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61.
An exception to the generally conservative nature of plastid gene evolution
is the gene coding for the beta" subunit of RNA polymerase, rpoC2. Previous
work by others has shown that maize and rice have an insertion in the
coding region of rpoC2, relative to spinach and tobacco. To assess the
distribution of this extra coding sequence, we surveyed a broad
phylogenetic sample comprising 55 species from 17 angiosperm families by
using Southern hybridization. The extra coding sequence is restricted to
the grasses (Poaceae). DNA sequence analysis of 11 species from all five
subfamilies within the grass family demonstrates that the extra sequence in
the coding region of rpoC2 is a repetitive array that exhibits more than a
twofold increase in nucleotide substitution, as well as a large number of
insertion/deletion events, relative to the adjacent flanking sequences. The
structure of the array suggests that slipped-strand mispairing causes the
repeated motifs and adds to the mechanisms through which the coding
sequence of plastid genes are known to evolve. Phylogenetic analyses based
on the sequence data from grass species support several relationships
previously suggested by morphological work, but they are ambiguous about
broad relationships within the family.
相似文献
62.
Recently, decreased activity levels have been observed in pigs treated postoperatively with transdermal delivery of fentanyl
(TD-fentanyl) after isoflurane anaesthesia. Whether the change in behaviour is related to opioid-induced sedation or to insufficient
pain relief remains to be investigated. This study was therefore undertaken to evaluate the effect of TD-fentanyl 50 μg h-1 on the activity level with and without isoflurane anaesthesia. Eight pigs (25.4 ± 5.2 kg) were submitted to a cross-over
study and given two treatments; 1) fentanyl patch applied after 30 minutes of anaesthesia (treatment A/F) and 2) fentanyl
patch without anaesthesia (treatment F). The pigs' behaviour was observed from a video recording instantaneously every 10
minutes for 24 h before treatments and up to 72 h after the patch attachment. Venous blood samples were taken 1, 6, 12, 24,
48 and 72 h after the patch application. The behaviour recordings showed that TD-fentanyl did not produce sedation in any
pig. No differences were found between the two treatments in activity level, weight gain or serum fentanyl concentration.
This concentration measured after 24 h was 0.27 ± 0.11 ng ml-1 and 0.47 ± 0.40 ng ml-1 in the A/F and F group, respectively. 相似文献
63.
Philippe GAC Vanden Bergh Thomas Fett Laurent LM Zecchinon Anne VT Thomas Daniel JM Desmecht 《BMC veterinary research》2005,1(1):1-7
Background
Lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18, alphaLbeta2), the most abundant and widely expressed beta2-integrin, is required for many cellular adhesive interactions during the immune response. Many studies have shown that LFA-1 is centrally involved in the pathogenesis of several diseases caused by Repeats-in-toxin (RTX) -producing bacteria. 相似文献64.
An increase in bioavailable tin in the environment could result in bioaccumulation thereof in agricultural crops, and therefore, have adverse health consequences on humans that eat these crops. The aims of the current study were thus to assess the uptake of Sn by spinach plants, and the subsequent effects this will have on the uptake of Na, Zn, K, Ca, and Mg as well as the growth of spinach plants. Spinach plants were grown in sand culture and received tin at concentrations of 0.02, 0.2, 2 and 20 mg/L along with a nutrient solution. The uptake of tin at detectible concentrations only occurred at the highest concentrations (2 and 20 mg/L), and it was mostly retained in the roots of the plants. Tin additions also resulted in no visual toxicity symptoms, and might be beneficial to biomass production. Further field trials are needed to ensure that these experimental results remain true under field conditions. 相似文献
65.
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67.
Bo Chang Richard S Smith Maureen Peters Olga V Savinova Norman L Hawes Adriana Zabaleta Steven Nusinowitz Janice E Martin Muriel L Davisson Constance L Cepko Brigid LM Hogan Simon WM John 《BMC genetics》2001,2(1):1-12
Background
Glaucoma is a common disease but its molecular etiology is poorly understood. It involves retinal ganglion cell death and optic nerve damage that is often associated with elevated intraocular pressure. Identifying genes that modify glaucoma associated phenotypes is likely to provide insights to mechanisms of glaucoma. We previously reported glaucoma in DBA/2J mice caused by recessive alleles at two loci, isa and ipd, that cause iris stromal atrophy and iris pigment dispersion, respectively. A approach for identifying modifier genes is to study the effects of specific mutations in different mouse strains. When the phenotypic effect of a mutation is modified upon its introduction into a new strain, crosses between the parental strains can be used to identify modifier genes. The purpose of this study was to determine if the effects of the DBA/2J derived isa and ipd loci are modified in strain AKXD-28/Ty. 相似文献68.