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1.
Jeff A Johnson Heather RL Lerner Pamela C Rasmussen David P Mindell 《BMC evolutionary biology》2006,6(1):65-12
Background
Populations of the Oriental White-backed Vulture (Gyps bengalensis) have declined by over 95% within the past decade. This decline is largely due to incidental consumption of the non-steroidal anti-inflammatory veterinary pharmaceutical diclofenac, commonly used to treat domestic livestock. The conservation status of other Gyps vultures in southern Asia is also of immediate concern, given the lack of knowledge regarding status of their populations and the continuing existence of taxonomic uncertainties. In this study, we assess phylogenetic relationships for all recognized species and the majority of subspecies within the genus Gyps. The continuing veterinary use of diclofenac is an unknown but potential risk to related species with similar feeding habits to Gyps bengalensis. Therefore, an accurate assessment of the phylogenetic relationships among Gyps vultures should aid in their conservation by clarifying taxonomic uncertainties, and enabling inference of their respective relatedness to susceptible G. bengalensis. 相似文献2.
Harder David B.; Capeless Christopher G.; Maggio John C.; Boughter John D. Jr; Gannon Kimberley S.; Whitney Glayde; Azen Edwin A. 《Chemical senses》1992,17(4):391-401
Mice have been characterized as either tasters or non-tastersof the bitter compound sucrose octa-acetate(SOA). However, 11of 17 supposedly non-taster inbred strains were found to avoid1 mM SOA. All 17 strains were indifferent to 0.1 mM SOA. Tasterstrains avoided both concentrations. The intermediate phenotypewas dubbed demitaster. A consistent phenotypic dominance orderwas found in crosses among both inbred and outbred strains (taster> non-taster > demitaster). Demitasters were found (withtasters) in an outbred strain showing monogenic segregationfor SOA avoidance. This, plus monogenic segregation in a back-crossof taster to demitaster inbred strains, suggested a third alleleat the Soa locus (Soac). Demitaster allelism was supported bythe strong associations found in 15 strains between the threeSOA phenotypes and HindIII restriction fragment patterns forthe closely linked Prp (proline rich protein) loci. SOA demitasterstrains were also intermediate in raffinose undeca-acetate (RUA)avoidance. Furthermore, B6.SW-Soa2 congenic mice avoided notonly SOA, but RUA and eight other acetylated sugars. A previouslyproposed separate RUA-sensitivity gene (Rua) thus appeared tobe redundant. 相似文献
3.
The release of endogenous amino acids from depolarized rat hippocampal mossy fiber synaptosomes was investigated to assess the possible role(s) of glutamate and aspartate in mediating the excitatory mossy fiber synaptic input. The relative proportions of prodynorphin-derived peptides concomitantly released with amino acids were also determined to further characterize the biochemical basis for mossy fiber synaptic transmission. Of the 18 amino acids shown to be present in superfusate fractions by liquid chromatographic analysis, only glutamate was released at a significantly enhanced rate from K+-stimulated (35 mM KCl) mossy fiber nerve endings. The rates of glutamate and aspartate release were increased by 360±27% and 54±12% over baseline respectively. However, the K+-evoked release of glutamate was substantially more Ca2+-dependent (80%) than was the release of aspartate (49%). The veratridine (45 M)-evoked release of both acidic amino acids was entirely blocked by 1 M tetrodotoxin. Depolarization (45 mM KCl) also stimulated the release of the four prodynorphin (Dyn) products examined, in a rank order of Dyn B >> Dyn A(1–17) > Dyn A(1–8) >> Dyn A(1–13), with Dyn B efflux increasing by more than 5-fold over baseline values. These results suggest that the predominant excitatory amino acid in hippocampal mossy fiber synaptic transmission may be glutamate and that this synaptic input may be modulated by at least four different products of prodynorphin processing.The animals involved in this study were procured, maintained and used in accordance with the Animal Welfare Act and the Guide for the Care and Use of Laboratory Animals prepared by the Institute of Laboratory Animal Resources—National Research Council. 相似文献
4.
S. Heinhorst G. C. Gannon E. Galun L. Kenschaft A. Weissbach 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1988,75(2):244-251
Summary Clone banks of PvuII, BamHI and XhoI fragments were generated of the Solanum tuberosum cv Katahdin plastome. These clone banks, in conjunction with molecular hybridization to tobacco ctDNA probes, were used to construct a physical map of potato ctDNA. The potato plastome was found to be a circular molecule of 155–156 Kbp containing two inverted repeat regions of 23–27 Kbp. The arrangement of restriction sites is very similar to that of other Solanaceae plastomes. Heterologous hybridization to known ctDNA encoded gene probes from tobacco allowed us to establish a genetic map of the potato chloroplast genome. The arrangement of these genes on the potato plastome resembles that on most higher plant ctDNAs. 相似文献
5.
T Barry S Geary S Hannify C MacGearailt M Shalloo D Heery F Gannon R Powell 《Nucleic acids research》1992,20(18):4940
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7.
A R Grivell M N Berry D C Henly J W Phillips P G Wallace B J Gannon D W Henderson T M Mukherjee J G Swift 《Experimental cell research》1986,165(1):11-28
The controlled centrifugation of isolated rat hepatocytes at 260 000 g results in the formation of membrane-bounded cell fragments that we have termed 'cytospheres'. A method is described for the isolation of these cytospheres. Cytospheres are spherical, have a mean diameter of 9.2 +/- 3.2 microns (SD) and a protein content of 225 +/- 12 mg/g wet wt. About 3% of the protein from the original isolated hepatocyte suspension is recoverable. Transmission electron microscopy (TEM) shows cytospheres to possess a trilaminar membrane, and a finely granular hyaloplasm generally devoid of organelles, filaments and microtubules. Freeze-fracture studies reveal a membrane structure typical of a plasma membrane. Ouabain and wheat germ agglutinin (WGA)-binding studies indicate that the original orientation of the plasma membrane is maintained throughout the formation of the cytospheres. The cytospheres have also been characterized biochemically. Cytospheres are enriched in the enzymes normally associated with the hyaloplasm, whereas the activities of enzymes localized in organelles are greatly diminished. Lipid analysis of the cytosphere membrane indicates that it is derived from the plasma membrane of the hepatocyte. Cytospheres are sensitive to changes in the osmolarity and ionic composition of their environment. Cytospheres should therefore prove a useful preparation for the study of hyaloplasm metabolism and of plasma membrane receptor and permeability properties. 相似文献
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10.
G K Snyder B Gannon R V Baudinette J Nelson 《The Journal of experimental zoology》1989,251(3):349-354
Capillaries within the central nervous system (CNS) of eutherian mammals form meshworks with numerous anastomoses, whereas capillaries in the CNS of marsupials consist entirely of hairpin-like loops, without anastomotic interconnections. Counter-current blood flow in capillary loops may have been important in the evolutionary development of a cerebral vascular supply. However, loops are not found in eutherian mammals, perhaps because of a limited benefit to the diffusive conductance of gases. 相似文献