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71.
Protoplasts isolated from four-week old cell suspension cultures ofGlycine canescens F. J. Herm andG. clandestina Wendl. were cultured in 8P or modified 8P to a multicellular stage. Colonies of 0.5 to 1.0 mm diameter were transferred to solid media for callus growth and regeneration. Callus consisted of friable masses with compact green nodular areas. Organogenesis of both species occurred primarily from the green nodular areas. Shoot buds ofG. clandestina did not mature, but shoots ofG. canescens proliferated on MS medium, with B5 vitamins, 0.33 mgL–1 each BA, KN, ZN, and 0.15 mgL–1 NAA. Shoots failed to root after multiple subcultures on four different rooting media.In vitro grafting ofG. canescens scions ontoG. max root stocks allowed plants to be transferred to soil. An overall protoplast division efficiency of 48% was achieved with moderately efficient shoot regeneration inG. canescens. Division efficiencies forG. clandestina were lower (11%). Refinements of this protocol should result in high efficiencies of regeneration which would allowin vitro manipulations of these wild soybean relatives at the single cell level and would make the derivation of somatic hybrid plants possible within the genusGlycine.Abbreviations BA
6-Benzyladenine
- KN
kinetin
- ZN
Zeatin
- NAA
Napthaleneacetic acid
- 2,4-D
2–4-dichlorophenoxyacetic acid
- PIC
Picloram
- CH
casein hydrolysate
- Gln
glutamine
- Met
methionine
- MES
2[N-morpholine] ethanesulfonic acid 相似文献
72.
Purification of L-[3H]nicotine eliminates low affinity binding 总被引:3,自引:0,他引:3
Some studies of L-[3H]nicotine binding to rodent and human brain tissue have detected two binding sites as evidenced by nonlinear Scatchard plots. Evidence presented here indicates that the low affinity binding site is not stereospecific, is not inhibited by low concentrations of cholinergic agonists and is probably due to breakdown products of nicotine since purification of the L-[3H]nicotine eliminates the low affinity site. 相似文献
73.
Millicent Masters John B. March I. R. Oliver J. F. Collins 《Molecular & general genetics : MGG》1990,220(2):341-344
Summary The sequence of the PcnB protein of Escherichia coli, a protein required for copy number maintenance of ColE1-related plasmids, was compared with the PIR sequence database. Strong local similarities to the sequence of the E. coli protein tRNA nucleotidyltransferase were found. Since a substrate of the latter protein, tRNA, structurally resembles the RNAs that control ColE1 copy number we believe that we may have identified a region in PcnB that interacts with these RNAs. Consistent with this idea is our observation that PcnB is required for the replication of R1, a plasmid whose replication is also regulated by a small RNA. 相似文献
74.
Standardized specimens with reproducible staining properties were fabricated from extracts of biological objects (bovine liver, nucleoprotamine and defatted muscle). The standard specimens were stained with two formulations of the Romanowsky-Giemsa stain (RG), using the same azure B and eosin Y. One formulation used methanol and Sorensen's buffer and the other DMSO and Hepes buffer as solvents. The standard specimens were stained either in the composite stain or in the individual dyes dissolved in the same solvents and at the same concentration as the composite stain. Solution spectroscopy demonstrated different spectra for the two formulations with some wavelength regions varying by more than an order of magnitude. The RG spectra were also very different from those of the individual dyes dissolved at the RG concentration in the respective solvents. The stained standard specimens were analyzed by microspectrophotometry and were found to have spectra similar to those of cell smears. Furthermore, the standard specimens were shown to be a repeatable substrate for stain uptake. The transmitted light intensity from random fields of the same standardized specimen varied +/- 5%. When specimens were stained at the same time, the specimen-to-specimen variation depended on preparation conditions and the measurement wavelength, but was as good as +/- 5% for some conditions. The quantitative stain performance of both formulations was studied and compared. The standardized specimens provide a tool for the quantitative study of staining processes and specimen preparation procedures and for stain calibration. 相似文献
75.
Correction of the cystic fibrosis defect in vitro by retrovirus-mediated gene transfer. 总被引:54,自引:0,他引:54
M L Drumm H A Pope W H Cliff J M Rommens S A Marvin L C Tsui F S Collins R A Frizzell J M Wilson 《Cell》1990,62(6):1227-1233
76.
The 1A protein of respiratory syncytial virus is an integral membrane protein present as multiple, structurally distinct species. 总被引:9,自引:7,他引:2 下载免费PDF全文
The respiratory syncytial virus (RSV) 1A protein was previously identified as a 7.5-kilodalton (kDa) nonglycosylated species that, on the basis of its predicted sequence determined from the sequence of its mRNA, contains a hydrophobic central domain that was suggestive of membrane interaction. Here, four major, structurally distinct intracellular species of the 1A protein were identified in cells infected by RSV or by a recombinant vaccinia virus expressing the 1A gene. The four species of 1A were: (i) the previously described, nonglycosylated 7.5-kDa species that appeared to be the full-length, unmodified 1A protein; (ii) a nonglycosylated 4.8-kDa species that was carboxy-coterminal with the 7.5-kDa species and might be generated by translational initiation at the second AUG in the sequence; (iii) a 13- to 15-kDa species that contained one or two N-linked carbohydrate side chains of the high-mannose type; and (iv) a 21- to 30-kDa glycosylated species that appeared to be generated from the 13- to 15-kDa species by further modification of the N-linked carbohydrate. All four forms of the 1A protein were synthesized and processed on intracellular membranes, and several lines of biochemical evidence showed that all four species were integral membrane proteins. Thus, the 1A protein is a third RSV integral membrane protein and is present as such in both glycosylated and nonglycosylated forms. With the use of antiserum raised against a synthetic peptide representing the C terminus of the 1A protein, indirect immunofluorescence showed that the 1A protein was expressed at the cell surface. Antibody-antigen complexes formed at the surface of intact infected cells were immunoprecipitated, showing that the 7.5-kDa, 13- to 15-kDa, and 21- to 30-kDa, but not the 4.8-kDa, species, were accessible to extracellular antibodies. Thus, the 1A protein is a candidate to be a viral surface antigen. The small size, gene map location integral membrane association, and cell surface expression of the 1A protein strongly suggested that it is a counterpart to the SH protein that has been described for simian virus type 5. We suggest that, in the future, the RSV 1A protein be given the same designation, namely, SH. 相似文献
77.
78.
A Wawrzynow J L Theibert C Murphy I Jona A Martonosi J H Collins 《Archives of biochemistry and biophysics》1992,298(2):620-623
The sarcoplasmic reticulum of rabbit skeletal muscle contains a small "proteolipid," i.e., a protein which is soluble in acidic CHCl3/CH3OH. We propose the name sarcolipin for this small protein, to signify its lipid-like solubility and association with the sarcoplasmic reticulum. We have determined the following amino acid sequence for sarcolipin, using protein chemistry methods: M E R S T R E L C L N F T V V L I T V I L I W L L V R S Y Q Y. This 31-residue sequence includes a 19-residue hydrophobic segment which probably spans the sarcoplasmic reticulum membrane. The molecular weight calculated from the sequence, 3733, agrees with that measured by fast atom bombardment mass spectrometry, showing that sarcolipin contains no attached fatty acyl or other prosthetic groups. 相似文献
79.
R N Butler K K Arora J G Collins I Flanigan M J Lawson I C Roberts-Thomson J F Williams 《Biochemistry international》1990,22(2):249-260
The colonic cells of the large intestine are one of the most proliferative tissues of the animal body. The pentose pathway has an essential role in cell division and growth being the only pathway forming ribose 5-P necessary for all nucleotide and nucleic acid sunthesis. The pentose pathway may also provide reducing potential as NADPH for biosynthesis and C-3- C-8 glycolyl compounds. The maximum catalytic capacities of the reactions of the non-oxidative pentose pathway for the conversion of ribose 5-P to hexose and triose phosphates by the proximal and distal colon under feeding and starvation regimes are among the highest in the animal body. The qualitative presence of the oxidative pentose pathway was assessed by measurement of the C-1/C-6 ratio value of 1.67-1.82. Enzymes of the F-type and L-type pentose pathways are present in colonocytes and their maximum catalytic activities in colonocyte cytosol are reported. The contribution of the F-type pentose cycle to the total glucose metabolism of colonocytes, measured by the specific yield method, is negligibly low (approximately 1.5%). Colonic epithelial cells use glucose at a high rate (7.1 +/- 0.33 mumol min-1g-1 dry wt) and 79% of the glucose is converted to lactate. Arabinose 5-P has an intermediary role in the formation of keto pentose, sedoheptulose and hexose phosphates from ribose 5-P by colonocyte cytosol. The intermediary and reaction products of [1-13C] ribose 5-P dissimilation by colonocytes is investigated by 13C NMR spectroscopy. The 13C positional isotope distributions show labelling of C-1 and C-3 of hexose 6-phosphates consistent with either the theoretical predictions of the F-type pentose pathway or of the activities of exchange reactions catalysed by transketolase and/or transaldolase. Measurements of exchange reactions showed that the C-1/C-3 labelling of these compounds is mostly, if not wholly, attributable to exchange catalysis by these group transferring enzymes. The results suggest that the F-type PC has little role in the glucose metabolism of colonocytes and pentose phosphate formation may thus occur by a contribution (approx 20% of the total glucose metabolism) by the alternate L-type pathway. 相似文献
80.
Orientation responses of the grasshopper, Melanoplus sanguinipes, to visual, olfactory and wind stimuli and their combinations 总被引:2,自引:0,他引:2
Árpád Szentesi Theodore L. Hopkins Robert D. Collins 《Entomologia Experimentalis et Applicata》1996,80(3):539-549
Prereproductive adults of the grasshopper, Melanoplus sanguinipes (F.) (Orthoptera, Acrididae), demonstrated orientation and movement towards both visual and olfactory stimulus sources in a still-air chamber. Visual stimuli (wheat and lima bean foliage, vertical black or yellow-green stripes, and a yellow-green broad leaf pattern) were approached more frequently than the control white background surface. Olfactory stimuli (chopped wheat foliage and a four-component, synthetic, grass odor blend of volatiles) elicited an even greater positive response than the visual stimuli. Changing the proportions of the four volatiles in the blend significantly reduced positive orientation responses to the stimulus source. Visual cues of wheat foliage and olfactory cues of either chopped wheat odor or the grass odor blend gave greater responses when combined than when presented separately.In flowing air or wind, nearly all insects demonstrated a rapid positive response to odors of chopped wheat and the grass odor blend, significantly greater than the response to the same stimuli in still air. However, positive responses to visual cues were not significantly greater in wind than in still air. When combined with the olfactory stimuli in flowing air, visual cues did not increase the incidence of response. Grasshoppers responding to grass odors in wind moved more rapidly and directly toward the source, and stopped less often and for shorter durations than insects responding to odor in still air or to visual cues.We conclude from these studies that M. sanguinipes adults show orientation behavior to both visual and olfactory stimuli from food plant sources, although leaf odors elicit a stronger positive response particularly when carried by wind. 相似文献