compounds to the Klason lignin contents reduced the noncorrected Klason lignin contents of the insoluble fibers from 28.7% (kale), 22.8% (pear), 14.8% (wheat), and 9.9% (corn) to maximum lignin contents of 6.5% (kale), 16.4% (pear), 4.9% (wheat), and 2.3% (corn). These data demonstrate that certain commonly used statements such as "cereal brans are highly lignified" need to be revised.  相似文献   

Multinucleated giant cells with an osteoclast phenotype derived from caprine peripheral blood mononuclear cells     

Giuliano Pisoni  Patrizia D’Amelio  Francesca Sassi  Giovanni Manarolla  Licia Scaccabarozzi  Clara Locatelli  Nausicaa Mazzocchi  Mirko Baruscotti  Dario DiFrancesco  Paolo Moroni 《Veterinary journal (London, England : 1997)》2011,189(3):361-363

Formation of multinucleated giant cells (MGCs) by macrophage fusion is a typical cytopathic effect of lentiviral replication in caprine monocytes and MGC formation from cultured caprine peripheral blood mononuclear cells (PBMCs) has been considered to be diagnostic for small ruminant lentivirus (SRLV) infection. In this study, formation of MGCs was observed after 7–14 days when PBMCs were cultured from healthy goats free from SRLV infection. These MGCs expressed tartrate-resistant acid phosphatase, calcitonin receptor, integrin αVβ3, cathepsin K and matrix metalloproteinase 9 and were able to resorb bone in vitro in the absence of RANKL and macrophage colony stimulating factor, consistent with an osteoclast phenotype.  相似文献   

Lignins and ferulate-coniferyl alcohol cross-coupling products in cereal grains     

Bunzel M  Ralph J  Lu F  Hatfield RD  Steinhart H 《Journal of agricultural and food chemistry》2004,52(21):6496-6502

Plant cell walls containing suberin or lignin in the human diet are conjectured to protect against colon cancer. To confirm the existence of authentic lignin in cereal grain dietary fibers, the DFRC (derivatization followed by reductive cleavage) method was applied to different cereal grain dietary fibers. By cleavage of diagnostic arylglycerol-beta-aryl (beta-O-4) ether linkages and identification of the liberated monolignols, it was ascertained that lignins are truly present in cereal grains. From the ratios of the liberated monolignols coniferyl alcohol and sinapyl alcohol, it is suggested that lignin compositions vary among cereals. Furthermore, dimeric cross-coupling products, comprising ferulate and coniferyl alcohol, were identified in most cereal fibers investigated. These ferulate 4-O-beta- and 8-beta-coniferyl alcohol cross-coupled structures indicate radical cross-coupling of polysaccharides to lignin precursors via ferulate.  相似文献   

Sinapate dehydrodimers and sinapate-ferulate heterodimers in cereal dietary fiber     

Bunzel M  Ralph J  Kim H  Lu F  Ralph SA  Marita JM  Hatfield RD  Steinhart H 《Journal of agricultural and food chemistry》2003,51(5):1427-1434

Two 8-8-coupled sinapic acid dehydrodimers and at least three sinapate-ferulate heterodimers have been identified as saponification products from different insoluble and soluble cereal grain dietary fibers. The two 8-8-disinapates were authenticated by comparison of their GC retention times and mass spectra with authentic dehydrodimers synthesized from methyl or ethyl sinapate using two different single-electron metal oxidant systems. The highest amounts (481 microg/g) were found in wild rice insoluble dietary fiber. Model reactions showed that it is unlikely that the dehydrodisinapates detected are artifacts formed from free sinapic acid during the saponification procedure. The dehydrodisinapates presumably derive from radical coupling of sinapate-polymer esters in the cell wall; the radical coupling origin is further confirmed by finding 8-8 and 8-5 (and possibly 8-O-4) sinapate-ferulate cross-products. Sinapates therefore appear to have an analogous role to ferulates in cross-linking polysaccharides in cereal grains and presumably grass cell walls in general.  相似文献   

Contingency nature of Helicobacter bizzozeronii oxygen-insensitive NAD(P)H-nitroreductase (HBZC1_00960) and its role in metronidazole resistance     

Pradeep Kumar Kondadi  Claudia Pacini  Joana Revez  Marja-Liisa H?nninen  Mirko Rossi 《Veterinary research》2013,44(1):56

Genomic analysis of a metronidazole resistant H. bizzozeronii strain revealed a frame length extension of the oxygen-insensitive NAD(P)H-nitroreductase HBZC1_00960 (RdxA), associated with the disruption of the C-terminal cysteine-containing conserved region (IACLXALGK). This was the result of the extension (from C₈ to C₉) of a simple sequence cytosine repeat (SSCR) located in the 3’ of the gene. A 3'' SSCR is also present in the rdxA homolog of H. heilmannii sensu stricto, but not in H. pylori. We showed that in the majority of in vitro spontaneous H. bizzozeronii metronidazole resistant mutants, the extension of the 3′ SSCR of rdxA was the only mutation observed. In addition, we observed that H. bizzozeronii ΔrdxA mutant strain showed the same MIC value of metronidazole observed in the spontaneous mutants. These data indicate that loss of function mutations in rdxA and in particular the disruption of the conserved region IACLXALGK is associated with reduced susceptibility to metronidazole in H. bizzozeronii. Slipped-strand mispairing of the SSCR located in the 3′ of the H. bizzozeronii rdxA appears to be the main mechanism. We also observed that H. bizzozeronii acquires resistance to metronidazole at high mutation rate, and that serial passages in vitro without selection induced an increased level of susceptibility. In conclusion, contrary to what was previously described in H. pylori, the H. bizzozeronii rdxA appears to be a contingency gene which undergoes phase variation. The contingency nature of rdxA should be carefully considered when metronidazole is used in the treatment of H. heilmannii-associated gastritis.  相似文献   

Carbon dioxide sequestration capability of an unmanaged old-growth broadleaf deciduous forest in a Strict Nature Reserve     

Mirko U. Granata  Loretta Gratani  Francesco Bracco 《Journal of Sustainable Forestry》2019,38(1):85-96

The seasonal trend of plant carbon dioxide (CO₂) sequestration is related to the photosynthetic activity, which in turn changes in response to environmental conditions. Great interest has turned to the CO₂ sequestration (CS) potential of temperate forests which play an important role in global carbon (C) cycle contributing to the lowering of atmospheric CO₂ concentration. In such context, the CS of an unmanaged old broad-leaf deciduous forest developing inside a Strict Nature Reserve, and its variations during the year were analyzed considering the monthly variations of leaf area index (LAI) and net photosynthetic rates (N_P). Overall, the total yearly CS of the forest was 141 Mg CO₂ ha^?1 year^?1 with the highest CS value monitored in June (405 Mg CO₂ month^?1) due to the highest LAI (5.0 ± 0.8 m² m^?2) and a high N_P in all the broadleaf species. The first CS decline was observed in August due to the more stressful climatic conditions that constrained N_P rates. Overall, the total CS of the forest reflects the good ecological health of the ecosystem due to its conservative management.  相似文献   

Investigation of infectious laryngotracheitis outbreaks in Namibia in 2018     

Molini  Umberto  Aikukutu  Gottlieb  Khaiseb  Siegfried  Kahler  Barbara  Van der Westhuizen  Jolandie  Cattoli  Giovanni  Dundon  William G. 《Tropical animal health and production》2019,51(7):2105-2108

Between July and August 2018, two outbreaks of infectious laryngotracheitis caused the death of over 116,000 commercial poultry (layers and broilers) near the city of Windhoek, Namibia. A third outbreak occurred in September 2018 in the north of the country approximately 800 km from the original outbreaks. Sample collection and molecular epidemiological analyses revealed that the outbreaks were most likely caused by poor vaccination practices leading to the reversion to virulence of an ILT vaccine strain. The analyses also indicate that inaccurate declarations were made by one of the farms involved and that illegal movement of animals most likely occurred.

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Barnacle culture: background,potential and challenges     

Daniel A. López  Boris A. López  Christopher K. Pham  Eduardo J. Isidro  Mirko De Girolamo 《Aquaculture Research》2010,41(10):e367-e375

There are approximately a dozen species of commercially interesting barnacles worldwide, some of which have been cultured on a semi‐industrial scale. These species are listed and information is provided with regard to geographical distribution, landings and prices. Traditionally, ‘goose’ barnacles (four species) are considered to be the most important for consumption. World production already stands at 500 tonnes year^?1, but this species has not been cultured to date. Some ‘acorn’ barnacles are also consumed (seven species), with harvest levels per species that do not exceed 200 tonnes year^?1 and selling prices that can reach US$17/kg. ‘Acorn’ barnacle culture on a world scale is still developing. Nevertheless, production has occurred on a semi‐industrial scale; specifically, spat have been collected from the wild and grown in suspended systems. Farming trials have focused on two species of acorn barnacles: Austromegabalanus psittacus (Molina 1782) ‘picoroco’ in Chile and Megabalanus azoricus (Pilsbry 1916) ‘craca’ in Portugal. The large‐scale production of these crustaceans will depend on the optimization of spat collection from the wild and/or the parallel development of mass production technologies for larvae (hatcheries). In addition, further development will be achieved by opening up new markets for commercialization.  相似文献   

Protective effect of the AT137RQ and ARQK176 PrP alleles against classical scrapie in Sarda breed sheep     

Gabriele Vaccari  Gaia Scavia  Marcello Sala  Gianmario Cosseddu  Barbara Chiappini  Michela Conte  Elena Esposito  Raniero Lorenzetti  Gabriella Perfetti  Paola Marconi  Francesco Scholl  Katia Barbaro  Antonino Bella  Romolo Nonno    Umberto Agrimi 《Veterinary research》2009,40(3)

The susceptibility of sheep to scrapie is under the control of the host’s prion protein (PrP) gene and is also influenced by the strain of the agent. PrP polymorphisms at codons 136 (A/V), 154 (R/H) and 171 (Q/R/H) are the main determinants of susceptibility/resistance of sheep to classical scrapie. They are combined in four main variants of the wild-type ARQ allele: VRQ, AHQ, ARH and ARR. Breeding programmes have been undertaken on this basis in the European Union and the USA to increase the frequency of the resistant ARR allele in sheep populations. Herein, we report the results of a multi-flock study showing the protective effect of polymorphisms other than those at codons 136, 154 and 171 in Sarda breed sheep. All ARQ/ARQ affected sheep (n = 154) and 378 negative ARQ/ARQ controls from four scrapie outbreaks were submitted to sequencing of the PrP gene. The distribution of variations other than those at the standard three codons, between scrapie cases and negative controls, was statistically different in all flocks. In particular, the AT₁₃₇RQ and ARQK₁₇₆ alleles showed a clear protective effect. This is the first study demonstrating a protective influence of alleles other than ARR under field conditions. If further investigations in other sheep breeds and with other scrapie sources confirm these findings, the availability of various protective alleles in breeding programmes of sheep for scrapie resistance could be useful in breeds with a low frequency of the ARR allele and would allow maintaining a wider variability of the PrP gene.  相似文献